How to get a crisp, exact color match for lossless screen-cast?

Capturing the video frames in XWD format then converting to PNG yields results that are almost pixel perfect when encoded with ffmpeg.

Install xvidcap:

mkdir -p $HOME/dev
cd $HOME/dev
svn checkout svn://svn.code.sf.net/p/xvidcap/code/trunk xvidcap-code
cd xvidcap*
./autogen.sh
LIBS="-ldl -lX11 -lXext" ./configure --prefix=/usr/local
make && sudo make install

Capture stills at 25 frames per second:

mkdir -p $HOME/video
cd $HOME/video
xvidcap --fps 25 --quality 100 --cap_geometry 1024x768+768+288 --file out%05d.xwd

This creates a series of X Windows capture files inside $HOME/video. Convert the files to PNG format using ImageMagick then combine into a video:

for i in out*.xwd; do convert -define png:color-type=2 $i $(basename $i .xwd).png; done
ffmpeg -i out%05d.png -c:v huffyuv -preset veryslow -qp 0 -qscale:v 0 output.avi

An example script:

echo "Click window to capture..."

INFO=$(xwininfo -frame)
WIN_GEO=$(echo $INFO | grep -oEe 'geometry [0-9]+x[0-9]+' | grep -oEe '[0-9]+x[0-9]+')
WIN_XY=$(echo $INFO | grep -oEe 'Corners:\s+\+[0-9]+\+[0-9]+' | grep -oEe '[0-9]+\+[0-9]+' | sed -e 's/\+/,/' )

OUTPUT_DIR=$HOME/video

echo Capturing to $OUTPUT_DIR...
rm -rf $OUTPUT_DIR
mkdir -p $OUTPUT_DIR
cd $OUTPUT_DIR

WIN_XY=$(echo $WIN_XY | tr , +)

xvidcap --fps 25 --quality 100 --cap_geometry $WIN_GEO+$WIN_XY --file out%05d.xwd

# Convert captured images to PNG format
echo "Converting XWD to PNG..."
for i in out*.xwd; do convert -define png:color-type=2 $i $(basename $i .xwd).png; done

ffmpeg -i out%05d.png -c:v huffyuv -preset veryslow -qp 0 -qscale:v 0 output.avi

This creates a high-quality video that looks sharp with VLC, can be edited in OpenShot, and uploaded to various video hosts. Playback with MPlayer yields slightly fuzzy and off-coloured results.


Canon 600d vs Sony PD170 for video production

It's a little bit subjective. DSLR footage, straight off the camera, is very crisp and clean. Whereas a PD170 has a bit more of a 'video' look. So first off you'd have to decide what kind of look you wanted to go for.

In most cases you would choose to shoot on a DSLR, simply because the image is more visually appealing.

Pros of DSLR:

better looking footage (subjective, although a common view)
can attach a variety of lenses (i.e. fish-eye)
smaller body, more mobility
no need to import footage off a tape, just copy and paste off SD card onto computer
it's cheaper

Pros of PD170:

don't have to worry about the camera overheating (can shoot as long as the tape and/or batter allow. DSLRs tend to overheat after 10minutes of straight shooting)
larger body. Easier to do handheld with just the body alone
can plug in a microphone directly into the camera. This avoids having to use a clapper before each take and avoids the need of syncing audio and video

For me, those are the main points. If you're looking to make a film cheaply, DSLR is the way to go. But don't forget about sound; good sound is integral to a film.


How to create screen capture video without losing it's quality?

QuickTime is included with macOS. This app has a built in screen capture tool. You can create a new screen recording by pressing Command-N to create a new screen recording after opening QuickTime, then set settings to Maximum Quality by clicking the drop down beside the record button. The video will save after recording to any location on your machine. See more Here on Apple's Webiste.

After this, you can ingest the footage onto your video editor and send it to someone.

Hope this helps.


FFmpeg : Error occurred while encoding audio stream from ac3 to aac

You're using an ffmpeg with a 2-year-old version of libx264.  It's been mostly feature-complete for a while now, but there are still small improvements and fixes happening.

As Mulvya says, get one built with libfdk_aac, since you should update your ffmpeg for libx264 anyway.  Your current ffmpeg is trying to use the VisualOn aac encoder.  That's a terrible choice.

Check the video encoding guide on ffmpeg's Trac wiki, too.  You should probably use -preset slow at least, to get more quality per bitrate. -crf 23 is the default target-quality, which might be more or less than you want.


What free video editor is best to stabilize video and fix choppy ones?

Resolve has pretty good stabilisation tools. Blender is more about 3D work and has a steeper learning curve in my opinion. Haven't used the other two.


Split-screen closed-circuit sports recording

Your best bet to easily do this is probably to set up two cameras with half the field of view being used.  Then simply setup a simple project that can combine the two and encode it for electronic distribution.  If you want to do an all digital route, you are still going to need to run an encoding after the fact to get the size down, so doing the combination of two feeds as a fixed project in post is probably the most straight forward.  Should be able to just copy the files and hit go.


Why do my Objects show up black in Cinema-4D?

This can either be an issue with OpenGL and you may want to disable it in the program settings (under "File) to test if thats the issue. Or you may have disabled the standard infinite light that is present in every new scene until you add your first light. Add an infinite light from the lights menu and see if that gives your objects some shading.
Also try what @Bart Arondson said and look if you have the "Use Color" option enabled and set to black. If yes set it to "off".


Ok, now that I'm home I think I see what you are noticing.  That is just an error with the block transitioning from black to white.  You can either slow down the fade or increase the keyframe frequency.  H.264 works by storing only certain frames and then storing the change in-between.  It breaks the image in to sections to analyse and so you can see if you go frame by frame that it is having a hard time figuring out what the change is around the edge between black and white.

Either decreasing the rate of change or increasing the frequency of keyframes should give it a better idea of what is happening.  You might also try 2 pass VBR if you were only doing one pass or CBR prior as the analysis pass should help clean up artifacts like that by directing more bitrate to harder areas to compress.


Software to capture high quality screen-casts

There are a lot of screen recording software, for example:

CamStudio (free)
Screenpresso (free/paid versions)
Movavi Screen Capture Studio ($49.95)
Camtasia Studio ($299.00)


How to convert a sequence of images to a video with different number of digits in the names?

Under Linux I use such command:

ffmpeg -f image2 -pattern_type glob -framerate 30 -i *.jpg output.mp4

Of course you should add encoder options etc. Or you can add leading 0's (zeros) to filenames, eg.: a000123.jpg instead of a123.jpg. Then -i a%06d.jpg should work.


What is the name of the transition where the new image slides left to right over the old?


Combining high res photo with low res video in a static shot

To extract the moving things, I'd try a difference matte. There's a tutorial on doing it in After Effects here and another one here. You'll need to somehow extract the static background, probably by averaging a few (or several) frames of it together. Then use the techniques described above to subtract out the static stuff from the moving stuff. (Maybe a combo of garbage mattes and difference matte could do it? Depends on the footage.)

Once you've done that, combining the moving matted footage over the hi-res image (probably using a "Normal" blend mode) should get you what you want. I'd be interested to know how it looks in the end. I've seen composites that looked bad because the composited object had a different amount or type of grain from the background. I suspect being at a different resolution may be just as bad, given that the grain will be huge compared with the background, but since I've never done it, I can't say for sure. Good luck!


What is the proper terminology for a device that can accept IP video streams and output that to RF as used by consumer televisions?

There is no special name for something that combines IP de-encapsulation and RF modulating. At least one company markets the device as a QAM modulator with IP input.


Miro does not convert the entire file when converting to webm

I tried using Miro as well to transcode H.264 MP4 into VP-8 WebM so that Firefox would play using HTML5 rather than a Flash fallback.

But at least when the mp4 source was exported from Premiere then the Miro conversion did not work properly
it finished in my case, but the webm file would always start to play from the last second of the video for some reason (try it with VLC, for instance).

FireFogg Worked
My solution was to use FireFogg, which can encode into webm as well
http://firefogg.org/
Instructions here, just choose webmsd or webhd instead of ogg: Video - Dive Into HTML5


As Jared said, probably not the most relevant question. But if I wanted to get a simmilar kind of shot I'd put a GoPro on a boom pole.


How can flicker from a slide projector be removed from existing video footage?

I didn't view the entire video, but from what I saw it looks like a series of static slides. You could grab a still frame from each slide and create a (say) five second repeat of that frame, and use it to cover the section in the video where that slide appears. Every editing package I'm aware of can do this.

Better yet, get the original slide stack and scan them, then do the same as above. You can correct for parallax etc and have more readable content.


Remove audio from video annotation in ActivePresenter

Yes, you can remove audio from any video in ActivePresenter. To do that, please follow the instruction in ActivePresenter's community:

  You just need to select the video, click Adjust Volume tool on the
  Timeline, and select Mute checkbox.


Would a large grass field make a good green screen?

It's doable, so long as you have some time, diddling around in After Effects with the Keylight chromakey and the camera tracker... Here's an example I made a while back at 4m25,5m17,
6m04, 8m33 (and a few other sections):


How to keyframe zoompan filter in ffmpeg?

With loop added, you are generating a video stream from the image. Now, zoom is applicable within the processing loop of a single frame, and pzoom for video streams. Also, zoompan doesn't have timeline editing support, no enable won't work. So,

ffmpeg -i $FOOTAGE -loop 1 -i $IMAGE -filter_complex \
"
[1:v]
 zoompan=
    z='if(gte(in,24),min(pzoom+1.3/18,2.3),19.3/18)'
    :x='iw/2-(iw/pzoom/2)'
    :y='ih/2-(ih/pzoom/2)'
    :d=1
    :s=500x100
[name];
[0:v][name]
  overlay=
    x=1005-250-3*n
    :y=406-50
    :enable='lte(n,173)'
" -t 7 -y  -hide_banner  out.mp4


What are the key PC specs for best editing HD videos?

Dealing with HD video has two main components.  The first is the ability to decode the highly compressed video (which is computationally intensive) and then is the ability to deal with the large uncompressed data (which is bandwidth intensive).

