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• Decoding RIMM streaming file format

  10 septembre 2011, par Thomas

  I want to decode the video (visual) frames within a Blackberry RIMM file. So far I have a parser, and some corresponding container documentation from RIM. 

  The video codec is H264 and is explicitly set on the device using one of the video.encodings properties. However, FFMPEG is not able to decode the frames and this is driving me nuts.

  Edit 1 : The issues seems to be lack of SPS and PPS in the frames, and artificially inserting them have proven unsuccessful so far (all grey image). Blackberry 9700 sends

  0x00 0x00 0x ?? 0x ?? 0xType

  where Type is according to table 7-1 in the H264 spec (I and P frames). We believe the 0x ?? 0x ?? represent the size of the frame, however the size does not always correspond to the size found by the parser (the parser seems to be working correctly).

  I have a windows decoder codec from blackberry, called mc_demux_mp2_ds.ax, and can play some MPEG-4 files captured the same way, but it is a binary for windows. And the H264 files will not play either way. I am aware of previous attempts. The capture url for javax.microedition.media.Manager is

  encoding=video-3gpp_width=176_height=144_video_codec=H264_audio_codec=AAC

  and I am writing to an output stream. Some example files here.

  Edit 2 :Turns out that about 3-4 of the 12-15 available video capture modes are flat out failing and refusing to output data, even in the simplest of test applications. So any working solution should implement MPEG-4, H264 and H263 in both AMR and AAC, in so getting fallback alternatives when one sound codec and/or resolution fails. Reboots, hangs and what not litters the Blackberry video implementation and vary from firmware to firmware ; total suckage.

• playback speed of ffmpeg-stitched python video plots

  30 juin 2012, par user1211129

  I've been generating videos out of plots made with matplotlib using a line of ffmpeg code. The output is in .mp4 format. However, when I tried to heighten the resolution of each individual plot to dpi=800, the resultant video (at 140 MB) lags severely when played back with quicktime. Is there a way around this ? I do wonder, if the file's too large to play efficiently, why does a movie of 6 GB play flawlessly ?

• iPhone HTTP Streaming .m3u8 and .ts files - how to create using ffmpeg

  8 septembre 2013, par ChessDev

  I'm trying to get apple-validated http media streams using ffmpeg and am getting errors. Here are some error examples :

  WARNING : Playlist Content-Type is 'application/x-mpegurl', but should
  be one of 'application/vnd.apple.mpegurl', 'audio/x-mpegurl' or
  'audio/mpegurl'.

  WARNING : 258 samples (88.966 %) do not have timestamps in track 256
  (avc1). 4 : us2-1.ts
   

  WARNING : Media segment duration outside of expected duration by 47.733
   % (5.23 vs. 10.00 seconds, limit is 20 %). 40 : us2-19.ts
   

  Average segment duration: 10.16 seconds
  
  Average segment bitrate: 320.12 kbit/s
  
  Average segment structural overhead: 175.89 kbit/s (54.94 %)
  
  
  
  Video codec: avc1
  
  Video resolution: 320x320 pixels
  
  Video frame rate: 29.72, 29.78, 29.82, 30.00, 29.64 fps
  
  Average video bitrate: 100.66 kbit/s
  
  H.264 profile: Baseline
  
  H.264 level: 3.0
  
  
  
  Audio codec: aac 
  
  Audio sample rate: 48000 Hz
  
  Average audio bitrate: 43.57 kbit/s

  ---

  Here is the end file I've been submitting : http://files.chesscomfiles.com/images_users/using/us2.m3u8

  Here is the file I used to create this : http://files.chesscomfiles.com/images_users/using/using-computers-1.mp4

  I've tried these commands, among others :

  ffmpeg -i using-computers-1.mp4 -f mpegts -acodec libfaac -ar 48000
  -ab 64k -s 320x320 -vcodec libx264 -vbsf h264_mp4toannexb -b 96k -flags +loop -cmp +chroma -partitions +parti4x4+partp8x8+partb8x8 -subq 5 -trellis 1 -refs 1 -coder 0 -me_range 16 -keyint_min 2 -sc_threshold 40 -i_qfactor 0.71 -bt 200k -maxrate 96k -bufsize 96k -rc_eq 'blurCplx^(1-qComp)' -qcomp 0.6 -qmin 10 -qmax 51 -qdiff 4 -level 30 -g 30 -async 2 us2.ts

  ffmpeg -i using-computers-1.mp4 -f mpegts -acodec libfaac -ar 48000
  -ab 64k -s 320x320 -vcodec libx264 -vbsf h264_mp4toannexb -b 96k -flags +loop -cmp +chroma -partitions +parti4x4+partp8x8+partb8x8 -subq 5 -trellis 1 -refs 1 -coder 0 -me_range 16 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -bt 200k -maxrate 96k -bufsize 96k -rc_eq 'blurCplx^(1-qComp)' -qcomp 0.6 -qmin 10 -qmax 51 -qdiff 4 -level 30 -g 30 -async 2 us1.ts

  ffmpeg -i using-computers-1.mp4 -vbsf h264_mp4toannexb -acodec copy -vcodec copy -f mpegts output.ts

  If someone can help me figure out what ffmpeg commands I should be running I'd really appreciate it !