[MPlayer-dev-eng] mjpeg yuv422 output from mencoder/mplayer

[Michael Niedermayer]

Hi

On Sun, Oct 01, 2006 at 07:50:27PM +0200, Baptiste Coudurier wrote:
> Michael Niedermayer a écrit :
> >Hi
> >
> >On Sun, Oct 01, 2006 at 04:49:07PM +0200, Baptiste Coudurier wrote:
> >>Hi
> >>
> >>Michael Niedermayer a écrit :
> >>>Hi
> >>>
> >>>On Sat, Sep 30, 2006 at 12:46:58PM +0200, Karolina Lindqvist wrote:
> >>>>I need something that outputs the MJPEG YUV422 format, that the zoran 
> >>>>(zr, zr2) drivers need, but I find nothing in the mencoder/mplayer 
> >>>>programs that can output that format to disc. 
> >>>>
> >>>>I tried mencoder with -lavcopts vcodec=mjpeg which almost appears to do 
> >>>>the job. Except for that it does not accept format=422p. It can only do 
> >>>>YV12 (YUV420).
> >>>a patch which adds 422p jpeg encoding support to lavc would be welcome 
> >>>...
> >>>
> >>>[...]
> >>Tried to. I have at least something working in progressive. Problem is 
> >>that mpegvideo.c is really hardcoded to 4:2:0 and since DCT on jpeg is 
> >>done on 8x8 mb it is quite hard to work around that.
> >
> >hmm lavc mpeg2 video supports 422 encoding over mpegvideo.c ...
> >
> >[...]
> 
> Yes. Mpeg2 macroblocks are orderded right out of encode_mb_internal. 
> Output is 8 blocks: 4 luma blocks, 4 chroma blocks in 4:2:2, and stored 
> that way.
> 
> In mjpeg_encode_mb, you will have 8 blocks while they must be coded 2 
> luma, 2 chroma, in 4:2:2 and 4 others will be on the next line in the 
> bitstream.

what is the problem with coding them like in mpeg2, IIRC the jpeg syntax
is flexible enough ...


[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In the past you could go to a library and read, borrow or copy any book
Today you'd get arrested for mere telling someone where the library is