The fastest encoders/decoders use the GPU on the graphics card to improve performance as a GPU is far more capable at attacking the problems related to rendering and compression than a traditional CPU is.  So if you have one of these, then the GPU is by far the most important piece.  If you don't however, then the CPU becomes by far the most important piece as encoding/decoding on a CPU is very, very intensive.

As far as dealing with the uncompressed data, the relatively small compressed files will be decompressed into memory and then played out of memory, so it is important to have high speed RAM, but not necessarily the need for a lot of it for play back.  For editing on the other hand, quantity becomes a bigger factor since the more video that can be stored in memory, the smoother your editing experience will be.

Finally, you have the hard drives.  It is very helpful if these are quick for loading videos (particularly for editing) and also for working as scratch disk (where editing stores temporary files that don't fit in memory), however it is probably the least critical part.  This can change though if you start working with higher quality, less compressed video where the file sizes start getting larger.

So, to summarize, GPU is highest priority if your software can use it, otherwise CPU and then speed of memory, quantity of memory and speed of hard drive in that order.  CPU is still second most important if you do have GPU processing support.  If you don't, then GPU is of almost no importance at all.


Id recommend going with a Rode Mic.

The Rode Shoe Mount Video Mic (around $250-$300) is more compact than even a short short shotgun. Secondly, there is a selector switch on the back that allows the user to select various pickup patterns, from cardiod, to stereo, directional, etc.

Theres a few models, but check BH and Amazon.

An entry level Shotgun would be a Sennheiser, but 1.) Its far less compact, and 2.) Price point for the capsule and power supply will run $500 and up. Lastly, youre going to be limited to XLR out without an adapter.

The Rode Mics to be honest, sound fantastic for their price point.

You can add an accessory Rycote Furry Windjammer to cut down the wind even further beyond the included Foam Windscreen. A Furry Windjammer will give you the best results (pricey but worth it), and last, you can add a lo-cut filter either on the Rode or in post to further reduce wind rumble.


How to display subtitles as default in an MKV file

There are two aspects to your query - 1)setting one of the subtitle streams as the default and 2)automatically displaying it during playback.I'm not aware of a method to force a player to display subtitles if that facility has been turned off in its settings.

For the first facility, try mkvpropedit from MKVToolNix to set the default flag for a subtitle stream. See 2nd example.


Can I paint a rough wall with chromakey paint to make a green screen?

It depends on some factors.

For example, how far is the wall from the main actors? If you have some good spacing, the texture can probably blur out due to DOF. But as on a green screen you need to maximize the focusing range, probably you will still have some texture visible.
How even is the light? You can probably lit good enough from both sides to eliminate the shadows on the texture produced by the other light.

In reality, you need to test. You do not need to paint in green before making these tests. Use your wall as it is, and use that color as a chroma key, you can even use white. Put a subject with clothing that has no white (or whatever current color you have now) and make a test. If it passes, it will probably work better when painted in green.

If you do not need a large green screen, you could probably use a frame made of PVC and green fabric.

But if it is sort of permanent thing... probably add a panel.


In the system preferences, in the display arrange dialogue you will see a menu bar. Move this bar to the monitor representation you want FCPX to have its main window.


How to use magicyuv & utvideo codec with ffmpeg

The following Linux command searches all codecs than can Encode anything containing ut.

  ffmpeg -codecs | grep --regexp="^ .E" | grep --ignore-case ut

and its output is:

 DEVI.S utvideo              Ut Video

so you can use:

ffmpeg -i ~/Videos/WebCam/me.mp4 -c:v utvideo -r 30 -c:a libmp3lame -b:a 512K /tmp/test.mkv

However:

ffmpeg -codecs | grep --regexp="^ .E" | grep --ignore-case magic

has no output at all on my version of ffmpeg, but if your version supports it, you will see an output and then you just use whatever is in the second column as per the example above for utvideo.


Things to consider when shooting through car window at night?

I'm making a short film that takes place mostly in a car at night. Will I need a polarizer to see the actors through the windshield?

A polarizer could help reduce reflections, but the best way to do such a shot if you desire no reflections is to shoot it in a way that there are no reflections to reduce. How you can best do this depends greatly on how you want the finished scene to look, particularly what angles you desire light to be illuminating your actors and the car's interior. One obvious solution would be to remove the windshield altogether.

Just because a scene takes place in a car at night doesn't mean you must shoot the scene at night - or even in an unmodified car.

Many of the tricks of the movie trade involve shooting in conditions that barely resemble the final look of the scene on screen. This was true in the film days just as it is true in the digital age. The use of green screens, CGI, etc. has expanded the possibilities of what can be done to footage after it is collected but the practice of using lighting and exposure to make a scene look different than it actually was when shot has been around almost as long as motion pictures have.

Most of those 'night' scenes you see in old westerns were shot in daylight with an 80B filter on the camera and the film underexposed by a couple of stops. So much so that the 80B and similar blue filters were nicknamed "American Midnight" filters in Europe.

More than a few scenes in films with characters in cars were shot with the windshields and other glass (or even parts of the car's roof) removed. Often such scenes could be shot with multiple sets (glassless stationary vehicle, moving intact vehicle, fabricated sets resembling parts of the interior of the car) and edited together in a way that made them appear seamless.


How to add timestamp of N mins between photos on a video combined from photos?

Timecode isn't suitable for this. It assumes real-time footage. You can use the eif and n functions to increment the text counter to advance by 30 mins for each frame i.e.

ffmpeg -framerate 24 -i %04d.png -vf format=yuv420p,scale=1650x1180,drawtext="fontsize=15:fontfile=/Library/Fonts/DroidSansMono.ttf:text='time\: %{eif\:n*(30/60)\:d} h %{eif\:mod(n*30\,60)\:d\:2} m':fontsize=72:fontcolor='white':x=860-text_w/2:y=960" out_24fps.mp4

(BTW, framerates for image sequences should be set on the input. Using fps filter here will cause ffmpeg to drop one frame from each second.)


How to cut a part of a video to make two horizontal black bars on the top and bottom

There are plenty of YouTube videos on how to do this and various different ways, such as cropping the top and bottom, or using a PNG image to the correct format you want to show, you could also even make the timeline the aspect ratio you want to use and expand the image up to fill the area.


Does the MP4 HTML5 compatible video type allow for mono audio?

The Mainconcept or Sony codecs in Vegas are subpar for low-bitrate output such as needed for HTML5 use. Use ffmpeg to generate your HTML5 videos. Yes, mono audio is acceptable for HTML5 use, but once you use ffmpeg/x264 for generating those videos, the 6kB/s savings you get from switching to mono audio won't matter much if at all.

Get the 32-bit static build of ffmpeg from here. Render a high bitrate Mainconcept MP4 from Vegas, say, 12 Mbps. And then run the following ffmpeg command:

ffmpeg -i "vegas-output.mp4" -crf 23 -c:a aac -b:a 96k -strict -2 -movflags +faststart "html5-video.mp4"

If you still want mono audio, insert

-ac 1

after aac.

If you don't like the quality or size is too large, then play around with the CRF value. They go from 0 to 63 with lower being better. 18 to 28 is the usual range you want to stick with.


Dark Video/Gama Shift from Davinci Resolve to YouTube

The MOV you exported from Resolve is tagged as Rec 601 (despite being UHD).

So, I transcoded your MOV using the command below, preserving all color characteristics and uploaded that to Youtube. Downloaded YT's transcoded video and compared it to the MOV, and in ffplay, VLC or Potplayer, they look the same.

ffmpeg -i Untitled.mov -crf 18
       -color_primaries 6 -color_trc 6 -colorspace 6 -color_range 1 resolve-upload.mp4

P.S. I also uploaded your MOV and downloaded its transcode from YT. Turns out that the transcode is flagged as Rec. 709, which is wrong, despite the MOV being tagged as 601. The rip of my transcode is tagged as 601.


How can you automatically trim a new layer in After Effects?

I don't think it's possible to automatically trim layers as you import them.  You can trim a comp to your work area, if you've selected a beginning and end point on your timeline (using B and N), but this isn't really going to help you.


Yes, that is possible. What you're searching for is a difference matte / difference key. For that technique, you supply a base image and the program keys everything out that equals that image. So you could key out your static background so that only you remain in the picture.

However, there are a few downsides:

This technique doesn't work nearly as good as a greenscreen. It will probably require a lot of work and there will still be some artifacts left in the video.
If you're using a bad camera (such as a laptop webcam), the result will be even worse.
If you move your camera even slightly, you'll have a problem. So if you do that with a webcam, don't touch it at all, if possible.
There probably aren't many applications that can do this effect live (as opposed to post-production). IIRC, there is some video chat app for Mac-Computers that can do this. I'm not sure if it is possible with Skype, you'll have to research that. However, keep in mind that it probably won't look as good as you imagine it.


How to downsample 4k to 1080p using ffmpeg while maintaining the quality?

The default settings for ffmpeg are very low quality, and since you don't specify any codec or quality parameters it's just using the defaults (I don't know why the devs don't fix that because it generates a lot of questions on forums everywhere).
Edit: the defaults are now quite sane. With a recent (as in later than 2017) build of ffmpeg you don't need to specify anything more than input and output files to achieve good useable results. You can, of course tweak to your heart's desire.
Try adding -c:v libx264 -crf 20 -preset slow to the command.

-c:v libx264 tells it to use the libx264 encoder, this is the default now, no need to specify it
crf 20 uses the Constant Rate Factor quantiser (which paradoxially means variable bit rate, but constant quality) with a value of 20 (pretty good quality; lower is better quality / larger files, higher is crappier / smaller)—default is 23,
the slow preset is a shortcut for a bunch of encoder settings that means it puts a bit more effort into it than the default (medium). Note that the speed presets don't change the quality of the encoded file, just the efficiency, meaning a slower encode will result in a smaller file of the same quality and a faster encode will mean a larger file of the same quality.

You can tweak these settings, see the h.264 encoding guide for instructions on what knobs to twiddle.
And if you're using the audio as-is, add c:a copy. That will do a straight copy of the audio stream without re-encoding.


How does one edit and save clips once and reuse in multiple videos with Adobe Premiere?

