SIGBUS Crash occurred when stream search with special MXF(SONY F55RAW)

[KengoSawa2]

Hello.

I love PyAV. Thank you for a wonderful library:)

I found a problem.
If you open a special MXF with PyAV, SIGBUS will occur.

As far as I've seen, it seems that some function becomes an infinite loop and destroys the stack frame.
The problem data and reproduction code, Mac crash report data are summarized below.
https://lespa.firestorage.jp/download/f80da205bc2e84ae0cb6e17f2025db6684484c9c

I am glad that this problem is solved.
(I am making software to search all folders and create a shotlist)
Thank you.

Environment:
PyAV 6.0.0
macOS 10.11.6
ffmpeg 4.0.2
Python3.4

[jlaine]

Could you please provide a sample file and some code to help reproduce?

[KengoSawa2]

Thank you reply:)

sample mxf file and reproduce code is below.

https://drive.google.com/file/d/1dbSUDwtBQnhug1B7XpaAq-gNPDUHPfuS/view?usp=sharing

[jlaine]

OK I'm also getting a crash, I'll try digging into it.

The file seems to be an odd one in anycase, ffprobe also gives me plenty of warnings.

[jlaine]

@mikeboers the problem seems to be due to the Stream.__getattr__ magic : if the stream contains an unknown codec, self.codec_context does not exist, and so calling something as basic as stream.type leads to an infinite loop:

• __getattr__('type')
• __getattr__('codec_context')
• __getattr__('codec_context')
  ...

@KengoSawa2 the crash definitely needs to be fixed, however as the video codec doesn't seem to be supported by ffmpeg I don't think you'll be able to do anything useful with it.

[jlaine]

@mikeboers I have a fix for the crash, but I'd like to lock it down with a unit test. Does the FATE suite contain examples of unsupported codecs?

[mikeboers]

@jlaine I've never found one.