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• why type casting on non-pointer struct give syntax error

  1er avril 2020, par Sany Liew

  I am using Visual C++ express 2008 try to compile code similar to below :

  



  no problem

  



  {
  ...
  AVRational test = {1, 1000};
  ...
}


  



  but has problem when it is as below :

  



  {
  ...
  AVRational test = (AVRational){1, 1000};
  ...
}


  



  gave errors :

  



  1>..\..\..\projects\test\xyz.cpp(1139) : error C2059: syntax error : '{'
1>..\..\..\projects\test\xyz.cpp(1139) : error C2143: syntax error : missing   ';' before '{'
1>..\..\..\projects\test\xyz.cpp(1139) : error C2143: syntax error : missing ';' before '}'


  



  where AVRational (ffmpeg.org library) is defined as :

  



  typedef struct AVRational{
    int num; ///< numerator
    int den; ///< denominator
} AVRational;


  



  FFmpeg come with some pre-define value such as

  



  #define AV_TIME_BASE_Q (AVRational){1, AV_TIME_BASE}


  



  which is used as below

  



  av_rescale_q(seek_target, AV_TIME_BASE_Q, pFormatCtx->streams[stream_index]->time_base);


  



  will failed to compile on Visual C++ express 2008

  



  It seem like the same code will be compiled with no error/warning on gcc compiler. Why I get this error on VC++ ? Is it a C/C++ standard way to do casting on struct value ? Anyway I can avoid this error while still able to use the defined AV_TIME_BASE_Q ?

  


• ffmbc : QuickTime to XDCAMHD422 MXF

  13 novembre 2018, par Ze'ev

  Trying to create an XDCAMHD422 MXF with video from a QuickTime and audio from a stereo WAV.

  Audio is pcm_s24le, 48000 Hz, 2 channels, s32

  But output is mixed :

  Stream #0.1(und): Audio: pcm_s16le, 48000 Hz, 1 channels, s16, 768 kb/s
  
  Stream #0.2(und): Audio: pcm_s24le, 48000 Hz, 1 channels, s32, 1152 kb/s

  And shows alert : Incompatible sample format 's32' for codec 'pcm_s16le', auto-selecting format 's16'

  (For XDCAM, it’s necessary to split stereo into dual mono.)

  Command :

  ffmbc -i "$v" -i "$a" -tff -timecode 07:00:00:00 \
  
  -map_audio_channel 1:0:0:0:1:0 \
  
  -map_audio_channel 1:0:1:0:2:0 \
  
  -acodec pcm_s24le -ar 48000 -ac 2 \
  
  -target xdcamhd422 -vtag xd5c -y  -t 1 "$o" \
  
  -acodec pcm_s24le -newaudio

  Output :

  FFmbc version 0.7.2
  
  Copyright (c) 2008-2014 Baptiste Coudurier and the FFmpeg developers
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'video.mov':
  
    Metadata:
  
      major_brand: qt
  
      minor_version: 537199360
  
      compatible_brands: qt
  
      timecode: 00:00:00:00
  
    Duration: 00:00:30.00, bitrate: 188317 kb/s
  
      Stream #0.0(eng): Video: prores, yuv422p10le, 1920x1080p, 186502 kb/s, PAR 1:1 DAR 16:9, 25.00 fps
  
      Metadata:
  
        codec_name: Apple ProRes 422 (HQ)
  
      Stream #0.1(eng): Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s
  
      Stream #0.2(eng): Data: unknown (tmcd)
  
  Input #1, wav, from 'audio.wav':
  
    Metadata:
  
      encoded_by: Pro Tools
  
      originator_reference: aaOpK7OBThOk
  
      date: 2018-11-08
  
      creation_time: 14:10:50
  
      time_reference: 175680000
  
    Duration: 00:00:30.00, bitrate: 2316 kb/s
  
      Stream #1.0(und): Audio: pcm_s24le, 48000 Hz, 2 channels, s32, 2304 kb/s
  
  [scale @ 0x7ff9f48009a0] w:1920 h:1080 fmt:yuv422p10le -> w:1920 h:1080 fmt:yuv422p flags:0x4 il:0
  
  Incompatible sample format 's32' for codec 'pcm_s16le', auto-selecting format 's16'
  
  Output #0, mxf, to 'mxftest3.mxf':
  
    Metadata:
  
      encoder: FFmbc 0.7
  
      Stream #0.0(und): Video: mpeg2video, yuv422p, 1920x1080i tff [PAR 1:1 DAR 16:9], cbr, 50000 kb/s, 25.00 fps
  
      Stream #0.1(und): Audio: pcm_s16le, 48000 Hz, 1 channels, s16, 768 kb/s
  
      Stream #0.2(und): Audio: pcm_s24le, 48000 Hz, 1 channels, s32, 1152 kb/s
  
  Stream mapping:
  
    Stream #0.0 -> #0.0
  
    Stream #1.0 -> #0.1 [channel: 0 -> 0]
  
    Stream #1.0 -> #0.2 [channel: 1 -> 0]
  
  Press [q] to stop, [?] for help
  
  frame=   25 fps=  8 q=2.0 Lsize=    7586kB time=00:00:01.00 bitrate=62145.0kbits/s
  
  video:7309kB audio:236kB global headers:0kB muxing overhead 0.541060%

• FFMPEG get an error message

  26 juillet 2018, par Tom

  I’m writing a batch script, encoding files using FFMPEG to MP3. Some files aren’t being converted, and FFMPEG doesn’t write in the terminal why. Is there a way to get any error messages in a case a process wasn’t successful ?

  Another example, I tried to convert with the same script a text file, obviously it didn’t work, but FFMPEG didn’t provide any error information. That’s why I’m asking if there’s a way, or if FFMPEG even has anything like that.

  Edit :

  The Code :

  FFMPEG.exe -loglevel quiet -i "%%F" -vn -ar 44100 -ac 2 -ab 192k -f mp3 output.mp3

  and the output is :

  FFmpeg version SVN-r13712, Copyright (c) 2000-2008 Fabrice Bellard, et al.
  
    configuration: --enable-memalign-hack --enable-avisynth --enable-libxvid --enable-libx264 --enable-libgsm --enable-libfaac --enable-libfaad --enable-liba52 --enable-libmp3lame --enable-libvorbis --enable-libtheora --enable-pthreads --enable-swscale --enable-gpl
  
    libavutil version: 49.7.0
  
    libavcodec version: 51.57.2
  
    libavformat version: 52.14.0
  
    libavdevice version: 52.0.0
  
    built on Jun  8 2008 21:33:14, gcc: 4.2.3
  
  D:\Documents\ffmpeg.exe: unrecognized option '-loglevel'