Recherche avancée

Sur d’autres sites (6973)

• Building a shared library from static libraries for ffmpeg 2.5.2

  7 janvier 2015, par abijinx

  I am currently building a shared library for ffmpeg as myffmpeg.so using ffmpeg 0.8.6. I am achieving by combining static libs of individual modules of ffmpeg, along with a few additional static libraries. The main makefile used is as follows :

  LOCAL_PATH := $(call my-dir)
  
  
  
  include $(LOCAL_PATH)/Android_Files.mk
  
  
  
  include $(CLEAR_VARS)
  
  LOCAL_MODULE:= libavcodec
  
  LOCAL_SRC_FILES:= $(MY_AVCODEC_FILES)
  
  include $(LOCAL_PATH)/Android_Common.mk
  
  include $(BUILD_STATIC_LIBRARY)
  
  
  
  include $(CLEAR_VARS)
  
  LOCAL_MODULE:= libavfilter
  
  LOCAL_SRC_FILES:= $(MY_AVFILTER_FILES)
  
  include $(LOCAL_PATH)/Android_Common.mk
  
  include $(BUILD_STATIC_LIBRARY)
  
  
  
  include $(CLEAR_VARS)
  
  LOCAL_MODULE:= libavformat
  
  LOCAL_SRC_FILES:= $(MY_AVFORMAT_FILES)
  
  include $(LOCAL_PATH)/Android_Common.mk
  
  include $(BUILD_STATIC_LIBRARY)
  
  
  
  include $(CLEAR_VARS)
  
  LOCAL_MODULE:= libavutil
  
  LOCAL_SRC_FILES:= $(MY_AVUTIL_FILES)
  
  include $(LOCAL_PATH)/Android_Common.mk
  
  include $(BUILD_STATIC_LIBRARY)
  
  
  
  include $(CLEAR_VARS)
  
  LOCAL_MODULE:= libswscale
  
  LOCAL_SRC_FILES:= $(MY_SWSCALE_FILES)
  
  include $(LOCAL_PATH)/Android_Common.mk
  
  include $(BUILD_STATIC_LIBRARY)
  
  
  
  include $(CLEAR_VARS)
  
  LOCAL_MODULE:= ffmpeg_myc
  
  LOCAL_SRC_FILES:= ffmpeg.c cmdutils.c
  
  include $(LOCAL_PATH)/Android_Common.mk
  
  include $(BUILD_STATIC_LIBRARY)
  
  
  
  include $(CLEAR_VARS)
  
  LOCAL_MODULE := myffmpeg
  
  LOCAL_WHOLE_STATIC_LIBRARIES := libavcodec libavfilter libavformat libavutil libswscale ffmpeg_c
  
  LOCAL_LDFLAGS += -lz -lm -llog
  
  ifeq ($(FF_ENABLE_AMR),yes)
  
  LOCAL_WHOLE_STATIC_LIBRARIES += opencore-amrnb opencore-amrwb
  
  endif
  
  ifeq ($(FF_ENABLE_AAC),yes)
  
  LOCAL_WHOLE_STATIC_LIBRARIES += vo-aacenc
  
  endif
  
  
  
  include $(BUILD_SHARED_LIBRARY)

  The above makefile uses only few selected source files to get the individual static libs as mentioned in the FF_SOURCE_FILES parameter.Then combines all of those with the additional libs to create a shared library myffmpeg.so.

  Now I am trying to get a similar output with ffmpeg 2.5.2 for 64-bit arm architecture. This time I have built the latest ffmpeg using the following configure script and generated the static libraries of different ffmpeg modules like libavcodec.a, libavfilter.a, etc

