Video editing with playable jump forward

I came up with the following solution.
Find the durations using your favorite player.
Then, use the following python script that employs ffmpeg:

# Cut out clips from a video given a text file with times, e.g.:
# 0.0-12.20
# 14.28-15.58
# 53.25-53.31
# 54.47-55.05

import sys, re, os
import datetime

fin = "8-01.mp4"
flist = "8-01_cut_out.txt"

def main():
    with open(flist) as f:
        lines = f.readlines()
    #print(lines)

    print("Durations to remove:")
    times = ["00:00:00.000"]
    #for line in sys.stdin:
    for line in lines:
        line = line.rstrip()

        reg = re.compile('(\d+)\.(\d+)-(\d+)\.(\d+)')
        m = reg.match(line)
        if not m:
            print("Couldn't find pattern:", line)
            return

        m0, s0, m1, s1 = [int(m.group(i+1)) for i in range(4)]
        t0 = "00:%02d:%02d.000" % (m0, s0)
        t1 = "00:%02d:%02d.000" % (m1, s1)
        print(t0, "...", t1)
        times.extend([t0, t1])
    # append last
    times.append("10:00:00.000")

    print(">> \nDurations:")
    fclip = open("clip_list.txt", "w")
    for i in range( len(times)//2 ):
        t0 = times[2*i]
        t1 = times[2*i+1]
        fout = "clip%02d.mp4" % i
        dur = datetime.datetime.strptime(t1[:8], "%H:%M:%S") - datetime.datetime.strptime(t0[:8], "%H:%M:%S")
        dur = dur.total_seconds()
        print(">>", fout, t0, "...", t1, "%dsec" % dur)
        if dur == 0:
            continue
        fclip.write( "file " + fout + "\n" )

        cmd = "ffmpeg -y -ss %s -i %s -t %d -c copy %s" % (t0, fin, dur, fout)
        print(">>", cmd)
        os.system( cmd )
    fclip.close()

    print("\n>> Concatenate:")
    cmd = "ffmpeg -y -f concat -i clip_list.txt -c copy out.mp4"
    print(">>", cmd)
    os.system( cmd )

if __name__ == "__main__":
    main()


Adobe Premiere: edit effect curve manually

It's possible in AfterEffects because AE has far more detailed controls for keyframing and the controls for it's effects.

As for film dissolve, The only way it would be possible would be to make sure you the effects panel, and keyframe the dissolve point (which I believe is possible with that specific filter).

But you don't access it from the pop up window, you select the transition once it's applied, then control it using keyframing on the effects control / modify panel.


Is there a video player where I can draw on top of video?

Why not just use an app that annotates the screen? Depending on whether you are on Windows, OS X, or Linux there should be plenty of apps when you search for "screen annotate" or "annotation". Maybe you've searched for the wrong thing until now.


How to set up Trapcode Particular as a bounded text object, then disperse it

You can use the layer-emitter for that. Particular will look for the alpha and spawn more particles where areas are more opaque. Just make sure that your text-layer is precomped and set as a 3D-layer. Then, from the drop-down menu of particular, choose the layer-emitter, open the tab of the layer-emitter further down and select your text-precomp. You might wanna up the particle count as thin text may not cause a single one to spawn, and you will think you did something wrong. Alternatively, use the layer-grid-emitter to significantly up the particle-count. Just make sure to disperse the particles using wind or Spin-Amplitude down in the physics->Air tab.
I hope I was able to help you, have a great day!


What is the best format for archiving digital movies?

If you're looking for an open source codec that is finding favour in archives and museums as an archival format, you might want to look at FFV1 from the FFMPEG project.

https://en.wikipedia.org/wiki/FFV1

It is reasonably fast, reasonably efficient, cross-platform (including linux), free, and supports up to 16-bit per channel colour. Storage size is similar to ProRes.

However the main advantage is that it is 100% open source and non-proprietary, so it's not going to suddenly disappear come the Patent Apocalypse. It comes with ffmpeg, which is hands-down the best tool for doing these kind of conversions anyway.


FFMPEG - Use drawtext and complex filters

Just chain the drawtext, at the end.

ffmpeg \
-i video1.mp4 -i video2.mp4
-filter_complex "[0:v:0] [0:a:0] [0:v:1] [0:a:1] concat=n=2:v=1:a=1 [v][a];
[v]drawtext=text='SOME TEXT':x=(w-text_w):y=(h-text_h):fontfile=OpenSans.ttf:fontsize=30:fontcolor=white[v]" \
-map "[v]" -map "[a]" -deinterlace \
-vcodec libx264 -pix_fmt yuv420p -preset $QUAL -r $FPS -g $(($FPS * 2)) -b:v $VBR \
-acodec libmp3lame -ar 44100 -threads 6 -qscale 3 -b:a 712000 -bufsize 512k \
-f flv "$YOUTUBE_URL/$KEY"


Modify video file for viewing in generic media player

You need to convert the codec used to encode the video to something that the players you are trying to use support. MPlayer supports a wider range of codecs than many players.

To allow you to view the video in other players you need to transcode the video using an application like ffmpeg. The command below will provide the conversion you need:

ffmpeg -i foo.264 -c:a aac -c:v libx264 -preset medium foo.mp4

i - input file
c:a - set audio codec to transcode to. Here I chose AAC
c:v - set video codec to transcode to. libx264 is used to transcode to H.264, one of the most common and widely used video codecs. Most players should be able to play files encoded with H.264.
preset - used to quickly define the H.264 encoding parameters. Choose from ultrafast,superfast, veryfast, faster, fast, medium, slow, slower, veryslow, placebo. There is obviously a trade-off between quality and transcode speed here.

After running this command I could play the video you uploaded in QuickTime on OS X.

If you use -copy or don't specify a codec, then ffmpeg will use the same codec as the source. So the command

ffmpeg -f h264 -i foo.264 -c copy foo.mp4

Will change the container around the video to mp4, but not the video encoding itself. You can read more about the difference between containers and codecs here.


How can I cut a few seconds at the beginning of a large video file?

Try this:

Open the file in the Quicktime player -- it'll have to be Quicktime Pro.
Select the frames that you want to remove with the input and output markers.
Hit 'Delete.'
Then save as a 'self-contained' movie.


Multiple Channels vs Playlists on YouTube

Generally, you are much better having one channel and placing all your videos into this single channel, with different playlists targeting the different audiences.

However, I'm assuming the videos are somewhat related. If they are on completely different topics (for example Gardening and Software Programming) you may find that it's better to separate so the subscribers don't get overwhelmed by videos in the wrong category.

If perhaps you have a brand, say a magazine (Home World, for example) and you have separate categories (Home World: Gardening and Home World: Decorating) I'd say stick to a single channel for branding purposes.

And to answer your final question, no, generally YouTube will treat separate accounts as separate entities for the purpose of monetization.


Automatically cut out sections of a video delineated by a sound.

I haven't done this myself, but I think it's quite doable.

First, you'd need to setup a ffmpeg script to demux the video into audio and video portions. Then, you'd need to apply a script that will analyze the audio file. Silence is easier to automatically detect in an audio file, assuming that you can produce the silence on site to mark the intervals (e.g. disconnect the mic for 2 seconds). You'd need to know some programming, but with something like Python it would be quite easy.

Finally, with the output of the script as times to cut between, feed this into ffmpeg again on the original file, using the -ss  -t  command.


Gstreamer 1.0 rtspsrc to rtp (audio and video)

Ok I've found the solution that works, it was here all along but needed some changes (link only since it's link to the stackoverflow)


Help needed editing music more precisely in Premiere

Perhaps the quickest option for better accuracy of audio editing would be to right-click on the actual numbers of the timeline and select "Show Audio Time Units" ?


how do 4k or 1080 images look like on a 720p monitor?

When displaying an image whose pixel sizes are larger than your monitor, you loose some information and your graphic card is doing some processing to fit the large image in a smaller screen. You will get the best result when watching the image on a monitor whose native pixel sizes are equal to the image pixel sizes.


ffmpeg.exe ignores yadif filter when using >1 filter on the command line

Use one filtergraph and join simple filters with a comma:

-filter:v "filter1,filter2,filter3"

Your scale isn't doing anything. For example, a 320x240 input with scale=in_w:in_h is the same as scale=320:240.


Unable to convert Avisynth script in ffmpeg

From FFmpeg source code:

  On Windows, FFmpeg supports AviSynth interface version 6 or higher.
  This includes AviSynth 2.6 RC1 or higher, and AviSynth+ r1718 or
  higher, and excludes 2.5 and the 2.6 alphas.

From doom9:

  The decision to drop support for anything below 2.6 RC1 was due to
  catastrophic header incompatibilities between 2.5 and 2.6 RC1* and the
  maintenance burden (and potential licensing minefield that could mean
  any additional 2.5 support would violate GPL) that would be incurred
  by trying to continue to support 2.5 while using properly updated 2.6
  headers.

Get AviSynth+ r2420 from
https://github.com/pinterf/AviSynthPlus/releases/tag/r2420-MT


Keyboard shortcut for cut video AND sound at current position in premiere cs5.5

the keyboard shortcut is Ctrl+Shift+K,

Ctrl+K didnt work for me for some reason.


How do I get screen captures from VLC to import properly into Premiere?

Looks like a codec that Premiere is unable to read.

I encountered a similar issue with Final Cut when trying to import an MP4 file encoded with H264.  Then came across this advice:  "H.264 is a delivery format, not a production format. You need to convert the media into a suitable format. What that is depends on what the files are and what their frame size is." https://forums.creativecow.net/thread/8/986671

So if you can't recapture with a suitable codec, you'll have to decompress your H264 MP4 file into something Premiere can import.


Well... You could try to place the clip that you want to fade in/out on top of the other clips. If that does not work, you will have to split all of the clips at the same place and make them all fade in/out. If doing this will ruin the whole project video because you have other effects on it, then I suggest rendering the video without adding any fade in-/outs and then opening a new project and adding the video you made, then making it fade in/out wherever you would like to. I hope this helped!


Can you give a tip how to create a video with such effect?

