Re: [mpeg2-dev] Decoding MPEG-TS stream

[Måns R. <mr...@in...>]

Bob Ingraham <bo...@br...> writes:

> Hi All,
>
> I've written an app which uses the Linux DVB API to pull down an MPEG2-TS.
>
> Currently it:
>
> 1. Decodes the TS header
> 2. Extracts the MPEG2 encoded frame
> 3. Decompresses it with libavcodec (an ffmpeg library)
> 4. Renders it with SDL
>
> But I wanted to try libmpeg2 to see if it's decoder will yield
> better results than libavcodecs.

Better in what way?

> Questions:
>
> 1. Does libmpeg2 perform steps 1 through 3 above?

No, it only does step 3.

> 2. Can I just pass an compressed MPEG2 frame to libmpeg2 (without
> any PS, TS or PES headers?)

Yes, in fact you have to.

> 3. Apparently, the Linux DVB API filter removes all PES headers and
> hands me a TS stream with just the raw mpeg2 frames after the
> TS/adaption field header.

No, this is incorrect.

> I don't think this is normal, because the MPEG2 spec says that mpeg2
> frames should be encapsulated within PES packets within the TS
> frames.
>
> Does this seem odd that there are no PES header?

Check again or change some setting.  I know I have got proper TS
streams from the Linux DVB interface.

-- 
Måns Rullgård
ma...@ma...