Within a new project, create a sequence/timeline; call it 'Basic Edits' if you like, and make your trim edits on the source clips there. For each of your multiple videos, create a new sequence and copy-paste the trimmed clips from the first sequence.

Or if you want to use these clips in another project, you can import the sequence by the File -> Import menu dialog.

Of course, I presume that by Adobe Premiere, you don't mean Premiere Elements - the lite version - which doesn't feature multiple sequences in a project, as far as I know.


How to manipulate video codec errors using ffmpeg

The effect you're looking for looks like datamoshing. Give that a quick google search - it might be what you want.


What CRF or settings I should choose for h265 in order to achieve a similiar quality of h264?

The CRF scales for x264 and x265 do not correspond. x265 CRF 28 is supposed to be equivalent to x264 CRF 23. But x265 is not yet as mature in its development as x264, so take that CRF equivalence with a pinch of salt.

That said, you can try to establish your own calibration between the current versions of the encoding libraries in your ffmpeg by running the following command, which executes two popular video quality metrics:

ffmpeg -i encoded-video.mp4 -i reference-video.mp4 -lavfi "ssim;[0:v][1:v]psnr" -f null -

The final lines of the console output will contain:

[Parsed_ssim_0 @ 000000000039ad80] SSIM Y:0.984483 U:0.980458 V:0.980921 All:0.983219 (17.751712)
[Parsed_psnr_1 @ 0000000000398320] PSNR y:42.63 u:43.19 v:44.09 average:42.90 min:42.07 max:46.16

So, run the command once with the x264 output and once with x265 and compare with different x265 outputs, till you get similar measures. Of course, these metrics aren't perfect but you can use them as a rough guide to establish equivalence.


Using Multicam Editing How to Color Correct an entire angle

If all is correct you enable the multi camera mode on a sequence containing the different angles in different tracks as shown in the image below (this is CS5.5, but CS6 is similar).
  The image shows a sequence containing 4 different clips which represent 4 different angles.
In this example these are just a collection of random footage, but it works the same if you have actual different footage from different angles.

Let's call this Sequence 01. Now put Sequence 01 in another sequence,

click on Multi-Camera -> Enable and then you can switch witch camera you want in Sequence 02.

According to the information in your question you've already come so far.

Now if you want to color correct one angle (lets take the angle called Leaf.MOV) just open Sequence 01, apply the effect to the clip (drag and drop on the Leaf.MOV clip) and this changes should propagate into your multi-cam edits.

Please feel free to ask any question if this doesn't work for you. I'll try to help.


Generating video thumbnails preview / contact sheet in batch, color issue

So here is what I found out, if anyone's interested (however unlikely this might be, considering the poor popularity of that question ! :)) :
– Scorp Video Thumbnails Maker gets the colors right for Bt.709 footage with its “Engine 2” rendering module (not the other three with the current 11.0.0.3 version) and the CCCP codec pack. I created a thread about that issue on the support forum for that tool.
– I managed to tweak VCSI by adding "-vf", "zscale=matrixin=709:matrix=709,format=rgb24", to each ffmpeg call, so that it preserves Bt.709 colors; it's still slower and less convenient than Scorp VTM (and that modified script won't get accurate colors for Bt.601 footage so both versions would have to be installed and used accordingly), but it's free.
– Since I created this thread I found a few other tools which can perform this task : StaxRip (which has an internal thumbnails preview generation module, in addition to the older MTN), PotPlayer, BSPlayer, Auto Movie Thumbnailer. The latter is based on MPlayer, and is supposed to give control over the rendering engine, but I couldn't get it to use Bt.709. Otherwise it's a good free dedicated GUI alternative to Scorp Movie Thumbnails Maker, with many customization options.

I also created a thread on VideoHelp regarding that specific issue, and another about the color accuracy of screenshots in general.


It's possible. Use

ffmpeg -loop 1 -i image.png -f lavfi -t 5 -i anullsrc -i video.mp4 -i music.wav \
-filter_complex "[0]trim=duration=5,fps=N[pre];[3]showwaves=WxH:r=N[b]; \
                 [b][0]overlay=shortest=1[post]; \
                 [pre][1:a][2:v][2:a][post][3]concat=n=3:v=1:a=1[v][a]" \
-map [v] -map [a] out.mp4

The image and video have to be of the same dimensions. If not, you should scale one of them, likely the image.

The fps filter should be set to the framerate of the video.

The showwaves is a kludge. Since the looped image stream does not terminate, I generate a video stream using showwaves from the audio, which will be of the same length as the WAV. WxH should be the same as the video, and r the same as the video's framerate.

Then the image is overlaid on top the filter is set to terminate when the waves video ends.

Finally, the concat filter assembles the full video.


Does anybody have suggestion to recreate this light trail effect?

There are two ways this can be accomplished.  The easiest is by using a slow shutter speed.  While most DSLRs may be limited to 30FPS and faster, it is possible through the use of third party firmwares to lower that arbitrarily further.  As you can see from the details on Vimeo, they were using GH2s with the EOSHD Vanilla hack.  This removes many of the limitations that would otherwise be on the system.  It is also possible with most Canon hardware using MagicLantern's FPS Override.

The other way to do it is to artificially do it in post production (though the result often isn't as good) by additive combining each frame with previous frames.  This results in a trail that can animate on and animate off and maintain the original frame rate, but it is likely to introduce gaps in the trails and either requires a pre-existing plugin or some creative layering in After Effects.  Layer each video one from apart and then apply blending until you get something that looks like you want.

It is hard to tell which technique is being used for sure without a downloadable copy that I can go through frame by frame, though my initial impression (particularly based on the hacked firmware and the general feel of the video) is that they are using the lower frame rate option in the hacked GH2.

Update: I managed to dig up my old Youtube downloader and got the video in to Premiere.  I can confirm that it is in fact a lowered frame rate (around 1/12 or 1/15 for most of the trail shots).


To the first question yes, you can, but try not to do it- the filament of the lamp is very delicate.
Respect to your second question, that's true! Turning your projector on and off decreases the life of the lamp, and that's true with most lamps. It also probably reduces the life of the components inside the projector, but that's not something we can go into detail here.

Good luck!


I intend to use OBS with the same objective but I'm getting pretty large files as well. Aiming to get 300mb ish videos and I'm ending up with 800mb - 1gb... and lowering bitrate and resolution didn't seem to make a difference.
While I wait and continue to look for an answer with a specific setting reccomendation, I'm using VLC to try and compress the recorded files. Don't know if this is useful to you, but on VLC go to "Media", then "Convert/Save", choose your recorded video and set the file type and settings you need. Manage to get it down to at least half the original file size.
Hope someone who actually knows what they're doing come and help soon haha


Remove echo when recording in say, a hallway

The attachment you are looking for is called a lav mic, though sometimes it can be a hand-held shotgun mic, too.  Sound intensity decreases as the square of distance and echoes decay exponentially.  The trick to eliminating the echo is to get the mic sufficiently close to your sound source that the original source is 10dB to 20dB louder than the environmental echo.  If you see how close a news reporter holds a mic up to a subject when interviewing them in the moment (and sometimes in a hallway), do that.

There's nothing you can put on the microphone that will solve the echo problem.  The only way to solve it is with proper distance (which is a function of proper distance ratios).


Why doesn't an FFT pitch filter fully 'mute' the selected pitch range?

First of all, tell us more about the filter. Is it really a brickwall filter, or are you actually using a low roll-off or low cut-off filter? In the latter case, it is perfectly normal, when using a high cut-off filter, the low frequencies decrease with -6dB per octave below the specified frequency, and are not completely gone. Roll-off is the same, but with less dBs per octave. (either 4,5 or 3, can't really remember.)

If you did use a brickwall filter, there is another possible explaination:

A phenomenon in psycho-accoustics is the hearing of a low note where it is not there, but when the harmonics (= overtones) are there. Every base tone has different overtones. (Really, if multiple overtones are there, there is really not much ambiguity.) The human brain actually processes these overtones and adds the base tone.


Unknown stream found in container (likely a subfile): need help identifying/opening it

The 3rd stream in your input is a regular stream. Attachments are basically extradata attached to streams.

You would use

ffmpeg -i input.mp4 -map 0:2 -c copy -f data subs.txt


Hardware acceleration in Adobe Media Encoder vs ffmpeg

Media Encoder and ffmpeg should generate the same quality if given the same encoding parameters.

GPU encoders are provided by GPU vendors. I haven't heard of any third-party implementations. The possible differences lie in the wrappers i.e. the code which initializes the encoder parameters, and written by the interfacing app. There, I would expect ffmpeg to offer more fine-grained choices although I haven't look at AME's offerings as of late.


Have you considered any file transfer accelerators like Aspera or File Catalyst?

They use a different network protocol to send your files over and give you significant transfer speed gains.


Is there an easy way to import textured 3D geometry from Maya into Nuke?

This still isn't as easy as it should be, but the way forward is to export your geometry as Alembic.  It supports many textured objects, and even animated sequences.  Depending on your version of Maya, you may need to install a plugin, but it is much better than dealing with OBJ and FBX as the interchange format in most cases.


What causes the VHS rewind effect? And how did rewind preview work?

In helical-scan video players, the tape is wrapped around a rotating drum that has one or more magnetic pickups (heads) that are the width of a track and angled slightly from true horizontal. Each track is several inches long and laid down diagonally at (roughly) the same angle as the head is tilted. (The angles differ because the relative motion of the tape and heads causes a precession, an "active angle").

When the tape is moving forward at normal speed, the rotating head aligns with the angled tracks and all is fine. When the tape moves in reverse the angles are misaligned, and when the motion is faster than normal the heads will "sample" more than one track during a video frame, and pick up some of the inter-track guard space as well (the static).

This is what you see when you rewind. Nothing about the orientation of the data on tape changes, so there's no reason for the images to be inverted. If the drum rotated in a different direction then you'd see something else.