The first one is a so called hyperlapse. Just not a smooth one. It is basically just speed up.

Same goes for the second one, just that it also has a diffrent shutter speed.

So how to do them:

Simply record the walking video and speed it up in post.

To achieve the special look in the second one, not every camera can do that. You need a camera with a really low FPS, for example 10, then you also expose 1/10 second. You should get a similair look, then you will need to experiment. But that effect may be hard to achieve on a digital/cheaper camera.


Premiere CC uses vertical aspect ratio in multi-camera shot

I have to thank @ProfessorSparkles for getting me to this solution, which doesn't require saving and reimporting, or making a duplicate of the source footage.  Here are the steps:

1) I started with the 2 clips I'm using in the same bin.

2) Drag the landscape-oriented clip to the timeline.  That creates a sequence with landscape orientation in the bin.

3) Select the clip in the timeline and delete it.  (The sequence is still in the bin.)

4) Select both of the clips within the bin.

5) Right-click and select "Create multi-camera source sequence...."

6) In that dialog box, click "OK".  Premiere will synch up the 2 clips.

7) When I first did this, it asked me a question before creating the sequence.  It was something like, "The settings on this sequence don't match the existing sequence.  Do you want to keep the source sequence settings?"  CLICK NO.  That will make your new sequence match the settings (landscape orientation) of the existing sequence!

8) You can then select the blank sequence you created a minute ago and "Clear" (delete) it.

9) Drag the new sequence to the timeline.

10) Hold down Ctrl or Cmd and double-click on the new sequence in the timeline.  A new sequence will be created that shows each clip separately.

11) In that new sequence, select the clip with portrait orientation.

12) Go over to "Effects Controls".  In "Motion", rotate the clip either 90 degrees or 270 degrees.

What a relief it was to figure that out!!!


Size of YouTube Subscribe Circle and Video Rectangle

When using brand identifiers such as the YouTube Logo, you want to check what guidelines the brand has on using their brand resources. A quick Google search yields the official Brand Resources guideline by YouTube. Here you will find all you need:

  Minimum size

  The word "YouTube" should always be easy to read. So in digital
  content the Logo should never appear smaller than 24dp in height.

  The minimum size for applying the Logo in print is 0.125 in/3.1 mm in
  height.

Check the linked page for more details on the usage of the Logo.

Sidenote: Since YouTube belongs to Google, they use the terminology of Google's Material Design guidelines. dp stands for Density-independent pixels, you will find an explanation on that on the Material Design website.


There is no good way to use an Android phone as an attached camera in the way you want. Your best bet is to get a GoPro or other dedicated camera which has a USB or hdmi output, or to use a microUSB adapter to connect your mic to the phone.


How to create a fireball effect with After Effects?

You might want to check out a class of effects known as "particle generators."

Trapcode Particular is a nice 3rd party option, but costs a bit of money.

AE has some built-in particle generator effects, too. Check out CC Particle World, CC Particle Systems II, and Particle Playground.

This tutorial here covers using CC Particle World to create fire. You could adapt that example to make a fireball instead of a wall of fire.

Particle Generator effects often have an source position property that you would need to match to the position of the football. This could be done with motion tracking, or simply keyframe it 'by hand' if the ball throw segment is fast enough.

Note that CC Particle World and CC Particle Systems II are very similar, but the first is a 3D effect while the second is a 2D effect. For shots where the ball goes from closeup to far away, the 3D variant would be helpful, but otherwise you might be able to get away with the simpler 2D variant.


How to move a layer using a slider control?

Yes, in short. But you will need to learn Expression Controls.

Search YouTube for "Expression Control Slider After Effects"

There are a lot of good tutorials which will walk you through the process.


ffmpeg and mapping against 2 target audio tracks!

Use

ffmpeg -loglevel verbose -i test.mov -map 0:1 -map 0:2
-codec:a:0 aac -b:a:0 160k  -codec:a:1 eac3 -ac:a:1 6 -ar:a:1 48000 -b:a:1 640k -dialnorm -24 -dsur_mode 0 -original 1 -dmix_mode 2 -channel_layout 63 -y test.ts

acodec is an alias for codec:a and it does not accept stream specifiers. Same goes for other codec-related options like bitrate.


How to make a film in black and white with some objects in color Final Cut Pro X

The simplest way to do this (also known as the Pleasantville effect) is to apply a Color Correction effect to your clip and then do the following:

Click on the Color Board to open the Color / Saturation / Exposure menu.  Select the Saturation menu and pull the Global (leftmost) slider to the bottom.  Your image should be fully desaturated.

Return to the Color Correction menu and select Add Color Mask.  It's disguised with an icon that shows an oval in a square.  When the eyedropper is blue (default), you can click (or better, click-drag) a spot on your image that has the color you want to preserve.  You can do this again and again until you get enough of the color selected to achieve the effect you want.  Select Invert Mask to get only the color you selected, or leave the mask as-is to desaturate only the color you selected.

This will work well for simple cases, but it is a far cry from the HSL qualifiers offered in programs like DaVinci Resolve, for many reasons.

A much, much more complicated thing to do is to use masks and manually composite in FCPX.  Compared with other NLEs, which all seem very intuitive to me, FCPX utterly baffles me when it comes to masks and layers.  YMMV.


Reducing the frame rate : the smooth video Issue

In order of preference,

Generate animation at 25 FPS and capture it at 25 FPS.
Generate animation at 50 FPS and capture it at 50 FPS. Then, use FFmpeg to generate a 25 frames & 50 fields per sec stream. Stream should be flagged as interlaced. x264 doesn't do interlaced well, so I suggest video codec ought to be MPEG-2 or DV.
Generate animation at 50 FPS and capture it at 25 FPS.


why is a video file with .mts extension so huge?

HD video is very, very large at high quality.  450MB for two minutes isn't actually that bad.  To put it in perspective, assuming you were shooting 1080P and 24fps, if there was no compression applied, that same 2 minutes of video would be 6 gigabytes of information.

The reason that videos you download or watch on bluray disks are so much smaller is that they are not source video, but rather highly compressed final output video.  When you compress video, a lot of quality is lost.  It isn't quality that the human eye can easily distinguish, but it is quality that impacts the quality of future encodings and the quality of edited results.

For best quality, you want to take those high quality, large files you captured, edit them to whatever the final output should be and then do a one time compression down to a final output format.  That final output won't be suitable for editing, but it will be perfectly suitable for viewing at a much smaller size.

If you have no desire to edit it and simply want the basic video to be smaller, using a free tool like Handbrake or FFMPEG will easily allow you to transcode to h.264 and a much, much smaller file size.  I recommend using two-pass VBR to maximize the quality you get for the size.


Compressing a large MP4 file that is on 2.30mins long

I can recommend you to one nicely done piece of software which can enable you to compress this file, it is called HandBrake. Its encoder options provide for manipulating the Frame width, rate, quality and resulting format size.


MPEG -TS. See here:

  All MPEG-2 TS operations from GPAC (client and MP42TS) are supported on
    HEVC. MP42TS can be used to generate TS files usable for DASH or for
    injection in modulation chains; it can also be used to send the TS over an
    UDP or RTP stream in unicast or multicast mode


Record on laptop from streaming camera via RCA cable

EasyCap 2.0 DC60+ is what I use, and they work great. Make sure you get the DC60+ version, you don't want the older versions.

There are a lot of knock-offs floating around--I'd stick with the official one.

There's also a good compilation of capture cards on this thread on the Wirecast Forum.


How to capture DVB-T using a generic RTL2832U USB stick on a mac

Seems unlikely as per this section on the MythTV wiki:

  Pretty much the only Capture Cards that are supported on OS X are the
  HDHomerun tuners from Silicondust


Ok, so I solved it myself, and it wasn't pretty.

To be able to work with my vector file in Davinci Resolve 12 (and in Final Cut Pro X without loosing any detail), I first had to convert it into a font. Yes, you read that correctly. I had to create a font where I assigned my logo to a specific character and then use the font in my editing program.

More specifically, to achieve this, I used the excellent Icomoon web app where I could import my vector image, assign it to a character code (in my case, I used "30", which stands for numeric zero in standard UTF-8 encoding).

Then I simply downloaded my font, installed it on the system as any other custom font, and accessed it as a text object in Davinci Resolve 12.

What a time to be alive!


Let's first review the basics of green screen:

1) screen about 5 or more feet behind subject so it is out of focus from subject.

2) flat screen, no wrinkles.

3) flat lighting, no shadows, no hot spots.

4) subject can not wear green or wear shiny things or see through things.

Review Vegas Chroma Key: Once you engage the chroma key effect, use the eye dropper and take a sample of the green screen to set the baseline color, engage the mask and tweak the level until you get a flat black on the screen area and white everywhere else then turn the mask off. If this can not be done then something in the basics above was not done correctly.

Another idea to assist. Make sure when you shoot your subject that you have properly set the white balance on the camera so that you have the correct color baseline.

Here are some tutorials to assist:

https://vimeo.com/34365256


Defining animation once, then repeating across a selection of shapes in a cascading manner?

Assuming the same thing happens in each window...
Make the action that will be inside the first window in its own comp.
Then duplicate the comp 19 times, and use something like the brilliant pt_shiftlayers script to stagger each of the layers half second after the previous one.


Sunsets and Sunrises
Battle scenes with fire
indoor dark scenes with source of light (window during day, lamp during evening)
concerts
disco (problems with moving objects...)


Is it ok to edit a public domain speech?

Public domain material isn't subject to any restrictions -- legally you can do anything you like with it. It would be respectful (but not required) to honor the intent of the material and not distort its meaning, and to credit the source.


Different names for video resp. audio filters

Mainly because this is how things got implemented / evolved from the start. Yes, it could be a single filter but that would need major changes to the current code.


Adobe premiere, how do i link two audio clips and one video clip for the purposes of the razor tool?

