[MPlayer-dev-eng] [PATCH - don't apply] extended MPEG/DVD muxer

[Nico Sabbi]

Hi,
I modified the current mpeg muxer (almost entirely rewritten) and the 
muxer layer so as to make
the muxer configurable for a variety of video formats: dvd, mpeg1, 
mpeg2, some of vcd/svcd.

Premise: I'm still developing the code, so it's not at all complete;  
some crucial aspects must still
be solved: a/v delay in primis.

What has changed: possible outputs formats mpeg1, mpeg2, and the 
corresponding variants (dvd/xvcd/xsvcd)
Ac3 muxing is now possible, both in mpeg2 and in mpeg1 (although it was 
never standardized there's
only one possible implementation).

Variable packet_size configurable up to 65535.

How it works: since mpeg requires a kind of soft PLL (system clock known 
as SCR), and since
the only reliable clock source is video frame duration => SCR is 
emulated in terms of video timer
(for every gop it's increased in percentages of the total video+audio 
bytes to write).
This method is usually quite accurate, but it may lead to audio_pts > 
0.7 secs + SCR,
that is forbidden by the standard; I added some code to try to 
compensate this situation,
but I still have to find a perfect solution.

Video is first reordered in decoding order (the current muxer doesn't do 
it) and
then written in Gops; I also added some preliminary code to handle 
correctly variable fps
movies, but currently it doesn't work well (yet).

Finally I added some utility function to patch the video sequence header 
parameters
(bitrate, resolution, fps, aspect ratio), that often are wrong.

Some changes were necessary in the muxer layer itself, that currently is 
too rigid and
optimistic (doesn't admit failure).

Performance will surely improve once I optimize the memory management.
Successfully tested with my standalone dvd player, mplayer and vlc (the 
closest
software approximation of a standalone player that I know of).

How to use:

./mencoder -of mpeg -mpegopts format=dvd ...

possible parameters:
- format: dvd/xvcd/xsvcd/mpeg1/mpeg2
- size: pack size (default is 2048)
- init_apts: initial audio pts [0..500] default is 300 (don't touch it)
- init_vpts same for video ...
- muxrate multiplexing rate in kbit/s , default is 10080 for dvd compliance
parameters to patch video:
- vaspect:  1/1, 4/3, 16/9, 2.21/1
- vframerate 23.976/24/25/29.97/30/50/59.94/60
- vwidth and vheight: 0..4095
- vbitrate in kbit/s

I'd like if people experimented with this new muxer and reported 
success/failer/suggestions.
Have fun.

P.S. please, don't complain because I changed the indentation style; I 
will eventually reindent the final file
(although I deeply dislike the current one).

    Nico


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