Sur d’autres sites (11608)

• 10bit DPX to DNXHR_444 with FFmpeg causing colour shift

  15 août 2019, par Josh Northeast

  I’m trying to build a python application to convert a 10bit DPX sequence to a 4k DNXHR_444 MOV with a Arri to Rec709 lut, just as I would in Davcincci resolve.

  ffmpeg -f image2 -framerate 24 -pattern_type glob -i INPUT.dpx -c:v dnxhd -profile:v dnxhr_444 -vf lut3d=ArriAlexa_LogCtoRec709_Resolve.cube,colormatrix=bt601:bt709 -pix_fmt yuv444p10le -c:a pcm_s16le -y -timecode 00:00:41:16 OUTPUT.mov

  When comparing the output to the dpx in resolve with the lut on it, there is a slight colour shift making everything slightly more red. Even when i take the lut out of the ffmpeg code, there is still a slight redness. The colourmatrix helps a bit to get it closer but it isn’t close enough. Any ideas why I can’t get them to match ?

  LOG :

  ffmpeg -f image2 -framerate 24 -pattern_type glob -i /dpx/*.dpx -c:v dnxhd -profile:v dnxhr_444 -vf lut3d=/Arri/ArriAlexa_LogCtoRec709_Resolve.cube,colormatrix=bt601:bt709 -pix_fmt yuv444p10le -c:a pcm_s16le -y -timecode 00:00:41:16 /dpx/test.mov
  
  ffmpeg version 4.2-static https://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2019 the FFmpeg developers
  
    built with gcc 6.3.0 (Debian 6.3.0-18+deb9u1) 20170516
  
    configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc-6 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-gmp --enable-libgme --enable-gray --enable-libaom --enable-libfribidi --enable-libass --enable-libvmaf --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librubberband --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libvorbis --enable-libopus --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libdav1d --enable-libxvid --enable-libzvbi --enable-libzimg
  
    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
  
    libswscale      5.  5.100 /  5.  5.100
  
    libswresample   3.  5.100 /  3.  5.100
  
    libpostproc    55.  5.100 / 55.  5.100
  
  Input #0, image2, from '/dpx/*.dpx':
  
    Duration: 00:00:07.67, start: 0.000000, bitrate: N/A
  
      Stream #0:0: Video: dpx, gbrp10le, 4096x1716 [SAR 1:1 DAR 1024:429], 24 tbr, 24 tbn, 24 tbc
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (dpx (native) -> dnxhd (native))
  
  Press [q] to stop, [?] for help
  
  Output #0, mov, to '/dpx/test.mov':
  
    Metadata:
  
      timecode        : 00:00:41:16
  
      encoder         : Lavf58.29.100
  
      Stream #0:0: Video: dnxhd (DNXHR 444) (AVdh / 0x68645641), yuv444p10le, 4096x1716 [SAR 1:1 DAR 1024:429], q=2-1024, 200 kb/s, 0.04 fps, 12288 tbn, 24 tbc
  
      Metadata:
  
        encoder         : Lavc58.54.100 dnxhd
  
  frame=  184 fps=1.9 q=1.0 Lsize= 1117250kB time=00:00:07.62 bitrate=1200316.8kbits/s speed=0.0799x       
  
  video:1117248kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000187%

  Here is a :

  • JPG - reference of what the DPX + LUT should look like
  • DPX - a frame of the dpx sequence I’m trying to convert to DNXHR_444
  • the ArriLogC_to_Rec709 LUT to be applied to the DPX
    Let me know if you need anything else.

  https://drive.google.com/drive/folders/1j2Qq1sV5ZJJsMYe3DOFOV0dnQ3VIotcw

  Cheers,
  Josh

• Nginx rtmp exec command not working in macOS

  8 janvier 2020, par Josh

  The nginx rtmp exec command not working on my macOS.
  I checked the error log file and saw this error.

  2019/05/19 19:45:24 [alert] 32986#0: kevent() error on 13 filter:-1 flags:4002 (2: No such file or directory)

  I have no idea what is that mean and i searched so much about it and i didn’t find anything.

