ffmpeg基本信息查询命令
Last login: Mon Jun 24 11:35:04 on ttys002
gensees-iMac:~ gensee$ ffmpeg -version
ffmpeg version N-94063-g86f04b918c Copyright (c) 2000-2019 the FFmpeg developers
built with Apple LLVM version 8.1.0 (clang-802.0.38)
configuration: --prefix=/usr/local/ffmpeg --enable-gpl --enable-nonfree --enable-libfdk-aac --enable-libx264 --enable-libx265 --enable-filter=delogo --enable-debug --disable-optimizations --enable-libspeex --enable-videotoolbox --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags=
libavutil 56. 29.100 / 56. 29.100
libavcodec 58. 53.100 / 58. 53.100
libavformat 58. 27.103 / 58. 27.103
libavdevice 58. 7.100 / 58. 7.100
libavfilter 7. 55.100 / 7. 55.100
libswscale 5. 4.101 / 5. 4.101
libswresample 3. 4.100 / 3. 4.100
libpostproc 55. 4.100 / 55. 4.100
gensees-iMac:~ gensee$ ffmpeg -devices
ffmpeg version N-94063-g86f04b918c Copyright (c) 2000-2019 the FFmpeg developers
built with Apple LLVM version 8.1.0 (clang-802.0.38)
configuration: --prefix=/usr/local/ffmpeg --enable-gpl --enable-nonfree --enable-libfdk-aac --enable-libx264 --enable-libx265 --enable-filter=delogo --enable-debug --disable-optimizations --enable-libspeex --enable-videotoolbox --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags=
libavutil 56. 29.100 / 56. 29.100
libavcodec 58. 53.100 / 58. 53.100
libavformat 58. 27.103 / 58. 27.103
libavdevice 58. 7.100 / 58. 7.100
libavfilter 7. 55.100 / 7. 55.100
libswscale 5. 4.101 / 5. 4.101
libswresample 3. 4.100 / 3. 4.100
libpostproc 55. 4.100 / 55. 4.100
Devices:
D. = Demuxing supported
.E = Muxing supported
--
D avfoundation AVFoundation input device
D lavfi Libavfilter virtual input device
E sdl,sdl2 SDL2 output device
录屏命令
ffmpeg -f avfoundation -i 1 -r 30 out.yuv
-f 指定使用 avfoundation 采集数据。
-i 指定从哪儿采集数据，它是一个文件索引号。在我的MAC上，1代表桌面（可以通过上面的命令查询设备索引号）。
-r 指定帧率。按ffmpeg官方文档说-r与-framerate作用相同，但实际测试时发现不同。-framerate 用于限制输入，而-r用于限制输出。
//开始录屏命令
gensees-iMac:~ gensee$ ffmpeg -f avfoundation -i 1 -r 30 out.yuv
ffmpeg version N-94063-g86f04b918c Copyright (c) 2000-2019 the FFmpeg developers
built with Apple LLVM version 8.1.0 (clang-802.0.38)
configuration: --prefix=/usr/local/ffmpeg --enable-gpl --enable-nonfree --enable-libfdk-aac --enable-libx264 --enable-libx265 --enable-filter=delogo --enable-debug --disable-optimizations --enable-libspeex --enable-videotoolbox --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags=
libavutil 56. 29.100 / 56. 29.100
libavcodec 58. 53.100 / 58. 53.100
libavformat 58. 27.103 / 58. 27.103
libavdevice 58. 7.100 / 58. 7.100
libavfilter 7. 55.100 / 7. 55.100
libswscale 5. 4.101 / 5. 4.101
libswresample 3. 4.100 / 3. 4.100
libpostproc 55. 4.100 / 55. 4.100
[avfoundation @ 0x7ffb51004000] Selected pixel format (yuv420p) is not supported by the input device.
