Recherche avancée

Sur d’autres sites (13305)

• Can't write out flv file in openCV in Windows

  7 août 2015, par dev_nut

  I’m trying to write out a flv file in openCV 2.4.9 in Windows 8.1 and it seems this gives an error.

      [flv @ 05821a00] Tag FLV1/0x31564c46 incompatible with output codec id '22' ([2]
  
  [0][0][0])

  After googling around, I noticed that I may have to recompile with ffmpeg support. I set up cmake (I’m a cmake noob) and did that. But, I didn’t change anything with regard to ffmpeg (like point to new libraries). I can’t seem to find a guide that would help me here.Is this the right way to go ? Would recompiling in this case, actually help at all ?

  • How do I solve this problem ?

• Why do I get different codecs on Windows and Linux with same code ?

  27 janvier 2016, par user3277340

  I am using the API version of FFMPEG to generate a MP4 file from a series of images. I specify the output by calling

  AVFormatContext *oc = NULL ;
  avformat_alloc_output_context2 (&oc,NULL,"mp4",NULL) ;

  Running the exact same code on Windows and Linux I get different codecs assigned. On Windows, the value of oc->oformat->video_code is AV_CODEC_ID_H264 (28), but on Linux I get AV_CODEC_ID_MPEG4.

  I tracked this down because on Windows my calls to avcodec_encode_video2(.,.,.,&got_packet) were always returning got_packet=0 so I never called av_interleaved_write_frame. I added a NULL AVFrame at the end to flush the video. But it was very small and did not contain the images I expected to see there.

  But on Linux everything worked just fine. So I went ahead and manually changed the value of oc->oformat->video_code and I got the expected results.

  My questions :

  1) Why do I get different codec types on different platforms with the same code ? Is there a parameter I need to set to force MPEG4 ?

  2) Is it "legal" to change this parameter after the call to avformat_alloc_output_context2 ? My concern is that "oc" has been properly initialized and, with the change, something may be inconsistent.

  3) Is there a way to force the MPEG4 codec on any machine ?

  Thanks.

• ffmpeg running on windows with java

  24 décembre 2013, par Karn_way

  I have simple test class as

  public static void main(String[] args) throws IOException {
  
  
  
           String[] line = {"ffmpeg -i D:\\hadoop-video\\testVideo\\xyz.mp4 %d.png"};
  
           Runtime.getRuntime().exec(line);
  
  
  
      }

  when I try to run this I am getting

  Exception in thread "main" java.io.IOException: Cannot run program "ffmpeg -i D:/hadoop-video/testVideo/xyz.mp4 %d.png": CreateProcess error=2, The system cannot find the file specified
  
      at java.lang.ProcessBuilder.start(Unknown Source)
  
      at java.lang.Runtime.exec(Unknown Source)
  
      at java.lang.Runtime.exec(Unknown Source)
  
      at ImageTest.main(ImageTest.java:13)
  
  Caused by: java.io.IOException: CreateProcess error=2, The system cannot find the file specified

  however file is present on my windows7 machine with location

  D:\hadoop-video\testVideo\xyz.mp4

  i tried removing .mp4 and then run also not working . please suggest what might be wrong