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• ALSA buffer xrun induced by low quality source in ffmpeg capture

  24 juin 2015, par Peter Becich

  I am attempting to transfer some old Video 8 tapes to my computer, though an EasyCap USB stick and the motherboard’s sound line-in, on Ubuntu. I believe the arguments are correctly laid out below to capture from two independent streams, and encode them both into the output MP4 file.

  Edit :

  I can simplify the question a bit, now.

  ALSA buffer overrun (or underrun ?) is induced by the unreliable/noisy audio source. For instance, if ffmpeg captures the beginning of tape playback, this causes "buffer xrun" far beyond when the tape gets up to speed and playback should be normal.

  It is interesting that the bitrate shown in the ffmpeg log shoots up higher than normal when it’s producing a garbage output ! (Is this bitrate a sum of of audio and video bitrates ?)

  I’ve tried a couple of audio encoding codecs, and had the same problem.

  Using libfdk_aac :

    Metadata:
  
      encoder         : Lavf56.15.102
  
      Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv422p, 640x480, q=-1--1, 29.97 fps, 11988 tbn, 29.97 tbc
  
      Metadata:
  
        encoder         : Lavc56.13.100 libx264
  
      Stream #0:1: Audio: aac (libfdk_aac) ([64][0][0][0] / 0x0040), 48000 Hz, mono, s16, 128 kb/s
  
      Metadata:
  
        encoder         : Lavc56.13.100 libfdk_aac
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264))
  
    Stream #1:0 -> #0:1 (pcm_s16le (native) -> aac (libfdk_aac))
  
  [alsa @ 0x22038a0] ALSA buffer xrun.  0kB time=00:00:00.00 bitrate=N/A    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.1934kB time=00:00:02.76 bitrate=5723.5kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.4795kB time=00:00:05.49 bitrate=7150.1kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.7668kB time=00:00:08.21 bitrate=7646.1kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.1475kB time=00:00:10.94 bitrate=8588.9kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.3822kB time=00:00:13.66 bitrate=8289.0kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.5388kB time=00:00:16.38 bitrate=7695.0kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.6896kB time=00:00:19.10 bitrate=7244.0kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.8980kB time=00:00:21.84 bitrate=7118.8kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.2032kB time=00:00:24.55 bitrate=7349.3kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.4612kB time=00:00:27.27 bitrate=7391.1kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.6660kB time=00:00:29.98 bitrate=7284.6kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.9123kB time=00:00:32.68 bitrate=7299.3kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.0641kB time=00:00:35.39 bitrate=7091.7kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.2601kB time=00:00:38.13 bitrate=7002.6kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.5828kB time=00:00:40.87 bitrate=7181.0kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.8481kB time=00:00:43.60 bitrate=7229.9kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.1461kB time=00:00:46.34 bitrate=7328.0kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.3982kB time=00:00:49.06 bitrate=7342.7kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.6565kB time=00:00:51.77 bitrate=7367.8kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.9718kB time=00:00:54.51 bitrate=7471.3kbits/s    
  
  [alsa @ 0x22038a0] ALSA buffer xrun.2341kB time=00:00:57.25 bitrate=7489.2kbits/s    
  
  ^Cframe= 1760 fps= 29 q=-1.0 Lsize=   53946kB time=00:01:00.04 bitrate=7360.3kbits/s    
  
  video:53880kB audio:53kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.022994%
  
  [libx264 @ 0x2217ac0] frame I:8     Avg QP:24.00  size: 55686
  
  [libx264 @ 0x2217ac0] frame P:1752  Avg QP:27.66  size: 31237
  
  [libx264 @ 0x2217ac0] mb I  I16..4: 100.0%  0.0%  0.0%
  
  [libx264 @ 0x2217ac0] mb P  I16..4: 15.0%  0.0%  0.0%  P16..4: 80.2%  0.0%  0.0%  0.0%  0.0%    skip: 4.8%
  
  [libx264 @ 0x2217ac0] coded y,uvDC,uvAC intra: 45.3% 86.6% 59.4% inter: 65.7% 81.3% 11.5%
  
  [libx264 @ 0x2217ac0] i16 v,h,dc,p: 40% 25% 26%  9%
  
  [libx264 @ 0x2217ac0] i8c dc,h,v,p: 45% 24% 19% 12%
  
  [libx264 @ 0x2217ac0] kb/s:7516.07
  
  Received signal 2: terminating.

