Re: [xine-devel] multiple audio streams

[Thibaut M. <tma...@no...>]

Hi James,

> On Wed, 07 Jan 2004 18:19:36 +0100, "Thibaut Mattern" <tma...@no...>
said:
> > ok.
> > is it ok to send the fragment offset table in a buffer, after the last 
> > fragment and with the FRAME_END flag ?
> > or do you have a better idea ?
> 
> Yes I think this is a fine way of doing things.

I've modified the libreal decoder.
The xine decoder use the following frame format:
  fragment
  fragment
  ...
  fragment
  fragment offset table
  number of fragment - 1

The first must have the FRAME_START flag, the last buffer must have the FRAME_END flag.
The frame can be splitted into any number of buffers, one buffer if ok (FRAME_START + FRAME_END flags).
It's not needed to copy the frament offset table into a separate buffer.
The last byte of the frame is the (number of fragment - 1), and it's used by the decoder to compute the size of the fragment offset table.
The fragment offset table is the real .so decoder format, so you can pass a pointer to it to the lib.

> 
> > my only mkv test stream with a RV40 video track contains some fragments 
> >  >8k  (matrix trailer available on matroska website)
> 
> Speaking of RV40 you'll see some code in the libreal decoder for skipping
> certain fragments which was necessary to get certain streams to playback
> correctly. I wonder if the matroska tools drop these fragments when
> reading real files.

The mkv matrix trailer works perfectly without dropping anything.
So i think the fragment dropping job is more a demuxer job.

Another problem: the frame duration
there is some code to guess the frame duration using pts in the libreal decoder,
i guess this is here because the real demuxer does'nt know the frame duration.
I think this code should be in the Real, the mkv demux provide the frame duration.
You can find the same frame duration guessing code in the ASF demuxer.

> James.

If you're ok with the frame format and with moving the fragment dropping code and the frame duration guessing code to the real demuxer, i will commit my decoder changes tonight.

cheers,
Thibaut