  Config file

  rtmp {
  
  
  
      server {
  
  
  
          listen 8080;
  
          chunk_size 4096;
  
  
  
          application publish {
  
  
  
              live on;
  
              record off;
  
  
  
              allow publish all;
  
              allow play all;
  
  
  
              exec echo "" > /test.txt;
  
  
  
              # I even test that command with bash file 
  
              exec /Users/josh/Projects/server/test.sh;
  
          }
  
  
  
          application hls {
  
  
  
              live on;
  
              record off;
  
  
  
              hls on;
  
              hls_path /usr/local/nginx/html/live;
  
              hls_fragment 15s;
  
          }
  
      }
  
  
  
  }

• Problems piping ffmpeg to flac encoder

  19 mai 2019, par Sebastian Olsen

  I need to encode a flac file with seektables, ffmpeg’s flac encoder does not include seektables, so I need to use the flac CLI. I’m trying to make it possible to convert any arbitrary audio file to a seekable flac file by first piping it through ffmpeg, then to the flac encoder.

  export const transcodeToFlac: AudioTranscoder<{}> = ({
  
    source,
  
    destination
  
  }) => {
  
    return new Promise((resolve, reject) => {
  
      let totalSize = 0
  
  
  
      const { stdout: ffmpegOutput, stderr: ffmpegError } = spawn("ffmpeg", [
  
        "-i",
  
        source,
  
        "-f",
  
        "wav",
  
        "pipe:1"
  
      ])
  
  
  
      const { stdout: flacOutput, stdin: flacInput, stderr: flacError } = spawn(
  
        "flac",
  
        ["-"]
  
      )
  
  
  
      flacOutput.on("data", (buffer: Buffer) => {
  
        totalSize += buffer.byteLength
  
      })
  
  
  
      ffmpegError.on("data", error => {
  
        console.log(error.toString())
  
      })
  
  
  
      flacError.on("data", error => {
  
        console.log(error.toString())
  
      })
  
  
  
      //stream.on("error", reject)
  
  
  
      destination.on("finish", () => {
  
        resolve({
  
          mime: "audio/flac",
  
          size: totalSize,
  
          codec: "flac",
  
          bitdepth: 16,
  
          ext: "flac"
  
        })
  
      })
  
  
  
      ffmpegOutput.pipe(flacInput)
  
      flacOutput.pipe(destination)
  
    })
  
  }

  While this code works, the resulting flac file is not correct. The source audio is of duration 06:14, but the flac file is of duration 06:45:47. Encoding the flac manually without piping ffmpeg to it works fine, but I cannot do that in a server environment where I need to utilize streams.

  Here’s what the flac encoder outputs when transcoding :

  flac 1.3.2
  
  Copyright (C) 2000-2009  Josh Coalson, 2011-2016  Xiph.Org Foundation
  
  flac comes with ABSOLUTELY NO WARRANTY.  This is free software, and you are
  
  welcome to redistribute it under certain conditions.  Type `flac' for details.
  
  
  
  -: WARNING: skipping unknown chunk 'LIST' (use --keep-foreign-metadata to keep)
  
  -: WARNING, cannot write back seekpoints when encoding to stdout
  
  -: 0% complete, ratio=0.357
  
  0% complete, ratio=0.432
  
  0% complete, ratio=0.482
  
  0% complete, ratio=0.527
  
  0% complete, ratio=0.541
  
  1% complete, ratio=0.554
  
  1% complete, ratio=0.563
  
  1% complete, ratio=0.571
  
  size=   36297kB time=00:03:30.70 bitrate=1411.2kbits/s speed= 421x
  
  1% complete, ratio=0.572
  
  1% complete, ratio=0.570
  
  1% complete, ratio=0.577
  
  1% complete, ratio=0.583
  
  1% complete, ratio=0.584
  
  1% complete, ratio=0.590
  
  1% complete, ratio=0.592
  
  size=   64512kB time=00:06:14.49 bitrate=1411.2kbits/s speed= 421x
  
  video:0kB audio:64512kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead:
  
  0.000185%
  
  
  
  -: WARNING: unexpected EOF; expected 1073741823 samples, got 16510976 samples
  
  2% complete, ratio=0.579