  Using libvorbis :

    Metadata:
  
      encoder         : Lavf56.15.102
  
      Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv422p, 640x480, q=-1--1, 29.97 fps, 11988 tbn, 29.97 tbc
  
      Metadata:
  
        encoder         : Lavc56.13.100 libx264
  
      Stream #0:1: Audio: vorbis (libvorbis) ([221][0][0][0] / 0x00DD), 48000 Hz, mono, fltp, 128 kb/s
  
      Metadata:
  
        encoder         : Lavc56.13.100 libvorbis
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264))
  
    Stream #1:0 -> #0:1 (pcm_s16le (native) -> vorbis (libvorbis))
  
  [alsa @ 0x1a948a0] ALSA buffer xrun.  0kB time=00:00:00.00 bitrate=N/A    
  
  [alsa @ 0x1a948a0] ALSA buffer xrun. 402kB time=00:00:04.37 bitrate= 752.3kbits/s    
  
  [alsa @ 0x1a948a0] ALSA buffer xrun.4122kB time=00:00:08.80 bitrate=3833.0kbits/s    
  
  [alsa @ 0x1a948a0] ALSA buffer xrun.8722kB time=00:00:13.14 bitrate=5436.3kbits/s    
  
  [alsa @ 0x1a948a0] ALSA buffer xrun.3903kB time=00:00:17.51 bitrate=6502.2kbits/s    
  
  [alsa @ 0x1a948a0] ALSA buffer xrun.6625kB time=00:00:21.89 bitrate=6221.4kbits/s    
  
  [alsa @ 0x1a948a0] ALSA buffer xrun.9548kB time=00:00:26.28 bitrate=6092.5kbits/s    
  
  ^Cframe=  851 fps= 26 q=-1.0 Lsize=   22018kB time=00:00:30.69 bitrate=5875.3kbits/s    
  
  video:21996kB audio:12kB subtitle:0kB other streams:0kB global headers:4kB muxing overhead: 0.044897%
  
  [libx264 @ 0x1aa8ac0] frame I:4     Avg QP:23.50  size: 62405
  
  [libx264 @ 0x1aa8ac0] frame P:847   Avg QP:25.58  size: 26297
  
  [libx264 @ 0x1aa8ac0] mb I  I16..4: 100.0%  0.0%  0.0%
  
  [libx264 @ 0x1aa8ac0] mb P  I16..4: 13.2%  0.0%  0.0%  P16..4: 72.0%  0.0%  0.0%  0.0%  0.0%    skip:14.8%
  
  [libx264 @ 0x1aa8ac0] coded y,uvDC,uvAC intra: 40.6% 81.0% 58.6% inter: 58.8% 72.7% 8.6%
  
  [libx264 @ 0x1aa8ac0] i16 v,h,dc,p: 41% 28% 22%  9%
  
  [libx264 @ 0x1aa8ac0] i8c dc,h,v,p: 54% 19% 16% 11%
  
  [libx264 @ 0x1aa8ac0] kb/s:6345.60
  
  Received signal 2: terminating.

  ---

  ffmpeg’s detection of the ALSA stream is seemingly goofed up by the inconsistencies of the tape. In the failure case, only short blips of the tapes audio exist in the output MP4. The audio bitrate of the output file is less than 10 kbps, averaged out across the whole file. The output video seems to be fine, even though the low frames-per-second in the failure case log below.

  The audio and video streams can be captured fine for short amounts of time before a source error occurs ; this provides the success case log. The failure case log was created by intentionally making an error in the source streams — turning on the camera makes a brief noisy signal.

  Is there a setting that needs to be forced to keep ffmpeg recording the audio stream, even when the tape is blank or noisy ?

  Could it be that the libfdk_aac audio encoder is tripped up by the low quality source ?

