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• flush encoded packets to disk when muxing audio and video

  23 juin 2016, par chandu

  I am using muxing.c example (without any modifications) provided with ffmpeg 3.0 version to create MP4 file (H.264 & AAC) with VS 2013. The sample is working fine with default width & height for video. But when changed the width to 1920 and height to 1080, sample is taking nearly 400MB (using task manager & in Release mode) through out the program and also never writing the encoded packets to the out file. It is writing to the out file (out.mp4) only when calling avcodec_close() at the end.

  I have tried to

  1. free the encoded packet after calling write_frame().
  2. used avio_flush()
  3. used avcodec_flush_buffers()

  but no success.

  Could anybody please tell me, how can I save the every encoded packet to disk by not keeping in RAM, so the memory usage would be low ?

  Note : There is no issue with flushing the buffers after recording is over, I am doing this by calling av_interleaved_write_frame() with AVPacket NULL.

• Webcam streaming from Mac using FFmpeg

  22 juillet 2016, par Galaxy

  I want to stream my webcam from Mac using FFmpeg.

  First I checked the supported devices using ffmpeg -f avfoundation -list_devices true -i ""

  Output :

  [AVFoundation input device @ 0x7fdf1bd03000] AVFoundation video devices:
  
  [AVFoundation input device @ 0x7fdf1bd03000] [0] USB 2.0 Camera #2
  
  [AVFoundation input device @ 0x7fdf1bd03000] [1] FaceTime HD Camera
  
  [AVFoundation input device @ 0x7fdf1bd03000] [2] Capture screen 0
  
  [AVFoundation input device @ 0x7fdf1bd03000] [3] Capture screen 1
  
  [AVFoundation input device @ 0x7fdf1bd03000] AVFoundation audio devices:
  
  [AVFoundation input device @ 0x7fdf1bd03000] [0] Built-in Microphone

  The device[0] is the webcam I want to use.

  ---

  Then I tried to capture the webcam using ffmpeg -f avfoundation -i "0" out.mpg

  Output :

  [avfoundation @ 0x7fe7f3810600] Selected framerate (29.970030) is not supported by the device
  
  [avfoundation @ 0x7fe7f3810600] Supported modes:
  
  [avfoundation @ 0x7fe7f3810600]   320x240@[120.101366 120.101366]fps
  
  [avfoundation @ 0x7fe7f3810600]   640x480@[120.101366 120.101366]fps
  
  [avfoundation @ 0x7fe7f3810600]   800x600@[60.000240 60.000240]fps
  
  [avfoundation @ 0x7fe7f3810600]   1024x768@[30.000030 30.000030]fps
  
  [avfoundation @ 0x7fe7f3810600]   1280x720@[60.000240 60.000240]fps
  
  [avfoundation @ 0x7fe7f3810600]   1280x1024@[30.000030 30.000030]fps
  
  [avfoundation @ 0x7fe7f3810600]   1920x1080@[30.000030 30.000030]fps
  
  [avfoundation @ 0x7fe7f3810600]   320x240@[30.000030 30.000030]fps
  
  [avfoundation @ 0x7fe7f3810600]   640x480@[30.000030 30.000030]fps
  
  [avfoundation @ 0x7fe7f3810600]   800x600@[20.000000 20.000000]fps
  
  [avfoundation @ 0x7fe7f3810600]   1024x768@[6.000002 6.000002]fps
  
  0: Input/output error

  ---

  After that, I tried stream this webcam from my Mac using ffmpeg -f avfoundation -framerate 30 -i "0" -f mpeg1video -b 200k -r 30 -vf scale=1920:1080 http://127.0.0.1:8082/

  Output :

  [avfoundation @ 0x7f8515012800] An error occurred: The activeVideoMinFrameDuration passed is not supported by the device.  Use -activeFormat.videoSupportedFrameRateRanges to discover valid ranges.0: Input/output error

  ---

  I cannot capture or stream this webcam. However when I used the Facetime camera instead of this webcam, everything was OK. I’ve been searching for this problem for a few days, but still cannot fix it. Does anyone have experience with webcam and FFmpeg on Mac ?

• ffmpeg combine images and audio into video and loop through images until end of audio

  12 avril 2022, par george

  I have found this code to combine multiple images and one audio file into video, but what I want is the images to loop until the end of audio. So what I mean, if I have 5 images and each image is shown for 5 seconds, after 25 seconds show again the first image, second image etc and this will continue until the end of audio.

  


  ffmpeg -r 0.2 -i Scan-130802-%04d.jpg -i "1.mp3" \
       -vcodec libx264 -vf scale=1920:1080 \
       -crf 25 -preset slow -acodec copy video.mp4


  


  another problem I have is that with the above code the images appear horizontally flipped for some reason.