ffmpeg使用命令行视频采集录制
电脑为mac系统
image-20210517174110404
ffmpeg -devices -hide_banner
Devices:
D. = Demuxing supported
.E = Muxing supported
--
D avfoundation AVFoundation input device
D lavfi Libavfilter virtual input device
E sdl,sdl2 SDL2 output device
D x11grab X11 screen capture, using XCB
- D. = Demuxing supported（支持视频/音频封装）
- E = Muxing supported（支持解封装视频/音频）
avfoundation支持的设备
ffmpeg -f avfoundation -list_devices true -i ''
[AVFoundation indev @ 0x7f97d2708b80] AVFoundation video devices:
[AVFoundation indev @ 0x7f97d2708b80] [0] FaceTime高清摄像头（内建）
[AVFoundation indev @ 0x7f97d2708b80] [1] Capture screen 0
[AVFoundation indev @ 0x7f97d2708b80] [2] Capture screen 1
[AVFoundation indev @ 0x7f97d2708b80] [3] Capture screen 2
[AVFoundation indev @ 0x7f97d2708b80] AVFoundation audio devices:
[AVFoundation indev @ 0x7f97d2708b80] [0] Built-in Microphone
image-20210517174828309
0号设备就是Mac自带的摄像头。
avfoundation支持的参数
ffmpeg -h demuxer=avfoundation -hide_banner
输出结果
Demuxer avfoundation [AVFoundation input device]:
AVFoundation indev AVOptions:
-list_devices .D........ list available devices (default false)
-video_device_index .D........ select video device by index for devices with same name (starts at 0) (from -1 to INT_MAX) (default -1)
-audio_device_index .D........ select audio device by index for devices with same name (starts at 0) (from -1 to INT_MAX) (default -1)
-pixel_format .D........ set pixel format (default yuv420p)
-framerate .D........ set frame rate (default "ntsc")
-video_size .D........ set video size
-capture_cursor .D........ capture the screen cursor (default false)
-capture_mouse_clicks .D........ capture the screen mouse clicks (default false)
-capture_raw_data .D........ capture the raw data from device connection (default false)
-drop_late_frames .D........ drop frames that are available later than expected (default true)
-video_size：分辨率-pixel_format：像素格式
- 默认是yuv420p
-framerate：帧率（每秒采集多少帧画面）
- 默认是ntsc，也就是30000/1001，约等于29.970030
-list_devices：true表示列出avfoundation支持的所有设备
ffmpeg -f avfoundation -video_device_index 0 -i "" -hide_banner
[avfoundation @ 0x7f8c3780bc00] Selected pixel format (yuv420p) is not supported by the input device.
[avfoundation @ 0x7f8c3780bc00] Supported pixel formats:
[avfoundation @ 0x7f8c3780bc00] uyvy422
[avfoundation @ 0x7f8c3780bc00] yuyv422
[avfoundation @ 0x7f8c3780bc00] nv12
[avfoundation @ 0x7f8c3780bc00] 0rgb
[avfoundation @ 0x7f8c3780bc00] bgr0
[avfoundation @ 0x7f8c3780bc00] Overriding selected pixel format to use uyvy422 instead.
Input #0, avfoundation, from '':
Duration: N/A, start: 32990.458967, bitrate: N/A
Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422, 1280x720, 30 tbr, 1000k tbn, 1000k tbc
At least one output file must be specified
录制
ffmpeg -f avfoundation -i 0 out.yuv -hide_banner
输出
[avfoundation @ 0x7f830a012e00] Selected pixel format (yuv420p) is not supported by the input device.
[avfoundation @ 0x7f830a012e00] Supported pixel formats:
[avfoundation @ 0x7f830a012e00] uyvy422
[avfoundation @ 0x7f830a012e00] yuyv422
[avfoundation @ 0x7f830a012e00] nv12
[avfoundation @ 0x7f830a012e00] 0rgb
[avfoundation @ 0x7f830a012e00] bgr0
[avfoundation @ 0x7f830a012e00] Overriding selected pixel format to use uyvy422 instead.
Input #0, avfoundation, from '0':
Duration: N/A, start: 31535.985400, bitrate: N/A
Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422, 1280x720, 15 tbr, 1000k tbn, 1000k tbc
Stream mapping:
Stream #0:0 -> #0:0 (rawvideo (native) -> rawvideo (native))
Press [q] to stop, [?] for help
修改参数 -pixel_format：像素格式
ffmpeg -f avfoundation -pixel_format uyvy422 -i 0 out.yuv -hide_banner
Input #0, avfoundation, from '0':
Duration: N/A, start: 33830.098033, bitrate: N/A
Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422, 1280x720, 25 tbr, 1000k tbn, 1000k tbc
File 'out.yuv' already exists. Overwrite? [y/N] y
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 : Lavf58.45.100
Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422, 1280x720, q=2-31, 368640 kb/s, 25 fps, 25 tbn, 25 tbc
Metadata:
encoder : Lavc58.91.100 rawvideo
添加-framerate试试
ffmpeg -f avfoundation -video_size 640x480 -framerate 30 -pixel_format yuyv422 -i 0 out.yuv -hide_banner
[avfoundation @ 0x7fb6a9817600] Selected framerate (30.000000) is not supported by the device.
