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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 ?

  


• VB Dot Net ffMpeg Network Web Server Cannot Execute JS Ajax Call to Private Web Server When Client is Outside Network

  29 septembre 2019, par Sonbelt

  I have a solution that is using Windows Server 2008 (Web Server), Windows Server 2008 (MS Sql Database Server), Computer with Windows 10 Home with IIS acting as a file server that runs command line calls where ffMpeg converts video files to html5 compliant files and then puts them on the NAS (a WD Network Drive.). Users then use the public website to view the videos streamed from the NAS.

  Windows Server 2008 cannot make a command line call to ffMpeg. If it could the performance hit would be too large.

  In order to get the public web server to call a private web page I’m using an Ajax post call to the file server web site. That site converts the videos and then there is a separate routine that moves the files using the same methodology. In order to get the file server where it can move the files to the NAS I’ve set the application pool identity to a specific user. The public web server is using the Network Service as the identity for the application pool.

  When I run the pages on the public server from behind the firewall where the calling ip address is in the same network the solution works fine but when I use any device or browser when the calling ip address is not in the local network the JS Ajax call to the private web site does not work. No lines appear in the IIS log on the file server.

  I’ve tried changing to the other built in choices and set the identity as the administrator on the public web server. Turned off the public server firewall, turned off the private files server firewalls without success.

  The solution needs to work when the calling ip address is not in the local network. I apologize for long post. Can you help me please ?

• 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%