  The relevant line ; rawvideo stream is piped to this in script at bottom :

  ffmpeg -pixel_format uyvy422 -s:v 720x480 -framerate 29.97 -f rawvideo \
  
  -i $PIPE  -f alsa -i hw:0,0 -vf scale=w=720:h=540 -vcodec libx264 \
  
  -preset ultrafast -shortest -c:a libfdk_aac -b:a 128k -af pan=1:c0=c0  \
  
  -ar 96000 $OUTFILE

  The ar argument was one attempt to force recording.

  ffmpeg log file for (short-lived) success ; high frames-per-second captured :

  ffmpeg version 2.5.3 Copyright (c) 2000-2015 the FFmpeg developers
  
    built on Jan 11 2015 17:53:45 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
  
    configuration: --extra-libs=-ldl --prefix=/opt/ffmpeg --enable-avresample --disable-debug --enable-nonfree --enable-gpl --enable-version3 --enable-libpulse --enable-libopencore-amrnb --enable-libopencore-amrwb --disable-decoder=amrnb --disable-decoder=amrwb --enable-libx264 --enable-libx265 --enable-libfdk-aac --enable-libvorbis --enable-libmp3lame --enable-libopus --enable-libvpx --enable-libspeex --enable-libass --enable-avisynth --enable-libsoxr --enable-libxvid --enable-libvo-aacenc --enable-libvidstab
  
    libavutil      54. 15.100 / 54. 15.100
  
    libavcodec     56. 13.100 / 56. 13.100
  
    libavformat    56. 15.102 / 56. 15.102
  
    libavdevice    56.  3.100 / 56.  3.100
  
    libavfilter     5.  2.103 /  5.  2.103
  
    libavresample   2.  1.  0 /  2.  1.  0
  
    libswscale      3.  1.101 /  3.  1.101
  
    libswresample   1.  1.100 /  1.  1.100
  
    libpostproc    53.  3.100 / 53.  3.100
  
  Input #0, rawvideo, from '/tmp/somagic-pipe':
  
    Duration: N/A, start: 0.000000, bitrate: 165722 kb/s
  
      Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422, 720x480, 165722 kb/s, 29.97 tbr, 29.97 tbn, 29.97 tbc
  
  Home directory not accessible: Permission denied
  
  Guessed Channel Layout for  Input Stream #1.0 : stereo
  
  Input #1, alsa, from 'hw:0,0':
  
    Duration: N/A, start: 1423202268.577088, bitrate: 1536 kb/s
  
      Stream #1:0: Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s
  
  No pixel format specified, yuv422p for H.264 encoding chosen.
  
  Use -pix_fmt yuv420p for compatibility with outdated media players.
  
  [Parsed_pan_0 @ 0x3335d60] This syntax is deprecated. Use '|' to separate the list items.
  
  Single channel layout '1' is interpreted as a number of channels, switch to the syntax '1c' otherwise it will be interpreted as a channel layout number in a later version
  
  [Parsed_pan_0 @ 0x3335d60] Pure channel mapping detected: 0
  
  [libx264 @ 0x3364bc0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.1 Cache64
  
  [libx264 @ 0x3364bc0] profile High 4:2:2, level 3.1, 4:2:2 8-bit
  
  [libx264 @ 0x3364bc0] 264 - core 142 r2389 956c8d8 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - http://www.videolan.org/x264.html - options: cabac=0 ref=1 deblock=0:0:0 analyse=0:0 me=dia subme=0 psy=1 psy_rd=1.00:0.00 mixed_ref=0 me_range=16 chroma_me=1 trellis=0 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=0 threads=3 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=250 keyint_min=25 scenecut=0 intra_refresh=0 rc=crf mbtree=0 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=0
  
  Output #0, mp4, to '/home/peterbecich/easycap/Videos/fpv_video_02_05_2015_21_57_48.mp4':
  
    Metadata:
  
      encoder         : Lavf56.15.102
  
      Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv422p, 720x540, q=-1--1, 29.97 fps, 11988 tbn, 29.97 tbc
  
      Metadata:
  
        encoder         : Lavc56.13.100 libx264
  
      Stream #0:1: Audio: aac (libfdk_aac) ([64][0][0][0] / 0x0040), 96000 Hz, mono, s16, 128 kb/s
  
      Metadata:
  
        encoder         : Lavc56.13.100 libfdk_aac
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264))
  
    Stream #1:0 -> #0:1 (pcm_s16le (native) -> aac (libfdk_aac))
  
