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• Missing audio and problems playing FLV video converted from 720p .mov file with FFMPEG

  18 novembre 2011, par undefined

  I have some .mov video files recorded from a JVC GC-FM1 HD video camera in 720p mode. I have FFMPEG running on a Linux box that I upload files to for encoding into FLV format. The video appears to be encoding ok, but there is no audio in the resulting FLV file. Also, when I play it back in Flash Player, in a browser or on Adobe Media Player, the video pauses at the start. It appears that Adobe Media Player waits for the progress bar to reach the end of the video before starting the playback - i.e. the video will load, the picture pauses, the progress bar seeks to the end as if the video were playing, then when it reaches the end the video picture starts. There is no audio on the video. I am noticing this in the video player I have built with Flash 8 using an FLVPlayback component and attached seekBar. The seek bar will start moving as if the video is playing but the picture remains paused.

  Here are some outputs from my FFMPEG log and the command I am using to encode the video.

  My FFMPEG command called from PHP :

  $cmd = 'ffmpeg -i ' . $sourcelocation.$filename.".".$fileext . '  -ab 96k -b 700k \
  
  -ar 44100 -s ' . $target['width'] . 'x' . $target['height'] . ' -ac 1 \
  
  -acodec libfaac ' . $destlocation.$filename.$ext_trans .' 2>&1';

  The output from my error log :

  FFmpeg version UNKNOWN, Copyright (c) 2000-2010 Fabrice Bellard, et al.
  
  built on Jan 22 2010 11:31:03 with gcc 4.1.2 20070925 (Red Hat 4.1.2-33)
  
  configuration: --prefix=/usr --enable-static --enable-shared --enable-gpl \
  
  --enable-nonfree --enable-postproc --enable-avfilter --enable-avfilter-lavf \
  
  --enable-libfaac --enable-libfaad --enable-libfaadbin --enable-libgsm \
  
  --enable-libmp3lame --enable-libvorbis --enable-libx264
  
  libavutil     50. 7. 0 / 50. 7. 0
  
  libavcodec    52.48. 0 / 52.48. 0
  
  libavformat   52.47. 0 / 52.47. 0
  
  libavdevice   52. 2. 0 / 52. 2. 0
  
  libavfilter    1.17. 0 /  1.17. 0
  
  libswscale     0. 9. 0 /  0. 9. 0
  
  libpostproc   51. 2. 0 / 51. 2. 0
  
  
  
  Seems stream 0 codec frame rate differs from container frame rate: 119.88 (120000/1001) -> 59.94 (60000/1001)
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'uploads/video/60974_v1.mov':
  
    Metadata:
  
      major_brand     : qt  
  
      minor_version   : 0
  
      compatible_brands: qt  
  
      comment         : JVC GC-FM1
  
      comment-eng     : JVC GC-FM1
  
    Duration: 00:00:30.41, start: 0.000000, bitrate: 4158 kb/s
  
      Stream #0.0(eng): Video: h264, yuv420p, 640x480 [PAR 1:1 DAR 4:3], 4017 kb/s, 59.94 fps, 59.94 tbr, 90k tbn, 119.88 tbc
  
      Stream #0.1(eng): Audio: aac, 48000 Hz, stereo, s16, 128 kb/s
  
  Output #0, rawvideo, to 'uploads/video/60974_v1.jpg':
  
      Stream #0.0(eng): Video: mjpeg, yuvj420p, 320x240 [PAR 1:1 DAR 4:3], q=2-31, 200 kb/s, 90k tbn, 59.94 tbc
  
  Stream mapping:
  
    Stream #0.0 -> #0.0
  
  Press [q] to stop encoding
  
  [h264 @ 0x8e67930]B picture before any references, skipping
  
  [h264 @ 0x8e67930]decode_slice_header error
  
  [h264 @ 0x8e67930]no frame!
  
  Error while decoding stream #0.0
  
  [h264 @ 0x8e67930]B picture before any references, skipping
  
  [h264 @ 0x8e67930]decode_slice_header error
  
  [h264 @ 0x8e67930]no frame!
  
  Error while decoding stream #0.0
  
  frame=    1 fps=  0 q=3.8 Lsize=      15kB time=0.02 bitrate=7271.4kbits/s dup=482 drop=0    
  
  video:15kB audio:0kB global headers:0kB muxing overhead 0.000000%

  Which are the important errors here ?

  B picture before any references, skipping ?
  decode_slice_header error ?
  no frame ?
  or
  Seems stream 0 codec frame rate differs from container frame rate : 119.88 (120000/1001) -> 59.94 (60000/1001)

• Use ffmpeg to watermark and scale an image on video

  11 mai 2015, par Ae.

  I want to be able to watermark videos with a logo image, which contains a website url.
  The videos can be of different formats and dimension.
  I’m trying to figure out a generic ffmpeg command to achieve it, so that i don’t have to tweak the command depending on the video i have to process.
  So far i got :

  ffmpeg -i sample.mov -sameq -acodec copy -vf 'movie=logo.png [watermark]; [in][watermark] overlay=main_w-overlay_w-10:main_h-overlay_h-10 [out]' sample2.mov

  In this way though the logo will look too big or too small with video of different size.
  I’ve seen there is a scale option for avfilter, but I haven’t figure out whether it’s possible to resize the image logo based on the dimension of the input video, so that I can say to scale the logo to 1/3 of the video length for example, and keep the image ratio.

  Any idea ? doesn’t need to be done in a single command, could even be a script.
  thanks in advance.

• Capture video on iOS device and live stream it to a server (or another mobile)

  13 février 2015, par theDuncs

  I want to be able to record footage using my iOS device and stream it directly to a server.

  There’s quite a few articles on S.O. that talk about this, but I’m not sure any have answered the question very well.

  Should I be using HTTP Live Streaming, or is this just for sending data to an iPhone ?
  Should I be using AVCaptureSession to grab the video (a segment at a time ?), sending each segment to the server ?
  Should I be using AVCaptureVideoDataOutput and ffmpeg for streaming ?

  I’m a little lost with all this, so any sample code or docs or links would be really appreciated.

  Thanks for your help guys.

  Duncan