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• How to make ffmpeg configure add to the end of compiling line ?

  28 octobre 2012, par myWallJSON

  I want to make ffmpeg not to use -fno-math-errno on compilation.

  I tried ./configure --extra-cflags="-fmath-errno"

  but it ads it before ffmpegs -fno-math-errno :

  gcc -I. -I./ -D_ISOC99_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -DHAVE_AV_CONFIG_H   -std=c99 -fomit-frame-pointer -I/cygdrive/c/Users/Avesta/Downloads/FlasCC_1.0.1121790_10-08-2012/sdk/usr/include/SDL -D_GNU_SOURCE=1 -Wdeclaration-after-statement -Wall -Wno-parentheses -Wno-switch -Wno-format-zero-length -Wdisabled-optimization -Wpointer-arith -Wredundant-decls -Wno-pointer-sign -Wwrite-strings -Wundef -Wmissing-prototypes -Wno-pointer-to-int-cast -Wstrict-prototypes -O3  -mllvm -stack-alignment=16  -MMD -MF libavformat/allformats.d -MT libavformat/allformats.o -c -o libavformat/allformats.o libavformat/allformats.c

  \so I wonder how to make configure to add flags after all -f including -fno-math-errno ?

  there are :

    --extra-cflags=ECFLAGS   add ECFLAGS to CFLAGS []
  
    --extra-cxxflags=ECFLAGS add ECFLAGS to CXXFLAGS []
  
    --extra-ldflags=ELDFLAGS add ELDFLAGS to LDFLAGS []
  
    --extra-libs=ELIBS       add ELIBS []
  
    --extra-version=STRING   version string suffix []

• Encoding video on H.263 to send over RTP

  20 novembre 2012, par Miguel Brito

  I'm developing an application to send video over RTP to a client that can play only H.263 (1996) and H263+ (1998).

  To do this i've encoded the video using libav following these steps : (this is only part of the code)

  av_register_all();
  
  avformat_network_init();
  
  Fmt = av_guess_format("rtp", NULL, NULL);
  
  ...
  
  st = add_video_stream(FmtCtx, CODEC_ID_H263);
  
  ...
  
  avio_open(&FmtCtx->pb, rtp_url, URL_WRONLY)

  To finally enter a loop where i encode the video, the problem is that the stream generated by this program is encoded in H.263-2000 (or H.263++) which the other side cannot undertand, even though i use CODEC_ID_H263 or CODEC_ID_H263P in the initialization the same thing happens.

  Is it possible to encode in those old H.263 versions using libav ? i havent managed to do it not even using ffmpeg commands. The stream is always h.263-2000 (PT=96)

• FFMpeg Commands definition in library source code

  25 janvier 2013, par SKC

  I tried running the ffmpeg commands from Android activity using an emulator in Windows OS, but i get errors.
  I tried keeping both my resource files in /mnt/sdcard as well the application package within /data/data, but none of the options worked out for running the ffmpeg commands.

  These are the following approach i had taken while running the command through an android activity.
  (Command to convert a series if images into a video)
  Approach 1 :

      String[] cmd =new String[4];
  
      cmd[0]="/data/data/com.example.commandlineffmpeg/files/ffmpeg";
  
      cmd[1]="-i";
  
      cmd[2]="/data/data/com.example.commandlineffmpeg/images/bpc_%03d.png";
  
      cmd[3]="/data/data/com.example.commandlineffmpeg/out/out.avi";
  
  
  
      Process p = Runtime.getRuntime().exec(cmd, null, new File("/data/data/com.example.ffmpegnew/out"));

  I have solved this, basically there was system permission issues and hence we were not allowed to access the system properties required to run the FFMpeg commands.
  Thus we need to sign the apps with the system certificates and hence we can use FFMpeg commands directly from any android activity.