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• Why process output reader returns null data ? When same code in other process works correct

  26 août 2019, par Владимир Водов

  I try to get output from ffmpeg process but cant get output.
  In another processes and commands it works correctly but output returns immideately when start !

          using (var process = new Process())
  
          {
  
              process.StartInfo = new ProcessStartInfo()
  
              {
  
                  FileName = LinkHelper.IPFS_PATH,
  
                  Arguments = cmd,
  
                  UseShellExecute = false,
  
                  CreateNoWindow = true,
  
                  RedirectStandardOutput = true
  
              };
  
  
  
              process.ErrorDataReceived += FfmpegErrorRecieved;
  
              process.Start();
  
  
  
              using (StreamReader reader = process.StandardOutput)
  
              {
  
                  string output = await reader.ReadToEndAsync();
  
                  Console.WriteLine(output);
  
              }               
  
              process.WaitForExit();
  
          }

  Before output handle !

  Update :
  As szatmary said ffmpeg use output error instead standard output, so when you initialize process.StandartInfo don’t forget initialize property "RedirectStandardError" to TRUE !

  Here is correct code :

  private async Task DetectFFmpegCamerasAsync()
  
      {
  
          var cmd = "-list_devices true -f dshow -i dummy";
  
          using (var process = new Process())
  
          {
  
              process.StartInfo = new ProcessStartInfo()
  
              {
  
                  FileName = LinkHelper.FFMPEG_PATH,
  
                  Arguments = cmd,
  
                  UseShellExecute = false,
  
                  CreateNoWindow = true,
  
                  RedirectStandardError = true
  
              };
  
  
  
              process.Start();
  
  
  
              using (StreamReader reader = process.StandardError)
  
              {
  
                  string output = await reader.ReadToEndAsync();
  
                  Console.WriteLine($"Camera detection output: \n {output}");
  
              }               
  
              process.WaitForExit();
  
          }
  
      }

• FFmpeg Convert to JPEG works in VLC but not in Mac Preview ?

  24 juillet 2019, par Evan Keeton

  I’m trying to convert a PNG image to a JPEG image using ffmpeg. As far as I can tell, it’s working fine, but it doesn’t display properly in Mac Preview.

  I’m running the following :

  $ ffmpeg -i foo.png foo.jpg

  And it produces the following output :

  ffmpeg version 4.1.3 Copyright (c) 2000-2019 the FFmpeg developers
  
    built with Apple LLVM version 10.0.0 (clang-1000.11.45.5)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/4.1.3_1 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags='-I/Library/Java/JavaVirtualMachines/adoptopenjdk-11.0.2.jdk/Contents/Home/include -I/Library/Java/JavaVirtualMachines/adoptopenjdk-11.0.2.jdk/Contents/Home/include/darwin' --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-libvorbis --enable-libvpx --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-videotoolbox --disable-libjack --disable-indev=jack --enable-libaom --enable-libsoxr
  
    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
  
  Input #0, png_pipe, from 'foo.png':
  
    Duration: N/A, bitrate: N/A
  
      Stream #0:0: Video: png, rgba(pc), 200x231, 25 tbr, 25 tbn, 25 tbc
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (png (native) -> mjpeg (native))
  
  Press [q] to stop, [?] for help
  
  [swscaler @ 0x7ffeaf00ae00] deprecated pixel format used, make sure you did set range correctly
  
  Output #0, image2, to 'foo.jpg':
  
    Metadata:
  
      encoder         : Lavf58.20.100
  
      Stream #0:0: Video: mjpeg, yuvj444p(pc), 200x231, q=2-31, 200 kb/s, 25 fps, 25 tbn, 25 tbc
  
      Metadata:
  
        encoder         : Lavc58.35.100 mjpeg
  
      Side data:
  
        cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: -1
  
  frame=    1 fps=0.0 q=3.7 Lsize=N/A time=00:00:00.04 bitrate=N/A speed= 4.7x    
  
  video:12kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown

  When I open foo.jpg in most applications, such as VLC or Google Chrome, I get exactly what I expected : an image that looks exactly the same as foo.png, the input.

  
  

  However, this is what is displayed in the Finder preview, and the same this is displayed when I open up the file in "Preview."

  

   I wonder if this has something to do with the deprecated pixel format used, make sure you did set range correctly error, but I’m not sure, especially since the image is fine, the problem seems to be elsewhere. 

  It seems the deprecated pixel format error is not the issue (that’s an internal thing), so I guess I just need to specify pixel formats properly.

• Conversion to HEVC using FFmpeg produces video s incompatible with Keynote, but Handbrake works

  15 mai 2019, par Gabriel

  I have a video
  ( https://www.dropbox.com/s/01rg7rgarqfruy3/Spore%20-%20Assymetrical%20Creatures%2C%20excerpt.mov?dl=0 )
  that I want to convert to HEVC (H265).

