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• Import BMP file into quicktime .mov file ?

  23 juillet 2015, par Neal Davis

  I am creating a quicktime container .mov file from one BMP file ; I am doing this in two ways :

  1. using the quicktime COM object API for .NET C# under windows
  2. using ffmpeg command line (rawvideo codec)

  Both resulting .MOV files open with quicktime player pro just fine and they look identical to my eyes. Both resulting .MOV files are either the same size as the original BMP or a larger.

  However when viewing the track properties under QT Player PRO of movie file number 1. track format = BMP ; when viewing track properties of number 2. track format = NONE.

  Is there likely a difference - since in 1. above I do not set a track properties format ? In other words is there likely any changes being made to the BMP bits in number 1 above (like compression, or alpha, or ???) ?

• libavcodec : ffprobe on file encoded with FFV1 codec reports "read_quant_table error"

  20 novembre 2016, par Ali Alidoust

  I’m using the following code to encode a series of frames into an mkv or avi file with FFV1 encoding :

     HRESULT Session::createContext(LPCSTR filename, UINT width, UINT height, UINT fps_num, UINT fps_den) {
  
      LOG("Exporting to file: ", filename);
  
  
  
      AVCodecID codecId = AV_CODEC_ID_FFV1;
  
      this->pixelFormat = AV_PIX_FMT_YUV420P;
  
  
  
      this->codec = avcodec_find_encoder(codecId);
  
      RET_IF_NULL(this->codec, "Could not create codec", E_FAIL);
  
  
  
      this->oformat = av_guess_format(NULL, filename, NULL);
  
      RET_IF_NULL(this->oformat, "Could not create format", E_FAIL);
  
      this->oformat->video_codec = codecId;
  
      this->width = width;
  
      this->height = height;
  
      this->codecContext = avcodec_alloc_context3(this->codec);
  
      RET_IF_NULL(this->codecContext, "Could not allocate context for the codec", E_FAIL);
  
  
  
      this->codecContext->codec = this->codec;
  
      this->codecContext->codec_id = codecId;
  
  
  
      this->codecContext->pix_fmt = pixelFormat;
  
      this->codecContext->width = this->width;
  
      this->codecContext->height = this->height;
  
      this->codecContext->time_base.num = fps_den;
  
      this->codecContext->time_base.den = fps_num;
  
  
  
      this->codecContext->gop_size = 1;
  
  
  
  
  
      RET_IF_FAILED_AV(avformat_alloc_output_context2(&fmtContext, this->oformat, NULL, NULL), "Could not allocate format context", E_FAIL);
  
      RET_IF_NULL(this->fmtContext, "Could not allocate format context", E_FAIL);
  
  
  
      this->fmtContext->oformat = this->oformat;
  
      this->fmtContext->video_codec_id = codecId;
  
  
  
      this->stream = avformat_new_stream(this->fmtContext, this->codec);
  
      RET_IF_NULL(this->stream, "Could not create new stream", E_FAIL);
  
      this->stream->time_base = this->codecContext->time_base;
  
      RET_IF_FAILED_AV(avcodec_parameters_from_context(this->stream->codecpar, this->codecContext), "Could not convert AVCodecContext to AVParameters", E_FAIL);
  
  
  
      if (this->fmtContext->oformat->flags & AVFMT_GLOBALHEADER)
  
      {
  
          this->codecContext->flags |= CODEC_FLAG_GLOBAL_HEADER;
  
      }
  
  
  
      av_opt_set_int(this->codecContext->priv_data, "coder", 0, 0);
  
      av_opt_set_int(this->codecContext->priv_data, "context", 1, 0);
  
      av_opt_set_int(this->codecContext->priv_data, "slicecrc", 1, 0);
  
      //av_opt_set_int(this->codecContext->priv_data, "slicecrc", 1, 0);
  
      //av_opt_set_int(this->codecContext->priv_data, "pix_fmt", pixelFormat, 0);
  
  
  
      RET_IF_FAILED_AV(avcodec_open2(this->codecContext, this->codec, NULL), "Could not open codec", E_FAIL);
  
      RET_IF_FAILED_AV(avio_open(&this->fmtContext->pb, filename, AVIO_FLAG_WRITE), "Could not open output file", E_FAIL);
  
      RET_IF_NULL(this->fmtContext->pb, "Could not open output file", E_FAIL);
  
      RET_IF_FAILED_AV(avformat_write_header(this->fmtContext, NULL), "Could not write header", E_FAIL);
  
  
  
      frame = av_frame_alloc();
  
      RET_IF_NULL(frame, "Could not allocate frame", E_FAIL);
  
      frame->format = this->codecContext->pix_fmt;
  
      frame->width = width;
  
      frame->height = height;
  
      return S_OK;
  
  }
  
  
  
  HRESULT Session::writeFrame(IMFSample * pSample) {
  
      IMFMediaBuffer *mediaBuffer = NULL;
  
      BYTE *pDataNV12 = NULL;
  
      DWORD length;
  
  
  
      RET_IF_FAILED(pSample->ConvertToContiguousBuffer(&mediaBuffer), "Could not convert IMFSample to contagiuous buffer", E_FAIL);
  
      RET_IF_FAILED(mediaBuffer->GetCurrentLength(&length), "Could not get buffer length", E_FAIL);
  
      RET_IF_FAILED(mediaBuffer->Lock(&pDataNV12, NULL, NULL), "Could not lock the buffer", E_FAIL);
  
      BYTE *pDataYUV420P = new BYTE[length];
  
      this->convertNV12toYUV420P(pDataNV12, pDataYUV420P, this->width, this->height);
  
