[MPlayer-users] a bug

[Tomasz Bury]

I've found a bug in audio decoding, can anyone else reproduce it?

Here are the details:
I was trying to convert DVD (MPEG-2 video + AC3 5.1 audio) to MPEG-4. 
There was a weird CRC problem in decoding audio but only in mencoder, 
mplayer played it witout any complains. After testing it extensively I 
have figured out that passing "-aid XXX" seems to fix this. See the 
details below.

FYI: I have tested 1.0pre3 and CVS HEAD - both with the same result.

gr,
Tomek


WITHOUT -aid: CRC weird errors
mencoder -v -v dvd://1 -chapter 2-2 -o /dev/null -oac copy -ovc copy 
-frames 1
[...]
==========================================================================
Opening audio decoder: [liba52] AC3 decoding with liba52
dec_audio: Allocating 3840 bytes for input buffer.
dec_audio: Allocating 6144 + 65536 = 71680 bytes for output buffer.
Using SSE optimized IMDCT transform
==> Found audio stream: 128
==> Found audio stream: 129
Navi  new pos=0xD623 
Found NAVI packet! lba=0xD623  len=117 
### CELL 1: Navi: 2/1  IFO: 2/1  
Navi  new pos=0xD699 
Found NAVI packet! lba=0xD699  len=251 
### CELL 1: Navi: 2/1  IFO: 2/1  
Navi  new pos=0xD795 
Found NAVI packet! lba=0xD795  len=279 
### CELL 1: Navi: 2/1  IFO: 2/1  
a52: len=348  flags=0x7  44100 Hz 80000 bit/s
a52: CRC check failed! 
AC3: 5.0 (3f+2r)  44100 Hz  80.0 kbit/s
A52 flags before a52_frame: 0x2A
A52 flags after a52_frame: 0xA
Using MMX optimized resampler
AUDIO: 44100 Hz, 2 ch, 16 bit (0x10), ratio: 10000->176400 (80.0 kbit)
Selected audio codec: [a52] afm:liba52 (AC3-liba52)
==========================================================================



NOW WITH -aid 128: or -aid 129 everything is fine:

mencoder -v -v dvd://1 -chapter 2-2 -o /dev/null -oac copy -ovc copy 
-frames 1 -aid 128
[...]
==========================================================================
Opening audio decoder: [liba52] AC3 decoding with liba52
dec_audio: Allocating 3840 bytes for input buffer.
dec_audio: Allocating 6144 + 65536 = 71680 bytes for output buffer.
Using SSE optimized IMDCT transform
a52: len=1792  flags=0x17  48000 Hz 448000 bit/s
==> Found audio stream: 129
AC3: 5.1 (3f+2r+lfe)  48000 Hz  448.0 kbit/s
A52 flags before a52_frame: 0x2A
A52 flags after a52_frame: 0xA
Using MMX optimized resampler
AUDIO: 48000 Hz, 2 ch, 16 bit (0x10), ratio: 56000->192000 (448.0 kbit)
Selected audio codec: [a52] afm:liba52 (AC3-liba52)
==========================================================================



mencoder -v -v dvd://1 -chapter 2-2 -o /dev/null -oac copy -ovc copy 
-frames 1 -aid 129
[...]
==========================================================================
Opening audio decoder: [liba52] AC3 decoding with liba52
dec_audio: Allocating 3840 bytes for input buffer.
dec_audio: Allocating 6144 + 65536 = 71680 bytes for output buffer.
Using SSE optimized IMDCT transform
a52: len=1024  flags=0xA  48000 Hz 256000 bit/s
AC3: 2.0 (dolby)  48000 Hz  256.0 kbit/s
A52 flags before a52_frame: 0x2A
A52 flags after a52_frame: 0xA
Using MMX optimized resampler
AUDIO: 48000 Hz, 2 ch, 16 bit (0x10), ratio: 32000->192000 (256.0 kbit)
Selected audio codec: [a52] afm:liba52 (AC3-liba52)
==========================================================================