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• ffmpeg - camera surface stutters with ffmpeg pulling thumbnails and audio from the mpegts stream

  11 mai 2019, par badtrader

  Android 6 NDK 23. I have a camera device which pulls content from HDMI-in port (capture card).

  I am displaying this input on a SurfaceView. At the same time, I am using MediaRecorder to access this h264 data in a mpegts container. I stream the mpegts into a ffmpeg process via pipe. I need this ffmpeg process to continuously extract thumbnails and PCM audio from the most recently captured data.

  The problem is that after varying amount of time(depending on ffmpeg and mediarecorder settings) the surfaceview display begins to stutter very heavily. It will work for about 30 minutes without error before stuttering begins to become more and more noticeable.

  Memory and cpu usage seems constant, cpu temps are low. I am stumped to what is happening here. Have exhausted nearly all the different ffmpeg settings. Should I be trying mediacodec rather than ffmpeg ?

  Even weirder this code works fine depending on the input device to hdmi-in capture. Some devices input will begin to stutter after a while while others won’t.

• How to add title screen to the video using ffmpeg ?

  25 mai 2019, par Rohan Patil

  I am making an story telling video application. In this application the videos which are basically interviews and footage provided by user are merged together, in addition to this the video title which is entered by user should also be merged with rest of the video. I am successfully able to make title video using the title and export it, But the problem occurs when i try to merge the title video with rest of the videos. My app crashes when i try to merge the title video with other videos. Below I have put two commands, first one is for making title video, and the second one is merging that title video with rest of the video. What I want is to merge the title video with other video and export it. Does anyone have any idea to do this ? Thank you !

  command = new String[]{"-f","lavfi","-i","color=c=black:s=1080x1920:d=0.5","-vf","drawtext=fontfile=/system/fonts/DroidSans.ttf:fontsize=45:fontcolor=white:x=(w-text_w)/2:y=(h-text_h)/2:text='hello world'",dest2.getAbsolutePath()}
  
  
  
  
  
  command2=new String[]{"-y","-i",dest2.getAbsolutePath(),"-i", originalpath1, "-i", originalpath2 ,"-strict", "experimental", "-filter_complex",
  
                              "[0:v]scale=1080x1920,setsar=1:1[v0];[1:v]scale=1080x1920,setsar=1:1[v1];[2:v]scale=1080x1920,setsar=1:1[v2];[v0][0:a][v1][1:a][v2][2:a] concat=n=3:v=1:a=1",
  
                              "-ab", "48000", "-ac", "2", "-ar", "22050", "-s", "1080x1920", "-vcodec", "libx264","-crf","27","-q","4","-preset", "ultrafast", dest.getAbsolutePath()};

• Making a ffmpeg screen capture on Mac OS X using YUV 4:2:0 Planar color model

  30 mai 2019, par Bass

  I make screen recordings with ffmpeg, using avfoundation on Mac OS X, x11grab on Linux and gdigrab on Windows.

  The resulting files should be compatible with modern web browsers (<video></video>), so I use H.264 codec and request YUV 4:2:0 Planar pixel format.

  On Mac OS X, however (unlike Linux and Windows), I receive the following logging :

  /usr/local/bin/ffmpeg -y -v error -f avfoundation -threads 0 -hide_banner -i 1:none -f mp4 -vcodec h264 -pix_fmt yuv420p -r 25/1 -qscale:v 1 -vf scale=-1:1080 target.mp4
  
  [avfoundation @ 0x7fdba2003a00] Selected pixel format (yuv420p) is not supported by the input device.
  
  [avfoundation @ 0x7fdba2003a00] Supported pixel formats:
  
  [avfoundation @ 0x7fdba2003a00]   uyvy422
  
  [avfoundation @ 0x7fdba2003a00]   yuyv422
  
  [avfoundation @ 0x7fdba2003a00]   nv12
  
  [avfoundation @ 0x7fdba2003a00]   0rgb
  
  [avfoundation @ 0x7fdba2003a00]   bgr0

  Still, according to mplayer, the resulting MP4 file seems to have YUV 4:2:0 Planar color model :

  [h264 @ 0x1048a8ac0]Format yuv420p chosen by get_format().
  
  [h264 @ 0x1048a8ac0]Reinit context to 1728x1088, pix_fmt: yuv420p
  
  [h264 @ 0x1048a8ac0]Format yuv420p chosen by get_format().
  
  [h264 @ 0x1048a8ac0]Reinit context to 1728x1088, pix_fmt: yuv420p
  
  [swscaler @ 0x1048c3cc0]bicubic scaler, from yuv420p to yuyv422 using MMXEXT
  
  *** [scale] Exporting mp_image_t, 1728x1080x12bpp YUV planar, 2799360 bytes
  
  *** [vo] Allocating mp_image_t, 1728x1080x16bpp YUV packed, 3732480 bytes

  the same confirmed by ffmpeg :

  $ ffmpeg -i target.mp4 -hide_banner
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'target.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.20.100
  
    Duration: 00:00:04.72, start: 0.000000, bitrate: 201 kb/s
  
      Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1728x1080, 197 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler

  Questions :

  1. Can someone explain the above ffmpeg logging ?
  2. If I still need to convert the avfoundation video stream to yuv420p, how do I make it on the fly (in a single ffmpeg pass) ?