README

简介

ffmpeg项目，主要适配avfilter中的scale_npp支持RGB24、BGR24格式，以减少CPU使用率。

• 20240125，下载ffmpeg官方源码:

git clone https://git.ffmpeg.org/ffmpeg.git ffmpeg/

• 当前最新log:

commit e0da916b8f5b079a4865eef7f64863f50785463d (HEAD -> master, origin/master, origin/HEAD)
Author: Anton Khirnov <anton@khirnov.net>
Date:   Wed Jan 24 20:21:37 2024 +0100

    fftools/ffmpeg: optimize inter-thread queue sizes
    
    Use 8 packets/frames by default rather than 1, which seems to provide
    better throughput.
    
    Allow -thread_queue_size to set the muxer queue size manually again.

编译方法

参考Using_FFmpeg_with_NVIDIA_GPU_Hardware_Acceleration文档中的2.2.2.1. Compiling for Linux章节。

FFmpeg with NVIDIA GPU acceleration is supported on all Linux platforms. To compile FFmpeg on Linux, do the following:

1. Clone ffnvcodec

git clone https://git.videolan.org/git/ffmpeg/nv-codec-headers.git

2. Install ffnvcodec

cd nv-codec-headers && sudo make install && cd –

3. Clone FFmpeg's public GIT repository.

git clone https://git.ffmpeg.org/ffmpeg.git ffmpeg/

4. Install necessary packages.

sudo apt-get install build-essential yasm cmake libtool libc6 libc6-dev unzip wget libnuma1 libnuma-dev

5. Configure

./configure --enable-nonfree --enable-cuda-nvcc --enable-libnpp --extra-cflags=-I/usr/ local/cuda/include --extra-ldflags=-L/usr/local/cuda/lib64 --disable-static --enableshared

6. Compile

make -j 8

7. Install the libraries.

sudo make install

测试命令

# 保存文件
ffmpeg -hwaccel cuda -hwaccel_output_format cuda -rtsp_transport tcp -i "rtsp://192.168.1.119/live/test" -vf "scale_npp=format=bgr24,hwdownload,format=bgr24" -fps_mode vfr out.rgb -y
# 不保存文件
ffmpeg -hwaccel cuda -hwaccel_output_format cuda -rtsp_transport tcp -i "rtsp://192.168.1.119/live/test" -vf "scale_npp=format=bgr24,hwdownload,format=bgr24" -fps_mode vfr -f rawvideo pipe: > /dev/null

测试结论

使用1路1080p、25fps的视频，在NVIDIA GeForce GTX 1080 Ti上测试：

# nv12直接硬转yuv420p，软转rgb24
ffmpeg -hwaccel cuda -hwaccel_output_format cuda -c:v hevc_cuvid -i "rtsp://192.168.1.119/live/test" -vf "scale_cuda=format=yuv420p,hwdownload,format=yuv420p,format=rgb24" -f rawvideo pipe: > /dev/null
212m, fps= 25, cpu 30

# nv12直接硬转yuv420p，不转rgb24
ffmpeg -hwaccel cuda -hwaccel_output_format cuda -c:v hevc_cuvid -i "rtsp://192.168.1.119/live/test" -vf "scale_cuda=format=yuv420p,hwdownload,format=yuv420p" -f rawvideo pipe: > /dev/null
212m, fps= 25, cpu 12

# 软件转码，默认yuv420p
ffmpeg -i "rtsp://192.168.1.119/live/test" -f rawvideo pipe: > /dev/null
0m, fps= 25, cpu 100

# 软件转码, 再转rgb24
ffmpeg -i "rtsp://192.168.1.119/live/test" -vf "format=rgb24" -f rawvideo pipe: > /dev/null
ffmpeg -i "rtsp://192.168.1.119/live/test" -f rawvideo -pix_fmt rgb24 pipe: > /dev/null
0m, fps= 25, cpu 112

# nv12直接硬转yuv420p，软转bgr24
ffmpeg -hwaccel cuda -hwaccel_output_format cuda -c:v hevc_cuvid -i "rtsp://192.168.1.119/live/test" -vf "scale_npp=format=yuv420p,hwdownload,format=yuv420p,format=bgr24" -f rawvideo pipe: > /dev/null
214m, fps= 25, cpu 28~31

# nv12直接硬转bgr24
ffmpeg -hwaccel cuda -hwaccel_output_format cuda -c:v hevc_cuvid -i "rtsp://192.168.1.119/live/test" -vf "scale_npp=format=bgr24,hwdownload,format=bgr24" -f rawvideo pipe: > /dev/null
222m, fps= 25, cpu 16~20

# nv12直接输出，2中方式
ffmpeg -hwaccel cuda  -c:v hevc_cuvid -i "rtsp://192.168.1.119/live/test"  -f rawvideo pipe: > /dev/null
196m, fps= 25, cpu 11~13
ffmpeg -hwaccel cuda -hwaccel_output_format cuda -c:v hevc_cuvid -i "rtsp://192.168.1.119/live/test" -vf "hwdownload,format=nv12" -f rawvideo pipe: > /dev/null
204m, fps= 25, cpu 11~13

结论：

1. 软解码缩放 -> 硬解码缩放（软转rgb24），cpu使用率从112%下降到30%；
2. nv12硬转yuv420p软转bgr24，cpu 28~31%；
3. nv12硬转bgr24, cpu 16~20%，cpu使用率从降约10%；
4. nv12直接输出，cpu 11~13%。

FFmpeg README

FFmpeg is a collection of libraries and tools to process multimedia content such as audio, video, subtitles and related metadata.

Libraries

• libavcodec provides implementation of a wider range of codecs.
• libavformat implements streaming protocols, container formats and basic I/O access.
• libavutil includes hashers, decompressors and miscellaneous utility functions.
• libavfilter provides means to alter decoded audio and video through a directed graph of connected filters.
• libavdevice provides an abstraction to access capture and playback devices.
• libswresample implements audio mixing and resampling routines.
• libswscale implements 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.
• Additional small tools such as aviocat, ismindex and qt-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.