Even though Michael Tiemanns answer is technically correct, it seems overly complicated given the description of your problem, as nested sequences may cause other problems and inconveniences down the road. So here are two other options that might help you:

Grouping

Select the three tracks you want to edit, then right-click → group (or press CTRL + G). The grouped clips will all be selected when you click on one of them. Then you can press CTRL + K to cut all clips in the group at the position of your playhead. The problem with this method is that the cut clips will still be grouped together, so if you select one of them, they will all be selected and moved simultaneously. The next option will be more convenient for your workflow:

Track locks

Click on the lock symbol on the left side of the timeline on the track that holds your background music. This will completely lock all clips on the track, preventing you from accidentally cutting or moving them.


Can you read video files off a HyperDeck Studio Pro 2?

As the HyperDeck manual mentions :

Accessing Your Clips
To access your clips, simply connect the SSD to
your computer using an SSD dock. You can either drag the files from
the SSD directly to a local hard drive, or you can work directly from
the SSD.

There's no mention of reading the clips via the Thunderbolt interface.


Is it possible to add easing to a looping, time remapped precomp in After Effects?

Add an expression control slider to the layer (Effects>Expression Controls>Slider Control). This will be what we use to control the rotation of the wheel.

now add this expression to the time remap property:

effect("Slider Control")("Slider") % 1

You could also drag the expression pickwhip from the time remap property to the slider property, and then type % 1 after the result.

The % 1 is the modulus operator, it returns the remainder when the first term is divided by the second, in this case the part after the decimal point, so if the slider is at 12.34 it will return 0.34.

Now you can animate the slider using whatever easing you like.


Can I Use Long Manfrotto QR Plates on a short head?

I have used the long plates on a shorter head.  Using it from a larger tripod on the monopod with no problems.


How can I do Camera Tracking of turnaround Camera Shot?

You can check PFTrack.
Also there are another good trackers options like Boujou, Syntheyes, Mocha Pro, Match mover, 3D Equializer ...
NukeX has also a good tracking suite.


I've used Backblaze for this. I understand that CrashPlan Pro and other similar services work in the same way. Basically, you install the software (free download), do some setup, and then it just runs in the background. Every time you create a new file or modify an existing one, it will (at some later point when there's less activity on your system) just back it up to the cloud. You can usually configure it to constrain how much bandwidth it uses, which folders you do and don't want backed up, and maybe even when backups occur. And if you have a very large initial backup, they'll even send you a hard drive to back it up to. You send it back once the backup has occurred. From then on, it's incremental over the internet.


How to create an effect of eyes opening and closing in first person perspective when awaking from syncope?

Syncope is also called "blacking out". So it kinda follows that you might fade in from black…? This effect is in every NLE usually as the default transition.

If you wanna get artsy, maybe you could add say, a blur that gets progressively less blurry as the transition proceeds.

But really, it totally depends on what you want it to look like. Is there a director for this video? Making creative decisions about stuff like this is their job.


Adobe Media Server appears to support the functionality you are looking for.  There is a free starter edition or the Extended or Professional editions also support live stream splitting.


How to avoid Premiere to YouTube upload errors?

Just export as a .mp4, and then upload it to Youtube! Simple as that! Also, I think the "directly uploading" features just make it more confusing. Hope this helps!


Is there a way to add text captions/subtitles to my videos on MacOS? (burn in)

Video Caption Maker is free (with watermark). Otherwise you can hack together title screens and png's in iMovie which takes a bit of work.


I would suggest you research a bit further and then refine your question. To me it seems that there is a bit of confusion in terms of the software components needed for creating a livestream. First you need to have a software component that acquires a live video from some device. This video needs to be encoded. Once it is encoded it can be streamed by a streaming server. There are a lot of softwares or software as service, that can do that. Also you should figure out what streaming protocol you want to use (rtmp, rtsp?) and how many concurrent streams you need to have.

Some pointers to check out:

Monaserver
https://github.com/MonaSolutions/MonaServer

Ffmpeg streaming guide
https://trac.ffmpeg.org/wiki/StreamingGuide

Nginx rtmp streaming
https://github.com/arut/nginx-rtmp-module/wiki/Getting-started-with-nginx-rtmp


Premiere failing to export long video "file does not exist" error

Try doing it as a two-step process:

Export your movie with the identical format as your sequence, using a reasonable high-quality ProRes format as your output (so you don't suffer much the damage of double-compression)
Compress the output of Step 1 into the format and codec you like

Premiere Pro and Adobe Media Encoder have all kinds of problems right now, and not only with El Capitan.  Many others have hit the same glitch you have, both on Yosemite and El Capitan, with or without hardware rendering.  CC2015 has been a big disappointment to many.


Final Cut Pro 10.1: How to move clip framewise in timeline?

Use the comma and period keys to nudge the clip left and right, respectively.


subtitles: show timed-fragments of the same text line

After suprisingly open the mkv with Aegisub itself, I found out that to achieve this effect, it uses a tag called alpha (like so:{\alpha&HFF&}) that changes the transparency of the text.

To do this effect, you need to duplicate the same line as many times as you need (no need to cut the original transcription), then use the alpha tag to make the text invisible afterwards, like so:

N-{\alpha&HFF&}No! It can't be!
N-No!{\alpha&HFF&} It can't be!
N-No! It can't be!

To achieve this:

N-
N-No!
N-No! It can't be!

Bear in mind that putting the tag before a comma or a dot could cause some trouble with text positioning (it is supposed to be centered). Instead I recommend use this after the comma or dot.


First we need a primer on I, P and B frames.  An I frame is a frame that is a completely independant picture of the frame.  It doesn't depend on any other frames and is a frame which B and P frames are based on.  A P frame stores only the changes from the previous frame and a B frame stores only the changes in either direction.  IPB uses a mix of all 3 frame types in a set sequence to capture video with much lower data usage, but every P and B frame is an approximation of what the frame that was originally captured was.  They are not exact.

For the same size I frame, all I will ALWAYS be better quality, however, it could be possible for IPB to be better if the camera has a set limit rate for I frame that could end up with larger I frames for the IPB due to the saved space, but that would depend on the exact data rates used by the camera.  The theory behind it would be to say we have all I with 3k per frame (making this number up completely) then we have 30 pictures of whatever quality we can get out of 3k.  Now, if the IPB frame, if we had say 1k per frame on average, but the P and B frames are very small, then it might be possible for the I frame to use 5k of data and the P and B frames to use only .5k each and result in a higher overall quality.

This would depend on the quality of the motion and the data rates being used by the camera however.  In most cases, recording all I on the camera is probably going to produce I frames equal or larger in size than those in IPB.  However, when doing a final output, the highest quality for a given size will almost always be compressing to IPB.  All I will also capture fast motion better since the difference between frames will be larger.


How to automate sync of 80-120 audio clips recorded at home on mobile phones?

At the start of the accompaniment track, about 15 seconds before the music starts, record a clap, or other loud but brief sound. Have your choir members record this clap sound from the accompaniment track onto their contributed recording, but not record the rest of the accompaniment.

You can do this by having the singers put on their headphones, but unplug the jack from the playback computer.  They start recording on their phone, then start playing back the accompaniment track. The sound of the clap will be played out loud, and captured on their recording, because the headphones are unplugged. Immediate after the clap, the singer plugs in their headphones. This stops any more of the accompaniment from being audible on the recording. (Important detail: experiment with how much time you need to leave between the clap and the start of the accompaniment, so that singers can plug in their headphones and get ready to sing.)

When the singers finish the piece, they stop recording, and send you their recordings. You need some system for naming the audio files, and tracking the identity and vocal part of each singer. (The details of this tracking are not germane to the sync question.)

Make a copy of the first few seconds of each contributed recording in .WAV format. Write a Python program to detect when the clap occurs relative to the start of a recording. Do this by reading the value of each audio sample of the .WAV file, and identifying the sample with the largest value. This is the moment of loudest sound. Convert the position of this largest value into an offset of seconds from the start of that recording.

Now, merge the recordings, applying an offset to each so that the clap occurs at the same moment for all all recordings. The recordings should now be in sync. Mix the recordings to taste, and save the mixed recording.

[Note: this is a speculative answer, based on reading Virtual Choir by Jed Scott, and CB Multitrack Editing 101 by Christopher Bill. Most of the virtual choir instructions I found on the web did not ask the contributors to record any sync moment at all. I guess they just have a human align all the parts by ear.]


Approximate render time in After Effects CS6

Sadly this isn't really answerable in an exact way.  There is simply too many variables at play.  How much motion is in your source and final videos as well as how computationally and memory dependent your effects that you are applying will all impact the overall performance.  Your best bet for getting an idea of the performance increase is to look at what is currently resource constrained on your system.  Are you maxing CPU usage, memory usage, graphics card processing or disk access?  Increasing whatever you are constrained by will produce a significant improvement.

Based on your current configuration though I can try to take a guess, you are really underpowered in pretty much all categories other than disk access.  Dual core 2.4 ghz with 4gb of ram and a low end 512mb graphics card is nothing when it comes to rendering.  I'm actually a bit surprised it manages an hour in 6 hours.

To give you an idea of a comparison, my computer is a 2.93 ghz original i7 with 12gb of ram, striped SSDs and a Radeon 6970 (which sadly can't make use of the CUDA support).  I can comfortably render clips that are higher than 1080p quality with 2 pass VBR compression in just over twice the runtime.  With the CUDA support on the GTX, you'd probably see even more of an improvement.  For your 720p case, I make no promises, but it wouldn't surprise me if it would run faster than real time.  (Not to mention the fact your experience just using the software will be infinitely better.)


Premiere Pro imports audio/video unlinked

Toggle on Linked Selection to have Premiere Pro respect the linked status of clips:

copied from community.adobe.com


How to export maximum quality in minimum size

You will want to use the H.264 codec, as it has one of the best quality/filesize-ratios of all the codecs out there. For this codec, your file size (and consequently it's quality) is mainly determined by the bitrate settings.

Let's do the math:

40 min = 2400 sec
400 MB = 3200 Mb (Megabit)
3200 Mb / 2400 sec = **1.33 Mb/s**

So you can set your Maximum Bitrate to 1,33 Mbps and the Target Bitrate to the same value or slightly below that. Make sure to change your Bitrate Encoding to VBR, 2 pass for best results (this will take longer than exporting with 1 pass though). This is already quite low, with these settings you will probably get significant artifacts in your video. However, Youtube uses an even lower bitrate for it's video encoding (at least up to Full HD, not sure about 4k), so you could argue that people are used to it anyway. The amount of quality loss also depends on how much entropy (that is, small particles et c.) is in your video, watch this for an explanation.


