Recherche avancée

Sur d’autres sites (15424)

• exec.Command error, no output to stdout or stderr

  19 février 2019, par n3wton

  I am trying to get the duration of a video using ffprobe and exec.Command but I keep getting an error. However, stdout and stderr are both empty so I don’t know what the problem is.

  func getVideoLength(filename string) float64 {
  
  cmd := exec.Command("ffprobe", "-i", filename, "-show_entries", "format=duration", "-v", "quiet", "-of", "csv=\"p=0\"")
  
  fmt.Println("ffprobe", "-i", filename, "-show_entries", "format=duration", "-v", "quiet", "-of", "csv=\"p=0\"")
  
      var out bytes.Buffer
  
      var stderr bytes.Buffer
  
      cmd.Stdout = &out
  
      cmd.Stderr = &stderr
  
      err := cmd.Run()
  
      if err != nil {
  
          fmt.Println("out: " + out.String())
  
          fmt.Println("stderr: " + stderr.String())
  
          log.Fatal(err)
  
      }
  
  
  
      length, err := strconv.ParseFloat(out.String(), 64)
  
      if err != nil {
  
          log.Fatal(err)
  
      }
  
  
  
  return length
  
  }

  Here is the output I get :

  ffprobe -i amelie.mp4 -show_entries format=duration -v quiet -of csv="p=0"
  
  out: 
  
  stderr: 
  
  2019/02/18 21:04:39 exit status 1

  not very helpful.

  Any ideas ?. Thanks.

• Adaptive part in MPD using MP4box

  28 janvier 2019, par enigmaVada

  I have used ffmpeg to encode audio and video files of my video sample.mp4 for the dash player. The commands are as follows :

  ffmpeg -i sample.mp4 -s 426x240 -c:v libx264 -b:v 640k -g 90 -an sample_video_240.mp4
  
  ffmpeg -i sample.mp4 -s 480x360 -c:v libx264 -b:v 960k -g 90 -an sample_video_360.mp4
  
  ffmpeg -i sample.mp4 -s 640x480 -c:v libx264 -b:v 1280k -g 90 -an sample_video_480.mp4
  
  ffmpeg -i sample.mp4 -s 1280x720 -c:v libx264 -b:v 2560k -g 90 -an sample_video_720.mp4
  
  
  
  ffmpeg -i sample.mp4 -c:a aac -b:a 128k -vn sample_audio.mp4

  I have generated 240p,360p,480p and 720p videos and audio file.

  Then I have used mp4box to generate the mpd file using the following command :

  mp4box -dash 10000 -rap -profile dashavc264:onDemand -mpd-title BBB -out sample.mpd -frag 5000 sample_audio.mp4 sample_video_240.mp4 sample_video_360.mp4 sample_video_480.mp4 sample_video_720.mp4 

  I am using the dash.js player to play the video. The problem is, the adaptive part of DASH isn’t working. The player is just using the 240p video and not switching to a better format even if proper bandwidth is available. I am checking using the network tab of chrome dev tools.

  What am i doing wrong ? Please help.

  Here is the mpd file for reference :

  <?xml version="1.0"?>
  
  
  
  <mpd xmlns="urn:mpeg:dash:schema:mpd:2011" minbuffertime="PT1.500S" type="static" mediapresentationduration="PT0H1M9.869S" maxsegmentduration="PT0H0M9.985S" profiles="urn:mpeg:dash:profile:isoff-on-demand:2011,http://dashif.org/guidelines/dash264">
  
   <programinformation moreinformationurl="http://gpac.io">
  
    
  
   </programinformation>
  
  
  
   <period duration="PT0H1M9.869S">
  
    <adaptationset segmentalignment="true" lang="und" subsegmentalignment="true" subsegmentstartswithsap="1">
  
     <representation mimetype="audio/mp4" codecs="mp4a.40.2" audiosamplingrate="44100" startwithsap="1" bandwidth="130920">
  
      <audiochannelconfiguration schemeiduri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2"></audiochannelconfiguration>
  
      <baseurl>sample_audio_dashinit.mp4</baseurl>
  
      <segmentbase indexrangeexact="true" indexrange="902-1017">
  
        <initialization range="0-901"></initialization>
  
      </segmentbase>
  
     </representation>
  
    </adaptationset>
  
    <adaptationset segmentalignment="true" group="1" maxwidth="426" maxheight="240" maxframerate="30" par="426:240" lang="und" subsegmentalignment="true" subsegmentstartswithsap="1">
  
     <representation mimetype="video/mp4" codecs="avc1.640015" width="426" height="240" framerate="30" sar="1:1" startwithsap="1" bandwidth="590708">
  
      <baseurl>sample_video_240_dashinit.mp4</baseurl>
  
      <segmentbase indexrangeexact="true" indexrange="914-1053">
  
        <initialization range="0-913"></initialization>
  
      </segmentbase>
  
     </representation>
  
    </adaptationset>
  
    <adaptationset segmentalignment="true" group="1" maxwidth="640" maxheight="480" maxframerate="30" par="4:3" lang="und" subsegmentalignment="true" subsegmentstartswithsap="1">
  
