[XviD-devel] Problem with MPEG-4 headers

[Matthew Kwan]

Hi.

I'm developing a video application for mobile phones, and tried both XviD and
ffmpeg (libavcodec) to generate MPEG-4 data. The XviD output doesn't work.
Although I can proceed using libavcodec, it would be nice if you could fix the
XviD problem so I have an alternative.

Details: Simple profile, level 0. QCIF (176x144) resolution. 5fps target, at
50kpbs.
No other options set.

I tested a number of encoder -> decoder combinations.

libavcodec -> phone: OK
libavcodec -> XviD: OK
XviD -> XviD: OK
XviD -> phone: garbage
XviD -> libavcodec: lots of errors - see below

Frame 1 OK
Frame 2 OK
Frame 3

Marker bit missing before time_increment
[mpeg4 @ 0x405a9160]hmm, seems the headers are not complete, trying to guess
time_increment_bits
[mpeg4 @ 0x405a9160]my guess is 16 bits ;)
Marker bit missing before vop_coded
                                                                               

Frame 4 OK
Frame 5

[mpeg4 @ 0x405a9160]2. marker bit missing in 3. esc
[mpeg4 @ 0x405a9160]Error at MB: 41
[mpeg4 @ 0x405a9160]concealing 99 DC, 99 AC, 99 MV errors

Frame 6

Marker bit missing before time_increment
[mpeg4 @ 0x405a9160]hmm, seems the headers are not complete, trying to guess
time_increment_bits
[mpeg4 @ 0x405a9160]my guess is 16 bits ;)
Marker bit missing before vop_coded
                                                                               

Frame 7 OK
Frame 8

[mpeg4 @ 0x405a9160]concealing 13 DC, 13 AC, 13 MV errors

Frame 9

Marker bit missing before time_increment
[mpeg4 @ 0x405a9160]hmm, seems the headers are not complete, trying to guess
time_increment_bits
[mpeg4 @ 0x405a9160]my guess is 16 bits ;)
Marker bit missing before vop_coded

Frame 10 OK
Frame 11
 
[mpeg4 @ 0x405a9160]hmm, seems the headers are not complete, trying to guess
time_increment_bits
[mpeg4 @ 0x405a9160]my guess is 3 bits ;)


Regards,


mkwan



		
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