[FFmpeg-devel] AAC/RTP crash

[Robert Swain]

Hello Ronald,

On 25/2/09 21:14, Ronald S. Bultje wrote:
> On Thu, Jan 15, 2009 at 9:40 AM, Robert Swain<robert.swain at gmail.com>  wrote:
>> 2009/1/15 Ronald S. Bultje<rsbultje at gmail.com>:
>>> With the built-in decoder instead of faad, RTP streams containing AAC
>>> data can crash ffplay. Example below:
>>>
>>> $ ./ffplay rtsp://video.medinfo.ufl.edu/opeta/MS_all.mov
>>>
>>> Program received signal EXC_BAD_ACCESS, Could not access memory.
>>> Reason: KERN_PROTECTION_FAILURE at address: 0x000000e5
>>> [Switching to process 28864 thread 0x7eab]
>>> 0x001467e3 in aac_decode_frame (avccontext=???, data=???,
>>> data_size=???, buf=???, buf_size=???) at libavcodec/aac.c:1493
>>> 1493                    if(che->ch[0].tns.present)
>>>
>>> I'm affraid I don't get a backtrace or any useful debugging data
>>> (which is a completely different issue that I should at some point ask
>>> questions about :-) ), but maybe one of the AAC decoder devs can
>>> reproduce this and look at it? This used to work fine with the faad
>>> decoder, and the RTP/AAC payload parser didn't change since then.
>> Compiled with --enable-debug=3 and run the ffplay_g binary in gdb I
>> assume...? I'll have a look later or tomorrow.
>
> Did you ever have a chance to look at this?

My internet connection is finally working well again. Better than before 
in fact. 450-500kB/s downstream for me, whoop!

Anyway, I tried the command line you pasted and I didn't observe any 
crash. I didn't see any video, just a black rectangle, and the audio was 
somewhat messed up. Can you still reproduce the issue?

This is what I see:

$ ffplay rtsp://video.medinfo.ufl.edu/opeta/MS_all.mov
FFplay version SVN-r17861, Copyright (c) 2003-2009 Fabrice Bellard, et al.
   configuration: --enable-gpl --enable-nonfree --enable-postproc 
--enable-avfilter --enable-avfilter-lavf --enable-pthreads 
--enable-libamr-nb --enable-libamr-wb --enable-libfaac 
--enable-libmp3lame --enable-libx264 --cc=ccache gcc-4.2 
--extra-cflags=-march=prescott
   libavutil     49.15. 0 / 49.15. 0
   libavcodec    52.21. 0 / 52.21. 0
   libavformat   52.31. 1 / 52.31. 1
   libavdevice   52. 1. 0 / 52. 1. 0
   libavfilter    0. 4. 0 /  0. 4. 0
   libswscale     0. 7. 1 /  0. 7. 1
   libpostproc   51. 2. 0 / 51. 2. 0
   built on Mar  6 2009 23:20:55, gcc: 4.2.1 (Apple Inc. build 5566)
2009-03-07 00:46:06.655 ffplay[65569:10b] Warning once: This 
application, or a library it uses, is using NSQuickDrawView, which has 
been deprecated. Apps should cease use of QuickDraw and move to Quartz.
[aac @ 0x1048c00]Transition from an ONLY_LONG or LONG_STOP to an 
EIGHT_SHORT sequence detected. If you heard an audible artifact, please 
submit the sample to the FFmpeg developers.

$ ffmpeg -i rtsp://video.medinfo.ufl.edu/opeta/MS_all.mov
FFmpeg version SVN-r17861, Copyright (c) 2000-2009 Fabrice Bellard, et al.
   configuration: --enable-gpl --enable-nonfree --enable-postproc 
--enable-avfilter --enable-avfilter-lavf --enable-pthreads 
--enable-libamr-nb --enable-libamr-wb --enable-libfaac 
--enable-libmp3lame --enable-libx264 --cc=ccache gcc-4.2 
--extra-cflags=-march=prescott
   libavutil     49.15. 0 / 49.15. 0
   libavcodec    52.21. 0 / 52.21. 0
   libavformat   52.31. 1 / 52.31. 1
   libavdevice   52. 1. 0 / 52. 1. 0
   libavfilter    0. 4. 0 /  0. 4. 0
   libswscale     0. 7. 1 /  0. 7. 1
   libpostproc   51. 2. 0 / 51. 2. 0
   built on Mar  6 2009 23:20:55, gcc: 4.2.1 (Apple Inc. build 5566)

Seems stream 1 codec frame rate differs from container frame rate: 
90000.00 (90000/1) -> 1500.00 (1500/1)
Input #0, rtsp, from 'rtsp://video.medinfo.ufl.edu/opeta/MS_all.mov':
   Duration: 00:18:19.46, start: 0.000000, bitrate: N/A
     Stream #0.0: Audio: aac, 32000 Hz, mono, s16
     Stream #0.1: Video: 0x0000, 1500 tbr, 90k tbn, 90k tbc
At least one output file must be specified

Regards,
Rob