[avfoundation @ 0x7fb6a9817600] Supported modes:
[avfoundation @ 0x7fb6a9817600] 160x120@[29.970000 29.970000]fps
[avfoundation @ 0x7fb6a9817600] 160x120@[25.000000 25.000000]fps
[avfoundation @ 0x7fb6a9817600] 160x120@[23.999981 23.999981]fps
[avfoundation @ 0x7fb6a9817600] 160x120@[14.999993 14.999993]fps
[avfoundation @ 0x7fb6a9817600] 176x144@[29.970000 29.970000]fps
[avfoundation @ 0x7fb6a9817600] 176x144@[25.000000 25.000000]fps
[avfoundation @ 0x7fb6a9817600] 176x144@[23.999981 23.999981]fps
[avfoundation @ 0x7fb6a9817600] 176x144@[14.999993 14.999993]fps
[avfoundation @ 0x7fb6a9817600] 320x240@[29.970000 29.970000]fps
[avfoundation @ 0x7fb6a9817600] 320x240@[25.000000 25.000000]fps
[avfoundation @ 0x7fb6a9817600] 320x240@[23.999981 23.999981]fps
[avfoundation @ 0x7fb6a9817600] 320x240@[14.999993 14.999993]fps
[avfoundation @ 0x7fb6a9817600] 352x288@[29.970000 29.970000]fps
[avfoundation @ 0x7fb6a9817600] 352x288@[25.000000 25.000000]fps
[avfoundation @ 0x7fb6a9817600] 352x288@[23.999981 23.999981]fps
[avfoundation @ 0x7fb6a9817600] 352x288@[14.999993 14.999993]fps
[avfoundation @ 0x7fb6a9817600] 480x360@[29.970000 29.970000]fps
[avfoundation @ 0x7fb6a9817600] 480x360@[25.000000 25.000000]fps
[avfoundation @ 0x7fb6a9817600] 480x360@[23.999981 23.999981]fps
[avfoundation @ 0x7fb6a9817600] 480x360@[14.999993 14.999993]fps
[avfoundation @ 0x7fb6a9817600] 640x480@[29.970000 29.970000]fps
[avfoundation @ 0x7fb6a9817600] 640x480@[25.000000 25.000000]fps
[avfoundation @ 0x7fb6a9817600] 640x480@[23.999981 23.999981]fps
[avfoundation @ 0x7fb6a9817600] 640x480@[14.999993 14.999993]fps
[avfoundation @ 0x7fb6a9817600] 960x544@[29.970000 29.970000]fps
[avfoundation @ 0x7fb6a9817600] 960x544@[25.000000 25.000000]fps
[avfoundation @ 0x7fb6a9817600] 960x544@[23.999981 23.999981]fps
[avfoundation @ 0x7fb6a9817600] 960x544@[14.999993 14.999993]fps
[avfoundation @ 0x7fb6a9817600] 1024x576@[29.970000 29.970000]fps
[avfoundation @ 0x7fb6a9817600] 1024x576@[25.000000 25.000000]fps
[avfoundation @ 0x7fb6a9817600] 1024x576@[23.999981 23.999981]fps
[avfoundation @ 0x7fb6a9817600] 1024x576@[14.999993 14.999993]fps
[avfoundation @ 0x7fb6a9817600] 960x720@[29.970000 29.970000]fps
[avfoundation @ 0x7fb6a9817600] 960x720@[25.000000 25.000000]fps
[avfoundation @ 0x7fb6a9817600] 960x720@[23.999981 23.999981]fps
[avfoundation @ 0x7fb6a9817600] 960x720@[14.999993 14.999993]fps
[avfoundation @ 0x7fb6a9817600] 1280x720@[29.970000 29.970000]fps
[avfoundation @ 0x7fb6a9817600] 1280x720@[25.000000 25.000000]fps
[avfoundation @ 0x7fb6a9817600] 1280x720@[23.999981 23.999981]fps
[avfoundation @ 0x7fb6a9817600] 1280x720@[14.999993 14.999993]fps
0: Input/output error
ffmpeg -f avfoundation -video_size 640x480 -framerate 29.970000 -pixel_format yuyv422 -i 0 out.yuv -hide_banner
Input #0, avfoundation, from '0':
Duration: N/A, start: 33899.406533, bitrate: N/A
Stream #0:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 640x480, 25 tbr, 1000k tbn, 1000k tbc
File 'out.yuv' already exists. Overwrite? [y/N] y
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 : Lavf58.45.100
Stream #0:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 640x480, q=2-31, 122880 kb/s, 25 fps, 25 tbn, 25 tbc
Metadata:
encoder : Lavc58.91.100 rawvideo
frame= 110 fps= 47 q=-0.0 Lsize= 66000kB time=00:00:04.40 bitrate=122880.0kbits/s dup=42 drop=0 speed=1.89x
image-20210517183353547
播放录制好的YUV。
ffplay -video_size 640x480 -pixel_format yuyv422 -framerate 25 out.yuv