  Press [q] to stop, [?] for help
  
  frame=   13 fps=0.0 q=26.0 size=     187kB time=00:00:00.30 bitrate=5102.7kbits/s    
  
  frame=   29 fps= 29 q=26.0 size=     469kB time=00:00:00.83 bitrate=4607.6kbits/s    
  
  frame=   44 fps= 29 q=26.0 size=     755kB time=00:00:01.33 bitrate=4635.2kbits/s    
  
  frame=   59 fps= 29 q=26.0 size=    1024kB time=00:00:01.83 bitrate=4572.1kbits/s    
  
  frame=   74 fps= 29 q=26.0 size=    1279kB time=00:00:02.33 bitrate=4486.5kbits/s    
  
  frame=   89 fps= 29 q=26.0 size=    1516kB time=00:00:02.83 bitrate=4378.0kbits/s    
  
  frame=  104 fps= 29 q=26.0 size=    1752kB time=00:00:03.33 bitrate=4301.0kbits/s    
  
  frame=  119 fps= 29 q=26.0 size=    1991kB time=00:00:03.83 bitrate=4251.1kbits/s    
  
  frame=  135 fps= 30 q=26.0 size=    2245kB time=00:00:04.37 bitrate=4207.5kbits/s    
  
  frame=  150 fps= 30 q=26.0 size=    2524kB time=00:00:04.87 bitrate=4245.0kbits/s    
  
  frame=  165 fps= 30 q=26.0 size=    2808kB time=00:00:05.37 bitrate=4282.0kbits/s    
  
  frame=  180 fps= 30 q=26.0 size=    3091kB time=00:00:05.87 bitrate=4311.5kbits/s    
  
  [rawvideo @ 0x3350640] Invalid buffer size, packet size 65536 < expected frame_size 691200
  
  Error while decoding stream #0:0: Invalid argument
  
  frame=  183 fps= 29 q=-1.0 Lsize=    3247kB time=00:00:06.11 bitrate=4351.5kbits/s    
  
  video:3142kB audio:96kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.254788%
  
  [libx264 @ 0x3364bc0] frame I:1     Avg QP:20.00  size:  2289
  
  [libx264 @ 0x3364bc0] frame P:182   Avg QP:25.99  size: 17664
  
  [libx264 @ 0x3364bc0] mb I  I16..4: 100.0%  0.0%  0.0%
  
  [libx264 @ 0x3364bc0] mb P  I16..4: 78.5%  0.0%  0.0%  P16..4: 20.2%  0.0%  0.0%  0.0%  0.0%    skip: 1.4%
  
  [libx264 @ 0x3364bc0] coded y,uvDC,uvAC intra: 84.1% 71.5% 18.9% inter: 51.9% 63.5% 0.4%
  
  [libx264 @ 0x3364bc0] i16 v,h,dc,p: 15%  8% 69%  8%
  
  [libx264 @ 0x3364bc0] i8c dc,h,v,p: 50% 19% 24%  7%
  
  [libx264 @ 0x3364bc0] kb/s:4215.02

  ffmpeg log for failure ; low FPS captured :

  ffmpeg version 2.5.3 Copyright (c) 2000-2015 the FFmpeg developers
  
    built on Jan 11 2015 17:53:45 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
  
    configuration: --extra-libs=-ldl --prefix=/opt/ffmpeg --enable-avresample --disable-debug --enable-nonfree --enable-gpl --enable-version3 --enable-libpulse --enable-libopencore-amrnb --enable-libopencore-amrwb --disable-decoder=amrnb --disable-decoder=amrwb --enable-libx264 --enable-libx265 --enable-libfdk-aac --enable-libvorbis --enable-libmp3lame --enable-libopus --enable-libvpx --enable-libspeex --enable-libass --enable-avisynth --enable-libsoxr --enable-libxvid --enable-libvo-aacenc --enable-libvidstab
  
    libavutil      54. 15.100 / 54. 15.100
  
    libavcodec     56. 13.100 / 56. 13.100
  
    libavformat    56. 15.102 / 56. 15.102
  
    libavdevice    56.  3.100 / 56.  3.100
  
    libavfilter     5.  2.103 /  5.  2.103
  
    libavresample   2.  1.  0 /  2.  1.  0
  
    libswscale      3.  1.101 /  3.  1.101
  
    libswresample   1.  1.100 /  1.  1.100
  
    libpostproc    53.  3.100 / 53.  3.100
  
  Input #0, rawvideo, from '/tmp/somagic-pipe':
  
