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  • FFMPEG to create an MPEG-DASH stream with VP8

    24 avril 2017, par Kenneth Worden

    I’m trying to use FFMPEG to stream a live video feed from my webcam /dev/video0. Following scattered tutorials and scarce documentation (is this a known problem for the encoding community ?) I arrived at the following bash script :

    #!/bin/bash

    ffmpeg \
       -y \
       -f v4l2 \
           -i /dev/video0 \
           -s 640x480 \
           -input_format mjpeg \
           -r 24 \
       -map 0:0 \
       -pix_fmt yuv420p \
       -codec:v libvpx \
           -s 640x480 \
           -threads 4 \
           -b:v 50k \
           -tile-columns 4 \
           -frame-parallel 1 \
           -keyint_min 24 -g 24 \
       -f webm_chunk \
           -header "stream.hdr" \
           -chunk_start_index 1 \
       stream_%d.chk &

    sleep 2

    ffmpeg \
       -f webm_dash_manifest -live 1 \
       -i stream.hdr \
       -c copy \
       -map 0 \
       -f webm_dash_manifest -live 1 \
           -adaptation_sets "id=0,streams=0" \
           -chunk_start_index 1 \
           -chunk_duration_ms 1000 \
           -time_shift_buffer_depth 30000 \
           -minimum_update_period 60000 \
       stream_manifest.mpd

    When I run this script, my webcam light turns on, the stream.hdr and stream_manifest.mpd files are written, and chunks start to be created (i.e. stream_1.chk, stream_2.chk, etc...). However, FFMPEG throws the following error :

    Could not write header for output file #0 (incorrect codec parameters
     ?) : Invalid data found when processing input

    I will explain what I think I am doing with this script, and hopefully this will expose any errors in my thinking.

    First, we invoke FFMPEG to use Video for Linux 2 (v4l2) to read from my webcam (/dev/video0) of a resolution 640x480. The input format is mjpeg with a framerate of 24fps.

    I then declare that FFMPEG should "map" (copy) the video stream output by v4l2 to a file. I specify the pixel format (YUV420P) and use libvpx (VP8 encoding) to encode the video stream. I set the size to be 640x480, use 4 threads, set the bitrate to be 50kbps, do some magic with tile-columns and frame-parallel options, and set the I-frames to be 24 frames apart.

    I then create a stream.hdr file. The starting index is 1. This command continues to run infinitely until I kill it, grabbing new video from my webcam and outputting it into chunks.

    I then sleep for 2 seconds to give the previous command time to generate a header file.

    And that’s really it. The next invocation of FFMPEG simply creates the MPEG-DASH manifest file given the header generated in the previous step.

    So what’s going on ? Why can I not view the video in a web browser (I’m using Dash.js) ? I serve the manifest, header, and chunks on a Node.js server so that trivial issue is not the problem.


    Edit : Here is my full console output.

