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• Android FFmpeg fbdev0

  17 juillet 2014, par nLL

  I have compiled FFmpeg and using to capture from fbdev with command

  adb shell /system/bin/ffmpeg -y -f fbdev -i /dev/graphics/fb0 -vcodec mpeg4 -b:v 4000000 -r 24 /sdcard/a.mp4

  On 2 test devices this works fine but on the 3rd one (Samsung s3 with Android 4.3) generated video is all mixed up. I can see from FFmpeg out put below that buffer from fbdev has only 50 height which is wrong. I have tried to resize it with FFmpeg without any luck

  Do you think it can be fixed by re processing it some how ? Or this is a bug with the firmware/rom ?

  [fbdev @ 0x1060d30] w:720 h:50 bpp:32 pixfmt:bgra fps:25/1 bit_rate:28800000
  
  Input #0, fbdev, from '/dev/graphics/fb0':
  
  Duration: N/A, start: 1405583288.995053, bitrate: 28800 kb/s
  
  Stream #0:0: Video: rawvideo (BGRA / 0x41524742), bgra, 720x50, 28800 kb/s,
  
  25 tbr, 1000k tbn, 25 tbc

• Bash : displaying selected output, do not print unnecessary output

  2 juillet 2014, par Guillaume

  I don’t know if it’s possible :
  I’m using ffmpeg and I would like to reduce the output of a command. I have this result :

  ffmpeg version 2.2.git Copyright (c) 2000-2014 the FFmpeg developers
  
    built on Jun 17 2014 11:08:12 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
  
    configuration: --prefix=/usr/local --enable-gpl --enable-nonfree --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxvid --enable-libvidstab --enable-libx265
  
    libavutil      52. 89.100 / 52. 89.100
  
    libavcodec     55. 67.100 / 55. 67.100
  
    libavformat    55. 43.100 / 55. 43.100
  
    libavdevice    55. 13.101 / 55. 13.101
  
    libavfilter     4.  8.100 /  4.  8.100
  
    libswscale      2.  6.100 /  2.  6.100
  
    libswresample   0. 19.100 /  0. 19.100
  
    libpostproc    52.  3.100 / 52.  3.100
  
  Input #0, hls,applehttp, from 'http://ftvodhdsecz-f.akamaihd.net/i/streaming-adaptatif_france-dom-tom/2014/S26/J7/104904507-20140629-,398,632,934,k.mp4.csmil/index_2_av.m3u8?null=':
  
    Duration: 00:51:05.07, start: 0.100667, bitrate: 0 kb/s
  
    Program 0 
  
      Metadata:
  
        variant_bitrate : 0
  
      Stream #0:0: Video: h264 (Main) ([27][0][0][0] / 0x001B), yuv420p, 704x396 [SAR 1:1 DAR 16:9], 25 fps, 25 tbr, 90k tbn, 50 tbc
  
      Stream #0:1: Audio: aac ([15][0][0][0] / 0x000F), 48000 Hz, stereo, fltp, 67 kb/s
  
      Stream #0:2: Data: timed_id3 (ID3  / 0x20334449)
  
  File '/media/path/video.mkv' already exists. Overwrite ? [y/N] y
  
  [matroska @ 0x2958840] Error parsing AAC extradata, unable to determine samplerate.
  
  Output #0, matroska, to '/media/path/video.mkv':
  
    Metadata:
  
      encoder         : Lavf55.43.100
  
      Stream #0:0: Video: h264 (H264 / 0x34363248), yuv420p, 704x396 [SAR 1:1 DAR 16:9], q=2-31, 25 fps, 1k tbn, 90k tbc
  
      Stream #0:1: Audio: aac ([255][0][0][0] / 0x00FF), 48000 Hz, stereo, 67 kb/s
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (copy)
  
    Stream #0:1 -> #0:1 (copy)
  
  Press [q] to stop, [?] for help
  
  [hls,applehttp @ 0x2864c20] Failed to open segment of playlist 0ate= 844.6kbits/s    
  
  frame= 3000 fps=174 q=-1.0 Lsize=   12325kB time=00:02:00.00 bitrate= 841.4kbits/s 

  I just would like to have this 4 informations :

  1) Duration: 00:51:05.07, start: 0.100667, bitrate: 0 kb/s
  
  2)  File '/media/path/video.mkv' already exists. Overwrite ? [y/N] y
  
  3)  Output #0, matroska, to '/media/path/video.mkv':
  
  4)  frame= 3000 fps=174 q=-1.0 Lsize=   12325kB time=00:02:00.00 bitrate= 841.4kbits/s 

  I’ve tried the -v option, but the output is either -v info (this long output), or -v warning, or -v error. There’s not what I would like to have.
  I’ve seen this question but the output is totally clear. Can I put an exception for specially string ?
  Thanks all

  Edit : my line in my script is like that :

  ffmpeg -i "${M3U2}" -vcodec copy -acodec copy "${Directory}/${PROG}_${ID}.mkv"

• Piping file contents to ffmpeg

  30 juin 2014, par user2739431

  I’m currently using this ffmpeg command to generate 2 png images from the raw image fb0 file on an android device.

  ffmpeg -vcodec rawvideo -f rawvideo -pix_fmt rgb32 -s 720x1280 -i fb0
  -f image2 -vcodec png image_%03d.png

  I’m pulling the fb0 file with adb pull before running this command but I’m wondering if I can just cat and pipe the output of it to the ffmpeg command rather than having to save the file locally beforehand. Is this possible, and if so how would it be done ? Thanks

  edit : this post from 2010 says piping in ffmpeg can only be done with video, is this still the case ?

  I tried to do this, and it does work except my image is distorted, any suggestions ?

  adb shell cat /dev/graphics/fb0 | ffmpeg -vcodec rawvideo -f rawvideo
  -pix_fmt rgb32 -s 720x1280 -i pipe:0 -f image2 -vcodec png image_%03d.png

  it gives an "Invalid buffer size" error too.