     <representation mimetype="video/mp4" codecs="avc1.64001E" width="480" height="360" framerate="30" sar="1:1" startwithsap="1" bandwidth="883873">
  
      <baseurl>sample_video_360_dashinit.mp4</baseurl>
  
      <segmentbase indexrangeexact="true" indexrange="914-1053">
  
        <initialization range="0-913"></initialization>
  
      </segmentbase>
  
     </representation>
  
     <representation mimetype="video/mp4" codecs="avc1.64001E" width="640" height="480" framerate="30" sar="1:1" startwithsap="1" bandwidth="1188712">
  
      <baseurl>sample_video_480_dashinit.mp4</baseurl>
  
      <segmentbase indexrangeexact="true" indexrange="913-1052">
  
        <initialization range="0-912"></initialization>
  
      </segmentbase>
  
     </representation>
  
    </adaptationset>
  
    <adaptationset segmentalignment="true" group="1" maxwidth="1280" maxheight="720" maxframerate="30" par="16:9" lang="und" subsegmentalignment="true" subsegmentstartswithsap="1">
  
     <representation mimetype="video/mp4" codecs="avc1.64001F" width="1280" height="720" framerate="30" sar="1:1" startwithsap="1" bandwidth="2365717">
  
      <baseurl>sample_video_720_dashinit.mp4</baseurl>
  
      <segmentbase indexrangeexact="true" indexrange="914-1053">
  
        <initialization range="0-913"></initialization>
  
      </segmentbase>
  
     </representation>
  
    </adaptationset>
  
   </period>
  
  </mpd>

• FFMPEG - How to pipe RMS_level and pts_time metadata without generating unwanted metadata

  6 février 2020, par Tovi Newman

  I am trying to find the loudest (highest rms_level) moment in an audio file, but I need to pipe the metadata rather than write to a file.

  I converted the answer found here : [https://superuser.com/questions/1183663/determining-audio-level-peaks-with-ffmpeg][1]

  By removing the write to file command and adding a pipe.
  Here’s what I’ve got.

  ffmpeg -i loudSoft.mp3 -af astats=metadata=1:reset=1,ametadata=print:key=lavfi.astats.Overall.RMS_level -f null - 2> result.txt

  The only problem is, now I’ve got a lot of unwanted metadata before and after the RMS_level and pts_time data as well as [Parsed_ametadata_1 @ 0x7f9d42c37500] being printed on each line. None of that was being written when I was writing to a file instead of piping. (all I need is the time and the rms.)

  Here is an abridged version of what I get when I write to file :

  frame:0    pts:0       pts_time:0
  
  lavfi.astats.Overall.RMS_level=-inf
  
  frame:1    pts:47      pts_time:0.00106576
  
  lavfi.astats.Overall.RMS_level=-165.163347
  
  frame:2    pts:1199    pts_time:0.0271882
  
  lavfi.astats.Overall.RMS_level=-99.736394
  
  frame:3    pts:2351    pts_time:0.0533107
  
  lavfi.astats.Overall.RMS_level=-88.112282
  
  frame:4    pts:3503    pts_time:0.0794331
  
  lavfi.astats.Overall.RMS_level=-86.554314
  
  frame:5    pts:4655    pts_time:0.105556
  
  lavfi.astats.Overall.RMS_level=-82.977501
  
  frame:6    pts:5807    pts_time:0.131678
  
  lavfi.astats.Overall.RMS_level=-79.698739
  
  frame:7    pts:6959    pts_time:0.1578
  
  lavfi.astats.Overall.RMS_level=-76.629393
  
  frame:8    pts:8111    pts_time:0.183923
  
  lavfi.astats.Overall.RMS_level=-71.581211
  
  frame:9    pts:9263    pts_time:0.210045
  
  lavfi.astats.Overall.RMS_level=-75.038503
  
  frame:10   pts:10415   pts_time:0.236168

  And here is what I’m looking at :

  ffmpeg version 4.2.2 Copyright (c) 2000-2019 the FFmpeg developers
  
    built with Apple clang version 11.0.0 (clang-1100.0.33.16)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/4.2.2_1 --enable-shared --enable-pthreads --enable-version3 --enable-avresample --cc=clang --host-cflags='-I/Library/Java/JavaVirtualMachines/adoptopenjdk-13.0.1.jdk/Contents/Home/include -I/Library/Java/JavaVirtualMachines/adoptopenjdk-13.0.1.jdk/Contents/Home/include/darwin -fno-stack-check' --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libmp3lame --enable-libopus --enable-librubberband --enable-libsnappy --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libspeex --enable-libsoxr --enable-videotoolbox --disable-libjack --disable-indev=jack
  
    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, mp3, from 'loudSoft2.mp3':
  
