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I've compiled ffmpeg from snapshot with vaapi enabled. 

$ ffmpeg -hwaccels
Hardware acceleration methods:
vaapi

I was curious about the available filter graph operations that I could do using my GPU, and found this page of documentation

https://ffmpeg.org/ffmpeg-filters.html#toc-VAAPI-Video-Filters

This page shows a single filter, tonemap_vaapi. I thought it was odd that there would only be a single filter and that it would be tonemap instead of something like scaling..

So I ran this command

$ ffmpeg -filters | grep vaapi
 ... deinterlace_vaapi V->V       (null)
 ... denoise_vaapi     V->V       (null)
 ... procamp_vaapi     V->V       (null)
 ... scale_vaapi       V->V       (null)
 ... sharpness_vaapi   V->V       (null)

And it shows more filters that I don't find documented anywhere. Is there a reason why these aren't documented and where would I find out how use them? Furhter, I notice that tonemap_vaapi is not one of those available filters..

While we're on the subject, I was really hoping for some way to transpose a video using hardware acceleration. I do not see a transpose_vaapi filter but I did notice this thread https://patchwork.ffmpeg.org/project/ffmpeg/patch/20181225061644.6384-1-zachary.zhou@intel.com/, was this feature ever added to ffmpeg or why was it not? Is there any way to perform transposition with OpenCL? I don't see anything mentioning transposing under the OpenCL filters here https://ffmpeg.org/ffmpeg-filters.html#OpenCL-Video-Filters

Thanks

EDIT -

I found the file ffmpeg/libavfilter/allfilters.c that lists many filters that are not documented.

https://github.com/FFmpeg/FFmpeg/blob/master/libavfilter/allfilters.c

This does how a transpose_vaapi

John Allard
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1 Answers1

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All these filters were added over a long period of time with reviewers not always diligent on presence of documentation. Over the next few months, I hope to document them.

Both transpose VAAPI and OpenCL variants are available.

Gyan
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