ср, 8 нояб. 2023 г., 00:36 Dennis Mungai <dmng...@gmail.com>: > On Tue, 7 Nov 2023 at 00:55, Andrew Randrianasulu <randrianas...@gmail.com > > > wrote: > > > FFmpeg today support some opencl filters (but I was unable to use them > > freely in Cinelerra-gg probably because they require not just > > initialization of hw device but also manual up and download of data ...) > > > > but I wonder if same opencl infra can be used in decoders and encoders > too? > > > > > > > https://cml.news/g/cml-raw-log-hdr/topic/braw_codec_analysis/25749037?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,25749037 > > > > apparently those big player codecs use it, so it should be possible > > technically, just at some dev time cost ... > > > > there is also some prores gpu accelerated decoder (closed source, win) > > > > https://mogurenko.com/2020/11/15/cuda-optimized-prores-decoder/ > > > > and of course old standby mjpeg: > > > > https://github.com/nctu-pp/mjpeg-encoder > > > > (opencl part does not seems to work for me, but may be it basically > > artefact of running in 32bit x86 mode , I filled mesa bug about it > > > > > Hello Andrew, > > I hope this email finds you well. > In FFmpeg, OpenCL is primarily utilized in specific filters, a list of them > which you can verify in your build(s) with OpenCL enabled via : > > ffmpeg -filters | grep opencl > > On the encoding side, to the best of my knowledge, the libx264 encoder > wrapper implements lookahead (LA) bits that can be offloaded to an OpenCL > capable GPU. >
yeah, something to test! thanks for reminder. Some users have reported potential performance gains in production, even > upstream where there's still consensus on whether this feature should be > deprecated. > See this merge request's comments on the same: > https://code.videolan.org/videolan/x264/-/merge_requests/66 > > Separate from FFmpeg: > > 1. There are also implementations of VP9 encoders utilizing OpenCL-based > offloading, such as the VP9 encoder by Ittiam systems: > > https://www.ittiam.com/resource/ittiam-enables-opencl-based-vp9-encode-for-mobile-and-consumer-applications/ > , > whose code can be viewed here https://github.com/ittiamvpx/libvpx nice find, it even builds like this on my end LDFLAGS="-lOpenCL" setarch i686 ./configure --enable-opencl after I fixed little 32bit configure bug: - check_cpp <<EOF && bits=x32 + check_cpp <<EOF && bits=32 in build/make/configure.sh otherwise my gcc 11.2 had no idea what to do do with -mx32 flag. now I have binary for testing, but localtime is 1am :) > 2. A VP8 OpenCL-based encoder: https://github.com/Aazmp/vp8oclenc > 3. And other derivatives of (1) above: > https://github.com/awatry/libvpx.opencl > > I had also posted on this mailing list earlier regarding OpenCL somewhere > in ~2018, may require verification for correctness: > https://ffmpeg.org/pipermail/ffmpeg-user/2018-April/039610.html > > Hope that helps :-) > surely! _______________________________________________ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
