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• so Confused, why my build of libffmpeg.so > 17M ?

  24 février 2012, par ghost

  I did build ffmpeg for Android in winxp and scientific linux , ffmpeg is in dolphin player — an open source video player (http://code.google.com/p/dolphin-player/), and i just build the ffmpeg, its seems like the same as in rockplayer 1.7.0, they all use build_andriod.sh below， it worked in both winxp and linux,
  and all successfully got bin/ffmpeg (less than 5MB), but libffmpeg.so ( > 17MB)， when put libffmpeg.so in dolphin-player libs , player can't work, the size 17MB is too large, the original libffmpeg.so in olphin-player libs is less than 5MB, please give some advice.

  #!/bin/bash
  
  
  
  ######################################################
  
  # FFmpeg builds script for Android+ARM platform
  
  #
  
  # This script is released under term of 
  
  #   CDDL (http://www.opensource.org/licenses/cddl1) 
  
  # Wrote by pinxue (~@gmail.com) from RockPlayer.com
  
  #                                   2010-8 ~ 2011-4
  
  ######################################################
  
  
  
  ######################################################
  
  # Usage:
  
  #   put this script in top of FFmpeg source tree
  
  #   ./build_android
  
  #
  
  # It generates binary for following architectures:
  
  #     ARMv6 
  
  #     ARMv6+VFP 
  
  #     ARMv7+VFM-ïd16 (Tegra2) 
  
  #     ARMv7+Neon (Cortex-A8)
  
  #
  
  # Customizing:
  
  # 1. Feel free to change ./configure parameters for more features
  
  # 2. To adapt other ARM variants
  
  #       set $CPU and $OPTIMIZE_CFLAGS 
  
  #       call build_one
  
  ######################################################
  
  
  
  export TMPDIR=D:/tmp/android
  
  export NDK=D:/android-ndk-r4
  
  
  
  #PLATFORM=$NDK/build/platforms/android-8/arch-arm/
  
  PLATFORM=$NDK/build/platforms/android-8/arch-arm
  
  #PREBUILT=$NDK/build/prebuilt/darwin-x86/arm-eabi-4.4.0
  
  PREBUILT=$NDK/build/prebuilt/windows/arm-eabi-4.4.0
  
  
  
  function build_one
  
  {
  
  
  
  # -fasm : required. Android header file uses asm keyword instead of __asm__ , but most of c dialect (like ansi,c99,gnu99) implies -fno-asm.
  
  #   ~/android/android-ndk-r4/build/platforms/android-5/arch-arm//usr/include/asm/byteorder.h: In function '___arch__swab32':
  
  #   ~/android/android-ndk-r4/build/platforms/android-5/arch-arm//usr/include/asm/byteorder.h:25: error: expected ')' before ':' token
  
  
  
  # -fno-short-enums : optimized.  Else FFmpeg obj will generate a huge number of warning for variable-size enums, 
  
  #   though we may suppress them by --no-enum-size-warning, it would be better to avoid it.
  
  #   .../ld: warning: cmdutils.o uses variable-size enums yet the output is to use 32-bit enums; use of enum values across objects may fail
  
  
  
  # --extra-libs="-lgcc" : required. Else cannot solve some runtime function symbols
  
  #   ... undefined reference to `__aeabi_f2uiz'
  
  
  
  # --enable-protocols : required. Without this option, the file open always fails mysteriously.
  
  #   FFmpeg's av_open_input_file will invoke file format probing functions, but because most of useful demuxers has flag of zero 
  
  #   which cause them are ignored during file format probling and fall to url stream parsing,
  
  #   if protocols are disabled, the file:// url cannot be opened as well.
  
  
  
  # $PREBUILT/bin/arm-eabi-ar d libavcodec/libavcodec.a inverse.o : required.
  
  #   FFmpeg includes two copies of inverse.c both in libavutil and libavcodec for performance consideration (not sure the benifit yet)
  
  #   Without this step, final ld of generating libffmpeg.so will fail silently, if invoke ld through gcc, gcc will collect more reasonable error message.
  
