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• Getting 'av_interleaved_write_frame() : Broken pipe' error

  2 juillet 2016, par Poornan

  I am trying this blog post.I am new to python, numpy as well as FFMPEG. I could not figure out what causes this issue.

  http://zulko.github.io/blog/2013/09/27/read-and-write-video-frames-in-python-using-ffmpeg/

  here is the code :

  import subprocess as sp
  
  import numpy
  
  
  
  print ("Hello World!");
  
  FFMPEG_BIN = "ffmpeg" # on Linux ans Mac OS
  
  #FFMPEG_BIN = "ffmpeg.exe" # on Windows
  
  
  
  command = [ FFMPEG_BIN,
  
              '-i', '/Users/eananthaneshan/Movies/myvideo.mp4',
  
              '-f', 'image2pipe',
  
              '-pix_fmt', 'yuv444p',
  
              '-s', '420x360',
  
              '-r', '24',
  
              '-vcodec', 'h264', '-']
  
  pipe = sp.Popen(command, stdout = sp.PIPE, bufsize=-1)
  
  
  
  # read 420*360*3 bytes (= 1 frame)
  
  raw_image = pipe.stdout.read(420*360*3)
  
  # transform the byte read into a numpy array
  
  image =  numpy.fromstring(raw_image, dtype='uint8')
  
  image = image.reshape((360,420,3)   )
  
  # throw away the data in the pipe's buffer.
  
  pipe.stdout.flush()

  This is the output :

  ffmpeg version 2.8 Copyright (c) 2000-2015 the FFmpeg developers
  
    built with Apple LLVM version 7.0.0 (clang-700.0.72)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/2.8 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-opencl --enable-libx264 --enable-libmp3lame --enable-libvo-aacenc --enable-libxvid --enable-libfreetype --enable-libtheora --enable-libvorbis --enable-libvpx --enable-librtmp --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libass --enable-ffplay --enable-libspeex --enable-libschroedinger --enable-libfdk-aac --enable-libopus --enable-frei0r --enable-libopenjpeg --disable-decoder=jpeg2000 --extra-cflags='-I/usr/local/Cellar/openjpeg/1.5.2_1/include/openjpeg-1.5 ' --enable-nonfree --enable-vda
  
    libavutil      54. 31.100 / 54. 31.100
  
    libavcodec     56. 60.100 / 56. 60.100
  
    libavformat    56. 40.101 / 56. 40.101
  
    libavdevice    56.  4.100 / 56.  4.100
  
    libavfilter     5. 40.101 /  5. 40.101
  
    libavresample   2.  1.  0 /  2.  1.  0
  
    libswscale      3.  1.101 /  3.  1.101
  
    libswresample   1.  2.101 /  1.  2.101
  
    libpostproc    53.  3.100 / 53.  3.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/Users/eananthaneshan/Movies/myvideo.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 1
  
      compatible_brands: isom
  
      creation_time   : 2014-04-07 02:02:31
  
    Duration: 01:00:10.03, start: 0.000000, bitrate: 1024 kb/s
  
      Stream #0:0(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 111 kb/s (default)
  
      Metadata:
  
        creation_time   : 2014-04-07 02:02:31
  
        handler_name    : GPAC ISO Audio Handler
  
      Stream #0:1(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709/unknown/unknown), 720x404, 909 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 47.95 tbc (default)
  
      Metadata:
  
        creation_time   : 2014-04-07 01:14:58
  
        handler_name    : L-SMASH Video Media Handler
  
        encoder         : AVC Coding
  
  Output #0, image2pipe, to 'pipe:':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 1
  
      compatible_brands: isom
  
      encoder         : Lavf56.40.101
  
      Stream #0:0(und): Video: rawvideo (444P / 0x50343434), yuv444p, 420x360, q=2-31, 200 kb/s, 23.98 fps, 23.98 tbn, 23.98 tbc (default)
  
      Metadata:
  
        creation_time   : 2014-04-07 01:14:58
  
        handler_name    : L-SMASH Video Media Handler
  
        encoder         : Lavc56.60.100 rawvideo
  
  Stream mapping:
  
    Stream #0:1 -> #0:0 (h264 (native) -> rawvideo (native))
  
  Press [q] to stop, [?] for help
  
  av_interleaved_write_frame(): Broken pipe
  
  frame=    2 fps=0.0 q=-0.0 Lsize=     886kB time=00:00:00.08 bitrate=87003.8kbits/s    
  
  video:886kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000000%
  
  Conversion failed!

• compile ffmpeg decode only without audio codecs

  28 juillet 2016, par Rob

  I work on a media manager and use ffmpeg.exe to extract screenshots.
  With the latest size of ffmpeg.exe exceeding 35MB, I am attempting to build ffmpeg without the majority of its functions, to allow only saving of a frame of video.

  I had thought disabling many of the filters, Audio Codecs etc would shrink the size of ffmpeg to something more manageable.

  Following this guide
  https://pracucci.com/compile-ffmpeg-on-windows-with-visual-studio-compiler.html
  to allow building of ffmpeg using Visual Studio 2015, I have come to the part of ./configuration and hit a wall.
  With so many options and no idea what all of them mean or do, I am asking if someone in the community can give me laymans instructions.

  I also know that I need to build x264, and possible x265 (HEVC), but am not sure if there is anything other codecs needed.
  In the end, I and am hoping to just have the one file, ffmpeg.exe for use in the media manager project.

