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• FFmpeg converted mp4 file fails to load in Quicktime

  21 décembre 2015, par wonea

  I’ve been using FFmpeg to convert a movie I need to play in MP4, however in Quicktime the following error is presented ;

  

  (Error -2041 : an invalid sample description was found in the movie (output.mp4)).

  I used the following FFmpeg command parameters to convert the file ;

  C :\Temp\EOBTemp>ffmpeg -i input.mp4 -y
  -acodec libmp3lame -ab 96k -vcodec libx264 -vpre lossless_slow -crf 22
  -threads 0 output.mp4

  Now this file plays absolutely fine, in Windows Media Player, and VideoLAN (FFmpeg based, so no surprise here. I using the latest build from HawkEye’s FFmpeg Windows Builds
  (FFmpeg git-a304071 32-bit Static (Latest)).

  I really hope this isn’t a AAC problem, as I’ve been trying to get FFmpeg to use the libfaac.dll library (in the same folder as the FFmpeg.exe) with the command ;

  -acodec libfaac

  Help ! I’m at a loss !

• Compiling ffmpeg for use in Android (ndk) for x86 architecture

  26 septembre 2012, par Ankur22

  I am trying to compile ffmpeg for Android but for the x86 architecture. I've successfully compiled an arm .so and it all works, and I though that by replacing arm with x86 in the relevant places within the build script would have done the trick. Unfortunately that's not the case and I get some strange things occurring.

  First I get this while it's compiling ffmpeg :

  /home/ankur/android-ndk-r8/platforms/android-8/arch-arm//usr/include/strings.h:49: warning: redundant redeclaration of 'index'

  Notice the arch-arm instead of arch-x86. Finally I get this :

  /home/ankur/android-ndk-r8/toolchains/x86-4.4.3/prebuilt/linux-x86/bin/i686-android-linux-ld: libavcodec/libavcodec.a(4xm.o): Relocations in generic ELF (EM: 40)
  
  /home/ankur/android-ndk-r8/toolchains/x86-4.4.3/prebuilt/linux-x86/bin/i686-android-linux-ld: libavcodec/libavcodec.a(4xm.o): Relocations in generic ELF (EM: 40)
  
  /home/ankur/android-ndk-r8/toolchains/x86-4.4.3/prebuilt/linux-x86/bin/i686-android-linux-ld: libavcodec/libavcodec.a(4xm.o): Relocations in generic ELF (EM: 40)
  
  libavcodec/libavcodec.a(4xm.o): could not read symbols: File in wrong format

  The build script I've created looks like this :

  #!/bin/bash
  
  
  
  NDK=~/android-ndk-r8
  
  PLATFORM=$NDK/platforms/android-8/arch-x86/
  
  PREBUILT=$NDK/toolchains/x86-4.4.3/prebuilt/linux-x86
  
  function build_one_r8
  
  {
  
  ./configure \
  
      --disable-shared \
  
      --enable-static \
  
      --enable-gpl \
  
      --enable-version3 \
  
      --enable-nonfree \
  
      --disable-doc \
  
      --disable-ffmpeg \
  
      --disable-ffplay \
  
      --disable-ffprobe \
  
      --disable-ffserver \
  
      --disable-avdevice \
  
      --disable-avfilter \
  
      --disable-postproc \
  
      --enable-small \
  
      --cross-prefix=$PREBUILT/bin/i686-android-linux- \
  
      --enable-cross-compile \
  
      --target-os=linux \
  
      --extra-cflags="-I$PLATFORM/usr/include" \
  
      --arch=x86 \
  
      --disable-symver \
  
      --disable-debug \
  
      --disable-stripping \
  
      $ADDITIONAL_CONFIGURE_FLAG
  
  sed -i 's/HAVE_LRINT 0/HAVE_LRINT 1/g' config.h
  
  sed -i 's/HAVE_LRINTF 0/HAVE_LRINTF 1/g' config.h
  
  sed -i 's/HAVE_ROUND 0/HAVE_ROUND 1/g' config.h
  
  sed -i 's/HAVE_ROUNDF 0/HAVE_ROUNDF 1/g' config.h
  
  sed -i 's/HAVE_TRUNC 0/HAVE_TRUNC 1/g' config.h
  
  sed -i 's/HAVE_TRUNCF 0/HAVE_TRUNCF 1/g' config.h
  
  make clean
  
  make  -j4 install
  
  $PREBUILT/bin/i686-android-linux-ar d libavcodec/libavcodec.a inverse.o
  
  $PREBUILT/bin/i686-android-linux-ld -rpath-link=$PLATFORM/usr/lib -L$PLATFORM/usr/lib  -soname libffmpeg.so -shared -nostdlib  -z,noexecstack -Bsymbolic --whole-archive --no-undefined -o $PREFIX/libffmpeg.so libavcodec/libavcodec.a libavformat/libavformat.a libavutil/libavutil.a libswscale/libswscale.a -lc -lm -lz -ldl -llog  --warn-once  --dynamic-linker=/system/bin/linker $PREBUILT/lib/gcc/i686-android-linux/4.4.3/libgcc.a
  
  }
  
  function build_one_r8_2
  
  {
  
  $PREBUILT/bin/i686-android-linux-ar d libavcodec/libavcodec.a inverse.o
  
  $PREBUILT/bin/i686-android-linux-ld -rpath-link=$PLATFORM/usr/lib -L$PLATFORM/usr/lib  -soname libffmpeg.so -shared -nostdlib  -z,noexecstack -Bsymbolic --whole-archive --no-undefined -o $PREFIX/libffmpeg.so libavcodec/libavcodec.a libavformat/libavformat.a libavutil/libavutil.a libswscale/libswscale.a -lc -lm -lz -ldl -llog  --warn-once  --dynamic-linker=/system/bin/linker $PREBUILT/lib/gcc/i686-android-linux/4.4.3/libgcc.a
  
  }
  
  #x86
  
  CPU=x86
  
  OPTIMIZE_CFLAGS="-march=$CPU "
  
  PREFIX=./android/$CPU
  
  ADDITIONAL_CONFIGURE_FLAG=
  
  build_one_r8

  I hope I'm doing something wrong rather than this not being possible.

  Thanks !

• Fundamentally, what exactly is a codec ?

  22 décembre 2013, par Bitwize

  I really hope I don't get down-voted for this, but this is something I have wondered for quite a while now.

  I have been reading through a series of articles describing what codecs are/what they do, and the difference between them and Containers, but where I become confused is in what a codec is fundamentally.

  Is a codec an executable binary/library that handles the compression/decompression of files for a specific program/API ?
  Or is it a form of library for programmers to use in order to handle these containers ?

  Reading various answers around the web it sounds as though it's almost treated as both, which is a little confusing.
  I'm hoping someone here can help clarify.

  Thanks !