    Metadata:
  
      encoder         : Lavf58.29.100
  
    Duration: 00:00:09.85, start: 0.025057, bitrate: 128 kb/s
  
      Stream #0:0: Audio: mp3, 44100 Hz, stereo, fltp, 128 kb/s
  
      Metadata:
  
        encoder         : Lavc58.54
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (mp3 (mp3float) -> pcm_s16le (native))
  
  Press [q] to stop, [?] for help
  
  [Parsed_ametadata_1 @ 0x7f9d42c37500] frame:0    pts:0       pts_time:0
  
  [Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-inf
  
  Output #0, null, to 'pipe:':
  
    Metadata:
  
      encoder         : Lavf58.29.100
  
      Stream #0:0: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s
  
      Metadata:
  
        encoder         : Lavc58.54.100 pcm_s16le
  
  [Parsed_ametadata_1 @ 0x7f9d42c37500] frame:1    pts:47      pts_time:0.00106576
  
  [Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-165.163347
  
  [Parsed_ametadata_1 @ 0x7f9d42c37500] frame:2    pts:1199    pts_time:0.0271882
  
  [Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-99.736394
  
  [Parsed_ametadata_1 @ 0x7f9d42c37500] frame:3    pts:2351    pts_time:0.0533107
  
  
  
  
  
  *** MIDDLE OMITTED FOR BREVITY ***
  
  
  
  
  
  [Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-88.532185
  
  [Parsed_ametadata_1 @ 0x7f9d42c37500] frame:375  pts:430895  pts_time:9.77086
  
  [Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-88.594276
  
  [Parsed_ametadata_1 @ 0x7f9d42c37500] frame:376  pts:432047  pts_time:9.79698
  
  [Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-88.654138
  
  size=N/A time=00:00:09.82 bitrate=N/A speed=82.6x    
  
  video:0kB audio:1692kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Channel: 1
  
  [Parsed_astats_0 @ 0x7f9d42c37280] DC offset: 0.000001
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Min level: -0.000106
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Max level: 0.000115
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Min difference: 0.000000
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Max difference: 0.000077
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Mean difference: 0.000017
  
  [Parsed_astats_0 @ 0x7f9d42c37280] RMS difference: 0.000022
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Peak level dB: -78.752617
  
  [Parsed_astats_0 @ 0x7f9d42c37280] RMS level dB: -88.654138
  
  [Parsed_astats_0 @ 0x7f9d42c37280] RMS peak dB: -88.654138
  
  [Parsed_astats_0 @ 0x7f9d42c37280] RMS trough dB: -88.654138
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Crest factor: 3.126627
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Flat factor: 0.000000
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Peak count: 2
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Bit depth: 32/32
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Dynamic range: 76.274252
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Zero crossings: 246
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Zero crossings rate: 0.222624
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Number of NaNs: 0
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Number of Infs: 0
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Number of denormals: 0
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Channel: 2
  
  [Parsed_astats_0 @ 0x7f9d42c37280] DC offset: 0.000001
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Min level: -0.000106
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Max level: 0.000115
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Min difference: 0.000000
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Max difference: 0.000077
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Mean difference: 0.000017
  
  [Parsed_astats_0 @ 0x7f9d42c37280] RMS difference: 0.000022
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Peak level dB: -78.752617
  
  [Parsed_astats_0 @ 0x7f9d42c37280] RMS level dB: -88.654138
  
  [Parsed_astats_0 @ 0x7f9d42c37280] RMS peak dB: -88.654138
  
  [Parsed_astats_0 @ 0x7f9d42c37280] RMS trough dB: -88.654138
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Crest factor: 3.126627
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Flat factor: 0.000000
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Peak count: 2
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Bit depth: 32/32
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Dynamic range: 76.274252
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Zero crossings: 246
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Zero crossings rate: 0.222624
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Number of NaNs: 0
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Number of Infs: 0
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Number of denormals: 0
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Overall
  
  [Parsed_astats_0 @ 0x7f9d42c37280] DC offset: 0.000001
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Min level: -0.000106
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Max level: 0.000115
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Min difference: 0.000000
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Max difference: 0.000077
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Mean difference: 0.000017
  
  [Parsed_astats_0 @ 0x7f9d42c37280] RMS difference: 0.000022
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Peak level dB: -78.752617
  
  [Parsed_astats_0 @ 0x7f9d42c37280] RMS level dB: -88.654138
  
  [Parsed_astats_0 @ 0x7f9d42c37280] RMS peak dB: -88.654138
  
  [Parsed_astats_0 @ 0x7f9d42c37280] RMS trough dB: -88.654138
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Flat factor: 0.000000
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Peak count: 2.000000
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Bit depth: 32/32
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Number of samples: 1105
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Number of NaNs: 0.000000
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Number of Infs: 0.000000
  
  [Parsed_astats_0 @ 0x7f9d42c37280] Number of denormals: 0.000000