    ffmpeg version 3.0.7-0ubuntu0.16.10.1 Copyright (c) 2000-2017 the FFmpeg developers
     built with gcc 6.2.0 (Ubuntu 6.2.0-5ubuntu12) 20161005
     configuration: --prefix=/usr --extra-version=0ubuntu0.16.10.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librubberband --enable-librtmp --enable-libschroedinger --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-chromaprint --enable-libx264
     libavutil      55. 17.103 / 55. 17.103
     libavcodec     57. 24.102 / 57. 24.102
     libavformat    57. 25.100 / 57. 25.100
     libavdevice    57.  0.101 / 57.  0.101
     libavfilter     6. 31.100 /  6. 31.100
     libavresample   3.  0.  0 /  3.  0.  0
     libswscale      4.  0.100 /  4.  0.100
     libswresample   2.  0.101 /  2.  0.101
     libpostproc    54.  0.100 / 54.  0.100
    [video4linux2,v4l2 @ 0x55847e244ea0] The driver changed the time per frame from 1/24 to 1/30
    [mjpeg @ 0x55847e245c00] Changing bps to 8
    Input #0, video4linux2,v4l2, from '/dev/video0':
     Duration: N/A, start: 64305.102081, bitrate: N/A
       Stream #0:0: Video: mjpeg, yuvj422p(pc, bt470bg/unknown/unknown), 640x480, -5 kb/s, 30 fps, 30 tbr, 1000k tbn, 1000k tbc
    Codec AVOption frame-parallel (Enable frame parallel decodability features) specified for output file #0 (stream_%d.chk) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of some encoder which was not actually used for any stream.
    Codec AVOption tile-columns (Number of tile columns to use, log2) specified for output file #0 (stream_%d.chk) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of some encoder which was not actually used for any stream.
    [swscaler @ 0x55847e24b720] deprecated pixel format used, make sure you did set range correctly
    [libvpx @ 0x55847e248a20] v1.5.0
    Output #0, webm_chunk, to 'stream_%d.chk':
     Metadata:
       encoder         : Lavf57.25.100
       Stream #0:0: Video: vp8 (libvpx), yuv420p, 640x480, q=-1--1, 50 kb/s, 30 fps, 30 tbn, 30 tbc
       Metadata:
         encoder         : Lavc57.24.102 libvpx
       Side data:
         unknown side data type 10 (24 bytes)
    Stream mapping:
     Stream #0:0 -> #0:0 (mjpeg (native) -> vp8 (libvpx))
    Press [q] to stop, [?] for help
    frame=   21 fps=0.0 q=0.0 size=N/A time=00:00:00.70 bitrate=N/A dup=5 drop=frame=   36 fps= 35 q=0.0 size=N/A time=00:00:01.20 bitrate=N/A dup=5 drop=frame=   51 fps= 33 q=0.0 size=N/A time=00:00:01.70 bitrate=N/A dup=5 drop=ffmpeg version 3.0.7-0ubuntu0.16.10.1 Copyright (c) 2000-2017 the FFmpeg developers
     built with gcc 6.2.0 (Ubuntu 6.2.0-5ubuntu12) 20161005
     configuration: --prefix=/usr --extra-version=0ubuntu0.16.10.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librubberband --enable-librtmp --enable-libschroedinger --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-chromaprint --enable-libx264
     libavutil      55. 17.103 / 55. 17.103
     libavcodec     57. 24.102 / 57. 24.102
     libavformat    57. 25.100 / 57. 25.100
     libavdevice    57.  0.101 / 57.  0.101
     libavfilter     6. 31.100 /  6. 31.100
     libavresample   3.  0.  0 /  3.  0.  0
     libswscale      4.  0.100 /  4.  0.100
     libswresample   2.  0.101 /  2.  0.101
     libpostproc    54.  0.100 / 54.  0.100
    Input #0, webm_dash_manifest, from 'stream.hdr':
     Metadata:
       encoder         : Lavf57.25.100
     Duration: N/A, bitrate: N/A
       Stream #0:0: Video: vp8, yuv420p, 640x480, SAR 1:1 DAR 4:3, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)
       Metadata:
         webm_dash_manifest_file_name: stream.hdr
         webm_dash_manifest_track_number: 1
    Output #0, webm_dash_manifest, to 'stream_manifest.mpd':
     Metadata:
       encoder         : Lavf57.25.100
       Stream #0:0: Video: vp8, yuv420p, 640x480 [SAR 1:1 DAR 4:3], q=2-31, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)
       Metadata:
         webm_dash_manifest_file_name: stream.hdr
         webm_dash_manifest_track_number: 1
    Stream mapping:
     Stream #0:0 -> #0:0 (copy)
    Could not write header for output file #0 (incorrect codec parameters ?): Invalid data found when processing input
    frame=   67 fps= 33 q=0.0 size
    frame=   82 fps= 32 q=0.0 size=N/A time=00:00:02.73 bitrate=N/A dup=5 drop=
    frame=   97 fps= 32 q=0.0 size=N/A time=00:00:03.23 bitrate=N/A dup=5 drop=
    frame=  112 fps= 32 q=0.0 size=N/A time=00:00:03.73 bitrate=N/A dup=5 ...
  • FFMPEG to create an MPEG-DASH stream with VP8

    16 septembre 2019, par Kenny Worden

    I’m trying to use FFMPEG to stream a live video feed from my webcam /dev/video0. Following scattered tutorials and scarce documentation (is this a known problem for the encoding community ?) I arrived at the following bash script :

