2016-10-03 13:28 GMT+03:00 Hendrik Leppkes <h.lepp...@gmail.com>: > On Mon, Oct 3, 2016 at 11:35 AM, Ali KIZIL <aliki...@gmail.com> wrote: > > Hello, > > > > This patch is done for performance increase on UHD or above resolution > > color space convertions. > > Some SDI sources provide yuv422p10 for 10bit source and uyvy422 for 8 bit > > source. > > To encode these sources with NVENC 10 bits, there is a need to convert > > these color spaces to P010. > > > > Before patch for UHD and above resolutions, convertion could not exceed > > ~25-30 fps, which can not be used for a 50 fps encoding. > > This patch fixes this problem. > > > > Also, color space convertion speed for 10bit YUV422P to 8bit YUV420P is > > having the same problem. > > If anybody wants to encode 10 bits source in 8 bits for UHD or above > > resolutions could not achive high frame rate ratio as well. > > This patch also fixes this problem. > > > > I think it will be good to apply this patch to avoid performance loss in > > high resolutions. > > > > These conversion functions butcher quality by using only every second > row of chroma for 422 -> 420 conversions without any interpolation, > and they don't dither for 10->8 bit conversions. > Not sure its a good idea to do that, even more so without an option to > defeat these low-quality variants with the swscale flags. > > - Hendrik > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel >
Hello Hendrik, Yes, only every second row of chroma for 422 -> 420 conversions without any interpolation is used. Where I can find an interpolation example ? Also, the code is done for performance criteria for UHD and above resolution in real time encoding. In myside test, I didnt notice a gap. For sure, I am not a video quality expert. Can you tell me how to compare quality ? Can you explain more for "they don't dither for 10->8 bit conversions." I couldnt understand this. Kind Regards, _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