Possible to reconstruct video from mbtree file?

It’s useless without the original media file.


The overlay filter draws on each base or 'main' frame as given; it does not create new frames.

In your command,

ffmpeg -hide_banner -y -loop 1 -r 2 -i 'bg.png' ...

The -r 2 sets the main video's framerate to 2, hence the result.

Use

ffmpeg -hide_banner -y -loop 1 -framerate 30 -i 'bg.png' ...


RTSP to RTMP converting fails after specific time only when IP camera enters night mode

I've solved the issue by rebuilding the timestamps from scratch with -use_wallclock_as_timestamps 1 and -fflags +genpts.

/usr/bin/ffmpeg -use_wallclock_as_timestamps 1 -i "rtsp://${source}" -fflags +genpts -vcodec copy -acodec aac -f flv "rtmp://${dest}"

This is only a partial solution, or rather workaround, as it's still unclear to me what causes this behavior.


ffmpeg - get green overlay instead of red when using multiply?

Your command is wrong, if you enable debug log messages, you would notice that yuv formats are still being used.
You need to put format=rgba filter to all inputs and outputs of blend filter to make it work as you want.


Does music under CC-SA license require the same license for video?

From the by-sa legal terminology:

  Section 1 – Definitions.

  Adapted Material means material subject to Copyright and Similar Rights that is derived from or based upon the Licensed Material and in which the Licensed Material is translated, altered, arranged, transformed, or otherwise modified in a manner requiring permission under the Copyright and Similar Rights held by the Licensor. For purposes of this Public License, where the Licensed Material is a musical work, performance, or sound recording, Adapted Material is always produced where the Licensed Material is synched in timed relation with a moving image.

In other words, using it as a sound track in a video makes the video a derivative work and requires share-alike unless that provision of the license is unenforceable in your local jurisdiction.  (ie, still see a lawyer, but you most likely must share alike the video.)


ffmpeg fade to specific color values over time

The lut filter expressions don't work with time. geq does.

geq=r='(1-0.7*min((T-S)/D,1))*p(X,Y)':g={the same as r}:b={the same}:enable='gte(t,S)'

S should be your start time in second. D is duration for the change in colours. T and p(X,Y) are variables and should be kept as is.


How to add a scoreboard to a pre-recorded video file

Have you ever heard the expression: 'Good, fast and cheap. Pick any two.'?

A good and fast way would be to hire a professional post-production studio capable of layering over the video a scorebdoard graphic, and layering over the graphic a character-generator input. You sit in the chair behind the editor and tell him what scores to input and when. The new edit master would have your scores popping on in sync with the action. This will not be cheap, but you didn't say that you want 'cheap.'

You could also use a programming environment like Flash to layer-on the scoreboard and add sequential cue-points to the video. Then you'd write some code that would insert the proper score at the proper points.

This is, potentially, cheap and good. But you'll need to get some programming skills and that won't be fast.

I think that a better idea would be to realize that good video work, like all good craft, is NOT painless. Just do the work. And, by the way, Adobe After Effects would make this job almost fun.


What kind of footage is this and where can I get it?

It's a (to be honest, quite old looking) 3D-Animation. I believe that looking into something like 3dsmax, Maya, Modo or Cinema4D might be the best bet for you. Otherwise you can search for "talent show display opener" as a Cinema4D template.


How do I resize a video layer (not the compossition) in After Effects?

Assuming you meant the composition is 1920x1080, and you wish to resize a layer to match the composition size, do one of the following:

Right-click on the layer name. In the menu that comes up, click on Transform --> Fit to comp.

Another method is, in the controls for Scale, under the Transform drilldown, right-click on one of the values. Click on Edit Value.  Change units to % of composition. Alter the value of the larger dimension, out of Width and Height, to 100%.


Problem with colors of camstudio recorded video

You might want to check the recording setting, maybe a non-standard color space is being used or the video is simply being interpreted falsely by your video player.
Try to play it with a different player.

If thats not the issue you should double check the record setting you are using for this codec or maybe change the codec you are recording with.


One frame at a time. Many film cameras (as opposed to video cameras) will allow the creator to shoot a single frame of film. The camera is set up on a tripod, pointing at countertop with the Quest Bar, strawberries, and peanuts on it. The filmmaker shoots one frame of film. Then he/she moves the Quest Bar a couple millimeters to the right. Then shoots another frame. Moves the Quest Bar a couple more millimeters. Shoots another frame. And so on, until the Quest Bar is in the middle of the shot. Then he/she opens the end of the wrapper a bit, and shoots another frame of film. Opens the wrapper a little more, shoots another frame. Slides the wrapper a couple millimeters to the left, shoots another frame.  And so on.

This is standard "clay animation" or "Claymation". You can read more about it here.


Instructional video creation: "see-through glass" whiteboard effect

The instructor is just standing behind glass and writing on it.


Exporting XML EDL from Premiere to Davinci Resolve

Fcp .xml  is limited in features. Although more powerful than other EDL types, most of Premiere's transformation and animation properties are not supported. You can read more about its capabilities here. However it appears Premiere CC neither exports the xml file as recommended by Apple nor in its latest version.

I'd suggest collapse your timeline and make sure there are no nested clips. Then save your timeline as .xml (at least for reference) and replace all faulty shots in Resolve, if required. Alternatively you can export the whole clip from Premiere via any production codec or ideally as image sequence (.exr, .dpx, whatever you like depending on your color management workflow) and use Resolve`s Scene Cut Detection function to chop the imported clip into multiple shots automatically.


mp4 file will not play video, only audio on quicktime, fine on VLC

You will have to re-encode or use a tool to change your h264 level, f.e. this one http://coolsoft.altervista.org/en/h264leveleditor but its windows only, there might also be a Mac tool that does the same. Your video is encoded with High Profile Level 4.1. iOS only support Level 3.1 and probably the same with QuickTime on Yosemite.


Highest quality way to extract a still from video

I doubt there will be much difference in the rendering capabilities between any of the software you list, as long as they play the video correctly. The biggest quality loss has already happened when the video was compressed to mp4.

Use whatever is easier. This is how you do it with ffmpeg

ffmpeg -i themovie.mp4 -ss 1.23 -t 1 -r 1 -f image2 outputImage.png

where 1.23 is the time in seconds you want to capture.

How that works is it tells ffmpeg to -ss search to 1.23, then -t 1 means only export 1 second's worth of video, -r 1 means at frame rate 1 frame per second (i.e. export only one frame). If you don't do the -t 1 -r 1 dance it will complain about not being able to export the entire movie as a frame sequence. -f image2 just telss ffmpeg to export as a still frame (it's probably redundant because you're specifying a .png as your output).

Many free, video players like MPV, MPC-HC or VLC can do this from a gui, meaning you can line up the exact frame by eye. They all use high quality video renderers which share a lot of code with ffmpeg. Using one of these, the task would be basically hitting the s key (or whatever) when you find the frame you want.


How to batch covert a folder of mp4 files to avi?

Change the ” to a ".

Avoid using TextEdit or other "smart" editors to edit your scripts and shell commands. They will mangle it with fancy quotes and other oddball characters and ruin your commands.


Final Cut Express 3.5 HD quits unexpectedly

The problem was with the cross-dissolve transition that I was trying to render. Technically, I haven't figured out the problem, but now I know what is causing the problem. I am able to render video in other sequences and that works just fine. I haven't tried rendering a cross-dissolve transition in another sequence.

https://apple.stackexchange.com/questions/17524/final-cut-express-3-5-hd-quits-unexpectedly


You can try FFMpeg.  There are examples showing how to strip all metadata and removing just a single item isn't much different.
Try
ffmpeg -i in.mp4 -metadata title= -c:v copy -c:a copy out.mp4
This can also be done with exiftool as of version 11.39. Exiftool can also do it in batch without need of a script.
exiftool -ext mp4 -Title= /path/to/files/
This command creates backup files.  Add -overwrite_original to suppress the creation of backup files.  Add -r to recurse into subdirectories.


Transfer videos from Sony HC9 tapes to Windows 10 laptop

iLink will give you a lossless digital transfer of the source material, if maintaining perfect quality is important, I would go with that connection. DON'T attempt an iLink/1394 to USB adaptor, if you do some research, those adaptors just don't work. You'd need to buy an interface card for your laptop to go this way, depending on whether your laptop has an ExpressCard or PCMCIA slot, there are interface cards available.

Otherwise search "HDMI to USB" on google, there are plenty of devices to connect that way as well. Downloading the video this way will re-encode it on the laptop side, so it might degrade the quality a little (although in most cases not noticeably), and might be a little more CPU intensive on the laptop, so just be aware of that.


Upload a video to Youtube without losing contrast

I worked out a satisfactory solution to this problem. It involves adding the 'Computer RGB to Studio RGB' Video FX to each video track in your Vegas Studio project. This effects the rendered file and project quite a lot but appears normal when uploaded to Youtube:
Quicktime

Youtube

It's possible to disable the track Video FX whilst you work on your project so you don't have to deal with dimmed video. The effects will need to be be re-enabled before you render the project.


How many NVIDIA NVENC engines a particular GPU have?

Since you are actually more interested in performance (Frame Per Second) than in the NVENC engines count, please consider my below rounded up figures.
I've compared GTX 1060 and GTX 1080 only.

H264, GTX 1080 encodes 70%  faster than GTX 1060
HEVC, GTX 1080 encodes 140% faster than GTX 1060


After Effects - How do I create animated coding

I dont know of any tutorials off hand (you will need to do a google) but to animate text to make it look as if its typing on isnt too hard:

Create your text layer
Expand the later (clicking the white triangle next to the name)
Click on the animate button > select Opacity
Now you can use the range selectors to animate what is changed.

There is also a typewriter preset in the Effects and Presets panel which does the same thing.


Does the M4V file type have direct support for Audio?

