[MPlayer-dev-eng] [PATCH] PVA demuxer

[Arpi]

Hi,

> >ok i've found taht you just skip the audio PES header, instead of parsing
> >and checking stream id out of it.
> >  
> >
> I skip the PES header because it is written in the PVA format spec at 
> the URL I've included in the source that PVA files only support one 
> audio stream.
> Maybe multiple stream support was included in a later revision of the 
> PVA specification, this I don't know as it was the only doc I had access to.
> Anyway, I checked the broken files with a test app I had written, and 
> the PES headers that are positioned according to the specifications (at 
> the beginning of packets with the PTS flag set) are all from a 0xC0 stream.

hmm.
there are many bytes skipped, there should be something telling teh
difference. teh audio plays about 2 times faster than video, and sounds like
2 streams interleaved.

> >i've changed the pva_check_file, to read and check only the first 5 byte
> >
> >it's commited to cvs.
> >
> It's ok. I wrote it that way because I remember I read somewhere (don't 
> remember where) that some DVB boards create a device node from which a 
> PVA stream can be taken. So, I thought that if playing from there we are 
> not sure that the stream will begin with a header...

yes, it also may happen if someone use 'dd' to cut out advertisements etc.
anyway detecting such files cleanly is not trivial, hinting code should be
added to teh mpeg demuxer, which also detects mp3, mpeg-es by recognizing
their in-stream 4byte headers. yes i know it's messy but currently no better
way to support detection of such formats in non-seekable streams.


A'rpi / Astral & ESP-team

--
Developer of MPlayer, the Movie Player for Linux - http://www.MPlayerHQ.hu