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• ffmpeg resample to flac loud clicks/noise

  4 août 2017, par Sjoerd Staal

  I’m using the ffmpeg-api to resample a DSD file to Flac & mp3. I don’t experience any problems with the mp3 resample, but with the flac resample there is always a loud click at the end of a track.

  I’m using the FFMpeg API which outputs the following command in command line :

  ffmpeg -i input.dsf -ar 192000 -acodec flac output.flac

  Output :

  ffmpeg version 2.8.5 Copyright (c) 2000-2016 the FFmpeg developers
  
    built with Apple LLVM version 7.0.2 (clang-700.1.81)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/2.8.5 --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-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
  
  [mjpeg @ 0x7fe617809000] Changeing bps to 8
  
  [dsf @ 0x7fe617000000] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, dsf, from 'input.dsf':
  
    Metadata:
  
      title           : Bach Brandenburg no. 6 - Allegro
  
      artist          : Florilegium
  
      album           : Brandenburg Concertos
  
      track           : 3
  
      Tool Version    : 18.0.212
  
      genre           : Classical
  
      composer        : Bach
  
      Catalog #       : 35914
  
      Format          : DSD
  
      ISRC            : NLA460912792
  
      Label           : Channel Classics
  
      Tool Name       : Media Center
  
      date            : 2014
  
    Duration: 00:06:00.31, bitrate: 5644 kb/s
  
      Stream #0:0: Audio: dsd_lsbf_planar, 352800 Hz, stereo, fltp, 5644 kb/s
  
      Stream #0:1: Video: mjpeg, yuvj444p(pc, bt470bg/unknown/unknown), 1429x1417 [SAR 300:300 DAR 1429:1417], 90k tbr, 90k tbn, 90k tbc
  
      Metadata:
  
        title           : Picture
  
        comment         : Cover (front)
  
  [flac @ 0x7fe617122000] encoding as 24 bits-per-sample
  
  Output #0, flac, to 'output.flac':
  
    Metadata:
  
      title           : Bach Brandenburg no. 6 - Allegro
  
      artist          : Florilegium
  
      album           : Brandenburg Concertos
  
      TRACKNUMBER     : 3
  
      Tool Version    : 18.0.212
  
      genre           : Classical
  
      composer        : Bach
  
      Catalog #       : 35914
  
      Format          : DSD
  
      ISRC            : NLA460912792
  
      Label           : Channel Classics
  
      Tool Name       : Media Center
  
      date            : 2014
  
      encoder         : Lavf56.40.101
  
      Stream #0:0: Audio: flac, 192000 Hz, stereo, s32 (24 bit), 128 kb/s
  
      Metadata:
  
        encoder         : Lavc56.60.100 flac
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (dsd_lsbf_planar (native) -> flac (native))
  
  Press [q] to stop, [?] for help
  
  size=  306541kB time=00:05:58.10 bitrate=7012.3kbits/s    
  
  video:0kB audio:306532kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.002733%

• How to force usage of specific codec with ffmpeg ?

  4 septembre 2013, par Srv19

  I am trying to read a certain video file using ffmpeg, and have run into a bit of trouble.

  This is the code that starts to read it :

  int _tmain(int argc, _TCHAR* argv[])
  
  {
  
      if (argc < 2)
  
      {
  
          fprintf( stderr, "Filename is needed as an argument\n" );  
  
          return 1;  
  
      }
  
      /* register all formats and codecs */
  
      av_register_all();
  
      AVFormatContext* fmt_ctx = NULL;
  
      /* open input file, and allocate format context */
  
      const char *src_filename = argv[1];
  
      if (avformat_open_input(&fmt_ctx, src_filename, NULL, NULL) < 0) {
  
          fprintf(stderr, "Could not open source file %s\n", src_filename);
  
          abort();
  
      }
  
      /* retrieve stream information */
  
      AVDictionary *      options;
  
      int res = avformat_find_stream_info(fmt_ctx, &options);
  
      if (res < 0) {
  
          fprintf(stderr, "Could not find stream information\n");
  
          abort();
  
      }
  
      ...
  
  }

  I am consistently getting the following message :

  [avi @ 005f2fe0] Could not find codec parameters for stream 0 (Video :
  none (GREY / 0x59455247), 1280x1024) : unknown codec

  Consider increasing the value for the 'analyzeduration' and 'probesize' options

  I get the same message when i run ffmpeg tool on the same file.

  However, i know what is in the video stream - raw video data with YUV8 format. In fact, when i pass that to ffmpeg via -c:v rawvideo option, there is no problem. Recoding, transforming etc - ffmpeg does it like the magic tool it is.

  Now, the question is : when using ffmpeg api, what is the equivalent of that option ? I desperately need access to the frames of file.

• FFMPEG Command to add text to a image

  4 octobre 2016, par Paba

  I need to create a video with a set of images and I successfully did this with ffmpeg. now i need a way to add credits to the singer and video creator. This is part of the work involved in the video creation tool im implementing. Can someone tell me how to add text to an image with ffmpeg.

  Thanks in advance.