I find the m4v extension a bit confusing.

For MPEG-2, the .m2v extension is associated with a raw video stream. Those files can have only video.

Now for MPEG-4, Apple uses the .m4v extension as a container format, and in fact if you rename an .m4v file to .mp4 it is likely to play on players that only read .mp4 files, since the two format are essentially equivalent.

I think you would need to check this .m4v file and make sure it is really the container format, and not an elementary video stream similar to what you find in .m2v files for MPEG-2.

If you feel comfortable inspecting files with a hex editor, just open this .m4v file, skip the first four bytes and check if the next four are the letters 'ftyp'. If they are, then you have an MP4 container file that should have no trouble holding audio along with the video. If, on the other side, you've got something else, then you may have an elementary stream, in which case you may want to recommend to your vendor to use a different extension for these files. Using .avc is probably more appropriate for an H.264 elementary stream.


Things to do during shoot to prevent loss of quality during extreme colour grading in post?

The biggest factor in planning for aggressive grading is your wardrobe and set design.

Eric Escobar gave an excellent speech about this in 2009 at the SF Supermeet, which the MacVideo guys made available online: "Plug-ins Won't Save You".

I know this isn't the technical solution you were looking for, but the nature of contrast and saturation is that they're more dependent on context than on absolute color values.

http://www.colorcube.com/illusions/chrmadptb.htm
http://www.colorcube.com/illusions/chrmadpt.htm

As you figured, underexposure will quickly destroy your ability to push your colors around.  Digital cameras love to underexpose the blue channel, so it really helps to have on-set monitoring like with OnLocation, or with a monitor with scopes, to help nail your exposure.

It appears that x.v.YCC (x.v. Color) information will only play through the camera's outputs, and it'll be down-sampled back to where you started if recording to HDV.  This is because the HDV standard is an 8-bit color depth, which can't represent the 16 bits of x.v.YCC.  If you did capture the x.v.YCC stream, you won't get higher contrast and saturation though, since contrast and saturation are more about the distribution of your colors, rather than their detail and accuracy.  It might occaisonaly make your colors a little less brittle, but I doubt you'd ever notice.

I'd shy away from color features in-camera, especially when going out to HDV.  Shoot as flat a profile as you can (grey and washed-out), and you'll have the most latitude in post.


Is there a buffering difference between increasing and decreasing stream quality?

1) It depends mainly on the streaming protocol. For HLS and HDS for example, yes because the player will usually download a number of segments before starting playback, and the download time is proportional to the size of each segment of course. For RTMP for example, the buffer is custom-set by the server which means it will theoretically depend on what the server has chosen for every bandwidth. E.g., it may chose a 0KB buffer for all streams, in which case there will be no difference in buffering time. In more realistic cases, however, I expect the server would set buffers to each stream according to its bitrate, which brings us back to what happens with HLS or HDS.

Note that the difference in buffering time really depends on your own bandwidth. If you have 50Mbps internet speed, you won't feel any difference whatsoever since it would be the difference between downloading ~3MB of data vs ~2MB/~1MB of data. Of course if the server is setup improperly and has high latency, then your speed means very little and you will feel a difference.

2) No because as far as the client is concerned, a livestream is basically the same as a prerecorded stream (apart from the fact the server may let you download the stream faster than you can see what you download, aka faster than real-time).


Glass/Magnification Effect — After Effects

You can use cc_glass for this sort of thing. There are great tutorials by andrew kramer from videocopilot, they might help you. Alternatively, this effect could also be created using a lens distort - you might want to try slapping it onto an adjustment-layer and masking the layer with a circle.


Codec genealogy / kinship: DivX, MPEG-4 Part 2, H.263

H.263 was a sole development of the ITU but I wouldn't bother all too much with the specified use case of video conferencing. It's a codec with the main purpose of improving the compression compared to older codecs which of course is beneficial for video conferencing where bandwidth is a very limiting factor, especially at the time the codec got developed.

The MPEG then developed MPEG4-Part 2 which is based upon H.263 and offers bit-stream compatibility to the base-line level of h.263, meaning there is a h.263 compatible bit-stream in an MPEG4-Part 2 encoded video that you could call the basis for the actual MPEG4-Part 2 video stream that extended the h.263 compatible stream. So MPEG4-Part 2 offers a few more features than h.263 but essentially they are very closely related.

With MPEG4-Part 2 started this weird age of many companies making their own implementation of these two codecs resulting in a few new container formats that were only used by these specific implementations f.e. RealMedia's .rmf/.rmvb or DivX's altered version of AVI, .divx.
RealMedia even made their own codec again based on h.263. A horrible age of a ton of different formats that needed their own browser plugins and players because they weren't fully compatible to each other, either because of their container or slight alterations to either h263 or MPEG-4 Part 2.

Which made this codec generation a bit special, while .MP4 was already present at the time in an early form it was barley used as the container format for MPEG4-Part 2. So h.263 and MPEG-4 Part 2 was found in a ton of different container formats unlike h.264 which has is also found in several container formats but with the intended container format MP4 being the defacto standard that is found everywhere. The most popular alternative being the open source Matroska container format (.mkv/.mka). Apple's QuickTime .mov also supports h.264 but even in the Apple Ecosystem MP4 is dominating. In my opinion the biggest reason why h.264 is such a huge success today.

DivX began as a reversed engineered version of Microsoft's MPEG4-Part 2 implementation. At that point there was no company behind DivX, it gained popularity because of its good compression at that time and also being free to use.
After DivX made it into a company they revamped the code for the codec as it was still based on some Microsoft code.

Though it still was an MPEG4-Part 2 implementation after the rewrite and became a pretty popular codec that was supported by a lot of DVD players at the time. Some developers of DivX went on and made the open source version called Xivd (that used AVI instead of .divx) that gained a lot of popularity in the movie "pirating" scene and was their standard for encoding videos for several years until h.264 came along. Though even after h.264 was readily in use by consumers Xvid was still used for a few years because of it's good understanding in the scene. It became somewhat of an art to encode movies in Xvid because of all those sophisticated encoding options available in the Xvid encoder.
Xvid had a few advanced features that weren't implemented in DivX which made videos encoded with those feature in-compatible with DivX certified devices.

Since MPEG4-Part 2 the MPEG and ITU-T are jointly developing codecs, H.264 being their first co-operation. This is the reason why the codec is often referred to as h.264/MPEG4-4 AVC. MPEG-4 AVC being the MPEG's/ISO name for the standard and h.264 that of the ITU-T. Different names but identical standards. The same goes for h.265/HEVC.

I hope that helped a bit clearing things up, though a lot of this is also knowledge taken from Wikipedia, so it might not be new to you but I tried to put it an order that made sense.


Video compression- how to prioritize one area over another?

This is an interesting question, but I don't think that you will find a good solution without changing your inputs (the video elements you are using). I'm not aware of any software that allows you to prioritize compression by area. The compressor itself usually makes all these kinds of decisions for you.

Aside from that, you said the magic (not good) word for compression: Youtube. Even if you could find a way to do the above, you basically give it all up when you upload it to Youtube, where they will run their own fixed compression algorithms that will ruin all your work.

I think there are a couple of things you can do (perhaps all of them in combination):

If you haven't already, try doing 2-pass compression, instead of one-pass. This will take longer, but the compressor will have a chance to analyze the video on the first pass, and that may possibly help improve your output a little.
Massage that water footage. If you can get rid of it completely and replace it with something else that causes less trouble, do it. If not, you can try things like:

Apply some blur (either chroma [color portion of the signal], luma [monochrome portion of the signal] or both) to the footage.
It would also help to run the water footage through a denoiser first.

Both denoising and slight blurring should help reduce the amount of bandwidth that your compressor needs to dedicate to that area of your video.


This seemed to work for me...

ffmpeg -i "video.mp4" -vcodec copy -bsf:v hevc_mp4toannexb -f mpegts output_file.ts


Vegas pro file size explosion - having to use Handbrake currently

The easy answer is to analyze the resulting files in order to determine what's happening. mediainfo is a multi-platform open source tool that will help you do exactly that. Handbrake is likely using a much lower bitrate by default than Sony Vegas Pro. If I'm not mistaken, the standard settings for SVP are pretty high. You can prove this to yourself with the aforementioned mediainfo tool, and then solve it by adjusting the SVP bitrate settings accordingly.


Resize target layer in perspective tracking

Pre-comp the replacement layer (using the option to keep all the settings in the outer comp), and match the aspect ratio of the pre-comp to the rectangle you're tracking. Then adjust the replacement layer so that it fills the comp as you wish.


Where is video color vector scope in Apple Motion?

I don't think there is a vectorscope in Apple Motion but in FCPX vectorscope comes in with the Color Grading tools. Apple Motion is not intended for this purpose, so I guess they did not require to add the vectorscope. I use version Apple Motion version 5.4.2


Thanks to @Gyan, I was able to fix it.

ffmpeg -i input.mp4 -vf "geq=p(mod(X+Y*2\,W)\, Y)" output.mp4


Ripped DVD Video Playback Stutters, original DVD does not

It sounds like the framerate of the rip doesn't match the framerate of the DVD. I would check if those match. The QuickTime Inspector can do this or a great tool called MediaInfo.


What is the highest rated HDMI category available?

The latest and greatest HDMI specification is 1.4a (and version 2 is expected to be released this year). The fastest/highest bandwidth category of HDMI cable is "HDMI with Ethernet." The rating of a cable's shielding (Class 2, Class 3) has more to do with fire resistance and US wiring code and is not really relevant to the matter of signal loss. MyCableMart.com has a great article with more information and cable recommendations: http://mycablemart.com/help/hdmi_which_one.php.

Whether a given cable available for purchase is higher quality with more more shielding is a matter of finding a good vendor and vetting their claims (caveat emptor). Longer cables with thicker wires inside, e.g., 22 AWG versus 24 AWG, will, all other things being equal have lower signal loss.