[avfoundation @ 0x7ffb51004000] Supported pixel formats:
[avfoundation @ 0x7ffb51004000] uyvy422
[avfoundation @ 0x7ffb51004000] yuyv422
[avfoundation @ 0x7ffb51004000] nv12
[avfoundation @ 0x7ffb51004000] 0rgb
[avfoundation @ 0x7ffb51004000] bgr0
[avfoundation @ 0x7ffb51004000] Overriding selected pixel format to use uyvy422 instead.
[avfoundation @ 0x7ffb51004000] Stream #0: not enough frames to estimate rate; consider increasing probesize
Input #0, avfoundation, from '1':
Duration: N/A, start: 319880.981333, bitrate: N/A
Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422, 1920x1080, 1000k tbr, 1000k tbn, 1000k tbc
Stream mapping:
Stream #0:0 -> #0:0 (rawvideo (native) -> rawvideo (native))
Press [q] to stop, [?] for help
Output #0, rawvideo, to 'out.yuv':
Metadata:
encoder : Lavf58.27.103
Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422, 1920x1080, q=2-31, 995328 kb/s, 30 fps, 30 tbn, 30 tbc
Metadata:
encoder : Lavc58.53.100 rawvideo
frame= 19 fps=0.0 q=-0.0 size= 76800kB time=00:00:00.63 bitrate=993388.3kbitframe= 34 fps= 33 q=-0.0 size= 137472kB time=00:00:01.13 bitrate=993680.3kbitframe= 49 fps= 32 q=-0.0 size= 198400kB time=00:00:01.63 bitrate=995077.4kbitframe= 64 fps= 31 q=-0.0 size= 259072kB time=00:00:02.13 bitrate=994836.6kbitframe= 80 fps= 31 q=-0.0 size= 323840kB time=00:00:02.66 bitrate=994836.4kbitframe= 96 fps= 31 q=-0.0 size= 388608kB time=00:00:03.20 bitrate=994836.5kbitframe= 112 fps= 31 q=-0.0 size= 453376kB time=00:00:03.73 bitrate=994836.6kbitframe= 126 fps= 30 q=-0.0 size= 510208kB time=00:00:04.20 bitrate=995148.6kbitframe= 127 fps= 30 q=-0.0 Lsize= 514350kB time=00:00:04.23 bitrate=995328.1kbits/s speed=1.01x
video:514350kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000000%
Exiting normally, received signal 2.
//这里control+c暂停
//然后播放yuv数据，需要指定分辨率，分辨率可以从上面录屏时的打印日志取到
gensees-iMac:~ gensee$ ffplay -s 1920x1080 /Users/gensee/out.yuv
ffplay version N-94063-g86f04b918c Copyright (c) 2003-2019 the FFmpeg developers
built with Apple LLVM version 8.1.0 (clang-802.0.38)
configuration: --prefix=/usr/local/ffmpeg --enable-gpl --enable-nonfree --enable-libfdk-aac --enable-libx264 --enable-libx265 --enable-filter=delogo --enable-debug --disable-optimizations --enable-libspeex --enable-videotoolbox --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags=
libavutil 56. 29.100 / 56. 29.100
libavcodec 58. 53.100 / 58. 53.100
libavformat 58. 27.103 / 58. 27.103
libavdevice 58. 7.100 / 58. 7.100
libavfilter 7. 55.100 / 7. 55.100
libswscale 5. 4.101 / 5. 4.101
libswresample 3. 4.100 / 3. 4.100
libpostproc 55. 4.100 / 55. 4.100
Option -s is deprecated, use -video_size.