    Duration: N/A, start: 0.000000, bitrate: 165722 kb/s
  
      Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422, 720x480, 165722 kb/s, 29.97 tbr, 29.97 tbn, 29.97 tbc
  
  Home directory not accessible: Permission denied
  
  Guessed Channel Layout for  Input Stream #1.0 : stereo
  
  Input #1, alsa, from 'hw:0,0':
  
    Duration: N/A, start: 1423201999.226455, bitrate: 1536 kb/s
  
      Stream #1:0: Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s
  
  No pixel format specified, yuv422p for H.264 encoding chosen.
  
  Use -pix_fmt yuv420p for compatibility with outdated media players.
  
  [Parsed_pan_0 @ 0x21cad60] This syntax is deprecated. Use '|' to separate the list items.
  
  Single channel layout '1' is interpreted as a number of channels, switch to the syntax '1c' otherwise it will be interpreted as a channel layout number in a later version
  
  [Parsed_pan_0 @ 0x21cad60] Pure channel mapping detected: 0
  
  [libx264 @ 0x21f9bc0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.1 Cache64
  
  [libx264 @ 0x21f9bc0] profile High 4:2:2, level 3.1, 4:2:2 8-bit
  
  [libx264 @ 0x21f9bc0] 264 - core 142 r2389 956c8d8 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - http://www.videolan.org/x264.html - options: cabac=0 ref=1 deblock=0:0:0 analyse=0:0 me=dia subme=0 psy=1 psy_rd=1.00:0.00 mixed_ref=0 me_range=16 chroma_me=1 trellis=0 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=0 threads=3 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=250 keyint_min=25 scenecut=0 intra_refresh=0 rc=crf mbtree=0 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=0
  
  Output #0, mp4, to '/home/peterbecich/easycap/Videos/fpv_video_02_05_2015_21_53_18.mp4':
  
    Metadata:
  
      encoder         : Lavf56.15.102
  
      Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv422p, 720x540, q=-1--1, 29.97 fps, 11988 tbn, 29.97 tbc
  
      Metadata:
  
        encoder         : Lavc56.13.100 libx264
  
      Stream #0:1: Audio: aac (libfdk_aac) ([64][0][0][0] / 0x0040), 96000 Hz, mono, s16, 128 kb/s
  
      Metadata:
  
        encoder         : Lavc56.13.100 libfdk_aac
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264))
  
    Stream #1:0 -> #0:1 (pcm_s16le (native) -> aac (libfdk_aac))
  
  Press [q] to stop, [?] for help
  
  frame=    1 fps=0.0 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A    
  
  frame=    1 fps=1.0 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A    
  
  frame=    1 fps=0.7 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A    
  
  frame=    1 fps=0.5 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A    
  
  frame=    1 fps=0.4 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A    
  
  frame=    1 fps=0.3 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A    
  
  frame=    1 fps=0.3 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A    
  
  frame=    1 fps=0.2 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A    
  
  frame=    1 fps=0.2 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A    
  
  frame=    1 fps=0.2 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A    
  
  frame=    1 fps=0.2 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A    
  
  [alsa @ 0x21e5ac0] ALSA buffer xrun.
  
  frame=    8 fps=1.3 q=19.0 size=      12kB time=00:00:06.03 bitrate=  15.9kbits/s    
  
  frame=   23 fps=3.5 q=18.0 size=      12kB time=00:00:06.03 bitrate=  16.4kbits/s    
  
  frame=   38 fps=5.4 q=18.0 size=      12kB time=00:00:06.03 bitrate=  16.7kbits/s    
  
  frame=   53 fps=7.0 q=18.0 size=      12kB time=00:00:06.03 bitrate=  16.9kbits/s    
  
  frame=   68 fps=8.4 q=26.0 size=     146kB time=00:00:06.03 bitrate= 198.8kbits/s    
  
  frame=   83 fps=9.7 q=26.0 size=     375kB time=00:00:06.03 bitrate= 510.0kbits/s    
  
  frame=   98 fps= 11 q=26.0 size=     608kB time=00:00:06.03 bitrate= 826.5kbits/s    
  
  frame=  114 fps= 12 q=26.0 size=     875kB time=00:00:06.03 bitrate=1189.1kbits/s    
  
  frame=  128 fps= 13 q=26.0 size=    1091kB time=00:00:06.03 bitrate=1481.6kbits/s    
  
  frame=  144 fps= 14 q=26.0 size=    1339kB time=00:00:06.03 bitrate=1819.2kbits/s    
  
  frame=  159 fps= 14 q=26.0 size=    1571kB time=00:00:06.03 bitrate=2134.6kbits/s    
  
  frame=  174 fps= 15 q=26.0 size=    1796kB time=00:00:06.03 bitrate=2440.1kbits/s    
  