Make white background in MP4 movie transparent

The MP4 format doesn't support an Alpha channel.  The question you've asked is very broad, and I've tried to answer to a certain extent below.  However you may need to decide what route you're going to try and then researching that route or asking further, more specific questions.
The file types that currently support an Alpha (transparency) channel are FLV, F4V, AVI, Quicktime, and WebM.  If you're using free programs, you may find they can export in these formats.  Often, there will be a named codec for an Alpha channel within the settings of these, or a PNG option.  Firstly, I would see if there's an option to export video within your PyMOL software in any of these formats - try exporting them in different ways to see if they have the Alpha channel.
Alternatively, if it's a one off video, you could use the free trial of Premiere Pro or After Effects to create and export your video, although it can be a learning curve if it's a complex project and you have never used Adobe Creative Cloud before.  Lastly, you could export your video and try and remove the background in a video editor. (If you want to use WebM, you need a third-party WebM codec for Adobe Media Encoder.)
PNG import /export
You could import the png sequence into either After Effects or Premiere Pro (free trials available for each).  I'm sure several free programs can import a PNG sequence automatically, or you could manually arrange the images on the timeline, one image per frame.
I mainly use Premiere Pro so below I've listed a couple of ways I can use it to export a transparent video directly from Premiere.  HOWEVER - there are likely to be similar options in other programs - most video programs will export in a variety of formats / codecs.
###Export a movie file with an alpha channel in Premiere Pro ###

Select the sequence.
Choose File > Export > Media.
In the Export Settings dialog box, choose one of the following
options:

Option 1 - QuickTime

Select "QuickTime" in the file format
Select "PNG" from the video codecs
Under Channels, select "RGB + Alpha"

Option 2 - Microsoft AVI

Select "AVI" in the file format
Select "RGBA + " from the video codecs
Under Channels, select "RGB + Alpha"

Once you have changed settings as per one of the sets of options above, continue to set other settings and click Export or Queue to export as you normally would.

Remove background
Another option is that if the background is a consistent colour - white, grey, green etc, most advanced video editors will have options to remove the background using a colour match.
In Premiere Pro, this is done using the Chroma key effect.  In essence, add the effect to the video, take a sample of the background colour, and the background should be removed, it's just left for you to export the video in one of the methods mentioned previously.


Illustrator "Release to Layers" but keep names?

I use this script from Carlos Canto. After releasing layers it will name new top level layers based on sublayer name. The link to the adobe forum is broken now so I don't think this is accessible through there anymore.

It is a little difficult to figure out how to properly select the layers  to make it work. You must select all the objects and also have the top layer selected in the layers palette, like in this screenshot.

Thanks Carlos for making this way back in 2014!

// carlos canto // 09/26/14
// https://forums.adobe.com/thread/287812
var idoc = app.activeDocument;
var ilayer = idoc.activeLayer;
for (i=0; i<ilayer.layers.length; i++) {
   var sublayer = ilayer.layers[i];
   sublayer.name = sublayer.pageItems[0].name || sublayer.pageItems[0].contents;
}


FFmpeg run multiple filters in parallel from C API

Filters cant really run in parallel because they can modify frames, and you can’t modify a frame in two threads at the same time. You can make a copy of the frame and run two filter graphs.


Output via Compressor comes with bad quality audio (no problem via Share of FCPX)

FCPX project -> Play through timeline = OK
FCPX project -> Compressor -> ProRes422 = NG (muffled sound)
FCPX project -> Compressor -> AAC Mono = NG (muffled sound)
FCPX project -> Compressor -> AAC Stereo = NG (muffled sound)
FCPX project -> "Share" -> Master (h264) = OK (but the size is too large)
FCPX project -> "Share" -> Master (h264) -> Compressor -> AAC Mono = OK

These are sum-up of results in my trial and error.
The 6th trial resolved my problem, although it is not a perfect solution.


How does ffmpeg record -timecode in different file formats?

FFmpeg only supports timecode in a limited set of formats. They are the MOV family (MOV/MP4/3GP..), MXF family, raw DV and Grass Valley GXF.
How the timecode is stored and flagged is specific to the format. MOV stores a DF flag, integer framerate and the timecode as a rate-adjusted integer frame index. MXF does essentially the same.


Creating the Star Trek warp effect in After Effects

All that looks like to me is a simple lense-flare that got its opacity and scaling keyframed. Startrek used very cheap methods for vfx due to the limited budget, so I believe that you can find assets such as these online quite easily.


Export Composition Background in After Effects

I hope the person receiving your 'green screen' lower third doesn't ever find you in a dark alley. If it was me I'd be looking to bring the hurt. Really, this is not the way to do it.

Firstly there are more space efficient codecs with alpha channels than the default Apple Animation, try proRes 4444 or the newer Cineform

If you really can't afford the bandwidth to send the video with alpha, render out the alpha channel as a separate movie and send them both. I'm old enough to remember that's the way things were done in the days when dinosaurs roamed the earth and when sending a Betacam SP videotape by courier was the highest bandwidth way of sending material. There's no such thing as an alpha channel on analogue tape.

You can achieve that by adding an output module to the render (right click the output module in the render queue and choose add output module). Change the Channels dropdown to Alpha instead of RGB or RGB+. If you want, you can use a compressed codec to save space (or compress after the render, which is what I'd recommend). Just don't compress too much or you'll end up with blockiness in your alpha channel.


You need to re-encode all vids to crop the bottom 100 px - you have to decide which codecs you want to use.... and think about the filters - this depends on the sourcefile.... The ffmpeg code is:

ffmpeg -i INPUTFILE -ss 00:00:04 -map v -vf "crop=out_h=in_h-100:y=0" -c:v libx264 -c:a copy OUTPUTFILE

The best would be to iterate the INPUTFILEs by a for-loop. put the new files in a new directory and you won't have any problems with the names.


Those are all very similar in terms of performance. I'd take the EVGA GeForce GTX 970, but other people will tell you something else.

One recommendation: Samsung SSDs are severely overpriced. People still buy them because Samsung has a good reputation (basically it's the same as buying a Mac for no other reason than 'all the graphics people have one'), but you won't notice any difference in any aspect between a Samsung and, say, a Crucial SSD. I recently bought the Crucial BX100 and I'm very content with it. Same price, but twice as much storage capacity.

Also, if you're getting a good GPU anyway, I would consider something like the lntel XEON E3-1231V3 over the i7 CPU, since you don't really need the inbuilt graphics unit of the latter.


Use ffmpeg to create a split screen video out of 5 videos- 4 videos in landscape one in portrait

Assuming you want a layout of:

0 1 2
0 3 4

Command is:

ffmpeg -i input0.mp4 -i input1.mp4 -i input2.mp4 -i input3.mp4 -i input4.mp4 -filter_complex "[0]scale=-1:720[v0];[1]scale=-1:360[v1];[2]scale=-1:360[v2];[3]scale=-1:360[v3];[4]scale=-1:360[v4];[v0][v1][v2][v3][v4]xstack=inputs=5:layout=0_0|w0_0|w0+w1_0|w0_h1|w0+w1_h1[v]" -map "[v]" output.mp4


Working with Frame Rates & Slow Motion in Adobe Premiere

To answer your Questions in order:

You can see the framerate of a clip or sequence by navigating to the metadata panel. It's usually one of the tabs in the upper left on the standard layout. If you don't see it, select Window -> Metadata.
Generally, you should set sequences to match you source material. So if your camera records 720p @ 60 fps, stick to that. You can review and change the sequence settings under Sequence -> Sequence settings. Some settings can't be changed later on though.
The best way to create a slowmotion effect is to use "time remapping". You will find that under the effect settings that every clip has by default. There you will see that your clip has a standard speed of 100%. You can change the speed of the entire clip by altering that value. If you want the clip to gradually slow down over time, you'll have to use keyframes. You can set a keyframe by clicking on the square symbol in the effects panel next to the time remapping line.
In this case, you'll need to create two keyframes, one at the beginning and one at the end of the transition from fast to slow. Let the first keyframe at 100 % speed and set the second to your desired target value, for example 50 % and that's it.
I hope this was somewhat understandable. If not, it's futher detailed at the adobe help site: http://helpx.adobe.com/premiere-pro/using/duration-speed.html
Can't really help you with that. If you're going for real slow slowmotion, you can always right-click on the clip and activate frame blending, which might result in a smoother video.

I hope i could help :)


GPU problem/replacement ? For Lightroom and Vegas

Problem solved for Vegas

Solution A

(optional) I have installed thedriver version I wanter (in my case I took the latest drivers,359.00 currently).
CTRL+Shift on Vegas icon, checked clear cache data. (Beware that you may lose some configuration in the process.)
After maybe a few starts (can't tell precisely), it finally works, WITH GPU acceleration.

Solution B
The problem happened again. Solution this time. It might look like a random thing but I've done it multiple times and tested alternatives.

(There was no driver update this time.)

Start Vegas with a blank projet.
Display Preview Window (content should be all black).
Resize preview window (not sure if this is optional, but if it doesn't crash at this point, that's a good sign).
Open the project you initially intended to work with.

Regarding Lightroom: no solution yet.


Assuming you're using H.264 for exporting, the bitrate is the main setting concerning the quality of your video. Increase it to raise the video quality and reduce compression artifacts at the cost of a larger file. Using VBR 2-Pass will yield better quality at the cost of longer rendering times compared to exporting with the same bitrate with VBR 1-Pass.

There is no standard per se (at least for internet video, there is for other media such as DVDs), but here are a few things to consider. First, raising the video bitrate higher than the original bitrate of the video that came out of your camera won't yield you any quality improvement. Personally, I haven't been able to notice any perceivable difference above about 6 Mbit/s for Full HD video at 25fps. Of course, that value has to be adjusted depending on your resolution and framerate (see Does raising the framerate while not changing the bitrate result in quality loss?). So if your video is e.g. shot at 50fps, I would recommend about 12 Mbit/s. However, this is only my personal experience. Another example is Youtube, their Full HD video is compressed using a bitrate of less than 1 Mbit/s (so that even people with slow connections can watch their videos without stuttering), but that does look pretty poor on a large monitor. I would suggest you experiment with by exporting a small portion of your video with consecutively higher bitrates until you don't see any compression artifacts and use the last value for your full export.

