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• Documentation + download history updates

  20 décembre 2011, par Scott Schiller

  m doc/download/index.html m doc/index.html Documentation + download history updates

• Undefined Reference - ffmpeg on android ndk

  28 décembre 2012, par Gabriel Simões

  I´ve spent many hours trying to figure out why I still get "undefined reference" when trying to link to ffmpeg.
  I´ve already read most if not all posts and sites about the subject, so I think I´m missing something little here and I hope you can help me.

  What I have :

  I´m using windows 7 + cygwin + crystax r4.
  I´ve compiled FFMPEG using RockPlayer's ffmpeg source plus some modifications I did (only to include / exclude demuxes, decoders, encoders, ...)
  After compiling, I get :

  • a new folder named armv5te, which includes :
  • a folder named "include" with all folders for each libs' .h
  • a folder named "lib" which includes all libs' .a
  • a shared library named libffmpeg.so (checked soname and it is libffmpeg)

  The shared library isn´t also placed on project/lib/armeabi/libffmpeg.so

  After compiling I tried to compile my project and link it. While my .cpp compiles ok, I get many undefined references.

  here is my build script :

  NDK=/cygdrive/c/Gabriel/Desenvolvimento/SDKs/Android/android-ndk-r4-crystax
  
  PLATFORM=$NDK/build/platforms/android-8/arch-arm/
  
  PREBUILT=$NDK/build/prebuilt/windows/arm-eabi-4.4.0
  
  
  
  
  
  function build_one
  
  {
  
  
  
  ./configure --target-os=linux \
  
      --prefix=$PREFIX \
  
      --enable-cross-compile \
  
      --extra-libs="-lgcc" \
  
      --arch=arm \
  
      --cc=$PREBUILT/bin/arm-eabi-gcc \
  
      --cross-prefix=$PREBUILT/bin/arm-eabi- \
  
      --nm=$PREBUILT/bin/arm-eabi-nm \
  
      --sysroot=$PLATFORM \
  
      --extra-cflags=" -O2 -fpic -DANDROID -DHAVE_SYS_UIO_H=1 -Dipv6mr_interface=ipv6mr_ifindex -fasm -Wno-psabi -fno-short-enums  -fno-strict-aliasing -finline-limit=300 $OPTIMIZE_CFLAGS " \
  
      --disable-shared \
  
      --enable-static \
  
      --extra-ldflags="-Wl,-rpath-link=$PLATFORM/usr/lib -L$PLATFORM/usr/lib  -nostdlib -lc -lm -ldl -llog" \
  
      --disable-stripping \
  
      --disable-debug \
  
      --disable-symver \
  
      --disable-ffprobe \
  
      --disable-devices \
  
      --disable-avfilter \
  
      --disable-swscale \
  
      --disable-ffplay \
  
      --disable-ffserver \
  
      --disable-network \
  
          (many more ...)
  
      --enable-asm \
  
      $ADDITIONAL_CONFIGURE_FLAG
  
  
  
  #make clean
  
  make  -j4 install
  
  
  
  $PREBUILT/bin/arm-eabi-ar d libavcodec/libavcodec.a inverse.o
  
  
  
  $PREBUILT/bin/arm-eabi-ld -rpath-link=$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  -lc -lm -lz -ldl -llog  --warn-once  --dynamic-linker=/system/bin/linker $PREBUILT/lib/gcc/arm-eabi/4.4.0/libgcc.a
  
  
  
  }
  
  
  
  #arm v5
  
  CPU=armv5te
  
  OPTIMIZE_CFLAGS="-marm -march=$CPU"
  
  PREFIX=./android/$CPU 
  
  ADDITIONAL_CONFIGURE_FLAG=
  
  build_one

  Here is my android.mk :

  LOCAL_PATH := $(call my-dir)
  
  
  
  #declare the prebuilt library
  
  include $(CLEAR_VARS)
  
  LOCAL_MODULE := ffmpeg-prebuilt
  
  LOCAL_SRC_FILES := $(LOCAL_PATH)/ffmpeg/android/armv5te/libffmpeg.so
  
  LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/ffmpeg/android/armv5te/include
  
  LOCAL_PRELINK_MODULE := true 
  
  include $(PREBUILT_SHARED_LIBRARY)
  
  
  
  include $(CLEAR_VARS)
  
  LOCAL_MODULE    := audiocodec
  
  LOCAL_SRC_FILES := ffmpeg_audio.cpp
  
  LOCAL_SHARED_LIBRARY := libffmpeg
  
  LOCAL_C_INCLUDES := $(LOCAL_PATH)/ffmpeg/android/armv5te/include
  
  LOCAL_LDLIBS    := -llog -ljnigraphics -lz -lm $(LOCAL_PATH)/ffmpeg/android/armv5te/libffmpeg.so
  
  include $(BUILD_SHARED_LIBRARY)

