[Mplayer-users] a question about ICDecompress

Jens Hoffmann hoffmajs at gmx.de
Mon Apr 23 10:42:44 CEST 2001

[embarrassing question snipped]
> There are _two_ BITMAPINFOHEADER structs. One for input and one for output
> frame. Input frame is compressed, so it's size isn't fixed. It's size
> is equal to packet size read from the file. Output's biSizeImage is
> really constant, see dll_init.c
yes, stupid me. i confused o_bih with bih, sorry

> > 2) ICDecompress gets always called with ICDECOMPRESS_NOTKEYFRAME.
> > i guess thats wrong...
> No it doesn't matter. Once I patched it to be correct but there was no
> difference. But this way we can play files with mising/broken index chunks.
ah, ok.

> > 3) whats the deal with drawslice (for IMGFMT_YV12, IMGFMT_IYUV
> > and IMGFMT_I420)? what is it used for?
> mpeg codecs. mpeg 1, 2 and opendivx.

sure, but why is it used for the VFW and DirectShow, too?
Note, that the draw_frame functions in the vo_*.c have special cases for the 
planar formats (e.g YV12). unfortunately this code gets never called, since
drawframe gets never called for the planar formats. (-> dead code!)
(id´ say just call drawframe for vfw and directshow (but with the right 
parameters for planar yuv. 8-)

> > the video driver should take care of that.
> > and at least for xv and sdl just one memcpy would be enough:
> > the codec gives some format (e.g. IMGFMT_YV12) and the video overlay
> > displays it. no need to special case.
> it's done this way. but 3 memcpy, because input planes aren't appended.
> they are allocated separately.
as i said, the code gets never called.
(at least the last time i checked it, it wasn´t)

[idea about removing memcpy snipped]
> yes, it's possible, and it's planned for the next release, when we
> leave libvo and move to libxmm. It has this feature, and get_surface
> interface.

> > Well just an idea, but it might be worthwhile to look into it.
> There are problems with stride. bytes per lines not always equal to
> image_width*bytesperpixel.
ah, didnt thought of that. but for yuv there shouldnt be a problem.


PS: thanks for your fast response.

Mplayer-users mailing list
Mplayer-users at lists.sourceforge.net

More information about the MPlayer-users mailing list