[FFmpeg-devel] Pixel format 12bit grayscale

[Michael Niedermayer]

On Mon, Apr 13, 2015 at 09:59:57AM +0000, Marco Porsch wrote:
> Hi,
> 
> our automotive cameras generate a weird kind of 12bit RAW format that I would like to encode using FFVHUFF. Unfortunately, the 12bit grayscale pixel format is not yet supported.
> Can you point me on the right track to implement this pixel format? And will the encoder be able to handle the 12bit depth?
> 
> I'll draw a little ASCII art concerning the bit mapping below. Basically a group of 4x8bit MSBs are given as block followed by a 4x4bit LSBs block. The pattern continues correspondingly.
> 
> |---------------------|---------------------|---------------------|---------------------|
> |      P0[11..4]      |      P1[11..4]      |      P2[11..4]      |      P3[11..4]      |
> |---------------------|---------------------|---------------------|---------------------|
> | P0[0..3] | P1[0..3] | P2[0..3] | P3[0..3] |      P4[11..4]      |      P5[11..4]      |
> |---------------------|---------------------|---------------------|---------------------|
> |      P6[11..4]      |      P7[11..4]      | P4[0..3] | P5[0..3] | P6[0..3] | P7[0..3] |
> |---------------------|---------------------|---------------------|---------------------|
> |      P8[11..4]      |      P9[11..4]      |     P10[11..4]      |     P11[11..4]      |
> |---------------------|---------------------|---------------------|---------------------|
> | P8[0..3] | P9[0..3] |P10[0..3] |P11[0..3] |
> |---------------------|---------------------|
> 
> Previously we had regular 16bit RAW that worked like a charm as input to FFmpeg. The naïve approach of upscaling the 12bit to 16bit destroys the compression efficiency of course...

add a AV_PIX_FMT_GRAY12BE / AV_PIX_FMT_GRAY12LE similar to the existing
planar 12 bit YUV formats, and add a decoder which decodes this
odd packing above into it, then add 12bit gray support to FFVHUFF
theres alreeadyy support for other 12bit planar formats in it

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Why not whip the teacher when the pupil misbehaves? -- Diogenes of Sinope
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