Recherche avancée

Sur d’autres sites (3319)

• Playing MP4 file in Powerpoint

  28 août 2014, par BrewGold

  I have a huge MP4 file (4GB) an hour long video. I want to extract port of the file. So I used the following command to extract 70 seconds(00:01:10) of video starting from 11 minutes

  ffmpeg -i INPUT.mp4 -ss 00:11:00 -t 00:01:10 -c:v copy -c:a copy OUTPUT.mp4

  Now I got a small file extracted from Input.MP4
  The output.mp4 file size is still big(90 MB). So I used the following command

  ffmpeg -i OUTPUT.mp4 -c:v libx264 -crf 30 SmallSizeVideo.avi

  I got SmallSizeVideo.avi file which is approximately 6MB.

  I am using Powerpoint 2010. I want to insert the video in Powerpoint and play.

  Unfortunately when I embed SmallSizeVideo.avi Powerpoint is unable to play

  1) Is my approach correct ?
  2) What is the best way to situation like me to play small portion of clips in powerpoint

  Thank you

• Why does linking different MSVC Run-Time Libraries crash in release mode ?

  9 septembre 2014, par UmNyobe

  I am using ffmpeg and Qt to build a small demo app.

  • FFmpeg is built with /MT (crossbuild or built with visual 2010)
  • Qt is always built with /MD
  • My little example is always built with /MD

  When the application

  int main(int argc, char *argv[])
  
  {
  
      QApplication a(argc, argv);
  
  
  
      av_gcd (75, 25);
  
  
  
      return a.exec();
  
  }
  
  
  
  //note : following is av_gcd source in ffmpeg libs:
  
  int64_t av_gcd(int64_t a, int64_t b)
  
  {
  
      if (b)
  
          return av_gcd(b, a % b);
  
      else
  
          return a;
  
  }

  is executed in release mode it crashes because it doesn’t see av_gcd as executable memory. The error is :

  First-chance exception at 0x0000000300905a4d in mylittleexample.exe :
  0xC0000005 : Access violation at location 0x0000000300905a4d.

  =======================================
  VERIFIER STOP 0000000000000650 : pid 0x1B9C : Attempt to execute code in
  non-executable memory (first chance).

  0000000300905A4D : Address being accessed.
  0000000300905A4D : Code
  performing invalid access.
  00000000009FF770 : Exception record. Use
  .exr to display it.
  00000000009FF280 : Context record. Use .cxr to
  display it.

  =======================================

  The address 0x0000000300905a4d doesnt change regardless of the function in the library (ffmpeg in this case), or the compiler used for the executable (vs2010, vs2012) or a different machine.

  If I use the FFmpeg built with /MD and it works as one would expect.

  1. I observe that the executable doesnt load the library when the
     library is compiled with /MT. Why is that ?
  2. Furthermore, If the library is compiled with /MT and debug
     information is enabled when the application is linked (/DEBUG
     param to the linker) then the library is loaded and everything
     execute correctly. Why ?

• Convert WMV to mp4 using ffmpeg get Black screen

  16 mars 2015, par HawkEye000

  When converting an .wmv file to .mp4 i used this command :

  exec("ffmpeg -i file.wmv -vcodec mpeg4 -acodec libfaac -b 1200 -r 15 -s 320x240 -pix_fmt yuv420p file.mp4") ;

  Sound is fine but i have no image (using html5 not when downloaded to pc) .
  this is the outputs :

  FFmpeg version 0.6.5, Copyright (c) 2000-2010 the FFmpeg developers
  
    built on Jan 29 2012 17:52:15 with gcc 4.4.5 20110214 (Red Hat 4.4.5-6)
  
    configuration: --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64 --mandir=/usr/share/man --incdir=/usr/include --disable-avisynth --extra-cflags='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic -fPIC' --enable-avfilter --enable-avfilter-lavf --enable-libdc1394 --enable-libdirac --enable-libfaac --enable-libfaad --enable-libfaadbin --enable-libgsm --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libx264 --enable-gpl --enable-nonfree --enable-postproc --enable-pthreads --enable-shared --enable-swscale --enable-vdpau --enable-version3 --enable-x11grab
  
    libavutil     50.15. 1 / 50.15. 1
  
    libavcodec    52.72. 2 / 52.72. 2
  
    libavformat   52.64. 2 / 52.64. 2
  
    libavdevice   52. 2. 0 / 52. 2. 0
  
    libavfilter    1.19. 0 /  1.19. 0
  
    libswscale     0.11. 0 /  0.11. 0
  
    libpostproc   51. 2. 0 / 51. 2. 0
  
  [wmv3 @ 0xc2daa0]Extra data: 8 bits left, value: 20
  
  
  
  Seems stream 1 codec frame rate differs from container frame rate: 1000.00 (1000/1) -> 30.00 (30/1)
  
  Input #0, asf, from '/home/xxx/public_html/new/zawmju.wmv':
  
    Metadata:
  
      Application     : Windows Movie Maker 2.6.4037.0
  
      WM/ParentalRating: 
  
      WMFSDKVersion   : 12.0.9200.16384
  
      WMFSDKNeeded    : 0.0.0.0000
  
      IsVBR           : 0
  
      title           : 
  
      author          : SahlaTube
  
      copyright       : 
  
      comment         : 
  
    Duration: 00:00:04.03, start: 2.000000, bitrate: 740 kb/s
  
      Stream #0.0: Audio: wmav2, 44100 Hz, 2 channels, s16, 64 kb/s
  
      Stream #0.1: Video: wmv3, yuv420p, 640x480, 30 tbr, 1k tbn, 1k tbc
  
  [wmv3 @ 0xc2daa0]Extra data: 8 bits left, value: 20
  
  Output #0, mp4, to '/home/xxx/public_html/new/zawmju.wmv.mp4':
  
    Metadata:
  
      encoder         : Lavf52.64.2
  
      Stream #0.0: Video: mpeg4, yuv420p, 320x240, q=2-31, 1 kb/s, 15 tbn, 15 tbc
  
      Stream #0.1: Audio: libfaac, 44100 Hz, 2 channels, s16, 64 kb/s
  
  Stream mapping:
  
    Stream #0.1 -> #0.0
  
    Stream #0.0 -> #0.1
  
  Press [q] to stop encoding
  
  frame=   61 fps=  0 q=24.8 Lsize=      82kB time=4.02 bitrate= 166.4kbits/s dup=0 drop=59    
  
  
  
  video:55kB audio:24kB global headers:0kB muxing overhead 3.828952%