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PSEUDOPAL pixel formats are not paletted, but carried a palette with the intention of allowing code to treat unpaletted formats as paletted. The palette simply mapped the byte values to the resulting RGB values, making it some sort of LUT for RGB conversion. It was used for 1 byte formats only: RGB4_BYTE, BGR4_BYTE, RGB8, BGR8, GRAY8. The first 4 are awfully obscure, used only by some ancient bitmap formats. The last one, GRAY8, is more common, but its treatment is grossly incorrect. It considers full range GRAY8 only, so GRAY8 coming from typical Y video planes was not mapped to the correct RGB values. This cannot be fixed, because AVFrame.color_range can be freely changed at runtime, and there is nothing to ensure the pseudo palette is updated. Also, nothing actually used the PSEUDOPAL palette data, except xwdenc (trivially changed in the previous commit). All other code had to treat it as a special case, just to ignore or to propagate palette data. In conclusion, this was just a very strange old mechnaism that has no real justification to exist anymore (although it may have been nice and useful in the past). Now it's an artifact that makes the API harder to use: API users who allocate their own pixel data have to be aware that they need to allocate the palette, or FFmpeg will crash on them in _some_ situations. On top of this, there was no API to allocate the pseuo palette outside of av_frame_get_buffer(). This patch not only deprecates AV_PIX_FMT_FLAG_PSEUDOPAL, but also makes the pseudo palette optional. Nothing accesses it anymore, though if it's set, it's propagated. It's still allocated and initialized for compatibility with API users that rely on this feature. But new API users do not need to allocate it. This was an explicit goal of this patch. Most changes replace AV_PIX_FMT_FLAG_PSEUDOPAL with FF_PSEUDOPAL. I first tried #ifdefing all code, but it was a mess. The FF_PSEUDOPAL macro reduces the mess, and still allows defining FF_API_PSEUDOPAL to 0. Passes FATE with FF_API_PSEUDOPAL enabled and disabled. In addition, FATE passes with FF_API_PSEUDOPAL set to 1, but with allocation functions manually changed to not allocating a palette. |
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| .. | ||
| cmdutils.c | ||
| cmdutils.h | ||
| ffmpeg_cuvid.c | ||
| ffmpeg_filter.c | ||
| ffmpeg_hw.c | ||
| ffmpeg_opt.c | ||
| ffmpeg_qsv.c | ||
| ffmpeg_videotoolbox.c | ||
| ffmpeg.c | ||
| ffmpeg.h | ||
| ffplay.c | ||
| ffprobe.c | ||
| Makefile | ||