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• Using GDIgrab in FFmpeg with dshow Audio produces black screen

  16 mars 2016, par Spreadys

  here is my command :

  ffmpeg -f gdigrab -framerate 25 -offset_x 10 -offset_y 10 -show_region 1 -draw_mouse 1 -video_size 1280x720 -i desktop -f dshow -i audio="Microphone (2- ATR USB microphone)" -r 25 -threads 4 -c:v libx264 -pix_fmt yuv422p -preset superfast -tune fastdecode -x264opts keyint=25:min-keyint=1 -crf 4 -c:a aac -profile:a aac_low -async 25 "C:\Users\david\Desktop\%output%.mp4"

  The gdigrab video works great when it is on its own (no audio). The audio works fine when it is on its own (no video). When I join the two commands to capture both together, as soon as I move a window within my capture area, the area goes black.

  In Windows 7, I used to get around this by stopping the desktop composition service prior to capture, (SC stop uxsms), but this is now not possible in Win10.

  I thought it may be something graphics card related.
  My main monitor is on an Nvidia card, with my second running from the onboard Intel. This is setup for Quicksync H264 playback and encoding with my NLE.

  I know that I could use a dshow screen capture driver such as UScreen but am trying to avoid that as I need the capture area to be specified each time from a simple batch.

  Any help appreciated to solve this black area problem- its driving me crazy !
  David

• Revision d9b62160a0 : Implements several heuristics to prune mode search Skips mode searches for intr

  3 juillet 2013, par Deb Mukherjee

  Changed Paths :
   Modify /vp9/encoder/vp9_encodeframe.c

  
   Modify /vp9/encoder/vp9_onyx_if.c

  
   Modify /vp9/encoder/vp9_onyx_int.h

  
   Modify /vp9/encoder/vp9_rdopt.c

  
  
  Implements several heuristics to prune mode search

  Skips mode searches for intra and compound inter modes depending
  on the best mode so far and the reference frames. The various
  heuristics to be used are selected by bits from a flag. The
  previous direction based intra mode search pruning is also absorbed
  in this framework.

  Specifically the flags and their impact are :

  1) FLAG_SKIP_INTRA_BESTINTER (skip intra mode search for oblique
  directional modes and TM_PRED if the best so far is
  an inter mode)
  derfraw300 : -0.15%, 10% speedup

  2) FLAG_SKIP_INTRA_DIRMISMATCH (skip D27, D63, D117 and D153
  mode search if the best so far is not one of the closest
  hor/vert/diagonal directions.
  derfraw300 : -0.05%, about 9% speedup

  3) FLAG_SKIP_COMP_BESTINTRA (skip compound prediction mode
  search if the best so far is an intra mode)
  derfraw300 : -0.06%, about 7-8% speedup

  4) FLAG_SKIP_COMP_REFMISMATCH (skip compound prediction search
  if the best single ref inter mode does not have the same ref
  as one of the two references being tested in the compound mode)
  derfraw300 : -0.56%, about 10% speedup

  Change-Id : I1a736cd29b36325489e7af9f32698d6394b2c495

• ffmpeg on ubuntu convert 3gp to iphone 5 format [closed]

  21 mars 2013, par Jistanidiot

  I'm desperately trying to convert a 3GP video into something the iphone 5 will import and play. Verizon says they cannot help me that it is not possible to convert a Droid video to iphone.

  After much trouble I came to the conclusion to try the conversion on my Ubuntu box using ffmpeg. Again after a long struggle, I removed the package and followed the directions at https://ffmpeg.org/trac/ffmpeg/wiki/UbuntuCompilationGuide

  Now with the new complied ffmpeg, I try the following command :

   ffmpeg -i foo.3gp -s 320x240 -r 30000/1001 -b:v 200k -bt 240k -vcodec libx264 -coder 0 -bf 0 -flags2 -wpred-dct8x8 -level 13 -maxrate 768k -bufsize 3M-acodec libfaac -ac 2 -ar 48000 -ab 192k output.mp4

  However I keep getting the error :

   [NULL @ 0xa9874a0] Unable to find a suitable output format for 'libfaac' libfaac: Invalid argument

  I found a random blog post saying you needed to add

  `-target type’

  and then specify target file type (“vcd”, “svcd”, “dvd”, “dv”, “dv50”, “pal-vcd”, “ntsc-svcd”, … ). However after trying all 8 of them listed I still got the same errors.

  I'm at a complete loss. How can I convert the 3gp video into the iphone 5 format ?

  Thanks in advance.