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• Is there any way to change bitrate of MP3 file in Android ? [closed]

  19 avril 2013, par illusion softworks

  In Android, there are no classes or libraries to change bitrate of MP3 files. So we must use extended libraries.

  There are two extended library to do this, one is ffmpeg and another is lame. But in a short time, you can't use it, because if you want to use those libraries in your project, you must learn alot of advanced topics,such as Android-NDK, JNI programming, so on. My question is "Is there another way to change bitrate of MP3 file in Android ?"

• Android video color adjustments

  9 octobre 2012, par Christian

  I'm working on an Android app that among other things will allow the users to make short videos, apply funny effects to them and share them with one another. To begin with, i'm looking for simple color-effects like grayscale, brightness, contrast, sepiatoning, and such.

  All this would be very simple by using the camera-class which can apply the color effects at recording-time - at least most phone's cameras can - i've tested some using Camera.getParameters().getSupportedColorEffects();. But the thing is : i need to do it after the recording has been done : the user would open a video, and choose among a set of effects to apply ; then upload that changed video to a shared server.

  I can't for the love of * find a good way to do this.

  Android doesn't seem to include any videoutilities in the sdk. The android.media.effect package can do some effects, but only backdropper for videos, the rest are for images. Extracting bitmaps from the surfaceview of a videoview during playback doesn't work, it just returns an all-black bitmap. It seems like there's no way to intercept the datastream between the storage and the screen. and apply the effects there. I've started to look into using the FFmpeg library to decode a video file so i can get access to the data, but that requires quite a bit of native coding, and also requires separate compiles for various CPU architectures, so it's very messy. I thought that as the camera can apply these effects (on a Sony LT26i : none, mono, negative, solarize, sepia, posterize), perhaps one could feed the recorder with a videostream not from the camera, but from the memory, and by that way use a stored video file ?

  Do anyone know if there is a good way to apply effects to a video - after it has been recorded ?

• FFMPEG 1.0 ANDROID NDK R8B

  6 février 2013, par user1613977

  I have tried to compile the last version of ffmpeg with the android ndk r8b, but i always have errors and i dont know how to solve them. I am reading this tutorial http://www.roman10.net/how-to-build-ffmpeg-for-android/ but the script doesnt work with my environment, i am using this :
   Ubuntu 12.04 LTS.
   Intel Core i7.
   Android ndk r8b
   Last version ffmeg (1.0)

  Basically i want to encode films from one format to other.

  And that is the script that i am using :

  NDK=../android-ndk-r8b
  
  PLATFORM=$NDK/platforms/android-8/arch-arm/
  
  PREBUILT=$NDK/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86
  
  function build_r8b
  
  {
  
  bash 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/arm-linux-androideabi- \
  
  --enable-cross-compile \
  
  --target-os=linux \
  
  --extra-cflags="-I$PLATFORM/usr/include" \
  
  --extra-ldflags="-L$PLATFORM/usr/lib -nostdlib" \
  
  --arch=arm \
  
  --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/arm-linux-androideabi-ar d libavcodec/libavcodec.a inverse.o
  
  $PREBUILT/bin/arm-linux-androideabi-ld -rpath-link=$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/arm-linux-androideabi/4.4.3/libgcc.a
  
  }
  
  #arm v7vfpv3
  
  CPU=armv7-a
  
  OPTIMIZE_CFLAGS="-mfloat-abi=softfp -mfpu=vfpv3-d16 -marm -march=$CPU "
  
  PREFIX=./android/$CPU
  
  ADDITIONAL_CONFIGURE_FLAG=
  
  #build_one
  
  build_r8b

  And that is the terminal result

  jllarraz@ubuntu:~/Descargas/ffmpeg$ bash build_android.sh
  
  /android-ndk-r8b/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86/bin/arm-linux-androideabi-gcc is unable to create an executable file.
  
  C compiler test failed.
  
  
  
  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.
  
  make: execvp: ./version.sh: Permiso denegado
  
  make: execvp: ./version.sh: Permiso denegado
  
  HOSTCC  doc/print_options.o
  
  CC  cmdutils.o
  
  CC  libavdevice/alldevices.o
  
  CC  libavdevice/avdevice.o
  
  In file included from doc/print_options.c:104:0:
  
  ./libavcodec/options_table.h: En la función ‘show_codec_opts’:
  
  ./libavcodec/options_table.h:85:1: aviso: ‘sub_id’ es obsoleto (declarado en  ./libavcodec/avcodec.h:1505) [-Wdeprecated-declarations]
  
  ./libavcodec/options_table.h:149:1: aviso: ‘luma_elim_threshold’ es obsoleto (declarado en ./libavcodec/avcodec.h:1740) [-Wdeprecated-declarations]
  
  ./libavcodec/options_table.h:150:1: aviso: ‘chroma_elim_threshold’ es obsoleto (declarado en ./libavcodec/avcodec.h:1747) [-Wdeprecated-declarations]
  
  ./libavcodec/options_table.h:284:1: aviso: ‘color_table_id’ es obsoleto (declarado en ./libavcodec/avcodec.h:1986) [-Wdeprecated-declarations]
  
  ./libavcodec/options_table.h:307:1: aviso: ‘inter_threshold’ es obsoleto (declarado en ./libavcodec/avcodec.h:2049) [-Wdeprecated-declarations]
  
  ./libavcodec/options_table.h:312:1: aviso: ‘quantizer_noise_shaping’ es obsoleto (declarado en ./libavcodec/avcodec.h:2056) [-Wdeprecated-declarations]
  
  cmdutils.c:52:21: error fatal: version.h: No existe el archivo o el directorio
  
  compilación terminada.
  
  make: *** [cmdutils.o] Error 1
  
  make: *** Se espera a que terminen otras tareas....
  
  build_android.sh: línea 59: ../android-ndk-r8b/toolchains/arm-linux-androideabi- 4.4.3/prebuilt/linux-x86/bin/arm-linux-androideabi-ar: Permiso denegado
  
  build_android.sh: línea 60: ../android-ndk-r8b/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86/bin/arm-linux-androideabi-ld: Permiso denegado