      RET_IF_FAILED(av_image_fill_arrays(frame->data, frame->linesize, pDataYUV420P, pixelFormat, this->width, this->height, 1), "Could not fill the frame with data from the buffer", E_FAIL);
  
      LOG_IF_FAILED(mediaBuffer->Unlock(), "Could not unlock the buffer");
  
  
  
      frame->pts = av_rescale_q(this->pts++, this->codecContext->time_base, this->stream->time_base);
  
  
  
      AVPacket pkt;
  
  
  
      av_init_packet(&pkt);
  
      pkt.data = NULL;
  
      pkt.size = 0;
  
  
  
      RET_IF_FAILED_AV(avcodec_send_frame(this->codecContext, frame), "Could not send the frame to the encoder", E_FAIL);
  
      delete[] pDataYUV420P;
  
      if (SUCCEEDED(avcodec_receive_packet(this->codecContext, &pkt))) {
  
          RET_IF_FAILED_AV(av_interleaved_write_frame(this->fmtContext, &pkt), "Could not write the received packet.", E_FAIL);
  
      }
  
  
  
      av_packet_unref(&pkt);
  
  
  
      return S_OK;
  
  }
  
  
  
  HRESULT Session::endSession() {
  
      LOG("Ending session...");
  
  
  
      LOG("Closing files...")
  
      LOG_IF_FAILED_AV(av_write_trailer(this->fmtContext), "Could not finalize the output file.");
  
      LOG_IF_FAILED_AV(avio_close(this->fmtContext->pb), "Could not close the output file.");
  
      LOG_IF_FAILED_AV(avcodec_close(this->codecContext), "Could not close the codec.");
  
      av_free(this->codecContext);
  
      LOG("Done.")
  
      return S_OK;
  
  }

  The problem is that the generated file is not playable in either VLC or MPC-HC. However, MPC-HC reports following info in file properties :

  General
  
  Unique ID                      : 202978442142665779317960161865934977227 (0x98B439D9BE859109BD5EC00A62A238CB)
  
  Complete name                  : T:\Test.mkv
  
  Format                         : Matroska
  
  Format version                 : Version 4 / Version 2
  
  File size                      : 24.6 MiB
  
  Duration                       : 147ms
  
  Overall bit rate               : 1 401 Mbps
  
  Writing application            : Lavf57.57.100
  
  Writing library                : Lavf57.57.100
  
  
  
  Video
  
  ID                             : 1
  
  Format                         : FFV1
  
  Format version                 : Version 0
  
  Codec ID                       : V_MS/VFW/FOURCC / FFV1
  
  Duration                       : 147ms
  
  Width                          : 1 280 pixels
  
  Height                         : 720 pixels
  
  Display aspect ratio           : 16:9
  
  Frame rate mode                : Constant
  
  Frame rate                     : 1 000.000 fps
  
  Color space                    : YUV
  
  Chroma subsampling             : 4:2:0
  
  Bit depth                      : 8 bits
  
  Compression mode               : Lossless
  
  Default                        : Yes
  
  Forced                         : No
  
  DURATION                       : 00:00:00.147000000
  
  coder_type                     : Golomb Rice

  Something to note is that it reports 1000 FPS which is weird since I’ve set AVCodecContext::time_base in the code.

  UPDATE 1 :

  I managed to set the correct fps by setting time_base property of the stream :

  this->stream->time_base.den = fps_num;
  
  this->stream->time_base.num = fps_den;

  VLC plays the output file but it shows VLC logo instead of the video, as if there is no video stream in the file.

  UPDATE 2 :

  Cleaned up the code. Now if I set codecId = AV_CODEC_ID_MPEG2VIDEO the output file is valid and is played in both VLC and MPC-HC. Using ffprobe on the file with FFV1 encoding yields the following result :

  C:\root\apps\ffmpeg>ffprobe.exe t:\test.avi
  
  ffprobe version 3.2 Copyright (c) 2007-2016 the FFmpeg developers
  
    built with gcc 5.4.0 (GCC)
  
    configuration: --disable-static --enable-shared --enable-gpl --enable-version3 --disable-w32threads --enable-dxva2 --enable-libmfx --enable-nvenc --enable-avisynth --enable-bzlib --enable-libebur128 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-decklink --enable-zlib
  
    libavutil      55. 34.100 / 55. 34.100
  
    libavcodec     57. 64.100 / 57. 64.100
  
    libavformat    57. 56.100 / 57. 56.100
  
    libavdevice    57.  1.100 / 57.  1.100
  
    libavfilter     6. 65.100 /  6. 65.100
  
    libswscale      4.  2.100 /  4.  2.100
  
    libswresample   2.  3.100 /  2.  3.100
  
    libpostproc    54.  1.100 / 54.  1.100
  
  [ffv1 @ 00000000006b83a0] read_quant_table error
  
  Input #0, avi, from 't:\test.avi':
  
    Metadata:
  
      encoder         : Lavf57.56.100
  
    Duration: 00:00:04.94, start: 0.000000, bitrate: 107005 kb/s
  
      Stream #0:0: Video: ffv1 (FFV1 / 0x31564646), yuv420p, 1280x720, 107717 kb/s, 29.97 fps, 29.97 tbr, 29.97 tbn, 29.97 tbc

• Normalize Fish Eye Video

  19 novembre 2016, par Optonom Scientific

  I use more advance super fish eye lens. Unfortunately, I couldn’t find any technical properties of this lens.

  I want to dewrap with ffmpeg software with this command :

  ffmpeg -i left.MP4 -vf lenscorrection=cx=0.055:cy=0.005:k1=-.2:k2=-.2 new1.mp4

  In lenscorrection filter there are four parameters.

  How can I find right value for my lens ?