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• fftools/ffmpeg : always read input in a thread

  21 mars 2022, par Anton Khirnov

  fftools/ffmpeg : always read input in a thread
  This will be required by the following architecture changes.
  

  • [DH] fftools/ffmpeg.c

• FFMpeg integration with iOS 7

  2 janvier 2014, par metsburg

  I am trying to integrate FFMpeg with iOS 7.

  My objective is to decode a video stream which is coming in through H.264 video codec.

  I've built the FFMpeg library using methodology described here : Trying to compile the FFMPEG libraries for iPhoneOS platform with armv6 and arv7 architecture

  When I compile using :

  ./configure 
  
  --prefix=armv7 
  
  --disable-ffmpeg 
  
  --disable-ffplay 
  
  --disable-ffprobe 
  
  --disable-ffserver 
  
  --enable-avresample 
  
  --enable-cross-compile 
  
  --sysroot="/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.0.sdk" 
  
  --target-os=darwin 
  
  --cc="/usr/llvm-gcc-4.2/bin/llvm-gcc-4.2" 
  
  --extra-cflags="-arch armv7 -mfpu=neon -miphoneos-version-min=6.1" 
  
  --extra-ldflags="-arch armv7 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.0.sdk -miphoneos-version-min=7.0" 
  
  --arch=arm --cpu=cortex-a9 --enable-pic

  all the *.a files do not get generated.

  I'm trying to create a sample FFMpeg project, as described in http://sol3.typepad.com/exotic_particles/2012/10/building-a-simple-frame-recorder-part-1.html?cid=6a00d8343a141353ef019b01f49c8e970d#comment-6a00d8343a141353ef019b01f49c8e970d

  However, I keep getting the following error while trying to build the project :

  Undefined symbols for architecture i386:
  
  
  
    "_av_close_input_file", referenced from:
  
  
  
        -[FrameExtractor dealloc] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_av_find_stream_info", referenced from:
  
  
  
        -[FrameExtractor initWithVideo:] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_av_free", referenced from:
  
  
  
        -[FrameExtractor dealloc] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_av_free_packet", referenced from:
  
  
  
        -[FrameExtractor stepFrame] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_av_open_input_file", referenced from:
  
  
  
        -[FrameExtractor initWithVideo:] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_av_read_frame", referenced from:
  
  
  
        -[FrameExtractor stepFrame] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_av_register_all", referenced from:
  
  
  
        -[FrameExtractor initWithVideo:] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_avcodec_alloc_frame", referenced from:
  
  
  
        -[FrameExtractor initWithVideo:] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_avcodec_close", referenced from:
  
  
  
        -[FrameExtractor dealloc] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_avcodec_decode_video2", referenced from:
  
  
  
        -[FrameExtractor stepFrame] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_avcodec_find_decoder", referenced from:
  
  
  
        -[FrameExtractor initWithVideo:] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_avcodec_flush_buffers", referenced from:
  
  
  
        -[FrameExtractor seekTime:] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_avcodec_open", referenced from:
  
  
  
        -[FrameExtractor initWithVideo:] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_avcodec_register_all", referenced from:
  
  
  
        -[FrameExtractor initWithVideo:] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_avformat_seek_file", referenced from:
  
  
  
        -[FrameExtractor seekTime:] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_avpicture_alloc", referenced from:
  
  
  
        -[FrameExtractor setupScaler] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_avpicture_free", referenced from:
  
  
  
        -[FrameExtractor setupScaler] in FFmpegDecoder(FrameExtractor.o)
  
  
  
        -[FrameExtractor dealloc] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_sws_freeContext", referenced from:
  
  
  
        -[FrameExtractor setupScaler] in FFmpegDecoder(FrameExtractor.o)
  
  
  
        -[FrameExtractor dealloc] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_sws_getContext", referenced from:
  
  
  
        -[FrameExtractor setupScaler] in FFmpegDecoder(FrameExtractor.o)
  
  
  
    "_sws_scale", referenced from:
  
  
  
        -[FrameExtractor convertFrameToRGB] in FFmpegDecoder(FrameExtractor.o)
  
  
  
  ld: symbol(s) not found for architecture i386
  
  
  
  clang: error: linker command failed with exit code 1 (use -v to see invocation)

  Please help.

• Android, AOSP tree, external project (ffmpeg) is built for AMD64

  22 avril 2015, par kagali-san

  I’m trying to build ffmpeg4android on current AOSP tree (from /external), which is lunch-configured to aosp_arm-eng and set to PLATFORM_VERSION=4.2.

  Resulting files are generated for AMD64 (host native) architecture, even though the major rest of tree is built (as expected) ARM :

  readelf -a android/aosp_arm-eng/ffplay|egrep "Class :|Machine :"
  Class : ELF64 Machine :
  Advanced Micro Devices X86-64

  versus

  readelf -a
  aosp/out/target/product/generic/symbols/system/lib/libril.so | egrep "Class :|Machine :"

  Class : ELF32
  Machine : ARM

  ---

  I will probably switch to other ways of getting ffmpeg-arm (presumably the one described here) ; the reason of asking this question is to understand, at which build stage does cross-compilation environment breaks.