However, my experience with long HDMI cables has been very hit and miss. Just this week during an install for a multicamera livestream, a brand new, 50ft HDMI cable with built-in "signal booster" would work when connected to a monitor but not when connected to the video switcher (a Blackmagic ATEM Television Studio). A Blackmagic technical support technician told me that TVs/monitors are engineered to be very forgiving of signals that have fallen off spec. The ATEM switcher is more strict (and rightly so) and would not display the signal. Furthermore, I was told by Blackmagic that after 10 feet, HDMI cables start to fall off spec. In the end, we purchased an HDMI to SDI converter and successfully got the signal from the computer to the switcher.

After this and other HDMI misadventures, my gut feeling is to avoid long HDMI runs in favor of SDI connections or CAT5 baluns/extenders. YMMV.


Is it possible to loop a 360 degree YouTube video offline?

You can use marzipano which will provide all the code necessary for the viewer and provide you with a Javascript API for customization.

A quick Google search found me this Wordpress plugin which claims to do what you want as well.

Honestly, what you're asking is quite complicated. If you can't do it on your own using the tools linked above, I suggest you hire a web developer to do it for you.


How can I record video with a Canon 1Dx DSLR which will feed straight into Adobe Premiere or Final Cut?

Any DSLR that can provide a live video signal (such as via HDMI) can feed that signal to a recording device (such as Atmos SHOGUN) or monitoring device (such as a TV monitor).  In order for your computer to handle live video, you need a live video input port, typically found on cards such as the Blackmagic Design Deck Link card.  BlackMagic's Media Express software can record and/or monitor live video.

I would be surprised if Adobe Premiere Pro (or other NLEs) can handle live video as an editable stream.  But MediaExpress can record with a confidence monitor, and then Premiere Pro can edit the resulting file.


Why have you set your ISO as low as ISO200?  You are telling the camera: go ahead and waste the light, I'll crank it up in post-production.  1/50s of exposure does not help.  And you have an f:1.2 lens and use it at f:1.8.  Which is probably sharper in sunshine.  But you don't have sunshine.  Stop telling the camera that it should behave like it has plenty of light to spare (it's not only the ISO but also your other choices) and tell it what it is actually dealing with.  There is no point to choose low ISO values and then magnify exposure digitally: that will give you considerably more noise than if you allow the camera to dial up its sensitivity.  And of course, decrease your shutter speed (what use is the cinematic exposure rule when your principal problem is light?) and open up your aperture.

You have good equipment.  Allow it to participate in problem solving as long as the problems you buy for its respective contributions are smaller than the main problem you are dealing with: a lack of light.


Easier Way To Narrate Over Paused Frame?

There is a simple Video editing suite called Camtasia.It is not free but you can try out the trial,If you like it you can purchase it.
It has an "Extend Frame" feature (also available in 7th version) that will allow you to extend a particular frame of video on the timeline as long as you want so that audio narration can continue.

That should achieve the same effect as pausing the video during recording, as in either case you will end up with a static image on the screen while the audio finishes playing out.

Then come in afterwards, play this pre-recorded screen video back... and lay down audio on top *WHILE being able to hit pause on the video, and continue talking, to whichever points in the video require more explanation.You can just simply check it out.


I only have the .mp4 files from a Sony XDCAM EX shoot, is there a way I can still convert them for use in AfterEffects on Windows?

MP4 files should be all you need.  There shouldn't be any encryption on the files.  It is possible you may need to download a codec.  MP4 files are just a container format, so different codecs could be used within it.  It is possible that you don't have the needed codec installed, but if you do, the files should just open in After Effects without issue.


How can a GIF made from a vid be larger than the vid itself?

There are several factors at play here. For example, your gif creation app may have a quality slider/setting that influences the size of the output. However, the most likely cause is the difference in compression.

The videos your iPhone records are probably compressed using a highly efficient codec such as H264 (I didn't find any information on what codec/file type the iPhone camera uses, but I'll take an educated guess and say it's mp4). This codec is very efficient at reducing the file size of a video while maintaining relatively high quality.

The gif-format, on the other hand, was built for an entirely different purpose. It was actually intended for small, animated graphics with limited color palettes, not complex videos. The original gif-format is lossless, meaning it stores every frame of the animation completely. Works great for those small animated graphics, but is terrible for actual video. Actually, because of this, many apparent gifs that you see on the internet aren't actually gifs.

In conclusion: Gif is a terrible format to store or transmit video, use a video format instead. Follow the link above if you are interested in the  technical side of this.


What HD projectors have a 80" screen at about 13 feet?

You need to look for the lens throw ratio. That number will tell you how big the size of the image is going to be. Also many projectors have zoom capabilities.
A lens with a 2.0 throw ratio means that for every unit you go away from the projecting surface, the size of the image will grow 2 times (simplest example, you won't find that specific throw distance). So 152"/ 70" gives you a throw ratio of around 2.17.


How to make a video presentation with a video of the slideshow and a video of me speaking in the corner?

Preferable depends... But possibilities are for example: MacOS offers the App iMovie which is available with no further cost. For more professional video editing you can use e.g. Adobe Premiere or Final Cut, but then you need to pay and you need much more effort doing research to get familiar with it. To sync two videos and the iMovie App will be fine.


Sources to learn more about Audio/Video compression, codecs, algorithms etc.

Compression codecs and methods are also based extensively in the field of Psychoacoustics.  For this, I thoroughly recommend the books available from the Focal Press, such as this one


I'm not sure why you would want to use normalize at all. You should use audio tracks and place the audio you need to adjust on it's own track.

Then, using the audio mixer, apply dynamics to the audio tracks. You can then use the compressor within the dynamics filter, which you can use on all your tracks, to get your dynamic range all in line.

On the clip that needs to be (from what it sounds) adjusted up, in the dynamics filter for that track/clip, you can from there manually adjust the gain up- it's a pot/knob center column bottom. Use a ratio of about 2:1 to 4:1.

Last, click the checkbox on the bottom right of the dynamics filter for each track to enable the limiter. The limiter; a good setting is -2 db.

This will balance out your audio so the soft sounds are adjusted up and can be heard, and the loud sections are not adjusted up; resulting in overmodulation. Its a much better way to smooth out your audio, decrease the dynamic range, and end up with audio that sounds far more balance.

Once you learn how to effectively use the dynamics filter on tracks, I think you will find you will never, ever, use the Normalize filter again.


How to save a stream to a file that would constantly change over time to have the right duration?

Computers don't let you delete from the start of a file, so every time you trim video away, would required the file to be completely re written. Not a great idea. It would be better use some a fragmented format like HLS or DASH, and delete old fragments.


DaVinci Resolve: Blur and fade title on top of video

DaVinci doesn't really have a strong toolset when it comes to working with titles and motion graphics, although given BlackMagic's current trajectory, that may change in the near future.  For now, you'll have more control over graphic element animations in other packages like AE, Motion, or even Premiere or FCPX.  Blackmagic Design also offer their own compositing software, Fusion, which is also fully capable of this type of effect, and has direct ties with DaVinci.

It is possible to animate both blur and fade out in DaVinci, but not gracefully.

The trick is to turn your text clip into a compound clip.  From there, DaVinci will treat it like any other piece of video.  Do this:

In the edit tab, make sure your text layer is the default white on
black.  You can change the color later.
Right-click on the text layer and select "New Compound Clip" from
the contextual menu.
Switch to the Color tab and select the compound clip.  Now you can
affect it with nodes.
Right-click anywhere in the background of the node editor and select
"Add alpha output" from the contextual menu that appears.  You
should see a little blue box appear at the right of the node editor.
Right-click anywhere in the background of the node editor again, and
select "Add node" -> corrector.  Do this twice so that you have a
total of three nodes in the node editor.  Node 01 should be wired at
this point, and 02 and 03 should not.
Unwire the RGB output of node 01 (green circle) and plug it into the
alpha input of node 02 (blue triangle).
Wire the alpha output of node 02 (blue triangle) into the master alpha output that you created in step 4 (far right blue box).
Wire the green master RGB input on the far left of the node editor
into the green input of node 03.  This master should now be routed
into two places, node 01 and node 03.
Wire the RGB output of node 03 into the input of node 02.
Finally, wire the RGB output of node 02 into the master RGB output
 (green box far right).
In the OFX library, drag the color generator onto node 03.  This is
 where you will now control the color of your text.
You may have noticed that everything is inverted.  To fix this,
 select node 02, move to the "key" tab, and invert the key input
 (the black dot in the white box) * edit * This step is no longer necessary in DVR R16.  New serial nodes used to reverse the previous node's alpha output by default.  Now, they do not.
Finally, you should be able to control the blur of your text from
 node 01.  You should be able to animate this parameter just like
 any other color adjustment in DaVinci.  For the fade, you'll have to animate the opacity of the composite on the edit page.

Here's what everything should look like when wired up properly:

Yes, this is a kludgy workaround which suffers from serious limitations (blur radius*, for one).  But hopefully, it's a good demonstration of why this type of operation is best approached from other software.  DaVinci just isn't built for it at the moment.

If you'd like an explanation of how to accomplish this in Fusion, I could add to this answer.

EDIT 01-24-2020
Blur radius is no longer a limitation.


Are you using a keying effect? Does your flicker look anything like the original images posted here?
https://forums.adobe.com/message/5112063

If so, this issue has been around for a while, and we never seemed to get an accurate response from Adobe. However, there are some workarounds spelled out in that post.


What is the relationship between hardware acceleration and DXVA/QuickSync/Cuda?

They are all forms of hardware acceleration, which broadly, just means that specialized hardware is doing things faster than the basic CPU normally could.  The exact nature of what each type of acceleration does depends entirely on the software you are using and the hardware you are using.

Some hardware is very purpose specific.  Something like Intel QuickSync is a specific hardware encoder and has limited functionality because it can only serve it's purpose driven role.  This is similar to any other dedicated encoder, such as the integrated encoder used for NVidia Shadowplay or the dedicated encoders on devices like the Matrox MXO2 or BlackMagic Intensity.  There are other rolls other than encoding that could be filled by a purpose driven card, but encoding is certainly one of the most common.