  
  
  # -llog: debug only, FFmpeg itself doesn't require it at all.
  
  #   With this option, we may simply includes "utils/Log.h" and use LOGx() to observe FFmpeg's behavior
  
  #   PS, it seems the toolchain implies -DNDEBUG somewhere, it would be safer to use following syntax
  
  #    #ifdef NDEBUG
  
  #        #undef NDEBUG
  
  #        #define HAVE_NDEBUG
  
  #    #endif
  
  #    #include "utils/Log.h"
  
  #    #ifdef HAVE_NDEBUG
  
  #        #define NDEBUG
  
  #        #undef HAVE_NDEBUG
  
  #    #endif
  
  
  
  # --whole-archive : required. Else ld generate a small .so file (about 15k)
  
  
  
  # --no-stdlib : required. Android doesn't use standard c runtime but invited its own wheal (bionic libc) because of license consideration.
  
  
  
  # space before \ of configure lines: required for some options. Else next line will be merged into previous lines's content and cause problem.
  
  #   Especially the --extra-cflags, the next line will pass to gcc in this case and configure will say gcc cannot create executable.
  
  
  
  # many options mentioned by articles over internet are implied by -O2 or -O3 already, need not repeat at all.
  
  
  
  # two or three common optimization cflags are omitted because not sure about the trade off yet. invoke NDK build system with V=1 to find them.
  
  
  
  # -Wl,-T,$PREBUILT/arm-eabi/lib/ldscripts/armelf.x mentioned by almost every articles over internet, but it is not required to specify at all.
  
  
  
  # -Dipv6mr_interface=ipv6mr_ifindex : required. Android inet header doesn't use ipv6mr_interface which is required by rfc, seems it generate this user space header file directly from kernel header file, but Linux kernel has decided to keep its own name for ever and ask user space header to use rfc name.
  
  
  
  # HAVE_SYS_UIO_H : required. Else:
  
  # In file included from ~/android/android-ndk-r4/build/platforms/android-5/arch-arm//usr/include/linux/socket.h:29,
  
  #                 from ~/android/android-ndk-r4/build/platforms/android-5/arch-arm//usr/include/sys/socket.h:33,
  
  #                 from libavformat/network.h:35,
  
  #                 from libavformat/utils.c:46:
  
  #~/android/android-ndk-r4/build/platforms/android-5/arch-arm//usr/include/linux/uio.h:19: error: redefinition of 'struct iovec'
  
  #
  
  
  
  # --disable-doc : required because of strange bug of toolchain.
  
  #
  
  
  
  #
  
  #--extra-ldflags=-Wl,-T,$PREBUILT/arm-eabi/lib/ldscripts/armelf.x -Wl,-rpath-link=$PLATFORM/usr/lib -L$PLATFORM/usr/lib -nostdlib $PREBUILT/lib/gcc/arm-eabi/4.4.0/crtbegin.o $PREBUILT/lib/gcc/arm-eabi/4.4.0/crtend.o -lc -lm -ldl"
  
  #
  
  
  
  ./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=" -O3 -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" \
  
      --enable-parsers \
  
      --disable-encoders  \
  
      --enable-decoders \
  
      --disable-muxers \
  
      --enable-demuxers \
  
      --enable-swscale  \
  
      --disable-ffplay \
  
      --disable-ffprobe \
  
      --disable-ffserver \
  
      --enable-network \
  
      --enable-indevs \
  
      --disable-bsfs \
  
      --disable-filters \
  
      --enable-protocols  \
  
      --enable-asm \
  
      --disable-doc \
  
      $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 v6
  
  CPU=armv6
  
  OPTIMIZE_CFLAGS="-marm -march=$CPU"
  
  PREFIX=./android/$CPU 
  
  ADDITIONAL_CONFIGURE_FLAG=
  
  build_one
  
  
  
  #arm v7vfpv3
  
  CPU=armv7-a
  
  OPTIMIZE_CFLAGS="-mfloat-abi=softfp -mfpu=vfpv3-d16 -marm -march=$CPU "
  
  PREFIX=./android/$CPU 
  
  ADDITIONAL_CONFIGURE_FLAG=
  
  build_one
  
  
  
  #arm v7vfp
  
  CPU=armv7-a
  
  OPTIMIZE_CFLAGS="-mfloat-abi=softfp -mfpu=vfp -marm -march=$CPU "
  
  PREFIX=./android/$CPU-vfp
  
  ADDITIONAL_CONFIGURE_FLAG=
  
  build_one
  
  
  
