[vlc-devel] Re: [VLC] VLC with ffmpeg compile + YUV play

Dusan Mudric dusan.mudric at rogers.com
Tue Jan 25 04:37:46 CET 2005


ffplay sounds like a solution. Can you give me a link to it please?

Dusan


----- Original Message ----- 
From: "Andrea Guzzo" <xant at xant.net>
To: <vlc-devel at videolan.org>
Sent: Sunday, January 23, 2005 7:50 AM
Subject: [vlc-devel] Re: [VLC] VLC with ffmpeg compile + YUV play


> mmm...
> what do you think about using directly the ffplay tool that comes with 
> ffmpeg distribution? ...
> i think it should be appropriate for your purpose ....
> 
> bye,
> x.
> 
> Il giorno 22/gen/05, alle 17:26, Dusan Mudric ha scritto:
> 
> > Find my explanation of our effort inlined. I need a reference to 
> > application
> > which uses ffmpeg and can run YUV video clips created by ISO. 
> > Application
> > needs to be open source so we can try our new encoding algorithms.
> >
> >
> > From: "Benjamin PRACHT" <bigben+spam at videolan.org>
> >
> >> On Thu, Jan 20, 2005, Dusan Mudric wrote :
> >>>> Well, for that, the best woulkd certainly be to have a look on one 
> >>>> of
> >>>> the pages linked here http://developers.videolan.org/vlc/, depending
> > on
> >>>> the destination architecture.
> >>>
> >>> [Dusan] Can you be more specific? We spent a lot of  time already on
> > this page without success.
> >>
> >> Well, what are you trying to do exactly ? Which OS ? What is the error
> >> / problem you are facing ?
> >>
> >
> > [Dusan] We want to test new DCT, wavelet and motion estimation 
> > algorithms in
> > VLC codec. To do that we want to find which part of VLC code we need to
> > replace. For MPEG4 it is in ffmpeg library. If we change this library, 
> > we
> > want to run VLC and test our algorithms. We have problem linking 
> > ffmpeg with
> > VLC. If there is another open source application using ffmpeg library 
> > and
> > can be used to run YUV video clips, please suggest.
> >
> > Based on my understaning of VLC, it uses ffmpeg library for encoding
> > algorithms. We want to modify MPEG4 encoder:
> >
> > ffmpeg-20041113\libavcodec\mpegvideo.c(6363):AVCodec mpeg4_encoder = {
> > MPV_encode_init, ...}
> >
> > Where motion is done by:
> > =================
> > ffmpeg-20041113\libavcodec\mpegvideo.c(4280):    encode_mb(s, motion_x,
> > motion_y);
> > C:\CYGWIN\VLC\ffmpeg\libavcodec\mpegvideo.c(4121):        
> > mpeg4_encode_mb(s,
> > s->block, motion_x, motion_y); break;
> > C:\CYGWIN\VLC\ffmpeg\libavcodec\h263.c(767):void
> > mpeg4_encode_mb(MpegEncContext * s,
> >
> > and texture:
> > ========
> > ffmpeg-20041113\libavcodec\mpegvideo.c(4063):
> > s->block_last_index[i] = s->dct_quantize(s, s->block[i], i, s->qscale,
> > &overflow);       <---- HERE IS DCT done
> > C:\CYGWIN\VLC\ffmpeg\libavcodec\mpegvideo.c(5980):static int
> > dct_quantize_c(MpegEncContext *s, ..)
> >
> >
> >
> >
> >>>>
> >>>> Well, If the YUV track is encapsulated in a muxing format VLC 
> >>>> support
> >>>> (well, do we have support for a muxing format that allows raw video
> > ?),
> >>>> it should work... But I'm not aware of any way to have VLC read any
> > raw
> >>>> video stream (excepted the particular case of DV streams).
> >>>>
> >>>
> >>> [Dusan] How do you test ffmpeg encoders if VLC doesn't run YUV?
> >>>
> >>
> >> Well, VLC does handle quite a lot of variants of the YUV chromas,
> >> What I meant is that I'm not aware of any way to feed VLC with a raw
> >> uncompressed YUV stream coming from a file. As I said, raw YUV streams
> >> from capture cameras (Video4linux, Directshow, etc) are handled. 
> >> Adding
> >> support for raw YUV files shouldn't be to hard, I guess. It would be a
> >> matter of creating a "raw" demux, that allows to specify the fourcc of
> >> the given track, as well as the dimensions of the picture (That might
> >> already exist without me being aware of it).
> >>
> >> Transcoding is mostly used to change the codec/bitrate of a already
> >> encoded stream on the fly, before re-streaming it. If your purpose is 
> >> to
> >> test the quality of the ffmpeg encoders, than VLC certainly isn't the
> >> application you are looking for...
> >
> > [Dusan] Sounds like you know other applications which use ffmpeg and 
> > can
> > encode/decode ISO reference YUV video clips. Would you mind to tell us 
> > which
> > application we can use instead?
> >
> >>
> >> --
> >> BigBen
> >>
> >> --
> >> This is the vlc-devel mailing-list, see http://www.videolan.org/vlc/
> >> To unsubscribe, please read http://developers.videolan.org/lists.html
> >>
> >>
> >
> > -- 
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> >
> 
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