    #!/bin/bash

    ffmpeg \
       -y \
       -f v4l2 \
           -i /dev/video0 \
           -s 640x480 \
           -input_format mjpeg \
           -r 24 \
       -map 0:0 \
       -pix_fmt yuv420p \
       -codec:v libvpx \
           -s 640x480 \
           -threads 4 \
           -b:v 50k \
           -tile-columns 4 \
           -frame-parallel 1 \
           -keyint_min 24 -g 24 \
       -f webm_chunk \
           -header "stream.hdr" \
           -chunk_start_index 1 \
       stream_%d.chk &

    sleep 2

    ffmpeg \
       -f webm_dash_manifest -live 1 \
       -i stream.hdr \
       -c copy \
       -map 0 \
       -f webm_dash_manifest -live 1 \
           -adaptation_sets "id=0,streams=0" \
           -chunk_start_index 1 \
           -chunk_duration_ms 1000 \
           -time_shift_buffer_depth 30000 \
           -minimum_update_period 60000 \
       stream_manifest.mpd

    When I run this script, my webcam light turns on, the stream.hdr and stream_manifest.mpd files are written, and chunks start to be created (i.e. stream_1.chk, stream_2.chk, etc...). However, FFMPEG throws the following error :

    Could not write header for output file #0 (incorrect codec parameters
     ?) : Invalid data found when processing input

    I will explain what I think I am doing with this script, and hopefully this will expose any errors in my thinking.

    First, we invoke FFMPEG to use Video for Linux 2 (v4l2) to read from my webcam (/dev/video0) of a resolution 640x480. The input format is mjpeg with a framerate of 24fps.

    I then declare that FFMPEG should "map" (copy) the video stream output by v4l2 to a file. I specify the pixel format (YUV420P) and use libvpx (VP8 encoding) to encode the video stream. I set the size to be 640x480, use 4 threads, set the bitrate to be 50kbps, do some magic with tile-columns and frame-parallel options, and set the I-frames to be 24 frames apart.

    I then create a stream.hdr file. The starting index is 1. This command continues to run infinitely until I kill it, grabbing new video from my webcam and outputting it into chunks.

    I then sleep for 2 seconds to give the previous command time to generate a header file.

    And that’s really it. The next invocation of FFMPEG simply creates the MPEG-DASH manifest file given the header generated in the previous step.

    So what’s going on ? Why can I not view the video in a web browser (I’m using Dash.js) ? I serve the manifest, header, and chunks on a Node.js server so that trivial issue is not the problem.


    Edit : Here is my full console output.