  [alsa @ 0x21e5ac0] ALSA buffer xrun.
  
  frame=  189 fps= 16 q=26.0 size=    2015kB time=00:00:12.04 bitrate=1370.4kbits/s    
  
  frame=  204 fps= 16 q=26.0 size=    2238kB time=00:00:12.04 bitrate=1522.3kbits/s    
  
  frame=  219 fps= 17 q=26.0 size=    2490kB time=00:00:12.04 bitrate=1694.2kbits/s    
  
  frame=  235 fps= 17 q=26.0 size=    2728kB time=00:00:12.04 bitrate=1855.8kbits/s    
  
  frame=  250 fps= 18 q=26.0 size=    2973kB time=00:00:12.04 bitrate=2022.4kbits/s    
  
  [rawvideo @ 0x21e5640] Invalid buffer size, packet size 65536 < expected frame_size 691200
  
  Error while decoding stream #0:0: Invalid argument
  
  frame=  261 fps= 18 q=-1.0 Lsize=    3269kB time=00:00:12.06 bitrate=2220.1kbits/s    
  
  video:3263kB audio:4kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.081101%
  
  [libx264 @ 0x21f9bc0] frame I:2     Avg QP:21.50  size: 21342
  
  [libx264 @ 0x21f9bc0] frame P:259   Avg QP:24.22  size: 12734
  
  [libx264 @ 0x21f9bc0] mb I  I16..4: 100.0%  0.0%  0.0%
  
  [libx264 @ 0x21f9bc0] mb P  I16..4: 62.8%  0.0%  0.0%  P16..4: 14.2%  0.0%  0.0%  0.0%  0.0%    skip:22.9%
  
  [libx264 @ 0x21f9bc0] coded y,uvDC,uvAC intra: 77.7% 61.2% 14.1% inter: 19.7% 24.8% 1.6%
  
  [libx264 @ 0x21f9bc0] i16 v,h,dc,p: 17% 10% 65%  8%
  
  [libx264 @ 0x21f9bc0] i8c dc,h,v,p: 52% 18% 24%  6%
  
  [libx264 @ 0x21f9bc0] kb/s:3068.90

  The whole script :

  #!/bin/sh
  
  
  
  PIPE=/tmp/somagic-pipe
  
  OUTFILEDIR=~/easycap/Videos/
  
  LOGDIR=~/.somagic-log/
  
  NOW=`date +"%m_%d_%Y_%H_%M_%S"`
  
  
  
  OUTFILE=${OUTFILEDIR}fpv_video_${NOW}.mp4
  
  
  
  mkdir $LOGDIR
  
  
  
  FFMPEG_LOG=${LOGDIR}ffmpeg.log
  
  SOMAGIC_LOG=${LOGDIR}somagic.log
  
  MPLAYER_LOG=${LOGDIR}mplayer.log
  
  
  
  rm $PIPE >/dev/null 2>&1
  
  rm $OUTFILE >/dev/null 2>&1
  
  
  
  rm $FFMPEG_LOG
  
  rm $SOMAGIC_LOG
  
  rm $MPLAYER_LOG
  
  
  
  mkfifo $PIPE >/dev/null 2>&1
  
  
  
  ffmpeg -pixel_format uyvy422 -s:v 720x480 -framerate 29.97 -f rawvideo \
  
  -i $PIPE  -f alsa -i hw:0,0 -vf scale=w=720:h=540 -vcodec libx264 \
  
  -preset ultrafast -shortest -c:a libfdk_aac -b:a 128k -af pan=1:c0=c0  \
  
  -ar 96000 $OUTFILE > $FFMPEG_LOG 2>&1 &
  
  
  
  somagic-capture --ntsc -c --luminance=2 --lum-aperture=3 2> $SOMAGIC_LOG \
  
  | tee $PIPE | \
  
  mplayer -vf yadif,screenshot -demuxer rawvideo -rawvideo \
  
  "ntsc:format=uyvy:fps=30000/1001" -aspect 4:3 - 2> $MPLAYER_LOG
  
  
  
