[Ffmpeg-devel] swscaler BUG in PIX_FMT_YUV410P -> PIX_FMT_RGBA32

[GizmoSDK]

20 feb 2007 kl. 08.29 skrev gizmo_video:

>
>
> 				Fr?n: Michael Niedermayer <michaelni at gmx.at>
> Skickat: den 20 februari 2007 01:10
> Till: FFmpeg development discussions and patches <ffmpeg- 
> devel at mplayerhq.hu>
> ?mne: Re: [Ffmpeg-devel] swscaler BUG in PIX_FMT_YUV410P ->  
> PIX_FMT_RGBA32
>
> Hi
>
> On Mon, Feb 19, 2007 at 10:11:07PM +0100, GizmoSDK wrote:
>>
>> 19 feb 2007 kl. 21.45 skrev GizmoSDK:
>>
>>> When converting a image of format PIX_FMT_YUV410P to
>>> PIX_FMT_RGBA32, using MMX but not MMX2 the blue rgb component is
>>> mixed into the green so a blue image gets green.
>>>
>>> The context is initialised with
>>>
>>> m_img_convert_ctx = sws_getContext(
>>> m_pVideoCodecCtx->width, m_pVideoCodecCtx->height,
>>> PIX_FMT_RGBA32,
>>> m_pVideoCodecCtx->width, m_pVideoCodecCtx->height,
>>> m_pVideoCodecCtx->pix_fmt,
>>> 0, NULL, NULL, NULL);
>>>
>>> and the conversion is done with
>>>
>>> sws_scale(m_img_convert_ctx, m_pFrame->data, m_pFrame->linesize,0,
>>> m_pVideoCodecCtx->height, m_pFrameRGB->data, m_pFrameRGB->linesize);
>>>
>>> The size of src==dst so its a plain translation of format A to B.
>>>
>>> This bug occurs in
>>> FFmpeg version SVN-r8028, Copyright (c) 2000-2007 Fabrice Bellard,
>>> et al.
>>> configuration: --disable-opts --disable-strip --enable-swscaler --
>>> enable-xvid --enable-libfaad --extra-cflags=-I/Users/amo/
>>> xvidcore-1.1.0/src -I/Users/amo/faad2/include --enable-gpl --extra-
>>> ldflags=-L/Users/amo/xvidcore-1.1.0/build/generic/=build -L/Users/
>>> amo/faad2/libfaad/.libs --disable-dv1394 --disable-ipv6 --disable-
>>> vhook --disable-bktr --disable-v4l2 --disable-v4l
>>> libavutil version: 49.3.0
>>> libavcodec version: 51.33.0
>>> libavformat version: 51.10.0
>>> built on Feb 19 2007 20:26:15, gcc: 4.0.1 (Apple Computer, Inc.
>>> build 5367)
>>
>> I suspect that the error is in swscale_template.c:1107
>>
>> switch(c->dstFormat)
>> {
>> case PIX_FMT_RGB32:
>> YSCALEYUV2PACKEDX
>> YSCALEYUV2RGBX
>> WRITEBGR32(%4, %5, %%REGa)
>> YSCALEYUV2PACKEDX_END
>> return;
>>
>>
>> where the rgb gets mangled some how. But its just a guess as all
>> these macros makes it virtually impossibly to debug without bettr
>> knowledge of the code...
>
>> mplayer -vf scale,format=YVU9,scale,format=bgr32,scale and rgb32  
>> works
>> that is with mmx2 disabled
>> -> bug closed / not reproduceable
>
> I think that there is a bug anyway ! Here is a sample that when  
> unpacked with the code above gets green instead of blue.
>
> swscaler is enabled. Bug reproducable on  OSX and on MingW Win32  
> when unpacking to PIX_FMT_RGB32.
>
> The bug doesn't occur using img_convert without swscaler enabled.
>
> http://www.gizmosdk.se/vid1.mov

I have now verified that the RGB values before the WRITEBGR32(%4, %5,  
%%REGa) macro is corrupt. So my guess is that there is something  
wrong in the unapcking or conversion of the PIX_FMT_YUV410P format.  
Will check more but there is definitely a bug. The vid1.mov played  
with ffplay gives a correct image but when dest format is rgb32  
something gets wrong.

/Anders Mod?n