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• playback of ffmpeg converted video on LDPI device (Samsung S5300 240 x 320)

  25 décembre 2013, par user737486

  I have Full HD video taken by Samsung Galaxy S4 camera.
  video stream info as follows :

  {"index":0,"codec_name":"h264","codec_long_name":"H.264 \/ AVC \/ MPEG-4 AVC \/ MPEG-4 part 10","profile":"High","codec_type":"video","codec_time_base":"1\/180000","codec_tag_string":"avc1","codec_tag":"0x31637661","width":1920,"height":1080,"has_b_frames":0,"sample_aspect_ratio":"0:1","display_aspect_ratio":"0:1","pix_fmt":"yuv420p","level":40,"r_frame_rate":"30\/1","avg_frame_rate":"21240000\/707831","time_base":"1\/90000","start_pts":0,"start_time":"0.000000","duration_ts":1415662,"duration":"15.729578","bit_rate":"16553536","nb_frames":"472","disposition":{"default":1,"dub":0,"original":0,"comment":0,"lyrics":0,"karaoke":0,"forced":0,"hearing_impaired":0,"visual_impaired":0,"clean_effects":0,"attached_pic":0},"tags":{"rotate":"90","creation_time":"2013-12-24 10:19:18","language":"eng","handler_name":"VideoHandle"}}

  in short it is 1920x1080, 16KK bitrate, rotation : 90.
  I'm converting it using ffmpeg by the following command :

  ffmpeg -y -threads 8 -i input.mp4 -vcodec libx264 -vpre ipod640 -s 324x576 -strict -2 -b:v 512k -acodec aac -ac 1 -ar 16000 -ab 32000 -vf "transpose=1" -metadata:s:v:0 rotate=0  output.mp4

  The output video stream info :

   {"index":0,"codec_name":"h264","codec_long_name":"H.264 \/ AVC \/ MPEG-4 AVC \/ MPEG-4 part 10","profile":"Constrained Baseline","codec_type":"video","codec_time_base":"1\/48","codec_tag_string":"avc1","codec_tag":"0x31637661","width":324,"height":576,"has_b_frames":0,"sample_aspect_ratio":"0:1","display_aspect_ratio":"0:1","pix_fmt":"yuv420p","level":30,"r_frame_rate":"24\/1","avg_frame_rate":"24\/1","time_base":"1\/12288","start_pts":0,"start_time":"0.000000","duration_ts":72192,"duration":"5.875000","bit_rate":"521597","nb_frames":"141","disposition":{"default":1,"dub":0,"original":0,"comment":0,"lyrics":0,"karaoke":0,"forced":0,"hearing_impaired":0,"visual_impaired":0,"clean_effects":0,"attached_pic":0},"tags":{"language":"eng","handler_name":"VideoHandler"}}

  The output video being played without any problem, on many different devices and OSes including different iOs and androids, but Samsung S5300 doesn't play it. From the device log I can see the following exception :

  E/AwesomePlayer( 1349): This resolution [324X576] Not Supported

  But, when I change the width and height to 576x324 the video can be played on S5300, but in wrong rotation.
  What should I add in ffmpeg parameters to make it play in correct orientation ?

  ffmpeg version :

  ffmpeg version git-2013-12-22-911676c Copyright (c) 2000-2013 the FFmpeg developers built on Dec 22 2013 22:55:31 with gcc 4.4.5 (Debian 4.4.5-8)

  Thanks

• Append video files of different width, height

  28 novembre 2013, par Jatin

  I am building an application where user can record a screencast. Integral part of application is that, one can pause recording and resume it later any time (the session is maintained on server side).

  So say when user starts recording the screen, the width and height is :1024*768. Using xuggler (java wrapper for ffmpeg), I am able to generate a video. But say later he is on a different system and wishes to resume screen cast, then resolution changes to 1080 * 720. At this stage, I record it seperately and then try merging two files. But because the width & height are not same, I get the below exception :

  16:38:03.916 [main] WARN com.xuggle.xuggler - Got error : picture is
  not of the same width as this Coder
  (../../../../../../../csrc/com/xuggle/xuggler/StreamCoder.cpp:1430)
  Exception in thread "main" java.lang.RuntimeException : failed to
  encode video

  What is the best way to solve this Issue. The user can be on screen with different width and height. How do I merge (or any other alternatives, probably append) video files of different width and height ?

• avfilter/vf_psnr : Prevent integer overflow.

  21 septembre 2013, par Neil Birkbeck

  avfilter/vf_psnr : Prevent integer overflow.
  The 32-bit integer accumulator in MSE computation can overflow for 8-bit frame data.
  
  (e.g., for 1080p white frame compared to a black frame can give sum of 255*255*1080*1920 > 2^32).
  Signed-off-by : Neil Birkbeck <neil.birkbeck@gmail.com>
  
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] libavfilter/vf_psnr.c