ffmpeg 以慢动作复制编解码器输出

Question

我有以下情况让我发疯:
我有一个捕获设备。这里的ffprobe就可以了:

pi@skycam:~ $ ffprobe /dev/video0
ffprobe version 4.1.6-1~deb10u1+rpt2 Copyright (c) 2007-2020 the FFmpeg developers
  built with gcc 8 (Raspbian 8.3.0-6+rpi1)
  configuration: --prefix=/usr --extra-version='1~deb10u1+rpt2' --toolchain=hardened --incdir=/usr/include/arm-linux-gnueabihf --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-opengl --enable-sdl2 --enable-omx-rpi --enable-mmal --enable-neon --enable-rpi --enable-vout-drm --enable-v4l2-request --enable-libudev --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared --libdir=/usr/lib/arm-linux-gnueabihf --cpu=arm1176jzf-s --arch=arm
  WARNING: library configuration mismatch
  avutil      configuration: --prefix=/usr --extra-version='1~deb10u1+rpt2' --toolchain=hardened --incdir=/usr/include/arm-linux-gnueabihf --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-opengl --enable-sdl2 --enable-omx-rpi --enable-mmal --enable-neon --enable-rpi --enable-vout-drm --enable-v4l2-request --enable-libudev --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --libdir=/usr/lib/arm-linux-gnueabihf/neon/vfp --cpu=cortex-a7 --arch=armv6t2 --disable-thumb --enable-shared --disable-doc --disable-programs
  avcodec     configuration: --prefix=/usr --extra-version='1~deb10u1+rpt2' --toolchain=hardened --incdir=/usr/include/arm-linux-gnueabihf --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-opengl --enable-sdl2 --enable-omx-rpi --enable-mmal --enable-neon --enable-rpi --enable-vout-drm --enable-v4l2-request --enable-libudev --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --libdir=/usr/lib/arm-linux-gnueabihf/neon/vfp --cpu=cortex-a7 --arch=armv6t2 --disable-thumb --enable-shared --disable-doc --disable-programs
  avformat    configuration: --prefix=/usr --extra-version='1~deb10u1+rpt2' --toolchain=hardened --incdir=/usr/include/arm-linux-gnueabihf --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-opengl --enable-sdl2 --enable-omx-rpi --enable-mmal --enable-neon --enable-rpi --enable-vout-drm --enable-v4l2-request --enable-libudev --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --libdir=/usr/lib/arm-linux-gnueabihf/neon/vfp --cpu=cortex-a7 --arch=armv6t2 --disable-thumb --enable-shared --disable-doc --disable-programs
  avdevice    configuration: --prefix=/usr --extra-version='1~deb10u1+rpt2' --toolchain=hardened --incdir=/usr/include/arm-linux-gnueabihf --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-opengl --enable-sdl2 --enable-omx-rpi --enable-mmal --enable-neon --enable-rpi --enable-vout-drm --enable-v4l2-request --enable-libudev --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --libdir=/usr/lib/arm-linux-gnueabihf/neon/vfp --cpu=cortex-a7 --arch=armv6t2 --disable-thumb --enable-shared --disable-doc --disable-programs
  avfilter    configuration: --prefix=/usr --extra-version='1~deb10u1+rpt2' --toolchain=hardened --incdir=/usr/include/arm-linux-gnueabihf --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-opengl --enable-sdl2 --enable-omx-rpi --enable-mmal --enable-neon --enable-rpi --enable-vout-drm --enable-v4l2-request --enable-libudev --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --libdir=/usr/lib/arm-linux-gnueabihf/neon/vfp --cpu=cortex-a7 --arch=armv6t2 --disable-thumb --enable-shared --disable-doc --disable-programs