Now for the settings in Premiere Pro, maxing out the Maximum Bitrate won't do much as the primary controller for the video bitrate is the Target Bitrate setting. With VBR (1- or 2-Pass), the encoder will increase and decrease the bitrate over the running time of the video as needed while trying to achieve an avarage bitrate that equates the Target Bitrate setting. The Maxium Bitrate is the ceiling for that margin, i.e. the Maximum Bitrate you set will never be exceeded.

If you don't see any problems with your video after uploading it to Vimeo, you can safely ignore the warning. If it still bothers you, just export it again using a Target Bitrate above their suggested setting.


how can I convert slow motion video into normal speed without losing fps or audio sample rate?

This is a contradiction.

If you want to change the frame rate speeding up you have to change the frame rate.

You could try to playback a video at 16,000 fps... Why would you need to playback a video to 16,000 fps if no human or living being could notice the difference to let's say 120 fps?

You also need a monster of a computer to playback that among other technical problems.

  But then when I need it slowed down, I could use software or something to view it in slow motion

Ok, so have two versions of it, one converted to normal speed and the original.


In video, can previous frames effect results seen in subsequent shots?

At a certain time you can see the rocket at two places at the same time.

What you are seeing has nothing to do with compression artifacts, but is frame-blending due to the slow motion effect applied (in the video)

Let's say the video is recorded at 30 frames per second. You only have 30 'pictures' per second to capture the information. If you want to slow the video down (to be able to see the rocket more slowly) you could play these frames back at a lower speed, let's say 15fps. Each frame will be visible twice as long as when playing back at 30fps. (you could also duplicate all the frames, and play them back at 30fps to have the same effect). The footage will kind of look jittery when doing this, like it is stuttering to continue, which is not nice.

Instead of just adding copies of the already existing frames, extra frames are calculated in between. The easiest way is to just calculate the average between the frame before and the frame after. This way all your frames will have different visual content and it will be a little more pleasant to the eye. The fact that you are seeing two rockets, is due to this averaging.

(source: apple.com)

There are other possibilities to generate new frames. Software like twixtor does some advanced calculations and will (try to) guess the rockets position on the frames in between. If configured correctly this is even more pleasant for the eye than the averaging method.

The obvious solution would be to shoot these kind of shots with a high framerate. If you shoot video at, let's say 1000 fps, you can slow it down to 30fps (33 times slower) without having to calculate values from in-between frames.

These artifacts are probably coming from the original video itself, because if you watch closely you can also see it at the original speed. But it's always possible that youtube also uses averaging for it's slowdown feature, so that these artifacts are introduced by the player.


Will lens softness be visible in DSLR video?

You are correct. You're shooting at a much lower resolution on video than stills, and so your effective circles of confusion are much bigger. So you can get away with glass that a decent stills photographer wouldn't touch. This is speaking from experience at work where I share DSLR equipment with a bunch of stills photographers who are always complaining about lenses that I use all the time for video with no problems.

"Get away with" being the critical phrase there. Crap lenses are still crappier than good ones.


3D layers not affected by camera zoom in After Effects

In After Effects, make sure your Cineware effect on the Cinema4D track has the Project Settings --> Camera set to Comp Camera, as shown below:

This setting means that the camera in your After Effects comp will control the viewpoint of the object, instead of any camera in your Cinema 4D project (I think C4D creates a camera by default, even though you can't see it in the Objects panel, otherwise nothing would render).


Something like this would be done in After-Effects. There is a free trial of the software - I would highly recommend trying this.


Why concat in ffmpeg 4.2.3 says too many arguments?

The concat filter has an option to set no. of inputs. Its default value is 2.

Change to [clpABCD][clpEF][clpG]concat=n=3[out1].


How to create and add video overlays like this?

The tool doesn't matter in this case.

For some kind of artistic or individual approach I'd suggest use a light table or graphics tablet. Draw the shapes 20-50 times by hand to get some nice variation and place all the drawings on top of each other like classic/traditional animation does in the old days.

Otherwise you can either use:

Any kind of pixel or vector based graphics package (Photoshop, Gimp, Affinity Designer etc.) together with Premiere or After Effects for additional tracking capabilities
A 2D Animation package which allows to draw directly on the plates
Or even Blender's grease pencil feature  along with its tracking capabilities


Fixing ISO value of each frame of a recorded AVI video

You can just turn off the AUTO ISO feature and set the ISO manually. This way it won't change throughout your recording, and this will also produce more consistent lighting, unless the lighting conditions change (i.e. your scene involves turning the lights on/off, opening/closing a window or something like that). Instructions on how to do that can be found in your camera's manual.
A quick google search yielded the following result:

By default the D3s won't give you much control of video capture and you'll have to unlock the manual video control by using a secret method. Don't worry, nothing will happen to your $5,000+ camera!
All you have to do is set your Live View-setting to "Tripod Mode", enter Live View using the Lv-button on the back of the camera and then press the OK-button on the left side of the LCD. That's it. You've now gained full manual control of video on your D3s. Congratulations!

Source
And here's an excerpt from a more extensive guide to the camera's shooting menu:

ISO sensitivity settings
ISO sensitivity
This duplicates the ISO button. I use ISO 200.
ISO sensitivity auto control
This is where we set the AUTO ISO feature ON or OFF. Auto ISO magically bumps up the ISO as the light gets weaker, saving you a lot of time since you no longer need to watch your lighting or shutter speeds. Set this and just shoot, from daylight to moonlight.

Source


Adobe Premiere is Non-linear editing application. Any changes made in it don't have any influence on footage on your hard drive. Not audio, not video.

It is feature, which prevent damaging footage files.

It is based on trimming, not cutting. However, if you really want it, you can trim your audio, export it from Premiere, and then import back. But I can't find any reason, why you can need that.


Use the concat filter to join the image to the video:

ffmpeg -framerate 25 -loop 1 -t 5 -i image.png -t 5 -f lavfi -i anullsrc=channel_layout=stereo:sample_rate=44100 -i video.mp4 -filter_complex "[2:v]drawtext=text='foo'[main];[0][1][main][2:a]concat=n=2:v=1:a=1[v][a]" -map "[v]" -map "[a]" output.mp4

The image should be the same width and height of the video, so you may have to add the scale, scale2ref, crop, and/or pad filters before concatenation.
If the main video has audio then the image needs have audio as well. Generating silent audio with anullsrc as shown in the example can suffice. Make sure to match the channel layout and sample rate of the main input.


Trying to resize a video by cropping the sides and adding height is it possible to do this with ffmpeg?

For a target size of 720x1280, you would use

ffmpeg -i img.png -vf scale=-1:1280:flags=lanczos,crop=720:1280:(iw-720)/2:0 out.png


Projecting slides on a large screen from 40 feet

You'd probably want to look for the following characteristics:

Min and max projection distance (from the data sheet, make sure the projector can focus correctly for the desired distance)
Lumen (some people recommend 500 lumen per square meter projection area, but of course, this also depends on your ambient lighting)
Native image resolution (projecting on a large area the image may become blurry with low resolution)
Diagonal image size (make sure the resulting image size fits your intended projection area)


How to make a “follow the bouncing ball” video?

There's a tutorial on how to make a bouncing ball karaoke-style lyric follower using After Effects here:

http://aescripts.com/beat-assistant/

The example you give should be simpler, as the ball only bounces on each quarter-note beat -there aren't any lyrics to worry about.


DaVinci Resolve: Track with points outside of a window

The tracker is designed to track whatever you put inside the tracker's window.  It doesn't matter whether you want to track something in the middle of your frame or on the edge.  All that matters to the tracker is that it can "see" enough detail of whatever it's being told to track that it can lock on it in the various dimensions it can track: pan, tilt, rotate, zoom, and 3d perspective.

Your background looks really tricky to track because it's very low contrast (relatively speaking).  You could dramatically boost the contrast of your background, for the purpose of building a good track, then use that tracker data on the non-contrast-enhanced image.  Just use a square or a circle over a small but distinct area you want to track and it should be good.

BTW, now you know why people who need to do VFX use Tracking Markers


How to create a video that can be uploaded to Twitter in Mac?

From Twitter's support page:

We currently support MP4 and MOV video formats on mobile apps.
On the web, we support the MP4 video format with H264 format with AAC
audio. You can upload videos up to 512MB, however you will be prompted
to edit videos to 2 minutes and 20 seconds or less in length.

You can export an h264 format video directly from Final Cut.


Looking for a DVD menu maker which works best with Sony Vegas

Sony makes a companion product that works for both Vegas and Vegas Pro called "DVD Architect Pro 6.0 Author DVD or Blu-ray Disc™ media" for $199.00. This is your best bet for Vegas since it has years of Sony compatibility behind it.

Link here:

http://www.sonycreativesoftware.com/dvdarchitectpro

Please note there is a FREE 30 day trial version here:

http://www.sonycreativesoftware.com/download/trials/dvdarchitectpro

There is also a tutorial here (webinar originally aired March 31, 2011.):
http://www.sonycreativesoftware.com/vegaspro10webinar02


If the overlay has transparency, you could use an Add strip instead. Then keyframe the Multiply setting for it going from 0.0 (invisible) to 1.0 (fully visible).


Start and stop capturing while video is playing

There are two main way I can think of to do this, the first, which requires a little work after the fact, but certainly won't interrupt your play back, is to set marker points as you watch through the timeline.  Put the entire video in the timeline and then use the M key to place timeline markers at each point you wish to make a cut.  After watching through, you can place razor cuts on each marker and ripple delete every other section.

The other option, which I'm not sure if it will work without interrupting playback or not, is to set in and out points using shortcut keys.  I will set an in point, O will set an outpoint and Ctrl-K to add the edit to the timeline.  If that does end up interrupting playback, there is one other option that might work indirectly.

You could also try using a multi-cam edit with nothing on the second track.  This would let you monitor what is on your main playback and you could cut to and away from it whenever you like.  At the end you would just have to remove the empty space and get rid of the other track.