[rawvideo @ 0x7fd7ee83be00] Estimating duration from bitrate, this may be inaccurate
Input #0, rawvideo, from '/Users/gensee/out.yuv':
Duration: 00:00:06.76, start: 0.000000, bitrate: 623306 kb/s
Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 1920x1080, 622080 kb/s, 25 tbr, 25 tbn, 25 tbc
2.63 M-V: -0.039 fd= 2 aq= 0KB vq=18225KB sq= 0B f=0/0
//这里发现yuv数据播放是花屏乱码，发现录制时采用的是uyvy422的yuv数据类型，而我们默认以yuv420p播放，这里使用-pix_fmt xxxx 指定像素格式，因为pixel是像素，format格式
gensees-iMac:~ gensee$ ffplay -s 1920x1080 -pix_fmt uyvy422 /Users/gensee/out.yuv
ffplay version N-94063-g86f04b918c Copyright (c) 2003-2019 the FFmpeg developers
built with Apple LLVM version 8.1.0 (clang-802.0.38)
configuration: --prefix=/usr/local/ffmpeg --enable-gpl --enable-nonfree --enable-libfdk-aac --enable-libx264 --enable-libx265 --enable-filter=delogo --enable-debug --disable-optimizations --enable-libspeex --enable-videotoolbox --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags=
libavutil 56. 29.100 / 56. 29.100
libavcodec 58. 53.100 / 58. 53.100
libavformat 58. 27.103 / 58. 27.103
libavdevice 58. 7.100 / 58. 7.100
libavfilter 7. 55.100 / 7. 55.100
libswscale 5. 4.101 / 5. 4.101
libswresample 3. 4.100 / 3. 4.100
libpostproc 55. 4.100 / 55. 4.100
Option -s is deprecated, use -video_size.
Option -pix_fmt is deprecated, use -pixel_format.
[rawvideo @ 0x7f95290afa00] Estimating duration from bitrate, this may be inaccurate
Input #0, rawvideo, from '/Users/gensee/out.yuv':
Duration: 00:00:05.08, start: 0.000000, bitrate: 829440 kb/s
Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422, 1920x1080, 829440 kb/s, 25 tbr, 25 tbn, 25 tbc
3.37 M-V: -0.040 fd= 2 aq= 0KB vq=16200KB sq= 0B f=0/0
gensees-iMac:~ gensee$
//到这里播放成功
如何查询设备索引号
ffmpeg -f avfoundation -list_devices true -i ""
gensees-iMac:~ gensee$ ffmpeg -f avfoundation -list_devices true -i ""
ffmpeg version N-94063-g86f04b918c Copyright (c) 2000-2019 the FFmpeg developers
built with Apple LLVM version 8.1.0 (clang-802.0.38)
configuration: --prefix=/usr/local/ffmpeg --enable-gpl --enable-nonfree --enable-libfdk-aac --enable-libx264 --enable-libx265 --enable-filter=delogo --enable-debug --disable-optimizations --enable-libspeex --enable-videotoolbox --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags=
libavutil 56. 29.100 / 56. 29.100
libavcodec 58. 53.100 / 58. 53.100
libavformat 58. 27.103 / 58. 27.103
libavdevice 58. 7.100 / 58. 7.100
libavfilter 7. 55.100 / 7. 55.100
libswscale 5. 4.101 / 5. 4.101
libswresample 3. 4.100 / 3. 4.100
libpostproc 55. 4.100 / 55. 4.100
//视频设备
[AVFoundation input device @ 0x7fc917e03dc0] AVFoundation video devices:
//摄像头
[AVFoundation input device @ 0x7fc917e03dc0] [0] FaceTime HD Camera (Built-in)
//屏幕
[AVFoundation input device @ 0x7fc917e03dc0] [1] Capture screen 0
//音频设备
[AVFoundation input device @ 0x7fc917e03dc0] AVFoundation audio devices:
[AVFoundation input device @ 0x7fc917e03dc0] [0] Built-in Microphone