Other hardware, such as modern GPUs (CUDA or OpenCL based, I think ATI has a term too, but can't remember it) and video editing or mixing acceleration cards, such as Black Magic's ATEMs or Matrox's older RT line of real time editing cards, are designed to provide more general purpose functionality.  Depending on the hardware they may either offer a wider array of specialized functionality or simply a general purpose parallel processor that works better for video purposes.  In these cases, the functionality is made available to software, but it is up to software to utilize the processing capabilities of the hardware and the exact nature of the acceleration will depend on which algorithms and processing they choose to offload to the hardware.

Another option, as far as APIs are concerned, is something like DXVA, which strives to unify multiple technologies.  DirectX in general is a system for interfacing software and diverse graphics hardware.  It looks for any hardware that tells it that it can fill a role and then will utilize that hardware to do a job when software asks for the job to be done.  I'm not super familiar with DXVA, so I don't know if it puts any specific requirements on hardware (some directX stuff does), but on the hardware end, the implementation could potentially differ greatly and could use either CPU features or GPU features, depending on what's available to it.  It may or may not be directly implemented in terms of the more hardware specific feature sets (CUDA, QuickSync, etc), but it is designed to work across diverse hardware, so you know less about what is going on under the hood.

All of the technologies can be used to speed encoding, but the general purpose technology can also be applied to just about anything that you can process in parallel, so they can (potentially) impact render times as well (the time it takes to make the images that are going to be encoded).


How can I find out the codec of a video I have exported from Premiere Pro?

Use MediaInfo to get technical information for a media file.
The codec id in the video section will print the exact identifier stored in the file for that video stream. The format entry in the same section will print the formal name of that codec.


How to create super smooth slow motion clips in After Effects that will be edited in Premiere Pro

As 50ndr33 says, you need to shoot/capture at as high an FPS as possible. The more FPS the better the slow motion effect afterwards.

Kronos is also a great plugin, but as he also states - it has some problems when footage isn't linear. If that's the case, you should have look at Twixtor. It's a bit more advanced (and more expensive) but it's better at handling advanced remaps, and gives you pin-point control.


Use Track Motion to create video wall - 9 tracks, each clip on its own track. There are tools that can help you to do it (I use Pan/Crop Assistant from Vegasaur toolkit).
Add another track (parent track) and make these 9 tracks composing childs of this parent track.
Use Parent Motion to create pan/zoom animation.

Read in the Help about Track Motion...


Crop the video in a new sequence in Premiere and then export it using Youtube's standard encoding settings.


Reading material for technical aspects of timecode and alignment

This doesn't cover the applications, but it gives a succint view into the nuts and bolts:

Phil Rees


How to turn video with spherical, equirectangular projection into an actual "360° video" playable with VLC?

you can use Spatial Media Metadata Injector to fix the metadata https://github.com/google/spatial-media/releases/tag/v2.0


Remember every time a video is transcoded or rendered you will loose some quality. Why not consider getting Vegas Movie Studio. Version 9 through the current version 11 are compatible with WinXP and can handle the AVCHD format just fine.

Vegas Movie Studio is the light or home version of Vegas Pro and costs about 84% less.

If you are only editing simple scene to scene, not multitracking video as in compositing, and keeping it simple, any of these versions should work on your WinXP machine. The older the version the cheaper the cost, for instance Vegas Movie Studio 11 (current verison) is running about $94 while the older version 9 maybe as little as $75 on amazon.com or less on EBay. This way you can edit your original AVCHD files and only have to render once.

I ran Vegas Movie Studio 9 before upgrading to the pro version and found it perfect for simple scene to scene edits, and it has a multitrack audio too so can have voice, effects, Foley, ambient, and music all on their own tracks.

If you choose to do this, I would run a test with how long vs how many effects you can get Vegas Movie Studio to do on this older machine so you will know what the limits are. Even with a quad core running 4 GB of DRAM on Win7, I have learned there are limits what I can do with the Pro Version of Vegas 10. This is extremely useful to know as you will be able to walk into a project knowing if your gear can handle it or if you will have to seek workarounds, like breaking a project in half and rendering separately or not.


Advantage of HLS/HDS over direct bytestream

CDNs. CDNs make delivering small static HTTP objects much cheeper due caching efficiency, supply and demand, and stateless servers (hence more viewers per server). Second is live video. HTTP does not really work well given a file of infinite length. Hence breaking the stream into segments to make the CDNs job easier.


An HDMI splitter is not what you need. You need either an HDMI capture card, or a standalone HDMI video recorder. The cheapest HDMI video recorder you're going to find is the Atomos Ninja Star, for $250 on B&H: https://www.bhphotovideo.com/c/product/1285811-REG/atomos_atomnjs001_64_ninja_star_recorder_with.html

HDMI capture cards start around $130. Here is a good one from Blackmagic, for $137.50 on B&H: https://www.bhphotovideo.com/c/product/964122-REG/blackmagic_design_decklink_mini_recorder.html


There is no specific title for this kind of video.

You can achieve what you want with any video editor that supports layers and masks. Adobe After Effects would be on solution.


Is there an inexpensive way to decompose a video into frames and apply a snapchat-like filter to each frame?

Most motion graphics applications can import most video types and apply filters to them. I believe that Adobe After Effects is available for a subscription (so cheap if you use it only for a month), and Apple's Motion is available for $49 from the Mac App Store.

Or if that's too much, I believe that iMovie is only $15 and has a number of simple snapchat-like filters available.


GoPro Recording Without A Phone Connection

Yes, it is entirely possible to use, operate and record on a GoPro.

You won't be able to view any of the photos/video you have taken without either connecting to a mobile device OR viewing the footage you have taken on the MicroSD with another device such as a PC or Mac.

The GoPro cameras have a fairly wide angle lens which is helpful considering the cameras don't have a display built-in. GoPro sell removable LCD touch screens that can help you to frame your shot.


Video in After Effects composition panel is pixelated during scrubbing

It's because you're using Adaptive Resolution, where AE will attempt to let you scrub through quickly, by reducing the resolution it shows in the viewer.  Higher powered computers will be able to show higher resolution in the viewer more quickly.

There's an explanation in Adobe's help here:
https://helpx.adobe.com/after-effects/using/previewing.html

There are also many things you can do to adjust the quality of your preview, depending upon what you're working on.. For example, if you're checking the movement of something, maybe you don't need as high resolution an image but full frame rate... Whereas if you're checking the pixel-perfect quality of a matte, maybe you don't need as high frame rate during preview.

Also bear in mind that there are different render engines in AE now - if you're using the 3D raytrace renderer for 3D work, previews will be very slow unless using a super-fast machine.


How to set baseline sound volume level before video editing & sound mixing

This article - How to Set Audio Levels for Video - offers some good advice. To summarize:

  Overall Mix Level: -10db to -14db

  Dialogue: -12db to -15db

  Music: -18db to -22db

  Sound Effects: -10db to -20db with occasional spikes up to -8db.

I usually set the voice a bit louder (-8 to -10 dB), but take these as a rough guide.


How do I record a computer monitor without banding/flickering with a Canon t2i/550D?

While reviewing the Instruction Manual for the Canon 2Ti EOS 550 on page 127 you will find information on how to manually set the shutter time. Here is the pdf download for the manual:
http://gdlp01.c-wss.com/gds/9/0300003169/01/eosrt2i-eos550d-im-en.pdf

There is wide range of 1/4000 to 1/30 of a second to work with depending on your frame rate.

For 50 fps or 60 fps the range is 1/4000 to 1/60.

For 24, 25, & 30 fps the range is 1/4000 to 1/30.

I suggest that you try different shutter times at your preferred frame rate. I know this is not definitive, as I don't have this camera, nor have I tested this. However, the flicker you are referring to is as you suggest a synchronization issue; you are trying to have the camera capture at a rate that synchronizes with the display. Another thing you can try is change the display frame rate, if you have this option on your monitor.

Hope this helps,


How long should video clips be to be in sync with a 90 BPM song?

If you want a new image at every beat, start with the frame rate of your video. 30 frames per second gives 1800 frames per minute. Divide that by 90 to get the number of frames per beat, in this case 20. So if you change the image every 20 frames the pace will be the same. You do have to align the cuts with the beat; just matching the pace is only part of the battle.

In the general case:

(FPS x 60) / BPM = number of frames per beat


How to up scale video resolution for Video Card

Your problem is not (only) resolution.  640x480 resolution VGA is analog video, so you need an analog -> digital video converter.  This $200 Analog -> SDI Mini Converter from Blackmagic Design will do what you need.

Then again, for not much more than $200, you can get a camera that speaks HDMI and gives you true 720p.


Premiere: Make clips from extracts of same clip

You can create subclips of the sequences in the source material that you want to use seperately. This will create a second instance of the source material in the Project Panel that is limited to a specific part of the source. A subclip is sort of a virtual copy of the original clip (the source material on the disk is not copied).

To create a subclip, you first have to set In- and Out-Points. The subclip will use those as boundaries, so only the part between them will be available in the subclip.

You can set In- and Out-Points at the current playhead position using the I- and O-keys. After you have set those points for the active clip in the Source Panel, right-click on the clip in the Project Panel and select Make Subclip. You can then set a name for the subclip, after that it's available in the Project Panel.

You can also edit your subclips after you created them, which is useful if you realize you need a longer part of the sequence after you created the subclip. The Edit Subclip option is available from the context menu as well, you can shift the start/end timecodes of the supclip this way. There's also an option to restrict the sequence to the subclip's boundaries, which is active by default, you might want to turn it off depending on your workflow.


What technique is used: Falling Whistles video

It has a stop motion animation feel to it.

With standard keyframes, motion is interpolated between two points smoothly.
The 'stop motion' effect is achieved by using hold keyframes instead.

  How are they animating the text

Usually the answer to these questions are keyframes, lots and lots of keyframes. Specifically keyframes on scale, position, rotation and occasionally opacity.

The timewriter effect applied to individual characters or words can be easily achieved in After Effects using the 'Animate Text' effect.

The subtle 3D text effect at 00:35 can be achieved using the 'Basic 3D' effect. In the current version of AE the effect is listed as obsolete but it's easy to use.

Also most of the text are used as masks on top of photographs to add a texture.

