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• Can't load ImageFile [FFmpeg on Android]

  11 août 2012, par user1586537

  My purpose is same here

  FFmpeg : Jpeg file to AVFrame
  
  but, I was stumble before that loading file.
  at
  

  if(av_open_input_file(&pFormatCtx, imageFileName, NULL, 0, NULL)!=0)
  
  {
  
      printf("Can't open image file '%s'\n", imageFileName);
  
      return NULL;
  
  }       

  This point return always Can't open image file /sdcard/test.jpg on Emulator(ICS) and real device(Froyo).
  
  ・Of cause wrote android.permission.WRITE_EXTERNAL_STORAGE in Manufest
  ・Change the file path is all failed sdcard/test.jpg,sdcard/test.jpeg,mnt/sdcard/test.jpeg,/mnt...
  
  ・My FFmpeg ver0.8.12
  
  And Video files are passed this point(FLV,MEPGVIDEO..)

  Anything else ?

• Revision f6582d6928 : Revert "Simplify mask checking in loop filters" Jingning saw bitstream change w

  4 décembre 2013, par Yunqing Wang

  Changed Paths :
   Modify /vp9/common/vp9_loopfilter.c

  
  
  Revert "Simplify mask checking in loop filters"

  Jingning saw bitstream change with this patch. It could be true
  that (mask_16x16_0 & 1) is 1, but (mask_16x16_1 & 1) is 0 in some
  edge cases.

  This reverts commit 8f05e70340533b9922be5b1c97c37e50607fd862.

  Change-Id : I0a529435ce816a1e14653eb510d5090de276070a

• WebRTC Stream Freezes When Picture Complexity Increases

  12 octobre 2021, par user1259576

  I am developing an application that uses WebRTC to display a live video stream being captured from a V4L2 source. The stream originates from a Linux box that has a DVI-USB capture card, is encoded to H264 by ffmpeg and sent to RTP, received by a Janus WebRTC server which is accessed by the web interface.

  


  Here is my current ffmpeg command - pretty simple :
ffmpeg -f v4l2 -i /dev/video0 -vf "transpose=1,scale=768:1024" -vcodec libx264 -profile:v baseline -pix_fmt yuv420p -f rtp rtp ://10.116.80.86:8004

  


  I can't go into details, but the DVI source generates a portrait 768x1024 image that initially is a simple image where the only movement is a small clock near the center that increments every second. At this stage, everything appears to work great. The image is high-quality and continuous/smooth in the browser.

  


  Once I interact with the DVI source, a more complex image is generated, with some text/lines in the upper half. Still not very complex - only 2 colors involved and some basic 1px line shapes, and only the little clock is moving. At this point, the video starts to freeze frequently, and only updates once in a while for a few seconds. Bandwidth should not be an issue here, and the bitrate appears to stay high. However, many fewer frames are decoded.

  


  I have also tried scaling the video down to 480x640 from 768x1024 and with that change the issue does not occur. However, I really need the full resolution and, again, there should not be a bandwidth issue here.

  


  I have also tried capturing the output of ffmpeg to a file rather than streaming to RTP and in the file everything is good.

  


  Here is a screenshot of the WebRTC internals (in Edge) for this stream. You can clearly see when the video image changes from the simple clock to including more shapes & text (nothing is changed here other than the image from the DVI source) :

  


  

  


  In Firefox, the video just freezes whenever frames are not decoded. In Edge, the video goes black after a moment with no frames decoded.

  


  Any ideas as to what might be causing this ?