  
  
  rm $PIPE >/dev/null 2>&1 

  Modified from here : https://gist.github.com/Brick85/0b327ac2d3d45e23ed33

• How can i create a portrait video using Android's MediaRecorder

  23 mars 2015, par urudroid

  I have an Android application which is able to record and play a videos in portrait mode, those features are working fine on Android phones.

  The issue comes up because this video is needed to be played also on iOS devices (after being shared through a server).

  iOS is not correctly showing the video as it looks "cropped", but videos recorded on iOS are played without issues.

  So, the main difference between videos created on Android and iOS’ is the size and the rotation.

  Im using CWAC-Camera library for preview and recording and ffmpeg to scale the video down to 320x568px (as this is the standard size for both Android and iOS apps).

  Here is the metadata from an video created from Android :

  General
  
  Complete name                            : android_video.mp4
  
  Format                                   : MPEG-4
  
  Format profile                           : Base Media
  
  Codec ID                                 : isom
  
  File size                                : 447 KiB
  
  Duration                                 : 5s 596ms
  
  Overall bit rate                         : 654 Kbps
  
  Encoded date                             : UTC 1904-01-01 00:00:00
  
  Tagged date                              : UTC 1904-01-01 00:00:00
  
  Writing application                      : Lavf56.4.101
  
  
  
  Video
  
  ID                                       : 1
  
  Format                                   : AVC
  
  Format/Info                              : Advanced Video Codec
  
  Format profile                           : High@L2.1
  
  Format settings, CABAC                   : Yes
  
  Format settings, ReFrames                : 4 frames
  
  Codec ID                                 : avc1
  
  Codec ID/Info                            : Advanced Video Coding
  
  Duration                                 : 5s 406ms
  
  Bit rate                                 : 536 Kbps
  
  Width                                    : 568 pixels
  
  Height                                   : 320 pixels
  
  Display aspect ratio                     : 16:9
  
  Original display aspect ratio            : 16:9
  
  Rotation                                 : 270°
  
  Frame rate mode                          : Constant
  
  Frame rate                               : 14.985 fps
  
  Color space                              : YUV
  
  Chroma subsampling                       : 4:2:0
  
  Bit depth                                : 8 bits
  
  Scan type                                : Progressive
  
  Bits/(Pixel*Frame)                       : 0.197
  
  Stream size                              : 354 KiB (79%)
  
  Writing library                          : x264 core 142
  
  Encoding settings                        : cabac=1 / ref=3 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=7 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=6 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=14 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=crf / mbtree=1 / crf=23.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
  
  Language                                 : English
  
  Encoded date                             : UTC 1904-01-01 00:00:00
  
  Tagged date                              : UTC 1904-01-01 00:00:00
  
  
  
  Audio
  
  ID                                       : 2
  
  Format                                   : AAC
  
  Format/Info                              : Advanced Audio Codec
  
  Format profile                           : LC
  
  Codec ID                                 : 40
  
  Duration                                 : 5s 596ms
  
  Bit rate mode                            : Constant
  
  Bit rate                                 : 132 Kbps
  
  Channel(s)                               : 2 channels
  
  Channel(s)_Original                      : 1 channel
  
  Channel positions                        : Front: C
  
  Sampling rate                            : 44.1 KHz
  
  Compression mode                         : Lossy
  
  Stream size                              : 89.4 KiB (20%)
  
  Language                                 : English
  
  Encoded date                             : UTC 1904-01-01 00:00:00
  
  Tagged date                              : UTC 1904-01-01 00:00:00

  And here is the metadata from the video created on iOS :

  General
  
  Complete name                            : ios_video.mp4
  
  Format                                   : MPEG-4
  
  Format profile                           : Base Media / Version 2
  
  Codec ID                                 : mp42
  
  File size                                : 673 KiB
  
  Duration                                 : 7s 38ms
  
  Overall bit rate                         : 783 Kbps
  
  Encoded date                             : UTC 2015-03-17 19:16:36
  
  Tagged date                              : UTC 2015-03-17 19:16:37
  
  
  