: Input/output error
gensees-iMac:~ gensee$
录制声音
ffmpeg -f avfoundation -i :0 out.wav
:0 表示音频设备
gensees-iMac:desktop gensee$ ffmpeg -f avfoundation -i :0 out.wav
ffmpeg version N-94063-g86f04b918c Copyright (c) 2000-2019 the FFmpeg developers
built with Apple LLVM version 8.1.0 (clang-802.0.38)
configuration: --prefix=/usr/local/ffmpeg --enable-gpl --enable-nonfree --enable-libfdk-aac --enable-libx264 --enable-libx265 --enable-filter=delogo --enable-debug --disable-optimizations --enable-libspeex --enable-videotoolbox --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags=
libavutil 56. 29.100 / 56. 29.100
libavcodec 58. 53.100 / 58. 53.100
libavformat 58. 27.103 / 58. 27.103
libavdevice 58. 7.100 / 58. 7.100
libavfilter 7. 55.100 / 7. 55.100
libswscale 5. 4.101 / 5. 4.101
libswresample 3. 4.100 / 3. 4.100
libpostproc 55. 4.100 / 55. 4.100
Input #0, avfoundation, from ':0':
Duration: N/A, start: 320614.552608, bitrate: 2822 kb/s
Stream #0:0: Audio: pcm_f32le, 44100 Hz, stereo, flt, 2822 kb/s
Stream mapping:
Stream #0:0 -> #0:0 (pcm_f32le (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
Output #0, wav, to 'out.wav':
Metadata:
ISFT : Lavf58.27.103
Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, stereo, s16, 1411 kb/s
Metadata:
encoder : Lavc58.53.100 pcm_s16le
size= 1946kB time=00:00:11.30 bitrate=1409.8kbits/s speed= 1x
video:0kB audio:1946kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.003914%
Exiting normally, received signal 2.
录制视频和声音
ffmpeg -f avfoundation -i 1:0 -r 30 -c:v libx264 -c:a libfdk_aac -profile:a aac_he_v2 -b:a 32k out.flv
-i 1:0 冒号前面的 “1” 代表的屏幕索引号。冒号后面的"0"代表的声音索相号。
-c:v 与参数 -vcodec 一样，表示视频编码器。c 是 codec 的缩写，v 是video的缩写。
-crf 是 x264 的参数。 0 表式无损压缩。
-c:a 与参数 -acodec 一样，表示音频编码器。
-profile 是 fdk_aac 的参数。 aac_he_v2 表式使用 AAC_HE v2 压缩数据。
-b:a 指定音频码率。 b 是 bitrate的缩写, a是 audio的缩写。
多媒体格式转换
ffmpeg -i out.flv -vcodec copy -acodec copy out.mp4
-i 输入文件
-vcodec 表示视频编码 copy表示复制，即参数不做调整
-acodec 表示音频频编码 copy表示复制，即参数不做调整
gensees-iMac:study gensee$ ffmpeg -i out.flv -vcodec copy -acodec copy out.mp4
ffmpeg version N-94063-g86f04b918c Copyright (c) 2000-2019 the FFmpeg developers
built with Apple LLVM version 8.1.0 (clang-802.0.38)
configuration: --prefix=/usr/local/ffmpeg --enable-gpl --enable-nonfree --enable-libfdk-aac --enable-libx264 --enable-libx265 --enable-filter=delogo --enable-debug --disable-optimizations --enable-libspeex --enable-videotoolbox --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags=
libavutil 56. 29.100 / 56. 29.100
libavcodec 58. 53.100 / 58. 53.100
libavformat 58. 27.103 / 58. 27.103
libavdevice 58. 7.100 / 58. 7.100
libavfilter 7. 55.100 / 7. 55.100
libswscale 5. 4.101 / 5. 4.101
libswresample 3. 4.100 / 3. 4.100
libpostproc 55. 4.100 / 55. 4.100
Input #0, flv, from 'out.flv':
Metadata:
major_brand : qt
minor_version : 512
compatible_brands: qt
artist : yinyuetai.com
album : Yinyuetai
date : 11/11/16 22:40:13
comment : Yinyuetai-1TR1042
