[FFmpeg-devel] [PATCH 3/5] avcodec/proresenc_kostya: do not write into alpha reserved bitfields

[Michael Niedermayer]

On Mon, Dec 11, 2023 at 08:06:53PM +0100, Clément Bœsch wrote:
> This byte represents 4 reserved bits followed by 4 alpha_channel_type bits.
> 
> alpha_channel_type currently has 3 differents defined values: 0 (no
> alpha), 1 (8b alpha), and 2 (16b alpha), all the other values are
> reserved. This part is correctly written (alpha_bits>>3 does the correct
> thing), but the 4 initial bits are reserved.
> ---
>  libavcodec/proresenc_kostya.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

This breaks fate (not just changing the value but actually breaking it)

--- ./tests/ref/vsynth/vsynth1-prores_444_int	2023-12-02 00:46:44.277042842 +0100
+++ tests/data/fate/vsynth1-prores_444_int	2023-12-13 00:11:22.144115839 +0100
@@ -1,4 +1,2 @@
-1d5e484fa8ca08781ef2ed8428963d12 *tests/data/fate/vsynth1-prores_444_int.mov
+d75a2ba07d0642340d040edab6cbb3bb *tests/data/fate/vsynth1-prores_444_int.mov
 9940947 tests/data/fate/vsynth1-prores_444_int.mov
-732ceeb6887524e0aee98762fe50578b *tests/data/fate/vsynth1-prores_444_int.out.rawvideo
-stddev:    2.83 PSNR: 39.08 MAXDIFF:   45 bytes:  7603200/  7603200

thx

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

The bravest are surely those who have the clearest vision
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