  Video
  
  ID                                       : 2
  
  Format                                   : AVC
  
  Format/Info                              : Advanced Video Codec
  
  Format profile                           : Main@L3.0
  
  Format settings, CABAC                   : Yes
  
  Format settings, ReFrames                : 2 frames
  
  Codec ID                                 : avc1
  
  Codec ID/Info                            : Advanced Video Coding
  
  Duration                                 : 7s 33ms
  
  Bit rate                                 : 711 Kbps
  
  Width                                    : 320 pixels
  
  Height                                   : 568 pixels
  
  Display aspect ratio                     : 0.563
  
  Frame rate mode                          : Constant
  
  Frame rate                               : 30.000 fps
  
  Color space                              : YUV
  
  Chroma subsampling                       : 4:2:0
  
  Bit depth                                : 8 bits
  
  Scan type                                : Progressive
  
  Bits/(Pixel*Frame)                       : 0.130
  
  Stream size                              : 610 KiB (91%)
  
  Title                                    : Core Media Video
  
  Encoded date                             : UTC 2015-03-17 19:16:36
  
  Tagged date                              : UTC 2015-03-17 19:16:37
  
  Color primaries                          : BT.709
  
  Transfer characteristics                 : BT.709
  
  Matrix coefficients                      : BT.709
  
  Color range                              : Limited
  
  
  
  Audio
  
  ID                                       : 1
  
  Format                                   : AAC
  
  Format/Info                              : Advanced Audio Codec
  
  Format profile                           : LC
  
  Codec ID                                 : 40
  
  Duration                                 : 7s 38ms
  
  Source duration                          : 7s 105ms
  
  Bit rate mode                            : Constant
  
  Bit rate                                 : 64.0 Kbps
  
  Channel(s)                               : 2 channels
  
  Channel(s)_Original                      : 1 channel
  
  Channel positions                        : Front: C
  
  Sampling rate                            : 44.1 KHz
  
  Compression mode                         : Lossy
  
  Stream size                              : 56.8 KiB (8%)
  
  Source stream size                       : 57.2 KiB (9%)
  
  Title                                    : Core Media Audio
  
  Encoded date                             : UTC 2015-03-17 19:16:36
  
  Tagged date                              : UTC 2015-03-17 19:16:37

  The values width and height are inverted on Android, also the Rotation parameter is set to 270º (this is the rotation parameter for portrait videos).

  This is a sketch of how iOS’ videos look on iOS app :

  

  And this is how Android’s videos look on iOS app :

  

  So, in order to get the videos correctly displayed both on iOS and Android i need to be able to set the width to 320 and height to 568 on Android. I tried it from several places (outside and inside CWAC-Camera library) but i always get a Camera.Parameters error.

  It is possible to do this on Android ?

  EDIT :

  This is the result i get when i set the rotation to 0 with ffmpeg :

  

• avformat/http: check the auth string contents not the pointer which cannot be NULL

  14 octobre 2013, par Michael Niedermayer

  avformat/http: check the auth string contents not the pointer which cannot be NULL
  It appears this bug originates from a "work in progress" patch from
  
  ffmpeg-devel that was heavily redesigned by and integrated in libav
  And that patch even had a reply and review on the mailing list pointing
  
  out that it had a bug.
  This fixes a deadlock with ffserver
  See : [FFmpeg-devel] [PATCH] Fix HTTP authentication problem for POST actions.
  
       [FFmpeg-devel] [PATCH 1/3] Introduce auth_phase flag, which will be true if authorization needs to be sent, but the type of authorization is not known yet Partial fix #3036
  
       [FFmpeg-devel] [PATCH 2/3] Only add Transfer-Encoding header when not in authorization phase, because server will wait (indefinitely) for data when receiving this header Partial fix #3036
  
       [FFmpeg-devel] [PATCH 3/3] Only allow posting data and/or forcing a 200 code, enabling posting isml chunks, -after- we did a possible first request to get a 403 from the server telling us which type of authentication to apply Final part fix #3036
  
  See : 71549a857b13edf4c4f95037de6ed5bb4c4bd4af
  
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] libavformat/http.c