  #!/bin/bash
  
  ABI=aarch64-linux-android
  
  NDK=
  
  SYSROOT=$NDK/platforms/android-21/arch-arm64/
  
  TOOLCHAIN=$NDK/toolchains/aarch64-linux-android-4.9/prebuilt/linux-x86_64
  
  CPU=arm64
  
  PREFIX=$(pwd)/android/$CPU
  
  ./configure \
  
  --prefix=$PREFIX \
  
  --cc=$TOOLCHAIN/bin/$ABI-gcc \
  
  --enable-static \
  
  --disable-doc \
  
  --disable-ffmpeg \
  
  --disable-ffplay \
  
  --disable-ffprobe \
  
  --disable-network \
  
  --disable-ffserver \
  
  --disable-devices \
  
  --disable-avdevice \
  
  --disable-swscale-alpha \
  
  --disable-doc \
  
  --disable-symver \
  
  --disable-neon \
  
  --enable-optimizations \
  
  --cross-prefix=$TOOLCHAIN/bin/aarch64-linux-android- \
  
  --target-os=linux \
  
  --arch=arm64 \
  
  --enable-cross-compile \
  
  --sysroot=$SYSROOT 
  
  
  
      --enable-libopencore-amrnb \
  
      --enable-libopencore-amrwb \
  
      --enable-libvo-aacenc \
  
      $ADDITIONAL_CONFIGURE_FLAG
  
  make clean
  
  make
  
  make install 

  Now I am trying to combine the generated static libraries i.e

  • libavcodec.a
    libavfilter.a
    libavformat.a
    libavutil.a
    libswresample.a
    libswscale.a
    with

  • ffmpeg_myc opencore-amrnb opencore-amrwb

  and generate a myffmpeg.so shared library by giving ndk-build.

  I tried to paste the generated ffmpeg static libraries from ffmpeg/android folder to obj/local/arm64-v8a (path where are all the static libs were previously created in 0.8.6 according the makefile). I also made changes to the makefile thinking that it will use the already generated ffmpeg libraries. But I found that the size of the generated shared library was too low and that it has not included the generated ffmpeg libs.

  LOCAL_PATH := $(call my-dir)
  
  include $(CLEAR_VARS)
  
  LOCAL_MODULE := myffmpeg
  
  LOCAL_WHOLE_STATIC_LIBRARIES := libavcodec libavfilter libavformat libavutil libswscale ffmpeg_c
  
  LOCAL_LDFLAGS += -lz -lm -llog
  
  ifeq ($(FF_ENABLE_AMR),yes)
  
  LOCAL_WHOLE_STATIC_LIBRARIES += opencore-amrnb opencore-amrwb
  
  endif
  
  ifeq ($(FF_ENABLE_AAC),yes)
  
  LOCAL_WHOLE_STATIC_LIBRARIES += vo-aacenc
  
  endif
  
  
  
  include $(BUILD_SHARED_LIBRARY)

  I would like to know whether I am going in a right way and have to do some minor changes. Or if I should start with an entirely different approach to achieve this. Any suggestions would be helpful.

  Thanks in advance

• How to convert images to video using FFMpeg for embedded applications ?

  19 avril 2019, par zthatch56

  I’m encoding images as video using FFmpeg using custom C code rather than linux commands because I am developing the code for an embedded system.

  I am currently following through the first dranger tutorial and the code provided in the following question.

  How to encode a video from several images generated in a C++ program without writing the separate frame images to disk ?

  I have found some "less abstract" code in the following github location.

  https://github.com/FFmpeg/FFmpeg/blob/master/doc/examples/encode_video.c

  And I plan to use it as well.

  My end goal is simply to save video on an embedded system using embedded C source code, and I am coming up the curve too slowly. So in summary my question is, Does it seem like I am following the correct path here ? I know that my system does not come with hardware for video codec conversion, which means I need to do it with software, but I am unsure if FFmpeg is even a feasible option for embedded work because I am yet to compile.

  The biggest red flag for me thus far is that FFmpeg uses dynamic memory allocation. I am unfamiliar with how to assess the amount of dynamic memory that it uses. This is very important information to me, and if anyone is familiar with the amount of memory used or how to assess it before compiling, I would greatly appreciate the input.

• JavaCV : Video concatenation [on hold]

  20 juin 2014, par user3266577

  I am working on a project that concatenates videos together but only found the option of using FFmpegFrameGrabbers to iterate through both files, getting their frames then generating a new file from them using a FFMpegRecorder which seems quite inefficient with the amount of frames I am having to loop through.

  Ideally it’s going the long way around about the problem, is there a simpler way of concatenating two videos generated by FFMpegRecorder ?