Convert 1920x1080 Video to 720x480 With Letterboxing

You can use ffmpeg, a free command-line tool, to do this:

Without letterboxing, NTSC wide pixel-aspect

ffmpeg -i input.mp4 -vf "scale=720x480,setdar=16/9" -r 30000/1001 -c:v libx264 -crf 20 -c:a aac -movflags +faststart output.mp4

With letterboxing, NTSC 4:3 pixel-aspect

ffmpeg -i input.mp4 -vf "pad=1920:1440:0:180,scale=720x480,setdar=4/3" -r 30000/1001 -c:v libx264 -crf 20 -c:a aac -movflags +faststart output.mp4

With letterboxing, square pixels

ffmpeg -i input.mp4 -vf "scale=720x404,pad=720:480:0:38,setsar=1" -r 30000/1001 -c:v libx264 -crf 20 -c:a aac -movflags +faststart output.mp4

Read up on sample or pixel aspect ratios, if you're unfamiliar with them. Your requirements make it sound like NTSC-spec files are expected, so try the commands in the order listed.

If your source audio is MP4-ready i.e. of codec AAC or MP3, then you can replace -c:a aac with -c:a copy


Fast pans and motion seem to strobe or stutter, why?

If the original High Frame Rate (HFR) source was recorded with a (non DSLR) video camera there is a good chance that each frame has been created interlaced. This means that when a shot is not moving you have full resolution, but when you pan or the subject moves it will be separated across the frame in alternating lines.

If you remove half of those alternating lines by using "De-interlace" technique you only see half the resolution. If you blur the lines vertically a bit (like 2 pixels) you will get soft pictures that smear during movement.

The reason that the original looks good is because it is played back at full speed interlaced. But that is really 50fps! That is why it looks so smooth.

Its like a ladder has every second rung removed, making you jump each step. It looks weird. This applies to high frame rate footage that is recorded progressively (not mixed as alternating lines), where there are more whole frames. Progressive recording is better vertical resolution because movement doesn't smear across the frame in the same way.

One potential solution would be to try Optical Flow retiming. Some applications like FCPX or Premier Pro use this for slow motion but you can also use it to try and fix interlace to progressive. By adding a 0.5 or 1% speed change, the optical flow effect will try to make new better frames using all of the interlace information.

Alternatively you can get the NLE software to "interpret" the footage when imported so that the interlacing or alternate frame is merged 50% with the first frame in the sequence.

So in future, if you want to make a 24fps or 25fps project from HFR footage, I suggest shooting at a wider shutter angle to make the motion blur more pronounced or avoid fast pans.


You should double-check:

your speakers' volume (just in case)
audio volume settings in VSDC (see the image)


If there's no electricity and you're not keen on using a generator, this is your solution: a DIY battery solar charger


http://www.openthefile.com/ext/mjp/4458 and http://www.fileinfo.com/extension/mjp both suggest mplayerx (http://mplayerx.org/) can play them. It would make sense to post a file for people to examine. If mplayer or ffmpeg can play them, chances are mencoder or ffmpeg can encode to the format.


To freeze your current state of work you need to load a Library and right click on a Project. Important is you need to choose Duplicate as Snapshot. Only then you make a protected copy of your current work.
Here is why: When you have compounded clips in your project, these clips living outside of your project, available to all Projects in the Library. When you Duplicate your Project only, any change you make inside a Compound Clip is rippling to any Project what is a duplicate to this Project you working on and has this completed Clip in your timeline.
Here is a link to a video that shows the effect. Watch maybe a couple of times as the guy is kind of fuzzy on his explanation.
Duplicate vs Duplicate as Snapshot


A dad and his young son sent an iPhone to space, had it fall back to earth and got it back safely. You could have a look at their rig for inspiration (basically a polystyrene box and a parachute).


FRAPS gets its speed specifically because of the large file size.  When dealing with video you have two conflicting goals, low CPU usage vs low space usage.  To use less space, more compression must be applied.  To apply more compression, more CPU must be consumed.

If CPU consumption gets too heavy, it impacts performance of games.  Thus FRAPS goes to the other side, rather than use compression, it saves nearly totally uncompressed.  This results in massive size files which hit the memory and hard disk more, but as most games tend to be more forgiving on these, it has less of an impact on frame rate as long as the memory and hard drive can keep up with the data rate coming out of FRAPS.

The fact you are trying to produce smaller files means you are running compression while the game is going.  This means more CPU consumption and thus lower frame rates.  If you want small files and good performance, use FRAPS and then compress down the files produced by FRAPS after recording.  Since they are basically uncompressed, there shouldn't be any measurable quality loss.


To project a video instead of a photo:

convert your video to an image sequence (with Nuke, AfterFX, Premiere, whatever...)
load it into your file node, then click on 'Use Image Sequence'
scroll in the timeline, and Maya will load the according frame


Apple Quicktime cannot open a video that has been brightened using ffmpeg?

Pixel data in videos is typically stored as YUV, whereas colorlevels works upon RGB format pixels, so it tells ffmpeg to convert it beforehand. After the filtering, the reverse conversion to YUV before re-encoding uses a YUV format not compatible with basic players, so one has to force conversion to a compatible format.
ffmpeg -i ORIGINAL_VIDEO1.MP4 -vf colorlevels=romin=0.4:gomin=0.4:bomin=0.4 -pix_fmt yuv420p -c:a copy BRIGHTER_VIDEO_1.MP4


Reasons for using DNxHD instead of ProRes?

I have used both on my Ninja Blade with my C100, no real difference in quality across drastically different circumstances (night vs day). Pro Res works better on Mac, DNXHD works better on Windows. It all comes down to your OS, and whether you have to share the files with broadcasters (in which case I would use DNX as a lot of editors use Avid).

Other then that, I haven't heard, or seen first hand any differences between the two and I can honestly say that any differences pointed out online are mostly conjecture.


I don't think you need an expression to achieve this.  You could just loop a cloud moving across the screen inside a precomp.


If you have your heart set on that particular lens, go for it! That's exactly what adapters are built for, after all. I have a Pentax 50mm F1.7 that I use with a K-Mount to EF-Mount adapter on my EOS 80D, and I love it.

However, there are a couple of considerations.

Image quality

The image quality should be largely unaffected. However, the adapter you use is an additional piece of metal/plastic between camera and lens that the manufacturer did not plan for. This might ever so slightly reduce the cameras speed, but in practice, I don't think you will even notice that. Another consideration is that even the smalles of adapters functions like an extension ring. This means it might slightly shift the focus range towards the camera. This might reduce the minimal focusing distance. In turn you might lose the ability to focus on infinity.

There are a couple of might's in there, as it all depends on the specific lens and mainly on the quality of the adapter. The first cheap adapter I found claims to allow lens focus to infinity, so it doesn't seem to be much of a problem in pracitcality. I wouldn't worry about those things too much.

Technical limitations

Depending on your filming habits, this might be a larger problem for you. Most (if not all, not quite sure) adapters you will find are purely mechanical, meaning there is no electronic communication between the camera and the lens. This has a few effects:

No autofocus (mostly). You might have to focus manually. My K-Mount to EF-Mount adapter has an autofocus confirm chip. With this, my camera will confirm whether my selected focus point is in focus when I press the AF-button. So I can manually focus and then check if it's focused properly by pressing the AF button. I only use that lens for photography though, manual focus only will probably be more of an issue if you're using the lens for filming.
Manual only. If the camera can't communicate with the lens, it can't control the aperture as well (nor know what aperture you set the lens to). So you have to manually set the aperture. This might also throw off your camera's auto exposure, so you will mostly be limited to using your camera fully manual.
Missing or wrong EXIF data. No communication means all the lens-dependent parameters such as lens model, focal length and aperture won't be recorded into your EXIF data / metadata. Some adapters have an EXIF-chip that present the camera with static info. My own adapter tells the camera that a 50mm lens with f/1.4 is mounted, independent of what lens I use it with or what aperture I set it to. This means, for example, that I won't be able to find out what aperture a particular shot was taken with afterwords. Depending on your editing needs and habits, this might either not be a problem at all or utterly disrupt your workflow.


Auto generate video clips using a CSV of times as markers from a single MPG video

You can use an EDL (Edit Decision List) in the CMX3600 format. An EDL is a very simple import/export format from the 1970s, when data was exchanged using floppy disks and videos were stored on tape. It's just a text file and most modern NLEs (including Premiere Pro) can import/export it. (Today there are some variations between NLEs, but that doesn't have to bother you.)

To understand EDLs, it's probably best that you create a new timeline and put your MPG video in it. Then export the timeline into an EDL (File > Export > EDL) and open the exported file with a simple text editor. Analyse the content. Then do some cut in your timeline and export it again.

Basically, an EDL consists of several text lines like this:

VJ0K006W V    C         00:00:00:00 00:00:18:19 00:00:22:02 00:00:40:21

The first column is an ID of your video clip, followed by V for a video track and C for a cut. An A instead of V indicates an audio track. The last 4 columns are timecodes which define the in and out point of the source and the in and out point in the timeline. You see that this clip is the first 18 seconds and 19 frames of the input video starting in the timeline at 22 seconds and 2 frames. It's only logical that the clip must end 18 seconds and 19 frames later, at the timeline position 40 seconds and 21 frames.

Now, to answer your question: You have to write a small program (or ask a friend to write) which takes your CSV file as input, extracts the time position, calculates the +/- 10 seconds, and writes an EDL file in the way that Premiere Pro exported. Premiere Pro should import it without problems and assemble the timeline.

Here are some footnotes:

Wikipedia explains how timecodes are constructed. If you have simple frame rates like 24, 25, or 30 fps, calculating your +/- 10 seconds is not so difficult. But if your clip has 29.97 fps, then you have to consider drop frames. (You know that leap years have an additional day - February 29, but only occur in distinct years. Clips with 29.97 fps have normally 30 frames per second, but at distinct times have 2 frames less.)
I didn't cover the problem of media file names here. When the EDL/CMX3600 format was defined, media only had tape numbers, which were written in the first column of the EDL. When file-based media came into existence, NLEs had to add the file names somehow to the EDL. They did it, but not in a consistent way. But since you only work with Premiere Pro, just see how your video file name appears in the EDL file and mimic the same when writing your file.


Cheap Method for Audio/video transmission in a building

There are two options, neither of which is particular expensive.  You can either use a component cable with a distribution amplifier or if you prefer a digital signal, there are wireless HDMI transmitters that will also work well.