  The code I use to get a screenshot is as follows

  Public Shared Function CreateScreenShot(ByVal FullPathAndFilename As String, ByVal SavePath As String, ByVal sec As Integer, Optional ByVal Overwrite As Boolean = False) As Boolean
  
      If Not File.Exists(SavePath) Or Overwrite Then
  
          Try
  
              IO.File.Delete(SavePath)
  
          Catch
  
              Return False
  
          End Try
  
          If IO.File.Exists(FullPathAndFilename) Then
  
              Dim myProcess As Process = New Process
  
              Try
  
                  Dim seconds As Integer = sec
  
                  myProcess.StartInfo.WindowStyle = ProcessWindowStyle.Hidden
  
                  myProcess.StartInfo.CreateNoWindow = False
  
                  myProcess.StartInfo.FileName = Utilities.applicationPath & "\Assets\ffmpeg.exe"
  
                  Dim proc_arguments As String = "-ss " & seconds.ToString & " -i """ & FullPathAndFilename & """ -vframes:v 1 -an " & """" & SavePath & """"
  
                  myProcess.StartInfo.Arguments = proc_arguments
  
                  myProcess.Start()
  
                  myProcess.WaitForExit()
  
                  If File.Exists(SavePath) Then Return True
  
              Catch ex As Exception
  
                  Throw ex
  
              Finally
  
                  myProcess.Close()
  
              End Try
  
          End If
  
      End If
  
      Return False
  
  End Function

  I hope this is sufficient information, and appreciated any help or suggestions.

• Could not open encoder using ffmpeg C APi for MOV format

  22 juin 2016, par lupod

  Context

  I am writing a program for doing some video processing on an input file. I wrote two classes for handling the "reading/writing frames" part that essentially wrap the functions of ffmpeg. These classes may be instantiated by providing an input and output file name, and in their constructor I initialize everything that is needed (or at least I hope so).

  This are the two routines that are called inside the constructors :

  // InputVideoHandler.cpp
  
  void InputVideoHandler::init(char* name) {
  
    streamIndex = -1;
  
    int numStreams;
  
  
  
    if (avformat_open_input(&formatCtx, name, NULL, NULL) != 0)
  
      throw std::exception("Invalid input file name.");
  
  
  
    if (avformat_find_stream_info(formatCtx, NULL)<0)
  
      throw std::exception("Could not find stream information.");
  
  
  
    numStreams = formatCtx->nb_streams;
  
  
  
    if (numStreams < 0)
  
      throw std::exception("No streams in input video file.");
  
  
  
    for (int i = 0; i < numStreams; i++) {
  
      if (formatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
  
        streamIndex = i;
  
        break;
  
      }
  
    }
  
  
  
    if (streamIndex < 0)
  
      throw std::exception("No video stream in input video file.");
  
  
  
    // find decoder using id
  
    codec = avcodec_find_decoder(formatCtx->streams[streamIndex]->codec->codec_id);
  
    if (codec == nullptr)
  
      throw std::exception("Could not find suitable decoder for input file.");
  
  
  
    // copy context from input stream
  
    codecCtx = avcodec_alloc_context3(codec);
  
    if (avcodec_copy_context(codecCtx, formatCtx->streams[streamIndex]->codec) != 0)
  
      throw std::exception("Could not copy codec context from input stream.");
  
  
  
    if (avcodec_open2(codecCtx, codec, NULL) < 0)
  
      throw std::exception("Could not open decoder.");
  
  
  
    codecCtx->refcounted_frames = 1;
  
  }
  
  
  
  // OutputVideoBuilder.cpp
  
  void OutputVideoBuilder::init(char* name, AVCodecContext* inputCtx) {
  
    if (avformat_alloc_output_context2(&formatCtx, NULL, NULL, name) < 0)
  
      throw std::exception("Could not determine file extension from provided name.");
  
  
  
    codec = avcodec_find_encoder(inputCtx->codec_id);
  
    if (codec == nullptr) {
  
      throw std::exception("Could not find suitable encoder.");
  
    }
  
  
  
    codecCtx = avcodec_alloc_context3(codec);
  
    if (avcodec_copy_context(codecCtx, inputCtx) < 0)
  
      throw std::exception("Could not copy output codec context from input");
  
  
  
    codecCtx->time_base = inputCtx->time_base;
  
  
  
    if (avcodec_open2(codecCtx, codec, NULL) < 0)
  
      throw std::exception("Could not open encoder.");
  
  
  
    stream = avformat_new_stream(formatCtx, codec);
  
    if (stream == nullptr) {
  
      throw std::exception("Could not allocate stream.");
  
    }
  
  
  
    stream->id = formatCtx->nb_streams - 1;
  
    stream->codec = codecCtx;
  
    stream->time_base = codecCtx->time_base;
  
  
  
    av_dump_format(formatCtx, 0, name, 1);
  
    if (!(formatCtx->oformat->flags & AVFMT_NOFILE)) {
  
      if (avio_open(&formatCtx->pb, name, AVIO_FLAG_WRITE) < 0) {
  
        throw std::exception("Could not open output file.");
  
      }
  
    }
  
  
  
    if (avformat_write_header(formatCtx, NULL) < 0) {
  
      throw std::exception("Error occurred when opening output file.");
  
    }
  
  
  
  }

  As you see, for the Init function of the output handler I require that an AVCodecContext must be provided. In my code, I pass to the constructor the AVCodecContext that is stored in the input handler and that was previously created.

  Question :

  The two functions work fine when I test my program with some video formats, like .mpg or .avi. When I try to process .mov/.mp4 files, however, my code throws the exception that I labeled "Could not open encoder." in OutputVideoBuilder::Init(). Why is this happening ? I read from the General documentation of ffmpeg that that format should be supported as well by ffmpeg. I am assuming that I am doing something wrong in my code, which I do not completely understand because it was created by trying to adapt the tutorials of the documentation to my specific case. Also for this reason, any comments on things that are useless or things that are missing will be greatly appreciated.