  #arm v7n
  
  CPU=armv7-a
  
  OPTIMIZE_CFLAGS="-mfloat-abi=softfp -mfpu=neon -marm -march=$CPU -mtune=cortex-a8"
  
  PREFIX=./android/$CPU-neon 
  
  ADDITIONAL_CONFIGURE_FLAG=--enable-neon
  
  build_one
  
  
  
  #arm v6+vfp
  
  CPU=armv6
  
  OPTIMIZE_CFLAGS="-DCMP_HAVE_VFP -mfloat-abi=softfp -mfpu=vfp -marm -march=$CPU"
  
  PREFIX=./android/${CPU}_vfp 
  
  ADDITIONAL_CONFIGURE_FLAG=
  
  build_one

• Easy Tricks for Finding WebM Videos in YouTube

  9 août 2010, par noreply@blogger.com (John Luther)

  Since the WebM project launch, YouTube has been encoding videos uploaded at 720p or higher resolution in the WebM format. Today, the one million most popular videos of any size on YouTube are also available in the WebM format.

  We have instructions on our project site for finding these videos but they require adding a special parameter onto the end of each search query. All of the browsers that support WebM can create search shortcuts with custom parameters, however, so we’ve compiled instructions for making it very simple to search for WebM videos in YouTube.

  Important : First, make sure you have a supported browser and are enrolled in the YouTube HTML5 beta by going to http://youtube.com/html5 and clicking Enter the HTML5 Beta.

  Creating a WebM Search Shortcut

  Firefox 4 Beta :
  

  1. Select Bookmarks > Organize Bookmarks. A bookmark manager dialog opens.
  2. In the left column, choose a location for the new bookmark you’re creating. Next, choose Organize > New Bookmark (on MacOS click the gear icon). The new bookmark dialog opens.
  3. In the Name box, type WebM.
  4. In the Location box, type http://youtube.com/results?search_query=%s&webm=1.
  5. In the Keyword box, type webm.
  6. Click Add.

  Google Chrome Early Release Channel :
  

  1. On Windows and Linux, click the Chrome wrench icon in the toolbar and select Options. On MacOS, select Chrome > Preferences.
  2. On the Basics tab, click the Manage button in the Default Search section.
  3. On Windows and Linux, click Add. On MacOS X, click the plus (+) button.
  4. In the Name box, type WebM.
  5. In the Keyword box, type webm.
  6. In the URL box, type http://youtube.com/results?search_query=%s&webm=1.
  7. Click OK.

  Opera 10.60 and later :
  

  1. Go to http://youtube.com.
  2. Right-click in the YouTube search box at the top of the page and select Create Search. On MacOS, use Ctrl+click if you don’t a secondary mouse button enabled.
  3. In the Name box, type WebM.
  4. In the Keyword box, type webm.
  5. In the Address box, type http://youtube.com/results?search_query=%s&webm=1.
  6. Click OK.

  
  

  
  Now you’re ready to search. In the location box of the browser, type webm monster trucks. The YouTube search results page will open with a selection of monster truck videos encoded in the WebM format. When watching a video, look for the HTML5 WebM indicator in the player control bar.

  If you can’t find WebM videos it is most likely a browser cookie problem. Your enrollment in the YouTube HTML5 beta test is stored in a browser cookie (not in your YouTube or Google account), and that cookie can expire. Visit http://youtube.com/html5 and opt-in again to re-set the cookie.

  Directly Accessing WebM Videos by URL

  To find out if any YouTube video is available in WebM, simply add &html5=True (make sure True is capitalized) to the end of the video URL. If there is a WebM version of the video, it will open instead of the Flash version. For example :
  

  • Flash version : http://www.youtube.com/watch?v=Dz6gFokvOr0
  • WebM version : http://www.youtube.com/watch?v=Dz6gFokvOr0&html5=True

  

• Saving H.264 RTP stream without re-encoding ?

  13 avril 2012, par Gene Vincent

  My C++ application receives a H.264 RTP video stream.

  Right now it decodes the stream, saves it into a YUV file and later I use ffmpeg to re-ecode the file into something suitable to watch on a Windows PC (eg. Mpeg4 AVI).

  Shouldn't it be possible to save the H.264 stream into a AVI (or similar) container without having to decode and re-encode it ? That would require some H.264 decoder on the PC to watch, but it should be much more efficient.

  How could that be done ? Are there any libraries supporting that ?