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User selectable surfaces are not working correctly, if you set number of surfaces on cmdline, it will always use minimum 32 or 48 depends on selected resolution, but in nvenc it is not necessary to use so many surfaces. So from now you can define as low as 1 surface and nvenc will still work, it will ofcourse lower GPU memory usage by 95% and async_delay to zero That was the easy part, now littlebit more... Next part of this patch is to always prefer rc_lookahead to be more important for number of surfaces, than user defined surfaces value. Maximum rc_lookahead from nvidia documentation is 32, but could increase in future generations so there is no limit for this yet. Value async_depth is still accepted and prefered over rc_lookahead. There were also bug when you request more than rc_lookahead > 31, it will always set maximum 31, because surface numbers recalculation was after setting lookahead, which is now fixed. Results: If you set -rc_lookahead 32 and -bf 3 it will now use only 40 surfaces and lower GPU memory usage by 20%, also it will now increase PSNR by 0.012dB Two more comments: 1. from my internal test, i don't understand addition of 4 more surfaces when lookahead is calculated, i didn't used this and everything works as with those 4 more extra surfaces, does anybody know what is going on there? I looks like it was used for B frames which are calculated separately, because B frames maximum is 4. 2. rc_lookahead is defined default to -1, but in test condition if (ctx->rc_lookahead) which sets lookahead it will be always true, i don't know if this is intended behavior, so in default behavior is lookahead always on! This is default condition when rc_lokkahead is -1 (not defined on cmdline), whis is maybe something that is not intended: ctx->encode_config.rcParams.enableLookahead = 1; ctx->encode_config.rcParams.lookaheadDepth = 0; ctx->encode_config.rcParams.disableIadapt = 0; ctx->encode_config.rcParams.disableBadapt = 0; Signed-off-by: Timo Rothenpieler <timo@rothenpieler.org>
FFmpeg README
FFmpeg is a collection of libraries and tools to process multimedia content such as audio, video, subtitles and related metadata.
Libraries
libavcodecprovides implementation of a wider range of codecs.libavformatimplements streaming protocols, container formats and basic I/O access.libavutilincludes hashers, decompressors and miscellaneous utility functions.libavfilterprovides a mean to alter decoded Audio and Video through chain of filters.libavdeviceprovides an abstraction to access capture and playback devices.libswresampleimplements audio mixing and resampling routines.libswscaleimplements color conversion and scaling routines.
Tools
- ffmpeg is a command line toolbox to manipulate, convert and stream multimedia content.
- ffplay is a minimalistic multimedia player.
- ffprobe is a simple analysis tool to inspect multimedia content.
- ffserver is a multimedia streaming server for live broadcasts.
- Additional small tools such as
aviocat,ismindexandqt-faststart.
Documentation
The offline documentation is available in the doc/ directory.
The online documentation is available in the main website and in the wiki.
Examples
Coding examples are available in the doc/examples directory.
License
FFmpeg codebase is mainly LGPL-licensed with optional components licensed under GPL. Please refer to the LICENSE file for detailed information.
Contributing
Patches should be submitted to the ffmpeg-devel mailing list using
git format-patch or git send-email. Github pull requests should be
avoided because they are not part of our review process and will be ignored.