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I had a HDR video and the format is ProRes. The colour bit depth of ProRes is 10-bit. I would like to extract the 10-bit RGB values from the HDR video.

As per this link, I have first converted the 10-bit HDR video to a number of 16-bit TIFF images. However, when I use some program like python to read back the RGB values from the TIFF image, some of the 16-bit RGB values are larger than 1024 (=2^10). It looks to me the 10-bit RGB value has been expanded to 16-bit and store the expanded value in the TIFF image but I am not sure if that is the case. How can I obtain the original 10-bit RGB values from the 16-bit RGB values stored in the TIFF image?

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The ProRes input will have YUV encoding, not RGB. If you need a raw dump, save as rawvideo.

ffmpeg -i in.mov -f rawvideo raw.yuv

Note that bit depths which aren't multiples of 8 are still stored in data layouts which are, with padding. So, if ProRes is yuv422p10le in limited / studio range, the 10-bit luma value for a white pixel will be 940 or 1110101100 but will be stored as 16 bits in the file: 1110110000000011 where the order is little-endian.

You can however save as RGB 10-bit (with padding),

ffmpeg -i in.mov -pix_fmt gbrp10be -f rawvideo raw.rgb

where the green plane is stored first, then blue, then red. The above is for big-endian so the byte order isn't reversed.

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  • Sorry for the late reply. If I use the second ffmpeg command to convert the file with the RGB 10-bit format as 'raw.rgb', how can I then convert 'raw.rgb' to TIFF image? I have tried ffmpeg -f rawvideo -pix_fmt gbrp10be -i raw.rgb -f image2 img%05d.tif but it complains [IMGUTILS @ 015ff914] Picture size 0x0 is invalid raw.rgb: Invalid argument
    – chesschi
    Commented Sep 18, 2018 at 7:45
  • Replace -f rawvideo raw.rgb with out.tiff
    – Gyan
    Commented Sep 18, 2018 at 9:02
  • It will show the following warning Incompatible pixel format 'gbrp10be' for codec 'tiff', auto-selecting format 'rgb48le' and I have used the python program to read the images but the values are not 10-bit.
    – chesschi
    Commented Sep 18, 2018 at 10:36
  • Can your app only read TIFFs?
    – Gyan
    Commented Sep 18, 2018 at 16:22
  • I am writing a python program to read the RGB values from the 10-bit HDR video. I was planning to convert the video to a number of images and read the 10-bit RGB values. Initially I thought tiff can store 16-bit values so it is suitable to store the 10-bit HDR frames. Unfortunately ffmpeg does not seem have tiff codec to support the gbrp10be format. Any alternative suggestions are welcome as long as I can read the 10-bit RGB values from the HDR video.
    – chesschi
    Commented Sep 19, 2018 at 3:56

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