A distribution amplifier and a repeater are essentially the same thing, just slightly different purposes. A distribution amplifier boosts the power of an analog signal to account for the attenuation when sending it over one or more lines or a long line. A repeater is similar, it reads the signal in on one side and outputs it again on the other. The main difference is that the repeater will reduce line noise since it is interpreting the signal rather than just boosting it.

You could try doing a wired HDMI, but it would likely be quite pricy.
HDMI is a digital signal that is designed in such a way that it doesn't handle long distances well on the wire. Currently, the effective reliable limit for an HDMI cable is about 10 meters. To make a 50 meter run reliable, you would need 4 repeaters and 5 10 meter rated HDMI cables. This is going to be far, far more expensive than a wireless HDMI unit that is rated for even twice the distance.

You could try just using a 50 meter cable and hope that your hardware on each side is powerful enough to make sense of the data on the line, but I wouldn't expect it to be a reliable connection if you use a physical HDMI wire without at least 2 or 3 repeaters minimum.

So for reliable solutions, you can probably do the analog wire & distribution amplifier solution for about $150 or the wireless for about $250 to 350.  Putting a DA on both sides of the wire solution would allow for you to choose which way you wanted to send signal by plugging in the DA on that side.


I'm not sure why they are not lining up, perhaps there is some problem with the audio track near the beginning that is causing truncation at the start.  Unless you have meaningful information there, my suggestion would be to remove the silence at the end of the audio file (since it is clear when it goes perfectly silent) and then end align rather than start align.  It appears that would likely give you proper sync.


Portable camera recommendation for interviews

Often, the best option, particularly for interviews, is a DSLR.  The particulars of your needs may change that or harden in on a specific level of DSLR, however in general they key thing for interviews is to be able to have a sharply focused subject with a nice blur to the background.

DSLR cameras shooting HD video with a fast lens (f/2.8 or faster preferably) can achieve very nice background blurs and make great looking video.  Most also have a line input that you can run a mic into, though use of the best quality mics will often require using an external device first to deal with the mic and convert it to the type of signal the camera wants.

Personally, I shoot with a Canon 5D Mark iii and use a Zoom h4n for audio.  I record the audio separately and sync in post production, but a line out from the Zoom can also be fed in to the camera directly.  You don't need something as advanced as the 5D Mark iii, but it hopefully gives you an idea of how a setup can work.  You could substitute any DSLR with a mic or line input for the 5D Mark iii.

If portability is super key however, it might be best to go with an actual camcorder.  They can get a little bit smaller than a full fledged DSLR though the smaller the camera, the harder it is to get the background blur that you often see in interviews.


How to soften the appearance of particles in Particular

I reckon try a lot more particles and make them much smaller. (But this will take much longer to process). You can feather the spheres too, which might give you the effect you need.


Try with the movie filter instead

ffmpeg -loop 1 -i image.jpg -filter_complex \
        "movie=video.mov:loop=999,setpts=N/(FRAME_RATE*TB)[1v]; \
        [0:v][1v]overlay=x=main_w*0.44:y=main_h*0.33[out]" \
       -map [out] -t 00:00:15  out.mp4


Is it better to scale video or images when doing time-lapse?

It is going to depend on which of the two provides a higher quality resize option.  If imagemagick's convert is higher quality than the scale of your encoder, then it will do better, if not, then it will be the other way around.

The one exception to this will be if there is any resolution dependent alterations made to the content along the way.  If for example, you add text to the video, it would be much better to scale the images so that the you are creating new content at the native resolution of the finished video.

Anything you can avoid scaling you should and if the images are larger than the output, the earlier you can scale them down, the faster everything else will run anyway.

So with that in mind, I would generally scale down the images initially, if it was necessary to have the video at native resolution already when encoding, though most decent editing software will make it irrelevant because they will use the full quality image and put any new content at the native resolution and still combine everything to the proper resolution when rendering out at the end.


CHDK on Canon Powershot S100: Is there a Video Bitrate sweet spot?

No, there is no sweet spot for compression, whether it is on a camera or in encoding after the fact.  The needed data rate depends heavily on the content being recorded and is a complex field, though the best bet to handle it simply is to try adjusting it and decide when it works for your needs.  You can eventually get an idea of the quality from each bitrate for your camera, but we can't really give you guidelines as both noise level and the particular encoder used by your camera will also impact the way things turn out.

One important caveat to keep in mind when dealing with compression on a camera is that if you are going to edit the footage, you want to make sure you use a high enough quality that re-compressing after editing does not result in quality loss either.  With lossy compression, each additional compression results in further quality loss and a video that looks fine initially may fall apart when compressed for final output.  The larger your source videos are, the smaller you are likely to be able to compress your final video to.  You may also want to shoot All-I if it is an option because this format is far more efficient in editing software than compressions that are group of picture based (IPB), though they also take far more space to get good quality.

Also, you say that 14MBps is obviously too high, but I would challenge you that it is not obviously too high.  Uncompressed, 1080p video at 24fps would still take 150MBps or 1194mbps.  You are still compressing over 90% at 14MBps.  Bluray will often use in the neighborhood of 35 to 50mbps which is still up to almost half of the 112mbps data rate you quoted as the max.  Particularly if that is All-I, 112mbps is not an unexpectedly high value at all.


I'm not sure that it would be ideal, but Lightroom is able to provide keyword and cataloging support for a variety of video clip types.  It isn't expressly designed for it, but it's a relatively cheap option that may be able to handle your needs.

As stib was nice enough to point out, Adobe Bridge also can do similar cataloging if you have the broader Adobe suite or you can try using Darktable which is an open source package similar to Lightroom, though I have no direct experience with Darktable's ability to catalog video.


Convert mp4 to avi while keeping frame rate and quality and being able to play in QuickTime?

An AVI file is just a container and can contain any codec, so if you want to encode to QuickTime and Media player, you need to:

ffmpeg -i input.mp4 -c:v libx264 -c:a libmp3lame -b:a 384K output.avi

and above means:

Use the h264 Codec which both QT and WPlayer can display nowadays
use 384 Kbps MP3 encoding for audio

don't touch anything else like frame rate, resolution, ... and copy these as is.


I believe You want to delete some objects from Your scene.
Adobe After Effects recently introduced a feature allowing users to do just that:

Documentation: https://helpx.adobe.com/pl/after-effects/using/content-aware-fill.html

Video example:

If You meant anything else please clarify Your question a little bit more.


Track Object in Premiere Pro / After Effects

Right click on your footage layer (either in the comp window or the timeline) and choose track motion from the context menu.

That will open up the layer in the layer viewer

and add a motion tracker to the layer.

It should also open the tracker pallette window. If it doesn't, open it from the window menu. Alternatively if the Tracker pallette is already open you could start tracking the layer by selecting the layer and hitting the Track Motion button in the pallette. Or you could choose Animation>Track Motion from the menu.

In the Tracker Pallette there are a few controls. The Motion Source drop down determines what layer we're tracking, the Current Track drop down lets us choose if there are multiple trackers on the layer (you can have as many as you want), and the Track Type drop down lets us choose what to do with our tracking data when we apply it. You shouldn't have to change any of these for your purposes, but it's good to know what they do.

Transform will apply the tracking data to the positon, rotation and scale properties of the target layer, depending on the checkboxes below. The other modes include stabilise - to use the tracking data to stabilise the layer, or the perspective and parallel corner pin modes which let you apply the track to a corner pin effect on a layer, which is useful when you're doing something like putting in the contents of a screen, or covering a graphic on a wall. Raw tracks just give you the track points as they are, without transferring it to the position/rotation/scale of another layer.

Finally the Edit Target button will determine to which layer the track is applied. This should be the only setting you need to change.

So for your purposes you need just the position checkbox checked. This will give you only one track point. In the layer window drag the trackpoint to the object you're tracking. Find a unique feature if you can, and preferably one that doesn't get obscured. It's also best if the entire area of the trackpoint is on the tracked object, and does not include any background. You can drag the corner handles of the inner box to increase or decrease the size of the tracked point.

The outer box is the search area - it defines where the tracker will look for the trackpoint. Make this box big enough so that the movement between frames will fit into it, but no bigger than you have to: making it too big will not only make the tracker go much more slowly, but can also cause false positives, where it sticks to something else in the frame that looks similar. If it's too small however the tracker will lose the trackpoint. You can stop and adjust it as you go, that is often the best way.

The little cross is the actual attach point. It is the point whose movement the tracker will output to the target. It doesn't have to be inside the track box - sometimes this can be useful if you're tracking something that gets obscured.

So once you've adjusted the tracked area, the search area, and the track point if necessary, hit the track forward (or backward, it works bothe ways) button and the tracker will start its magic.

You can as I said start and stop the tracker and if it goes wonky you can go back to the last good frame, adjust it and start again. If you hold the alt key when you move the track box it will move the track box without moving the attach point, meaning that you can keep the motion of the track point stable while changing the part of the image you're tracking. This is very useful for tracks where the track point is obscured.

Weirdly enough in this shot the next zebra appears exactly where the first one was. But as you can see, the motion tracker has nicely followed the zebra's nose to the edge of frame.

Now it's time to apply this track to something. Choose the layer you want to apply the track data to by hitting Edit Target. This will bring up this dialog - as you can see you can either use the track data to move a layer, or to move a point control for an effect (of course with expressions you can also use the data for anything your heart desires, but that's beyond the scope of this answer).

Choose the layer and hit OK, then hit Apply to apply the data. You'll get asked if you want to apply the data to x and/or y, and then the tracking data will be written to the position property of the target layer.


KdenLive: Nothing is being rendered on Windows?

I was having the same problem. Found this fix from the bug reports.  I did it all, exactly as it says, including the part that changes the melt directory in the program as opposed to moving the melt file to match the directory, and it worked. I did not lose my saved project that previously wouldn't render. It's saved in a different location and keeping it did not effect the fix.

https://bugsfiles.kde.org/attachment.cgi?id=108162


You have a few options for disguising a voice, but several of them intentionally make the sound unnatural.

