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• FFMPEG iOS 7 Library

  15 septembre 2017, par Destiny Dawn

  I’ve tried reading many tutorials.
  I’ve spent hours on google, and stackoverflow trying answer.
  So far I’ve read : Trying to compile the FFMPEG libraries for iPhoneOS platform with armv6 and arv7 architecture FFMPEG integration on iphone/ ipad project and https://github.com/lajos/iFrameExtractor few of the many.

  I’m trying to build this library for iOS 7/Xcode 5 compatibility but it’s not working.
  A common error I’d get is :

  Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
  
  yasm/nasm not found or too old. Use --disable-yasm for a crippled build.
  
  
  
  If you think configure made a mistake, make sure you are using the latest
  
  version from Git.  If the latest version fails, report the problem to the
  
  ffmpeg-user@ffmpeg.org mailing list or IRC #ffmpeg on irc.freenode.net.
  
  Include the log file "config.log" produced by configure as this will help
  
  solving the problem.

  I’d also get many more once that is finished. Such as :

  rm: illegal option -- .
  
  usage: rm [-f | -i] [-dPRrvW] file ...
  
         unlink file
  
  make: *** [clean] Error 64

  I’ve mostly tried using this command to start, but it always crashes on "make clean" :

  ./configure \
  
  --cc=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc \
  
  --as='/usr/local/bin/gas-preprocessor.pl /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc' \
  
  --sysroot=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.0.sdk \
  
  --target-os=darwin \
  
  --arch=arm \
  
  --cpu=cortex-a8 \
  
  --extra-cflags='-arch armv7' \
  
  --extra-ldflags='-arch armv7 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.0.sdk' \
  
  --prefix=compiled/armv7 \
  
  --enable-cross-compile \
  
  --enable-nonfree \
  
  --enable-gpl \
  
  --disable-armv5te \
  
  --disable-swscale-alpha \
  
  --disable-doc \
  
  --disable-ffmpeg \
  
  --disable-ffplay \
  
  --disable-ffprobe \
  
  --disable-ffserver \
  
  --disable-asm \
  
  --disable-debug

• Copying timecode into output file ffmpeg or ffmbc

  3 avril 2012, par user989056

  I have media files in various formats that I want to be able to segment using ffmbc, same acodec, vcodec and container as original. I would like to be able to maintain the timecode data e.g. start_delay, from the original to destination media files ( with the segmented offset taken into account ).

  At the moment when I copy using the command -i inputfile.mxf -vcodec copy -avodec copy outputfile.mxf ( segmenting options omitted ) the output file start timecode is set to 00:00:00.

  The original files are mainly in .mxf and .mov container formats.

  Is there a command for this that I am missing ?

• What is the most suitable H265 setting converting from H264 on ffmpeg ?

  9 juin 2017, par minion007

  Currently, I was trying to convert my videos no matter personal videos or movies from H264 to H265. But that was much harder than what I expected.

  Firstly, it took me over 10 hours to build ffmpeg on Linux and I believe I’m still having some problems on dealing with this.

  Secondly, I notice there is degradation after converting by using the setting or parameters from Internet or ffmpeg official website. On the other hand, the video size would be the same or even bigger than the original video size if I use small crf like 23 or 28.

  For instance, sudo ffmpeg -i input.mp4 -c:v hevc -x265-params lossless -preset medium -crf 30 -c:a copy output.mkv

  sudo ffmpeg -i input.mp4 -c:v libx265 -x265-params lossless -preset medium -crf 30 -c:a copy output.mkv

  the above two settings give me the very small video size (between 21% 23% of the original video) which is the main reason why I want to convert my videos to H265 but drawback would be the quality of converted video is worse than the original video (I would may be between 30% 35% degradation).

  Thirdly, the size of video would be much bigger than the original size of video if I use the lossless parameter.

  sudo ffmpeg -i input.mp4 -c:v libx265 -x265-params lossless=1 -preset medium -crf 30 -c:a copy output.mkv

  the above setting can keep the quality of the original video but size would be huge (above 200% of original video).

  Is there any suggestion ?