> -----Original Message----- > From: ffmpeg-devel [mailto:ffmpeg-devel-boun...@ffmpeg.org] On Behalf > Of Mark Thompson > Sent: Saturday, August 31, 2019 23:10 > To: ffmpeg-devel@ffmpeg.org > Subject: Re: [FFmpeg-devel] [PATCH 1/2] lavu/pixfmt: add AYUV pixel format > > On 31/08/2019 05:22, Fu, Linjie wrote: > >> -----Original Message----- > >> From: ffmpeg-devel [mailto:ffmpeg-devel-boun...@ffmpeg.org] On > Behalf > >> Of Carl Eugen Hoyos > >> Sent: Friday, August 30, 2019 00:12 > >> To: FFmpeg development discussions and patches <ffmpeg- > >> de...@ffmpeg.org> > >> Subject: Re: [FFmpeg-devel] [PATCH 1/2] lavu/pixfmt: add AYUV pixel > format > >> > >> Am Do., 29. Aug. 2019 um 16:16 Uhr schrieb Fu, Linjie > <linjie...@intel.com>: > >> > >>> Thus AYUV will make more sense. > >> > >> If your hardware decoding does not produce valid alpha data (0xFF > >> for opaque, 0x00 for completely transparent), you cannot use an > >> FFmpeg pix_fmt that defines alpha for decoding. > >> If you define a pix_fmt that does not contain alpha information (as > >> needed for your hardware decoder), please do not use "A" in its > >> name. > > > > The hardware decode output is in packed 4:4:4:4 8 bit(32 bits in total). > > Apart> > from Y/U/V channel, there is an additional need for a channel to store the > > zero byte in surfaces(nb_components = 4). And it is designed in > hardware/driver > > for VA_FourCC_AYUV and AYUV format. > > > > It's not quite proper to use something like "0YUV" directly which indicates > that > > there is no Alpha channel data like"RGB0" or "0RGB"(nb_components = 3). > > > > "0YUV": YUV0/YUV0/... > > "RGB0":RGB/RGB/... > > I think you've misread what RGB0 is. The component step is 4, not 3 (see > libavutil/pixdesc.c) - the format with a step of 3 is RGB24. > > RGBA: R G B A R G B A ... > RGB0: R G B 0 R G B 0 ... > RGB24: R G B R G B R G ...
Thanks for pointing out this. Just took the nb_components into account and misread the step info at first. > Following the same pattern we would have: > > AYUV: A Y U V A Y U V ... > 0YUV: 0 Y U V 0 Y U V ... > > To me it looks like 0YUV is exactly what you want here. Will update the patch if 0YUV is more acceptable. And thanks Carl. - linjie _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
