[xine-devel] mpg + frame number based subtitles

[Boszormenyi Z. <zb...@fr...>]

Hi,

I got a movie in mpeg format with an external subtitle file.
The subtitle is in microdvd format, so it is frame number based.
The subtitles get out of sync quickly, e.g. after ~8 minutes, the 
subtitles are
late by ~20 seconds.

Gzipped log of "MPEG2_DEBUG=255 xine movie.mpeg#subtitle:movie.sub" is 
attached.

The interesting parts are:

Using MMXEXT for IDCT transform
Using MMXEXT for motion compensation
 (sequence_error)
 (seq) 592x448 1:1, 30 fps, 104857 kbps, VBV 0 kB
 <---- 30 FPS and frame size is obviously wrong for the movie. It is the 
xine logo.
 (user_data)
 (group)
 (picture) I-type temporal_reference 0, vbv_delay 65535
 (picture) P-type temporal_reference 1, vbv_delay 65535
 (picture) P-type temporal_reference 2, vbv_delay 65535
....
 (picture) P-type temporal_reference 15, vbv_delay 65535
 (sequence_error)
 (seq) 352x288 Invalid frame_rate_code, 25 fps,  1120 kbps, VBV 40 kB , CP
 <---- Later I get this. 25 FPS and the frame size is correct.
 (group)
 (picture) I-type temporal_reference 2, vbv_delay 26277
 (picture) B-type temporal_reference 0, vbv_delay 21415
 (picture) B-type temporal_reference 1, vbv_delay 22011
...

The above message with the correct frame size and frame rate
is repeated several times patching libsputext/xine_decoder.c
and logging this->img_duration shows that it is using the correct fps value.
demux_mpeg/elem/etc. does not provide extra_info.frame_number
so a computation is needed obviously. But it seems to be incorrect.

An  interesting issue is that the "Invalid frame_rate_code" message
should be something else because in line 127 in stats.c the fprintf() 
contains
aspect_ratio_information_str [aspect_ratio_information]
at that position.

I will try this movie+subtitle with mplayer tomorrow.

Best regards,
Zoltán Böszörményi