encoder : Lavf58.27.103
Duration: 00:05:18.04, start: 0.067000, bitrate: 1103 kb/s
Stream #0:0: Video: h264 (Main), yuv420p(progressive), 960x540, 999 kb/s, 30 fps, 30 tbr, 1k tbn, 60 tbc
Stream #0:1: Audio: aac (LC), 48000 Hz, stereo, fltp, 93 kb/s
Output #0, mp4, to 'out.mp4':
Metadata:
major_brand : qt
minor_version : 512
compatible_brands: qt
artist : yinyuetai.com
album : Yinyuetai
date : 11/11/16 22:40:13
comment : Yinyuetai-1TR1042
encoder : Lavf58.27.103
Stream #0:0: Video: h264 (Main) (avc1 / 0x31637661), yuv420p(progressive), 960x540, q=2-31, 999 kb/s, 30 fps, 30 tbr, 16k tbn, 1k tbc
Stream #0:1: Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 93 kb/s
Stream mapping:
Stream #0:0 -> #0:0 (copy)
Stream #0:1 -> #0:1 (copy)
Press [q] to stop, [?] for help
frame= 9534 fps=0.0 q=-1.0 Lsize= 42800kB time=00:05:17.95 bitrate=1102.7kbits/s speed= 944x
video:38771kB audio:3635kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.927725%
gensees-iMac:study gensee$
从日志看出，音视频参数没有变
分离视频
ffmpeg -i out.flv -an -vcodec copy out.h264
-an 意思为audio no 不输出音频
gensees-iMac:study gensee$ ffmpeg -i out.flv -an -vcodec copy out.h264
ffmpeg version N-94063-g86f04b918c Copyright (c) 2000-2019 the FFmpeg developers
built with Apple LLVM version 8.1.0 (clang-802.0.38)
configuration: --prefix=/usr/local/ffmpeg --enable-gpl --enable-nonfree --enable-libfdk-aac --enable-libx264 --enable-libx265 --enable-filter=delogo --enable-debug --disable-optimizations --enable-libspeex --enable-videotoolbox --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags=
libavutil 56. 29.100 / 56. 29.100
libavcodec 58. 53.100 / 58. 53.100
libavformat 58. 27.103 / 58. 27.103
libavdevice 58. 7.100 / 58. 7.100
libavfilter 7. 55.100 / 7. 55.100
libswscale 5. 4.101 / 5. 4.101
libswresample 3. 4.100 / 3. 4.100
libpostproc 55. 4.100 / 55. 4.100
Input #0, flv, from 'out.flv':
Metadata:
major_brand : qt
minor_version : 512
compatible_brands: qt
artist : yinyuetai.com
album : Yinyuetai
date : 11/11/16 22:40:13
comment : Yinyuetai-1TR1042
encoder : Lavf58.27.103
Duration: 00:05:18.04, start: 0.067000, bitrate: 1103 kb/s
Stream #0:0: Video: h264 (Main), yuv420p(progressive), 960x540, 999 kb/s, 30 fps, 30 tbr, 1k tbn, 60 tbc
Stream #0:1: Audio: aac (LC), 48000 Hz, stereo, fltp, 93 kb/s
Output #0, h264, to 'out.h264':
Metadata:
major_brand : qt
minor_version : 512
compatible_brands: qt
artist : yinyuetai.com
album : Yinyuetai
date : 11/11/16 22:40:13
comment : Yinyuetai-1TR1042
encoder : Lavf58.27.103
Stream #0:0: Video: h264 (Main), yuv420p(progressive), 960x540, q=2-31, 999 kb/s, 30 fps, 30 tbr, 30 tbn, 30 tbc
Stream mapping:
Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
frame= 9534 fps=0.0 q=-1.0 Lsize= 38771kB time=00:05:17.73 bitrate= 999.6kbits/s speed= 768x
video:38771kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000156%
分离音频
ffmpeg -i out.flv -vn -acodec copy out.mp3
-vn 意思为video no 不输出视频