  How are they doing the rotate in and out transitions (Are they
  rotating in the entire precomp file?)

It's likely that individual elements such as text and images are being rotated individually with the rotation offset of each element at different places.


Still Photo Rendering in Premiere Pro CC 2015 is Yellowy After Export

Try re-saving the image to different formats. Often this will do the trick.


Depends on whether or not you care about the image appearing squashed/stretched.

If you don't care, then you can hold the shift key while dragging the corners of the transform tool to unlock the aspect ratio.  You can also do this by clicking the chain link icon between the x and y values of the "Zoom" item in the inspector pane, and then altering the numeric values.

If you care about squashing/stretching, you care about cropping, you care about the image not being too small, and you have a fixed screen size, then the answer is no. There's nothing you can do.  It's just the geometry of rectangles, not a limitation of the software.  You have to compromise in one of these areas.  Maybe you crop an equal amount off of each mirrored half, for instance.

But when you say, "take up half the screen," many of us make automatic assumptions about the size and shape of the rectangle you're trying to fill.  We assume that you're talking about a television, most likely, or maybe a YouTube video, but almost certainly something with a 16:9 aspect ratio (a width which is 1.7777 of the height).  But DaVinci Resolve will let you arbitrarily decide the dimensions of the movie file you're trying to create.  So, you could just set your timeline resolution to twice the width of your source media.

To do this, in the Project Settings -> Master Settings, set the "Timeline Resolution" dropdown to "Custom" and enter numeric values in the boxes below.  The left field is width, so you'd enter double the source media's width in that field, and keep the other field the same as the original.  If you set it up right from the beginning, when you go to the Deliver tab to export, you shouldn't have to touch the "Resolution" dropdown menu.  If you do find yourself reaching for that menu, chances are you've made a mistake in the Project Settings.

Of course, If you do try to play a double-wide movie on a 16:9 television screen, you're going to run into the same problems you had in the first place.  Most likely, the TV will add black bars to the top and bottom, and scale your image down to smaller than you wanted.  But it could also stretch, or crop, depending on it's default behavior.  However, if your end goal was always a movie file that would play back windowed on a computer, you're golden.  Just don't think too much about how that window fits into the rectangular display of whatever device the viewer uses ;-}


You could use the particle engine CC Particle World.

Set the particles to be shaded spheres, adjust the X&Y radius of the producer to fill the screen, adjust the birth rate to produce particles at the rate you need, turn off gravity and velocity.  set the end size to be so big that they fill the screen.  Set the Particle Transfer Mode to "black matte", and you'll get something like this:

then precomp the particle layer, moving everything inside the comp

Now add your two layers (the files for before & after the transition). Put the "before" layer at the bottom, then the "after" layer, then the "particle" comp layer.
Turn of the particle layer by clicking the eyeball.
In the example below, I'm using a pink and blue layer for the before and after.

Add a "Set Matte" to the "after" layer, and set the "Take matte from layer" setting to your particle layer.

When you drag through the comp, your "before" layer should reveal the "after" layer via your circles.


How to generate this animated view of wave form?

That is not a waveform, it is an animation simulating one. :o)

Most likely the shapes are it is in vector format, so you can morph it from state A to state B, etc.

There is not a simple way, it needs some work, for example you need to define the exact frame where you want Shape A and where you want Shape B. So make some timelines.

Then use vector-based animation software. Either After effects or the free one Synfig.


Stack images with "hstack"-filter from video or image sequence in ffmpeg

You're better off using the tile filter for this:

ffmpeg -i INPUT.mov -vf fps=1,scale=192:108,tile=54x1 output.jpg

The tile argument is the size of a rectangle. So for a 54 second video, 54x1 produces a horizontal stack of 54 frames. Use 1x54 for a vertical stack.


After Effect: Create Stroke from Motion Track Path

Select the motion keyframes & copy. Now create a new mask on the layer on which you have the stroke effect, any old mask shape will do. Set its mode to none. Now select the mask's Mask Path property and paste. The mask can now be used to provide the path for the stroke effect (it's the first property in the stroke effect). You have to directly select the Mask Path property, just pasting it on the layer will paste it to the position property of the layer.

Because there's always more than one way of doing things in AE:

You can also create a shape layer with the pen tool. Once you've done expand the new shape layer until you see the Contents>Shape 1>Path property (it could be called Shape 2, 3 etc) and paste the motion path on to it. Then you can use it as a normal stroked shape layer.

Note As Alyssa points out below, when pasting a motion path to some other property you have to explicitly select that property, otherwise AE will just paste it on to the layer's position.


ffmpeg - 'Unable to find a suitable output format for 'libfdk_aac''

There is a space missing in -tune fastdecode-c:a libfdk_aac, so FFmpeg thinks the value of tune is fastdecode-c:a and thus the next word is the output filename. Insert space after fastdecode.


What software was used to create this stylized screencast for Disqus 2012?

In order to grab the screencast itself, a number of applications have been discussed here before.

Then use whatever video suite you feel most comfortable with - the angled view used in that clip can be done in Premier or various others, but it isn't very complex.


Ghost position keyframes in After Effects

It's because of spatial interpolation.  Here's a previous answer:

Object moving to a position I didn't specify


adobe premiere cc / picture in picture / editing video shape by its corners removed?

Double click the layer in the program monitor (the sequence viewer) or click on the little icon in the source view next to the Motion effect to bring up the drag handles.


Removing streams in HEVC H.265 MKV file?

In the syntax -map 1:a:24, 1 stands for the input file index. Counting starts from 0, so 1 refers to the 2nd input file but the command only has one input. a stands for stream type, and in this case, it's audio - v is for video, s for subtitles, d for data. 24 represents the 25th (0-indexed, remember) audio track. If your command has one input file with three video, three audio and three subtitle streams in the following order: V A S A V S V A S, then the 2nd video will be -map 0:v:1 You can reference it using absolute index by using -map 0:4. With absolute indexing, there's no stream type specifier.
Assuming the stream numbering in your description is correct, use
ffmpeg -i IN.MKV -map 0:0 -map 0:a:0 -map 0:a:2 -map 0:s:23 -map 0:s:24 -c copy OUT.MKV

Note that if -c copy is omitted, all streams will be re-encoded - not what you want normally.


DSLR chip overheating and max clip length

First, while sensor temperature is a real thing that can result in elevated noise levels, I'm not aware of a sensor in recent history that had a heat related shutdown (outside of harsh conditions anyway) or that could accumulate enough heat to be a threat to the chip.  Most of the non-sense out there about sensor's overheating is completely uninformed rumors or based on older sensors where heat was more of an issue.  There may be some exceptions in specific models, but they are not a major issue in runtimes or live view itself wouldn't work regardless of recording.  (Live view uses the sensor just as much or more than video recording does.)  There are three main factors that can limit record time.

The first is card speed.  If you have a memory card which is not fast enough to sustain writing at the data rate of the video you are recording, the buffer of the camera will slowly fill and when it runs out of space, there is no way for the camera to continue recording.

The second is a limitation of the FAT file system used in many digital cameras.  Video files are very large and the FAT file system used in many cameras is simple and outdated.  It has a limit of 4GB per file and when you reach that limit, the file has to end or it will become unreadable.  In the case of your D5200, this is the reason for the 20 minute cut off.  Other cameras get around this either by using exFAT (a newer card format) or simply splitting the video between files.  (One file ends and a new file begins while the camera uses it's buffer to store frames.)  The later is, for example, how the Canon 5D Mark iii deals with 4GB file size limits.

The third and largest limitation is that of import taxes that the EU imposes on "video recording devices."  Video recording devices are defined as anything that can record more than 30 minutes of video and it is a 15% tax.  Thus, most manufacturers impose a completely artificial 29 minute 59 second time limit on video recording so that the device is not a video recording device.  Some manufacturers offer different versions in Europe than the rest of the world, but most just put the limit everywhere.

Third party firmwares are often able to deal with both the second and third situation (both by file splitting methods normally), however the first situation can only be addressed by getting a new, faster memory card.


What happens when a compressed video is played back?

In most common compression schemes, there isn't a 1::1 correspondence between "video" frames and "file" (or stream) frames **. Any particular video frame may require the contents of several file frames to become a complete viewable image. So a player will read and buffer as many file frames as needed to reconstruct the video frame in question. The player may buffer much more, but it's not required to.

For example, if some video frame ends up as a P frame when encoded in the file, the player will need to look back to find the previous I frame, decode that, then apply the differences encoded in the intervening P frames to get the complete result.

** EDIT: There is of course a file frame for each video frame, but the point is that you can't usually read one frame from the file and get a complete video frame: that's only true for I frames.


ASS subtitle - Different alignment at block and inner level

If you're familiar with an ass file, you can position your text by using \pos(150,250).
Example:
Dialogue: 0,0:01:00.00,0:01:15.00,Default,,0,0,0,,{\fad(500,500)\pos(150,250)}{\i1}{\b1}Your Text

The first number is from the left, and the second one is from the top of the video.
An easier solution, rather than write each line yourself, is to download Aegisub to make the ass files for you.
Using Aegisub, you can drag the text lines to the position you need.


The following command shows a video with a waveform of the corresponding audio:

ffmpeg -i input.mp4 -filter_complex "[0:a]showwaves=s=1280x720,format=yuv420p[vid]" -map "[vid]" -map 0:a -codec:v libx264 -crf 18 -preset fast -codec:a aac -strict -2 -b:a 192k output.mp4

I replaced avectorscope with showwaves: avectorscope is for showing the difference between stereo pairs.
Try showcqt,showfreqs,showspectrum for other visualization effects.


I managed to get an acceptable result by exporting as Mov/Prores 4444 and a Timeline Colorspace of Rec 709 Gamma 2.2.


Why does all timecode start at 1 hour? (01:00:00:00)

It's to leave room before first picture, for slates, countdowns, test signals etc, while still preserving an easy count of running time for the video. Yes, it traces historically to broadcast and in particular videotape.

Many tape-based editing systems couldn't deal with 24-hour wraparound, so the next even hour became traditional 'time zero'. I suspect that most non-linear systems are the same.