  The result :

  Compile++ thumb: audiocodec <= /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFM
  
  PEG/jni/ffmpeg_audio.cpp
  
  SharedLibrary  : libaudiocodec.so
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/obj/local/armeabi/objs/audi
  
  ocodec/ffmpeg_audio.o: In function `Java_gabriel_audioslower_pro_ffmpegDecoder_r
  
  eadSamples':
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/jni/ffmpeg_audio.cpp:172: u
  
  ndefined reference to `avcodec_decode_audio3(AVCodecContext*, short*, int*, AVPa
  
  cket*)'
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/jni/ffmpeg_audio.cpp:178: u
  
  ndefined reference to `av_read_frame(AVFormatContext*, AVPacket*)'
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/obj/local/armeabi/objs/audi
  
  ocodec/ffmpeg_audio.o: In function `Java_gabriel_audioslower_pro_ffmpegDecoder_s
  
  eekToPosMS':
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/jni/ffmpeg_audio.cpp:147: u
  
  ndefined reference to `av_rescale_q(long long, AVRational, AVRational)'
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/jni/ffmpeg_audio.cpp:150: u
  
  ndefined reference to `av_seek_frame(AVFormatContext*, int, long long, int)'
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/jni/ffmpeg_audio.cpp:151: u
  
  ndefined reference to `avcodec_flush_buffers(AVCodecContext*)'
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/jni/ffmpeg_audio.cpp:152: u
  
  ndefined reference to `av_read_frame(AVFormatContext*, AVPacket*)'
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/obj/local/armeabi/objs/audi
  
  ocodec/ffmpeg_audio.o: In function `Java_gabriel_audioslower_pro_ffmpegDecoder_c
  
  loseFile':
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/jni/ffmpeg_audio.cpp:82: un
  
  defined reference to `avcodec_close(AVCodecContext*)'
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/jni/ffmpeg_audio.cpp:83: un
  
  defined reference to `av_free(void*)'
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/jni/ffmpeg_audio.cpp:84: un
  
  defined reference to `av_close_input_file(AVFormatContext*)'
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/obj/local/armeabi/objs/audi
  
  ocodec/ffmpeg_audio.o: In function `Java_gabriel_audioslower_pro_ffmpegDecoder_o
  
  penAudioFile':
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/jni/ffmpeg_audio.cpp:37: un
  
  defined reference to `av_open_input_file(AVFormatContext**, char const*, AVInput
  
  Format*, int, AVFormatParameters*)'
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/jni/ffmpeg_audio.cpp:44: un
  
  defined reference to `av_find_stream_info(AVFormatContext*)'
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/jni/ffmpeg_audio.cpp:52: un
  
  defined reference to `avcodec_find_decoder(CodecID)'
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/jni/ffmpeg_audio.cpp:60: un
  
  defined reference to `avcodec_open(AVCodecContext*, AVCodec*)'
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/jni/ffmpeg_audio.cpp:67: un
  
  defined reference to `av_malloc(unsigned int)'
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/jni/ffmpeg_audio.cpp:70: un
  
  defined reference to `av_read_frame(AVFormatContext*, AVPacket*)'
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/obj/local/armeabi/objs/audi
  
  ocodec/ffmpeg_audio.o: In function `JNI_OnLoad':
  
  /cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/jni/ffmpeg_audio.cpp:25: un
  
  defined reference to `av_register_all()'
  
  collect2: ld returned 1 exit status
  
  make: *** [/cygdrive/c/Gabriel/Desenvolvimento/Workspace/FFMPEG/obj/local/armeab
  
  i/libaudiocodec.so] Error 1

  Something interesting is that some functions from ffmpeg, as av_register_all(), do now show up on the list of undefined references.

  Any ideas on what I can do to fix it ? I´ve spent 3 days trying to make things work ..
  Thanks !

• FFMpeg for android [on hold]

  2 mai 2016, par Mike Albren

  Android media player only supports video playback from file or RTSP , but I need to stream RTP video the comes from UDP network socket so I am thinking to use FFMpeg, but I do not have have any knowledge how to use FFMpeg API,and I do not know if it is an easy task or not , I know FFMpeg is written in c and I know how to compile it and how to use NDK , but I need more information how to use FFMpeg to stream from socket, any one knows good tutorial,example code or open source project do the same job , how should I start ? or if there is another easy way to do the same task on android ?