  When I convert it using Handbrake, it produces an output video that I can then include in a presentation in Keynote.

  When I convert it using ffmpeg on the command line myself, then the output cannot be included in a Keynote presentation ;
  the error message I get is "Operation could not be completed".
  The ffmpeg version plays fine in Quicktime Player, though.
  I have already googled, but could not find a solution to the mystery.
  Also, I have already looked at Handbrake’s Activity Log, but could not find a substantial difference .
  I have already tried to change some of the options and parameters I usually use for running ffmpeg, to no avail.

  Question is : how do I have to run ffmpeg, which options should I use, so that the output can always be included in Keynote ?

  Note that some ffmpeg output videos can be inserted in Keynote.
  I know that I could, of course, always use Handbrake to manually convert the videos, but I’d rather use ffmpeg on the command line so that I can convert lots of my videos in batch.

  Steps to reproduce the problem :

  Convert this video
  https://www.dropbox.com/s/01rg7rgarqfruy3/Spore%20-%20Assymetrical%20Creatures%2C%20excerpt.mov?dl=0
  using Handbrake using the H265 codec.

  Convert it also using ffmpeg. My command line is :
  /opt/local/bin/ffmpeg -loglevel level+info -hide_banner -nostats -nostdin -i "Spore - Assymetrical Creatures, excerpt copy.mov" -map 0 -map -0:v:1 -c:s copy -map_metadata 0 -map_metadata:s:v 0:s:v -dn -map_metadata:s:a 0:s:a -c:a aac -b:a 128k -filter:v crop=in_w-mod(in_w\,2):in_h-mod(in_h\,2) -codec:v hevc -tag:v hvc1 -max_muxing_queue_size 1024 -preset faster -crf 25 -x265-params me=umh:subme=5:ref=4:aq-mode=2:aq-strength=1.0:psy-rd=2.0:psy-rdoq=1.0:rd=6:profile=main:log-level=2 -ignore_unknown -f mp4 "Spore - Assymetrical Creatures, excerpt copy.h265.mp4_converting"

  Go to Keynote / Insert / Choose .. , select the video (either the Handbrake or the ffmpeg version).

  My HandBrake version (e.g., 1.0.0) :
  Version 1.2.0 (2018122200)

  My ffmpeg version :

    built with Apple LLVM version 10.0.0 (clang-1000.11.45.5)
  
    configuration: --prefix=/opt/local --enable-swscale --enable-avfilter --enable-avresample --enable-libmp3lame --enable-libvorbis --enable-libopus --enable-librsvg --enable-libtheora --enable-libopenjpeg --enable-libmodplug --enable-libvpx --enable-libsoxr --enable-libspeex --enable-libass --enable-libbluray --enable-lzma --enable-gnutls --enable-fontconfig --enable-libfreetype --enable-libfribidi --disable-libjack --disable-libopencore-amrnb --disable-libopencore-amrwb --disable-libxcb --disable-libxcb-shm --disable-libxcb-xfixes --disable-indev=jack --enable-opencl --disable-outdev=xv --enable-audiotoolbox --enable-videotoolbox --enable-sdl2 --disable-securetransport --mandir=/opt/local/share/man --enable-shared --enable-pthreads --cc=/usr/bin/clang --arch=x86_64 --enable-x86asm --enable-libx265 --enable-gpl --enable-postproc --enable-libx264 --enable-libxvid --enable-version3 --enable-libsmbclient --enable-nonfree --enable-libfdk-aac
  
    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

  Operating system and version :
  macOS 10.14.3 (Mojave)

  Handbrake log : https://www.dropbox.com/s/4zsn7b2agwwyu1x/Spore%20-%20Assymetrical%20Creatures%2C%20Excerpt%201%202019-04-29%2014-44-28.txt?dl=0

  CLI ffmpeg log : https://www.dropbox.com/s/qx2wf1h5svbrjbc/Spore%20-%20Assymetrical%20Creatures%2C%20Excerpt%201%20-%20ffmpeg%20cli.txt?dl=0

  Output from Console.app, which occurred at the point when I tried to insert the ffmpeg version of the video, filtered by "keynote" : https://www.dropbox.com/s/2oam7cp3az9kp34/Console-keynote-output.txt?dl=0

  Here are the logs of ffmpeg when I run ffmpeg -i ...
  on the video that was output by ffmpeg, and for the video output by Handbrake (as suggested by Gyan) :
  https://www.dropbox.com/s/kddpit4sbq8vdhp/log_on_ffmpeg_result.txt?dl=0
  https://www.dropbox.com/s/v8n1ihgsp4tdwvp/log_on_handbrake_result.txt?dl=0

  Any hints, suggestions , or insights will be highly appreciated.

  Best regards, Gabriel