Have someone else record the voiceover. This is the only technique that results in a truly natural sound because it is an unmodified voice. There are some relatively inexpensive voiceover services available if you don't already know someone. Because the person is never seen on screen in what you describe, you don't have to worry about lip sync, just rough timing.
A simple pitch shift. Change the key of your voice with a pitch shift filter and correct the timing. This is easily reversible if you have serious concerns about your identity. This video describes how to do that in Premier.
Randomize the pitch shift, layer multiple pitches, or add other distortions. Sound designers get creative with plugins.


So you set the resolution of your TH2G to 720p50? In that case you don't get 720p on every output but 1/3 of that vertically. You have to set your th2g to 3840x720 so you get three 720p signals on your outputs.

I also recommend using the Matrox App for setting resolution modes instead of the windows/osx display manager.


Paperwork is important.  Beyond a simple Excel spreadsheet, you should have appropriate releases from everyone involved in your project.  Depending on your jurisdiction, it is likely that you can't make commercial use of someone's likeness without their consent, and if they decide they don't like your project for some reason they could force it to be taken down until you can edit them out of it without a release.

Similarly, for crew, by default, copyright sits with the person producing the work in most jurisdictions, unless there is an agreement otherwise or there is an employee relationship.  You need agreements with everyone from the project and you need to keep these organized so you can present them if necessary.

Yes, having a master list somewhere like Excel or in a text file is helpful for being able to more quickly add them to the credits, but you need far more than just a simple list of names to properly document a project.


Adobe After Effects is the go to program for motion graphics. There are a lot of resources available online in the form of tutorials and guides to help you get started. Something like you are describing is a simple enough task, but still requires a basic understanding of AE.


Output of FFmpeg has a "slow motion" part - what is it and how to avoid?

Your source is variable frame-rate with a peak rate of 120 and an average rate of close to 60. Editors tend to want constant frame rate streams. If you can interpret your whole transcoded file as 120 fps, then you should get the expected result. Alternatively, you can preserve the original variable frame rate,

ffmpeg -i test-source.mov -vsync vfr test-result.mov

or transcode to a constant 60 fps,

ffmpeg -i test-source.mov -r 60 test-result.mov


Setting format to H.264 in After Effects

I would not recommend trying to output your AE Comp using H.264. Unfortunately, regardless of the settings, you will get less than desirable results (typically terrible).

The proven workflow / best practice in terms of output is:

Under your Output Module Settings:

Render out using

Format:     Quicktime
Format Options Button -> Video Codec:    Animation
Quality:    100
Options: You can select your Channels as to include or not include Alpha along with RGB. Including Alpha will increase file size.
Audio Output: Check if needed.

Now this will output your composition to a lossless QT Animation file, which yes, will be very large, especially if you include an alpha channel. But the output will be perfect in terms of what you are seeing in AE.

NEXT...

Use AME (Adobe Media Encoder, or import the file into Premiere Pro and Sequence the comp), and render out using export/AME and H.264 using the MP4 option.

NOTE:  There is absolutely no need and I don't recommend using the QT in premiere either. Use H.264 MP4. Again, H.264 and MOV simply are not friendly within the CS suite.

However, after you have rendered out your H.264 MP4 at the desired bitrate and resolution; if you need the file to be QT compatible, or the client specifically wants an MOV file, simply change the extension from "FILE.mp4" to "FILE.mov".

There is absolutely zero difference file structure wise, the MP4/MOV is simply the wrapper for the H.264 codec.

This will give you perfect outputs every time.

Hope this helps.


Imported video getting out-of-sync audio in Adobe Premiere

It sounds like your source media went through quite a lot of different operations, which makes it difficult to say what exactly has upset the audio/video sync.

I would start by trying to isolate the problem: repeat the process on a smaller scale (just one cut/edit, instead of the whole thing) and verify the output at each stage. That will help you understand where exactly things have gone wrong. Then, you could edit your question and present us with an isolated example of an operation that affects the sync. That should make it easy to resolve the problem.


Screen refresh rate above 100 Hz noticeable?

No, there is no practical limit that we know of yet to what would be best, there is however a practical limit to what we can capture and display.

In tests with airforce pilots, subjects were able to identify a plane from being shown a frame for only 1/220th of a second.1  They eye is able to pull information out of extremely short periods of time, but unfortunately our eyes are also very good at concealing lack of information (which is actually why video works in the first place), so it is extremely hard (possibly impossible) to determine the actual point at which we wouldn't benefit from more information.

Either way, it is almost certainly upward of the current 1/600 mark and often theorized to be beyond the 1/1000 mark.  The problem comes not from how much information we present, but that we don't have enough information to present.

Generally videos are normally not played back faster than 48 frames per second at the fastest and video games normally don't go beyond actually displaying 120 or so.  This is due to a lack of being able to store sufficient data and stream it in an efficient enough manner to display in an affordable manner.

Instead, to make things appear more smoothly, the TV interpolates additional frames to fill the gaps.  It looks at where one frame is and where the next frame will be and generates frames in-between to smooth it out.  The problem is, not all motion is perfectly smooth and interpolation isn't a perfect process.  The result is that unnatural artifacts appear in the video which we can detect and end up being unsettling and eventually start causing more harm to the persistence of vision than the extra frames help.

This is why, when you move in to higher refresh rates it is sometimes better to use a lower setting without the interpolation.  Video is about simulating reality for your eyes.  In reality, there is no refresh rate, any time your eyes chose to process, they get whatever is there at the time.  Thus, higher and higher frame rates will more closely emulate reality as long as the information is actually based around reality rather than something invented by electronics on the fly.

Eventually, we may exceed the "refresh rate" of the eye, but as of yet, we don't definitively know what that is and are pretty certain we haven't hit it yet.


I think you want to capture at 640x480. VHS uses interlaced video, so the recorded content provides half the lines every 1/30th of a second. The effective resolution is horribly low, 352x240.

Have a look at VHS capture DIVX information, which seems to discuss all the issues.

Regardless of the workflow you use, be sure your de-interlacer is high-quality or the output will suffer greatly.


Is it possible to install the Quicktime backend without getting the frontend?

Sadly there isn't really an alternative, many dll's coming with QuickTime are needed by programs like LightWorks or Premiere and After Effects.
You can probably delete a portion of the QuickTime installation but in the end why bother?
Just don't let it take over any of the file associations and disable the auto-updater so it doesn't nag you whenever there is an update to QuickTime or any other Apple product. Then it wont bother you in any way. You can also delete any icons and start menu entries if you dislike those aswell.

Though generally its advised to have QuickTime installed when working with video even if your tools don't need it. Its a widely used player in the Apple Ecosystem and the .mov format is still very popular in video production even on Windows. While you don't need quicktime to check .mov files it's the most reliable solution there is.


How to emphasize a faint white line among a yellow background?

A screenshot is a still image, so you would need to use image-editing software like Photoshop to enhance the image. I recommend messing around in the "Edit > Adjust" menu.  You may be able to show off your effect by increasing the Contrast of the image, or by changing the Hue of the image.  You could probably also replace the yellow color with a different color (though Hue would produce a similar effect).


Can you encode intra-frame videos from inter-frame without loss?

An encoder receives and works upon uncompressed frames and does not know or care about the encoding of the source stream.

To avoid any information loss, you have to set lossless mode. For x264, this is by done by adding -qp 0 to your ffmpeg command. But for most purposes, strict mathematical losslessness is not required. See What's the difference between "visually lossless" and real lossless and what does this mean for future encodes?


How to specify CRF quality settings for different encoding software

Any decent encoder can hit a target bitrate (with 2pass), but still spend the bits intelligently to achieve similar quality throughout the file.  x264 2pass figures out what CRF will give the desired bitrate (pass1), and then uses it (pass2).  (source: Dark Shikari.  cf. the links I dug up for my answer on this question about VBR streaming).

You only get CBR with x264 if vbv-maxrate = bitrate, and even then it's can be VBR within the buffer size.  (h.264 is never going to be strictly CBR like mp3 or something, unless your I frames look HORRIBLE :P)

However, you probably meant variable-across-clips, rather than the usual within-one-file meaning, because CFR as a quality target is clearly much better than blindly setting a target bitrate for many different sources.

(Is there a word for this?  flexible bitrate?  Other than target-quality, as opposed to target-bitrate.  CRF targets a heuristic for quality, not strictly a quality target.)

Anyway, in that case, I have no idea what other encoders support.  Lossless h.264 is probably the best format for sending files around.  It's significantly smaller than huffyuv or utvideo, and can support up to 10bit.  (actually, I think FFmpeg can decode higher bit depths, but x264 can only produce files up to 10bit.)  Or I guess you could get them to send you slightly-lossy pro-res files, if that's a lot easier for your workflows.

LordNeckBeard brings up the question of whether you're delivering these files directly to clients.  If that's the case, you should probably require that they encode with x264 with at least preset=slower, so you can just give them a crf value if you're already requiring x264.  The rate-distortion tradeoff matters for final files that you're going to stream many times.


Crossfading audio at beginning and ending of video

For purposes of this answer I'll assume the audio is encoded with an aac codec.

For each video:

Use ffmpeg to extract the sound track to its own file.

ffmpeg -i "${f%.mp4}" -vn -acodec copy "${f%-sound.aac}"

If not yet known, determine the duration of the audio file.  In some cases ffmpeg is known to give an incorrect duration (https://stackoverflow.com/questions/10437750/how-to-get-the-real-actual-duration-of-an-mp3-file-vbr-or-cbr-server-side), so I'd use sox.

duration=$(sox soundtrack_before_processing.mp3 -n stat 2>&1 | sed -n 's#^Length (seconds):[^0-9]*\([0-9.]*\)$#\1#p')

Use sox to apply fades in and out.

sox "${f%-sound.aac}" "${f%-sound-with-fades.aac}" fade t $fade_in_seconds $duration $fade_out_seconds

Replace the audio track in the original video file with the faded track.

ffmpeg -y -i "${f%.mp4}" -i "${f%-sound-with-fades.aac}" -map 0:v -map 1 -vcodec copy -acodec aac -strict experimental -shortest "${%f-new.mp4}"


Any video editing software with own codecs?

I installed Sony Vegas Movie Studio HD ($34). The download took half a minute, the same to install it, no prerequisities ( except the software updated windows installer ) and everything worked and has been working like a charm.