在WSL上使用FFmpeg
此文章使用的是Linux下的FFmpeg,发行版为Ubuntu 20.04 LTS
"A complete, cross-platform solution to record, convert and stream audio and video."
"Converting video and audio has never been so easy."
使用的是Ubuntu,所以可以直接使用apt install ffmpeg -y
$ man ffmpeg
$ ffmpeg [global_options] {[input_file_options] -i input_url} ... {[output_file_options] output_url} ...
使用-i来输入文件,例如
ffmpeg -i input.avi
,这样可以获取文件的细节,例如
$ ffmpeg -i Example.mp4
ffmpeg version 4.2.4-1ubuntu0.1 Copyright (c) 2000-2020 the FFmpeg developers
built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)
configuration: --prefix=/usr --extra-version=1ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
libavutil 56. 31.100 / 56. 31.100
libavcodec 58. 54.100 / 58. 54.100
libavformat 58. 29.100 / 58. 29.100
libavdevice 58. 8.100 / 58. 8.100
libavfilter 7. 57.100 / 7. 57.100
libavresample 4. 0. 0 / 4. 0. 0
libswscale 5. 5.100 / 5. 5.100
libswresample 3. 5.100 / 3. 5.100
libpostproc 55. 5.100 / 55. 5.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Example.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf57.71.100
description : Bilibili VXCode Swarm Transcoder v0.2.42(gap_fixed:False)
Duration: 00:00:45.25, start: 0.000000, bitrate: 434 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 448x336 [SAR 1:1 DAR 4:3], 364 kb/s, 12 fps, 12 tbr, 16k tbn, 24 tbc (default)
Metadata:
handler_name : VideoHandler
Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 65 kb/s (default)
Metadata:
handler_name : SoundHandler
At least one output file must be specified
如果你不想看 FFmpeg 标语和其它细节,而仅仅想看媒体文件信息,使用 -hide_banner
$ ffmpeg -i Example.mp4 -hide_banner
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Example.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf57.71.100
description : Bilibili VXCode Swarm Transcoder v0.2.42(gap_fixed:False)
Duration: 00:00:45.25, start: 0.000000, bitrate: 434 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 448x336 [SAR 1:1 DAR 4:3], 364 kb/s, 12 fps, 12 tbr, 16k tbn, 24 tbc (default)
Metadata:
handler_name : VideoHandler
Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 65 kb/s (default)
Metadata:
handler_name : SoundHandler
At least one output file must be specified
下图描述了每个输出的转码过程:
_______ ______________
| | | |
| 输入| 解复用器| 编码数据| 解码器
| 文件 ---------> | 包| ----- +
| _______ | | ______________ | |
v
_________
| |
| 解码|
| 框架|
| _________ |
________ ______________ |
| | | | |
| 输出| <-------- | 编码数据| <---- +
| 文件 多路复用器| 包| 编码器
| ________ | | ______________ |
$ ffmpeg -formats
$ ffmpeg -i Example.mp4 Example.avi
$ ls
Example.avi
Example.mp4
$ ffmpeg -i Example.mp4 Example.mp3
$ ls
Example.mp3
Example.mp4
$ ffmpeg -i Example.mp4 -vn Example.mp3
$ ffmpeg -i Example.mp4 -an output.mp4
$ ffmpeg -i Example.mp4 -s 1280x720 -c:a copy output.mp4
$ ffmpeg -i Example.mp4 -vf scale=1280:-1 -c:v libx264 -preset veryslow -crf 24 output.mp4
$ ffmpeg -i Example.mp3 -ab 128 output.mp3
其中,-ab后面的是比特率
#!/bin/bash
ffmpeg -i 【屑制作】阿狗的故事.mp4 -vn agou.mp3
ffmpeg -i agou.mp3 -ss 00:00:09 -codec copy -t 21 AAAAAAAAAAgou.mp3