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• Compiling ffmpeg with emscripten

  18 septembre 2018, par noel

  I’m trying to compile ffmpeg into javascript so that I can decode H264 video streams using node. The streams are H264 frames packed into RTP NALUs so any solution has to be able to accept H264 frames rather than a whole file name.

  I found the Broadway.js library, but I couldn’t get it working and it doesn’t handle P-frames which I need. I also found ffmpeg.js, but could get that to work and it needs a whole file not a stream. Likewise, fluent-ffmpeg doesn’t appear to support file streams ; all of the examples show a filename being passed to the constructor. So I decided to write my own API.

  I have been able to compile ffmpeg into one big js file, but I can’t use it like that. I want to write an API around ffmpeg and then expose those functions to JS. So it seems to me like I need to do the following :

  1. Compile ffmpeg components (avcodec, avutil, etc.) into llvm bitcode.
  2. Write a C wrapper that exposes the decoding functionality and uses EMSCRIPTEN_KEEPALIVE.
  3. Use emcc to compile the wrapper and link it to the bitcode created in step 1.

  I found WASM+ffmpeg, but it’s in Chinese and some of the steps aren’t clear. In particular there is this step :

  emcc web.c process.c ../lib/libavformat.bc ../lib/libavcodec.bc ../lib/libswscale.bc ../lib/libswresample.bc ../lib/libavutil.bc \

  I don’t understand how all the ffmpeg components get compiled into separate *.bc files. I followed the emmake commands in that article and I end up with one big .bc file.

  Does anyone know the steps to compile ffmpeg using emscripten so that I can expose some API to javascript ?

  Is there a better way (with decent documentation) to decode h264 video streams using node ?

• How can I develop a 264 "codec format worked in VideoView API on android ?

  31 juillet 2018, par lscodex

  I have got a big problem. I have a video "tc10.264" I downloaded from live555.com. I can not play the video that using videoview,exoplayer and vitamio sdk
  on android.
  I know that the video is codec.it is not container like mp4,flv etc.
  Later, I played the video with "ffplay -f h264 tc10.264 " via on windows console.
  and ffmpeg shows me this spec.
  h264(baseline), yubj420p and 25 fps.

  Okay this video is exist.
  After, I downloaded ffmpeg from on ubuntu in virtual machine. And I build(compile) the ffmpeg with x264 it as shown below.

  my directory path is like ffmpeg > x264 and I compiled libx264.a for ffmpeg from x264 folder.

  Note : my android phone has architecturally armeabi_v7a

  There is build_android_arm.sh script.

  #!/bin/bash
  
  echo starting building .... 
  
  NDK=/home/lscodex/android-sdk/ndk-bundle
  
  PLATFORM=$NDK/platforms/android-19/arch-arm/
  
  TOOLCHAIN=$NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64
  
  PREFIX=./android/arm
  
  
  
  function build_one
  
  {
  
    ./configure \
  
    --prefix=$PREFIX \
  
    --enable-static \
  
    --enable-pic \
  
    --host=arm-linux \
  
    --cross-prefix=$TOOLCHAIN/bin/arm-linux-androideabi- \
  
    --sysroot=$PLATFORM
  
  
  
    make clean
  
    make
  
    make install
  
  }
  
  
  
  build_one
  
  
  
  echo Android ARM builds finished....

  After, I have a folder called android containing lib,include and bin files.So, I compiled script that shown below to achieve shared folder (".so") in ffmpeg folder.
  there is build_android_armeabi_v7a.sh script

  #!/bin/bash
  
  
  
  echo Android starting armeabi_v7a
  
  NDK=/home/lscodex/android-sdk/ndk-bundle
  
  PLATFORM=$NDK/platforms/android-19/arch-arm/
  
  PREBUILT=$NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64
  
  CPU=armeabi_v7a
  
  PREFIX=$(pwd)/android/$CPU
  
  
  
  GENERAL="\
  
  --enable-small \
  
  --enable-cross-compile \
  
  --extra-libs="-lgcc" \
  
  --arch=arm \
  
  --cc=$PREBUILT/bin/arm-linux-androideabi-gcc \
  
  --cross-prefix=$PREBUILT/bin/arm-linux-androideabi- \
  
  --nm=$PREBUILT/bin/arm-linux-androideabi-nm \
  
  --extra-cflags="-I../x264/android/arm/include" \
  
  --extra-ldflags="-L../x264/android/arm/lib" "
  
