On Tue, Apr 7, 2020 at 7:58 AM Paul B Mahol <one...@gmail.com> wrote:
> On 4/7/20, Vittorio Giovara <vittorio.giov...@gmail.com> wrote: > > On Sat, Dec 22, 2018 at 3:18 PM Paul B Mahol <one...@gmail.com> wrote: > > > >> On 12/22/18, Steinar H. Gunderson <steinar+ffm...@gunderson.no> wrote: > >> > On Sat, Dec 22, 2018 at 09:04:26PM +0100, Paul B Mahol wrote: > >> >> I can not accept internal conversion to RGB. This is subsampled > format > >> >> after all. > >> > > >> > Well, it's not Y'CbCr, so if so, you'd need to add a new AVPixelFormat > >> value > >> > (e.g. AV_PIX_FMT_YCC420P). I'm not sure what applications would do > with > >> it > >> > except convert it to RGB, though. (You can't convert subsampled YCC to > >> > subsampled Y'CbCr without upsampling, converting and then subsampling > >> again, > >> > which is obviously lossy.) > >> > >> Unacceptable, I'm not adding another yuv420p variant. > >> > > > > Agreed, no need for another pixel format variant, but maybe you could > just > > leave the buffer as is and tag the color transfer with > > AVCOL_TRC_IEC61966_2_1? > > Hmm, you sure that thing is exactly same what photocd uses? > Is there a way to check it, in way that there is tool that converts > that one to 709? > Sorry I'm unfamiliar with photocd to answer that, I just saw YCC mentioned and remembered I saw it eslewhere. If you have the tools to verify correct output, you could try with with zimg/zscale, as it's one of the supported transfer. Just make sure swscale is not inserted randomly in the filter chain. -- Vittorio _______________________________________________ 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".
