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• Compiling x264 for iOS 7

  25 janvier 2016, par user500

  I’m getting error on compiling x264 for iOS.

  I have Xcode Version 5.0 (5A1413) with Apple LLVM version 5.0 (clang-500.2.75) (based on LLVM 3.3svn). I’m compiling x264-snapshot-20130925-2245.

  Config :

  CC=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang ./configure \
  
  --host=arm-apple-darwin \
  
  --sysroot=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.0.sdk \
  
  --prefix=armv7 \
  
  --extra-cflags='-arch armv7' \
  
  --extra-ldflags="-L/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.0.sdk/usr/lib/system -arch armv7" \
  
  --enable-pic \
  
  --enable-static

  Getting error :

  common/arm/cpu-a.S:29:7: error: unknown token in expression
  
  .align
  
        ^
  
  common/arm/cpu-a.S:139:5: error: instruction 'suble' can not set flags, but 's' suffix specified
  
      subles ip, ip, #1
  
      ^

• how to make any filter's value that accept integer value be a function of the timestamp in ffmpeg ? [closed]

  30 novembre 2023, par rosner altamira

  For example, i am trying to apply blur effect to video in ffmpeg using gblur filter, i want the blur strength to gradually increase from 0 to 50 in 2 secs starting at 5 secs and fade back from 50 to 0 in 3 secs thus finishing at 15 secs. In summary the blur is between 5 and 15 secs but from 5 to 7, the effect will gradually grow from 0 to 50 and from 12 to 15 it will fade from 50 back to 0.

  


  here is what i tried :

  


  


  ffmpeg -i test-video.mp4 -loop 1 -t 5 -i test-image.jpg -filter_complex "[0:v]gblur=sigma='if( lte(t,5) + gte(t, 15), 0, if( between(t, 7, 12), 50, min( max(25t - 125, 0), max(-16.67t + 250, 0) ) ) )':enable='between(t,5,15)'[bg] ;[1:v]fade=in:0:30[ol] ;[ol]fps=fps=15[ol] ;[bg][ol]overlay=(W-w)/2 :(H-h)/2:enable='between(t,5,15)'[out]" -map "[out]" -map 0:a output_video.mp4

  


  


  Expectations :

  


  


  [0:v]gblur=sigma='if( lte(t,5) + gte(t, 15), 0, if( between(t, 7, 12), 50, min( max(25t - 125, 0), max(-16.67t + 250, 0) ) ) )':enable='between(t,5,15)'[bg] :

  


  


  The blur strength depends dynamically on the time (t) as described above, controlled by the expression.
The enable parameter ensures that this filter is only applied between 5 and 15 seconds.

  


  


  [1:v]fade=in:0:30[ol] :
[ol]fps=fps=15[ol] :
[bg][ol]overlay=(W-w)/2 :(H-h)/2:enable='between(t,5,15)'[out] :

  


  


  The overlay input should be faded in for 2 secs starting from 5secs and will last 10secs (same time for the blur)

  


  As result, i am getting Invalid char error. Seems like sigma does not accept the "t" timestamp variable.

  


• ffmpeg encode timestamp on a timelapse video

  20 avril 2023, par Kyeotic

  I have a video that is a timelapse (generated by a GoPro, if that matters) with images every 5 seconds. I want to encode a timestamp onto it. Previously I've used a command like this one to get a timestamp burned in

  


  # Convert the date to EPOCH. This will be used to set the time for the draw text
# method.
EPOCH=$(date --date="${STARTDATE}" +%s)

# we assume that the STARTDATE is in UTC 0000, Zulu time, GMT and that we want
# to convert it to the local time on the computer.
ffmpeg -i "${INPUT}" -vf drawtext="fontsize=30:fontcolor=yellow:text='%{pts\:localtime\:${EPOCH}}':x=(w-text_w) - 10:y=(h-text_h) - 10" -vcodec libx265 -crf 28 "${OUTPUT}"


  


  The issue is that the timestamps generated by this progress as if it is a normal video, stamping a 30 minute timelapse as if it were 25 seconds. What I want are timestamps that match the timelapse.

  


  I've looked at the drawtext docs. I thought rate might be the key, but 1/5 and 150 both produce errors like this one :

  


  Parsed_drawtext_0 @ 0x10c607370] Failed to parse expression: (h-text_h) - 10 r=1/5 


  


  I figure I might need to multiply the current frame value to get the correct time, but I don't know how to do that.