Re: [VCDImager Bugs/Devel] code to parse mpeg-2 down to frame level.

[Mike Bernson]

Herbert Valerio Riedel wrote:
> 
> a big thank you! :)
> 
> I've learned a lot (again) by this code of yours. I've merged it in, while
> rewriting vcd_mpeg.c and related modules...
> 
> take a look at cvs, I'd like to know if I really have to fill that
> search.dat with i-frame-points (if so, I'll make it quick'n'dirty by
> estimating the scanpoints... only if this does not work I'll make the
> right way -- well... and for version 1.0 I'll do it the right way anyway
> :)
> 
> I'm estimating the playtime by looking at the timecode at the beginning
> and the end of the mpeg1/2 stream, and then taking the difference of it...
> 
The time code can be off by almost a second. I do we need to keep
them to the real time. Meaning seconds plus number of frames past
the second mark. (1/29.97 for nts)


> ...this should work most of the time for genuine mpeg streams, right?
> 
> btw, I've been looking at the dumped mpeg frame output... why does the
> timecode offset to last GOP timestamp sometimes decrement from one frame
> to the next one? :-/
I have only see the frame part timecode less on the few streams that is have
seen. That is frame is sub-second part of the time stamp. 

Are you talking about why each frame does not move up in the timestamp or
are the timecodes in the gop not alway move up. Could you send me a dump
of frame/gop that you are talking about.

Just a note that the frame in gop are not display in the same
order that they exist in the stream. The stream order is the
order needed to decoded in. mpeg-2 frame have forward and backward
links.

I will trying burning svcd with the current version and see how
things work. I do not have any info on the search.dat details.
The doc i have does not state anything more then this file
contains a list of access point sector address for the 
nearest intra pictures on regular time interval.  This
file is usefull for features such as time search.

With the above it sound like you should be able to
play the mpeg-2 image without the file but will
not be able to move around in it based on time.


Is there any other data you need to parse from the mpeg
streams.....
> --
> Herbert Valerio Riedel      /     Finger address@hidden for GnuPG Public Key
> GnuPG Key Fingerprint: AC2A CD57 A5C8 A1CB 0A18  DA95 CB0B DB23 60B6 16F5
> 
> _______________________________________________
> Bug-VCDImager mailing list
> address@hidden
> http://mail.gnu.org/mailman/listinfo/bug-vcdimager