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• FFMPEG in android

  11 octobre 2011, par Krishnendu

  Ii am trying to reduce the video size capture by default camera (it's generating high resolution video) in Android. Does FFMPEG have a property to encode a video with given resolution ? I try to Google, but all examples are using command line mode for FFMPEG.

  My questions are :

  1. Can we use ffmpeg command line in Android ?
  2. If not then how we will achieve it ?
  3. Can we able record a video directly using ffmpeg in Android ?
  4. Is there any other solution for this ?

• isom : lpcm in mov default to big endian

  1er novembre 2013, par Mark Himsley

  isom : lpcm in mov default to big endian
  It is my understanding that "Unless otherwise stated, all data in a
  
  QuickTime movie is stored in big-endian byte ordering" [1] in MOV files.
  I have a couple of thousand files, which technically are invalid because
  
  their sound sample description element 4CC is ’lpcm’ but its version is
  
  0 - and "Version 0 supports only uncompressed audio in raw (’raw ’) or
  
  twos-complement (’twos’) format" [2]
  Because isom.c only contains a mapping for 4CC ’lpcm’ to
  
  AV_CODEC_ID_PCM_S16LE, these files have their audio decoded as LE when
  
  it is actually BE.
  This commit adds AV_CODEC_ID_PCM_S16BE as the first match for 4CC ’lpcm’.
  [1]
  
  https://developer.apple.com/library/mac/documentation/quicktime/QTFF/qtff.pdf
  
  page 21
  
  [2]
  
  https://developer.apple.com/library/mac/documentation/quicktime/QTFF/qtff.pdf
  
  page 178
  Reviewed-by : Yusuke Nakamura <muken.the.vfrmaniac@gmail.com>
  

  • [DBH] libavformat/isom.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.