  
  
  
  
  MODULES="\
  
  --enable-gpl \
  
  --enable-libx264"
  
  
  
  H264TEST="\
  
  --enable-encoder=libx264 \
  
  --enable-encoder=libx264rgb \
  
  --enable-decoder=h264 \
  
  --enable-muxer=h264 \
  
  --enable-demuxer=h264 \
  
  --enable-parser=h264"
  
  
  
  function build_ARMv7
  
  {
  
    ./configure \
  
    --target-os=android \
  
    --prefix=$PREFIX \
  
    ${GENERAL} \
  
    --sysroot=$PLATFORM \
  
    --enable-shared \
  
    ${H264TEST} \
  
    --disable-static \
  
    --extra-cflags="-march=armv7-a -mfloat-abi=softfp -mfpu=vfpv3-d16 -fomit-frame-pointer -fstrict-aliasing -funswitch-loops -finline-limit=300" \
  
    --extra-ldflags="-Wl,-rpath-link=$PLATFORM/usr/lib -L$PLATFORM/usr/lib -nostdlib -lc -lm -ldl -llog" \
  
    --enable-zlib \
  
    ${MODULES} \
  
    --disable-doc \
  
    --enable-neon
  
  
  
    make clean
  
    make
  
    make install
  
  }
  
  
  
  
  
  build_ARMv7
  
  echo Android ARMv7-a builds finished

  finally, I obtained another an android folder that contain shared library.
  I integrated the files from the android studio. I created CMakeLists.txt and cpp folder.
  So, Everything is perfectly working, I think.
  this ndk code helping me for receive a duration of bugs_bunny.mp4 video.

  extern "C"
  
  JNIEXPORT jint JNICALL
  
  Java_com_lscodex_just_videoplayertesting2_VideoProcessing_videoDuration(
  
          JNIEnv *env,
  
          jobject obj,
  
          jstring input) {
  
  
  
  
  
      AVFormatContext *pFormatCtx = NULL;
  
  
  
       if(avformat_open_input(&pFormatCtx,convertStringFileToChar(env,input),NULL,NULL)<0){
  
           throwException(env,"Could not open input file ");
  
           loge("Could not open input file ");
  
           return 0;
  
       }
  
       if (avformat_find_stream_info(pFormatCtx,NULL)<0){
  
           throwException(env,"Failed to retrieve input stream information");
  
           loge("Failed to retrieve input stream information");
  
           return 0;
  
       }
  
  
  
      logd("I reached it here :) ");
  
  
  
  
  
      int64_t duration = pFormatCtx->duration;
  
      avformat_close_input(&pFormatCtx);
  
      avformat_free_context(pFormatCtx);
  
      return (jint) (duration / AV_TIME_BASE);
  
  }

  at least for mp4 video format.
  So, my question is, How can I run tc10.264 codec video format via ffmpeg on exoplayer or on videoview api ?

• Revision 50038 : Petites améliorations du formulaire de configuration On retrouve le ...

  28 juillet 2011, par kent1@… — Log

  Petites améliorations du formulaire de configuration
  On retrouve le logo pour CFG2
  Un peu de ménage dans les sites :
  Les éléments enlevés de la liste :
   Bluegger => fermé
   Furl => renvoit vers diigo.com
   Kirtsy => ne semble plus être un site de ce type
   Mixx => racheté et ne fonctionne plis
   pioche.fr => N’existe plus
   propeller.com => Racheté par aol news
   Shoutwire => semble avoir disparu de la toile
   ​http://simpy.com/ => semble avoir disparu de la toile
   ​http://www.tagtooga.com/ => semble avoir disparu de la toile
   twine => pointe vers evri.com => url à trouver ?
  Les éléments ajoutés :
   BarraPunto ? => ​http://barrapunto.com
   Bitacoras => ​http://bitacoras.com
   Dzone => ​http://www.dzone.com/
   Friendfeed => ​http://www.friendfeed.com
   identi.ca => ​http://identi.ca
   linkedin => ​http://www.linkedin.com
   Plaxo
  Petite modification de l’url de facebook
  On incrémente le numéro de version