out20.ac3​ (1.5 MB) - added by mt 6 years ago.
Does the following command line also crash?
Yes, also crashes with that command line.
Tried three different input samples with AC3, they all crash.
A second sample may be useful.
I attached an AC3 sample, the DTS one is too large and only produces a segfault also.
G4 here also, try running the sample several times.
2 out of 3 times it crashes here.
Did some more testing, compiled it with the standard gcc 4.0.1 and it didn't crash then.
Could it be some problem with compiler optimization on gcc 4.2/ppc7400?
It is much more likely that it is a thermal problem with your hardware (I have to compile FFmpeg with nice -n19 on my G4 to make sure I get no internal compiler errors, the PPC fate instances fail randomly iirc).
I don't think it's a thermal problem.
The gcc 4.0.1 version and a gcc 4.2 with libfdk-aac work at the same time when the gcc 4.2 version crashes.
Recompiling with --disable-pthreads for testing.
The quicksilver G4 tend to pile up dust on the CPU cooler, maybe check your G4 for that.
I had a thermal problem years ago due to that, but I also replaced the thermal paste on the CPUs then.
I don't care about my G4 (I just use it for rare tests), but "2 out of 3 times it crashes here" is usually an indication for a hardware problem.
Were you able to test with --disable-pthreads ?
Yes, I tried --disable-pthreads. It crashed too (ffmpeg emulated the threads when running).
Even cleaned out the dust and ran the apple hardware test to check the hardware, no problen found.
Compiled gcc 4.7 via macports to check with a newer compiler, same crash with that binary.
Just tried some older binaries 0.11, 1.0 and 1.1/1.1.1.
0.11 and 1.0 work ok, 1.1 and above crahes.
To rule out a thermal problem I tried to start up with only one cpu (nvram boot-args="cpus=1"), but then the machine shutdowns down on booting.
Maybe a faulty cpu? Not sure though.
Running hardware test right now again.
I will let it cool off for some time and then try to boot again.
Testing a very old version of FFmpeg, I see random fate crashes but no aac crash for the given sample on my G4, so I don't think there ever was an issue that could be fixed within FFmpeg.