  avresample  configuration: --prefix=/usr --extra-version='1~deb10u1+rpt2' --toolchain=hardened --incdir=/usr/include/arm-linux-gnueabihf --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-opengl --enable-sdl2 --enable-omx-rpi --enable-mmal --enable-neon --enable-rpi --enable-vout-drm --enable-v4l2-request --enable-libudev --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --libdir=/usr/lib/arm-linux-gnueabihf/neon/vfp --cpu=cortex-a7 --arch=armv6t2 --disable-thumb --enable-shared --disable-doc --disable-programs
  swscale     configuration: --prefix=/usr --extra-version='1~deb10u1+rpt2' --toolchain=hardened --incdir=/usr/include/arm-linux-gnueabihf --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-opengl --enable-sdl2 --enable-omx-rpi --enable-mmal --enable-neon --enable-rpi --enable-vout-drm --enable-v4l2-request --enable-libudev --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --libdir=/usr/lib/arm-linux-gnueabihf/neon/vfp --cpu=cortex-a7 --arch=armv6t2 --disable-thumb --enable-shared --disable-doc --disable-programs
  swresample  configuration: --prefix=/usr --extra-version='1~deb10u1+rpt2' --toolchain=hardened --incdir=/usr/include/arm-linux-gnueabihf --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-opengl --enable-sdl2 --enable-omx-rpi --enable-mmal --enable-neon --enable-rpi --enable-vout-drm --enable-v4l2-request --enable-libudev --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --libdir=/usr/lib/arm-linux-gnueabihf/neon/vfp --cpu=cortex-a7 --arch=armv6t2 --disable-thumb --enable-shared --disable-doc --disable-programs
  postproc    configuration: --prefix=/usr --extra-version='1~deb10u1+rpt2' --toolchain=hardened --incdir=/usr/include/arm-linux-gnueabihf --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-opengl --enable-sdl2 --enable-omx-rpi --enable-mmal --enable-neon --enable-rpi --enable-vout-drm --enable-v4l2-request --enable-libudev --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --libdir=/usr/lib/arm-linux-gnueabihf/neon/vfp --cpu=cortex-a7 --arch=armv6t2 --disable-thumb --enable-shared --disable-doc --disable-programs
  libavutil      56. 22.100 / 56. 22.100
  libavcodec     58. 35.100 / 58. 35.100
  libavformat    58. 20.100 / 58. 20.100
  libavdevice    58.  5.100 / 58.  5.100
  libavfilter     7. 40.101 /  7. 40.101
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  3.100 /  5.  3.100
  libswresample   3.  3.100 /  3.  3.100
  libpostproc    55.  3.100 / 55.  3.100
[mjpeg @ 0x18a79b0] No JPEG data found in image
[mjpeg @ 0x18a79b0] Found EOI before any SOF, ignoring
[mjpeg @ 0x18a79b0] No JPEG data found in image
Input #0, video4linux2,v4l2, from '/dev/video0':
  Duration: N/A, start: 3716.774220, bitrate: N/A
    Stream #0:0: Video: mjpeg, yuvj422p(pc, bt470bg/unknown/unknown), 1920x1080, 60 fps, 60 tbr, 1000k tbn, 1000k tbc

