[FFmpeg-devel] DTS transcoding error: where to file a bug?

Benjamin Larsson banan
Wed Apr 9 18:54:21 CEST 2008


Benjamin Larsson wrote:
> Guido Ledermann wrote:
>   
>> 2008/4/8 Benjamin Larsson <banan at ludd.ltu.se>:
>>
>>   
>>     
>>> There seems to be a problem logging in, just describe here on the
>>> mainlinglist for now.
>>>
>>>     
>>>       
>> I'm trying to transcode DTS. FFmepg crashed. I often have DTS problems so
>> for now I start writing bug reports because ffmpeg is my favorite tool. I
>> placed "small-sample-file" into your ftp /MPlayer/incoming/dtsprob2.
>>
>> This is what happens on the console:
>>
>> $ ffmpeg -y -i small-sample-file  -vcodec copy -map 0:0  -acodec ac3 -map
>> 0:1 -ab 192k -ar 48000 -ac 6 eagles.ts
>> FFmpeg version SVN-r12755, Copyright (c) 2000-2008 Fabrice Bellard, et al.
>>   configuration:
>>   libavutil version: 49.6.0
>>   libavcodec version: 51.54.0
>>   libavformat version: 52.13.0
>>   libavdevice version: 52.0.0
>>   built on Apr  5 2008 13:42:12, gcc: 4.1.2 20070925 (Red Hat 4.1.2-33)
>>
>> Seems stream 0 codec frame rate differs from container frame rate: 29.97
>> (30000/1001) -> 59.94 (60000/1001)
>> Input #0, mpeg, from 'small-sample-file':
>>   Duration: 00:00:08.5, start: 120.545400, bitrate: 9771 kb/s
>>     Stream #0.0[0x1e0]: Video: mpeg2video, yuv420p, 720x480 [PAR 8:9 DAR
>> 4:3], 6600 kb/s, 59.94 tb(r)
>>     Stream #0.1[0x89]: Audio: dca, 48000 Hz, 5:1, 1536 kb/s
>>     Stream #0.2[0xa0]: Audio: pcm_s16be, 48000 Hz, stereo, 1536 kb/s
>> Output #0, mpegts, to 'eagles.ts':
>>     Stream #0.0: Video: mpeg2video, yuv420p, 720x480, q=2-31, 6600 kb/s,
>> 29.97 tb(c)
>>     Stream #0.1: Audio: ac3, 48000 Hz, 5:1, 192 kb/s
>> Stream mapping:
>>   Stream #0.0 -> #0.0
>>   Stream #0.1 -> #0.1
>> Press [q] to stop encoding
>> ERROR: block code look-up failed    4727kB time=5.5 bitrate=7076.9kbits/s
>>
>>   
>>     

This is the bt for this bug:

#0  0x080fa24c in ac3_5p1_mux (output=0x864e600, input1=0x86b2c82, 
input2=0x1, n=3072) at libavcodec/resample.c:119
#1  0x080fa6eb in audio_resample (s=0x85d2e80, output=0x864e600, 
input=0x861c8e0, nb_samples=527) at libavcodec/resample.c:233
#2  0x0805cb30 in do_audio_out (s=0x85d3790, ost=0x85d2bc0, 
ist=0x85f1290, buf=0x861c8e0 "", size=6144) at ffmpeg.c:523
#3  0x0805f40e in output_packet (ist=0x85f1290, ist_index=1, 
ost_table=0x85d2460, nb_ostreams=2, pkt=0xbfa35094) at ffmpeg.c:1227
#4  0x0806243b in av_encode (output_files=0x84afa00, nb_output_files=1, 
input_files=0x84af900, nb_input_files=1, stream_maps=0x84afa60, 
nb_stream_maps=2) at ffmpeg.c:1992
#5  0x08067970 in main (argc=19, argv=0xbfa356a4) at ffmpeg.c:3933

For some reason the resampling context thinks there is 1 input channel 
and 6 output channels. I think the bug is in dca.c the codec might 
change the channels during decode and the rest of FFmpeg doesn't support 
that.

MvH
Benjamin Larsson







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