Hi, On 8/11/16, ST <[email protected]> wrote: > I'm currently having 2 issues with the FFmpeg implementation of 3D LUTs and > am wondering if there is any way of fixing the issues. > > LUT Range > > We have some LUTs which are designed to be used over the legal video range > (64-940) and some which are designed to be used over the full video range > (4-1019). This is important for maintaining details in superwhites and to > prevent errors in hue and saturation when changing video from one colour > volume to another. > > Is there a method for flagging if an RGB LUT should be applied over the > range 64-940 or 4-1019?
Doesn't that depends on LUT itself? > > Input and output conversions > > 3D LUTs operate in the RGB domain, but many video formats use the YCbCr > domain. Therefore the video processing must look like (simplified): > > YCbCr video -> YCbCr to RGB -> LUT applied -> RGB to YCbCr -> YCbCr video > > One use for a 3D LUT is converting from ITU-R BT.709 YCbCr video to ITU-R > BT.2020/2100 YCbCr video. The matrices for converting between YCbCr and RGB > are different for BT.709 and BT.2020/2100, therefore one needs to flag > which colour conversion matrix should be used on the input and output of > the LUT. This cannot be estimated based on frame size as 1920x1080 is > allowed in both BT.709 and BT.2100. > > Is there a method for flagging which conversion matrices should be applied > before and after the 3D LUT? Yes, use zscale filter to do RGB->YUV and YUV->RGB conversion. _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