    ffmpeg version 3.0.7-0ubuntu0.16.10.1 Copyright (c) 2000-2017 the FFmpeg developers
     built with gcc 6.2.0 (Ubuntu 6.2.0-5ubuntu12) 20161005
     configuration: --prefix=/usr --extra-version=0ubuntu0.16.10.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librubberband --enable-librtmp --enable-libschroedinger --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-chromaprint --enable-libx264
     libavutil      55. 17.103 / 55. 17.103
     libavcodec     57. 24.102 / 57. 24.102
     libavformat    57. 25.100 / 57. 25.100
     libavdevice    57.  0.101 / 57.  0.101
     libavfilter     6. 31.100 /  6. 31.100
     libavresample   3.  0.  0 /  3.  0.  0
     libswscale      4.  0.100 /  4.  0.100
     libswresample   2.  0.101 /  2.  0.101
     libpostproc    54.  0.100 / 54.  0.100
    [video4linux2,v4l2 @ 0x55847e244ea0] The driver changed the time per frame from 1/24 to 1/30
    [mjpeg @ 0x55847e245c00] Changing bps to 8
    Input #0, video4linux2,v4l2, from '/dev/video0':
     Duration: N/A, start: 64305.102081, bitrate: N/A
       Stream #0:0: Video: mjpeg, yuvj422p(pc, bt470bg/unknown/unknown), 640x480, -5 kb/s, 30 fps, 30 tbr, 1000k tbn, 1000k tbc
    Codec AVOption frame-parallel (Enable frame parallel decodability features) specified for output file #0 (stream_%d.chk) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of some encoder which was not actually used for any stream.
    Codec AVOption tile-columns (Number of tile columns to use, log2) specified for output file #0 (stream_%d.chk) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of some encoder which was not actually used for any stream.
    [swscaler @ 0x55847e24b720] deprecated pixel format used, make sure you did set range correctly
    [libvpx @ 0x55847e248a20] v1.5.0
    Output #0, webm_chunk, to 'stream_%d.chk':
     Metadata:
       encoder         : Lavf57.25.100
       Stream #0:0: Video: vp8 (libvpx), yuv420p, 640x480, q=-1--1, 50 kb/s, 30 fps, 30 tbn, 30 tbc
       Metadata:
         encoder         : Lavc57.24.102 libvpx
       Side data:
         unknown side data type 10 (24 bytes)
    Stream mapping:
     Stream #0:0 -> #0:0 (mjpeg (native) -> vp8 (libvpx))
    Press [q] to stop, [?] for help
    frame=   21 fps=0.0 q=0.0 size=N/A time=00:00:00.70 bitrate=N/A dup=5 drop=frame=   36 fps= 35 q=0.0 size=N/A time=00:00:01.20 bitrate=N/A dup=5 drop=frame=   51 fps= 33 q=0.0 size=N/A time=00:00:01.70 bitrate=N/A dup=5 drop=ffmpeg version 3.0.7-0ubuntu0.16.10.1 Copyright (c) 2000-2017 the FFmpeg developers
     built with gcc 6.2.0 (Ubuntu 6.2.0-5ubuntu12) 20161005
     configuration: --prefix=/usr --extra-version=0ubuntu0.16.10.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librubberband --enable-librtmp --enable-libschroedinger --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-chromaprint --enable-libx264
     libavutil      55. 17.103 / 55. 17.103
     libavcodec     57. 24.102 / 57. 24.102
     libavformat    57. 25.100 / 57. 25.100
     libavdevice    57.  0.101 / 57.  0.101
     libavfilter     6. 31.100 /  6. 31.100
     libavresample   3.  0.  0 /  3.  0.  0
     libswscale      4.  0.100 /  4.  0.100
     libswresample   2.  0.101 /  2.  0.101
     libpostproc    54.  0.100 / 54.  0.100
    Input #0, webm_dash_manifest, from 'stream.hdr':
     Metadata:
       encoder         : Lavf57.25.100
     Duration: N/A, bitrate: N/A
       Stream #0:0: Video: vp8, yuv420p, 640x480, SAR 1:1 DAR 4:3, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)
       Metadata:
         webm_dash_manifest_file_name: stream.hdr
         webm_dash_manifest_track_number: 1
    Output #0, webm_dash_manifest, to 'stream_manifest.mpd':
     Metadata:
       encoder         : Lavf57.25.100
       Stream #0:0: Video: vp8, yuv420p, 640x480 [SAR 1:1 DAR 4:3], q=2-31, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)
       Metadata:
         webm_dash_manifest_file_name: stream.hdr
         webm_dash_manifest_track_number: 1
    Stream mapping:
     Stream #0:0 -> #0:0 (copy)
    Could not write header for output file #0 (incorrect codec parameters ?): Invalid data found when processing input
    frame=   67 fps= 33 q=0.0 size
    frame=   82 fps= 32 q=0.0 size=N/A time=00:00:02.73 bitrate=N/A dup=5 drop=
    frame=   97 fps= 32 q=0.0 size=N/A time=00:00:03.23 bitrate=N/A dup=5 drop=
    frame=  112 fps= 32 q=0.0 size=N/A time=00:00:03.73 bitrate=N/A dup=5 ...
  • rails / streamio-ffmpeg - How to execute 2-pass encoding ?

    20 mars 2017, par R4ttlesnake

    I’m using streamio-ffmpeg to encode videos uploaded to my Rails application via ffmpeg. I want to encode the videos to .webm-format using the VP9 coding format and the VP9 Encoding Guide of the WebM Project recommends using 2-pass encoding. I managed to get the videos encoding via streamio-ffmpeg using 1-pass encoding, but I can’t figure out how to handle the 2-pass encoding.

    Here my setup so far :

    # create two tempfiles for the video and a still
    video = Tempfile.new(["video", ".webm"], binmode: true)
    still = Tempfile.new(["still", ".jpg"], binmode: true)

    # new FFMPEG
    movie = FFMPEG::Movie.new(original.path)

    # extract still from video
    movie.screenshot(still.path)

    # encode video
    options = %w(-c:v libvpx-vp9 -b:v 1000K -threads 8 -speed 4 -tile-columns 6 -frame-parallel 1 -auto-alt-ref 1 -lag-in-frames 25 -c:a libvorbis -b:a 64k -f webm)
    movie.transcode(video.path, options)

    The command to do a 2-pass encoding with ffmpeg would be :

    ffmpeg -i <source> -c:v libvpx-vp9 -pass 1 ... -f webm /dev/null
    ffmpeg -i <source> -c:v libvpx-vp9 -pass 2 ... -f output.webm
    </source></source>

    In particular, I don’t get how to pass the file of the first encoding step to the second step with streamio-ffmpeg. How would I apply these two steps to the syntax of movie.transcode(output, options) ?

    Thanks !