现在我想通过 FFMPEG 尽可能流畅地录制。
因此我进行了测试，以下命令给了我一个很好的结果:

ffmpeg -r 60 -an -i /dev/video0 -preset ultrafast -vcodec copy test.mjpeg 

但问题是，我得到了慢动作的结果。似乎 mjpeg 文件在 VLC 中以半速播放。为什么会这样？
多谢，
欢呼鲁迪
编辑:这里的输出:

[mjpeg @ 0x762250] No JPEG data found in image
[mjpeg @ 0x762250] Found EOI before any SOF, ignoring
[mjpeg @ 0x762250] No JPEG data found in image
Input #0, video4linux2,v4l2, from '/dev/video0':
  Duration: N/A, start: 5174.036617, bitrate: N/A
    Stream #0:0: Video: mjpeg, yuvj422p(pc, bt470bg/unknown/unknown), 1920x1080, 60 fps, 60 tbr, 1000k tbn, 1000k tbc
Output #0, mjpeg, to '/home/pi/java_workspace/skycam_data/test14.mjpeg':
  Metadata:
    encoder         : Lavf58.20.100
    Stream #0:0: Video: mjpeg, yuvj422p(pc, bt470bg/unknown/unknown), 1920x1080, q=2-31, 60 fps, 60 tbr, 1000k tbn, 1000k tbc
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
frame=   33 fps=0.0 q=-1.0 size=    2560kB time=00:00:00.51 bitrate=40952.2kbits/s speed=1.01x    
frame=   63 fps= 63 q=-1.0 size=    5120kB time=00:00:01.01 bitrate=41434.6kbits/s speed=   1x    
frame=   94 fps= 62 q=-1.0 size=    7680kB time=00:00:01.53 bitrate=41062.1kbits/s speed=1.01x    
frame=  124 fps= 61 q=-1.0 size=   10496kB time=00:00:02.03 bitrate=42309.4kbits/s speed=1.01x    
frame=  154 fps= 61 q=-1.0 size=   13568kB time=00:00:02.53 bitrate=43890.8kbits/s speed=   1x    
frame=  184 fps= 61 q=-1.0 size=   17152kB time=00:00:03.03 bitrate=46334.8kbits/s speed=   1x    
frame=  214 fps= 61 q=-1.0 size=   20736kB time=00:00:03.53 bitrate=48087.4kbits/s speed=   1x    
frame=  245 fps= 61 q=-1.0 size=   25088kB time=00:00:04.04 bitrate=50763.2kbits/s speed=   1x    

ffplay 在同一文件上的输出:

./ffplay test14.mjpeg 
ffplay version N-106494-g1291568c98-tessus Copyright (c) 2003-2022 the FFmpeg developers
  built with Apple clang version 11.0.0 (clang-1100.0.33.17)
  configuration: --cc=/usr/bin/clang --prefix=/opt/ffmpeg --extra-version=tessus --enable-avisynth --enable-fontconfig --enable-gpl --enable-libaom --enable-libass --enable-libbluray --enable-libdav1d --enable-libfreetype --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libmysofa --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvmaf --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-libzmq --enable-libzvbi --enable-version3 --pkg-config-flags=--static --enable-librtmp --enable-ffplay --enable-sdl2 --disable-ffmpeg --disable-ffprobe
  libavutil      57. 24.101 / 57. 24.101
  libavcodec     59. 25.100 / 59. 25.100
  libavformat    59. 20.101 / 59. 20.101
  libavdevice    59.  6.100 / 59.  6.100
  libavfilter     8. 30.100 /  8. 30.100
  libswscale      6.  6.100 /  6.  6.100
  libswresample   4.  6.100 /  4.  6.100
  libpostproc    56.  5.100 / 56.  5.100
[mjpeg @ 0x7fd70be22500] Format mjpeg detected only with low score of 12, misdetection possible!
[mjpeg @ 0x7fd70be2bfc0] Found EOI before any SOF, ignoring
Input #0, mjpeg, from 'test14.mjpeg':
  Duration: N/A, bitrate: N/A
  Stream #0:0: Video: mjpeg (Baseline), yuvj422p(pc, bt470bg/unknown/unknown), 1920x1080, 25 tbr, 1200k tbn
[mjpeg @ 0x7fd70bd91600] Found EOI before any SOF, ignoring
[swscaler @ 0x7fd70e043000] [swscaler @ 0x7fd70e7eb000] deprecated pixel format used, make sure you did set range correctly
[swscaler @ 0x7fd70e043000] [swscaler @ 0x7fd70f923000] deprecated pixel format used, make sure you did set range correctly
[swscaler @ 0x7fd70e043000] [swscaler @ 0x7fd70f932000] deprecated pixel format used, make sure you did set range correctly

Answer 1

*.mjpeg是原始流格式。 raw muxers 的 FFmpeg 文档状态:“它们不存储时间戳或元数据。”因此，请尝试将数据存储在 mp4 容器中:

ffmpeg -r 60 -an -i /dev/video0 -vcodec copy test.mp4