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• How to solve bad instruction `vadd.i16 q0,q0,q0' when attempting to check gcc for neon instruction

  6 juillet 2012, par newentry

  Checking  gcc supports failed for neon instruction vadd.i16 q0,q0,q0
  
      test.c
  
  
  
      int main ()
  
      {
  
       __asm__("vadd.i16 q0, q0, q0"); return 0;
  
      }
  
  
  
      arm-linux-androideabi-gcc test.c
  
      /tmp/ccfc8m0G.s: Assembler messages:
  
      /tmp/ccfc8m0G.s:24: Error: bad instruction `vadd.i16 q0,q0,q0'

  Tried with flags -mcpu=cortex-a8 -mfpu=neon but stil no success

  Above code was used to test gcc support for neon instruction.

  Actually i am trying to build x264 with NEON support for ARM platformAfter running configure script
  x264 config log file contains

  Command line options : "—cross-prefix=arm-linux-androideabi-" "—enable-pic" "—extra- cflags=-mcpu=cortex-a8" "—host=arm-linux"

  checking whether arm-linux-androideabi-gcc works... yes
  
  checking whether arm-linux-androideabi-gcc supports for( int i = 0; i < 9; i++ ); with -std=gnu99... yes
  
  checking whether arm-linux-androideabi-gcc supports __asm__("rev ip, ip");... yes
  
  checking whether arm-linux-androideabi-gcc supports __asm__("movt r0, #0");... yes
  
  checking whether arm-linux-androideabi-gcc supports __asm__("vadd.i16 q0, q0, q0");... no
  
  
  
  arm-linux-androideabi-gcc conftest.c  -Wall -I. -I$(SRCPATH) -mcpu=cortex-a8 -std=gnu99    -lm -o conftest
  
  E:\cygwin\tmp\ccVtVI1i.s: Assembler messages:
  
  E:\cygwin\tmp\ccVtVI1i.s:24: Error: bad instruction `vadd.i16 q0,q0,q0'
  
  --------------------------------------------------
  
  Failed program was:
  
  --------------------------------------------------
  
  int main () { __asm__("vadd.i16 q0, q0, q0"); return 0; }
  
  --------------------------------------------------
  
  
  
  
  
  config.h contains
  
  
  
  #define HAVE_MALLOC_H 1
  
  #define HAVE_ARMV6 1
  
  #define HAVE_ARMV6T2 1
  
  #define ARCH_ARM 1
  
  #define SYS_LINUX 1
  
  #define HAVE_VECTOREXT 1
  
  #define fseek fseeko
  
  #define ftell ftello
  
  #define HAVE_GPL 1
  
  #define HAVE_INTERLACED 1
  
  #define HAVE_ALTIVEC 0
  
  #define HAVE_ALTIVEC_H 0
  
  #define HAVE_MMX 0
  
  #define HAVE_NEON 0
  
  #define HAVE_BEOSTHREAD 0
  
  #define HAVE_POSIXTHREAD 0
  
  #define HAVE_WIN32THREAD 0
  
  #define HAVE_THREAD 0
  
  #define HAVE_LOG2F 0
  
  #define HAVE_VISUALIZE 0
  
  #define HAVE_SWSCALE 0
  
  #define HAVE_LAVF 0
  
  #define HAVE_FFMS 0
  
  #define HAVE_GPAC 0
  
  #define HAVE_GF_MALLOC 0
  
  #define HAVE_AVS 0
  
  #define HAVE_CPU_COUNT 0
  
  
  
  
  
  Running make command build x264 static lib  based on above config.h which contains HAVE_NEON 0
  
  
  
  
  
  **Compiler Version**
  
  
  
  
  
  
  
  arm-linux-androideabi-gcc -v
  
  Using built-in specs.
  
  Target: arm-linux-androideabi
  
  Configured with: /tmp/ndk-digit/src/build/../gcc/gcc-4.4.3/configure --prefix=/usr/local/google/digit/repo/opensource/ndk/toolchains/arm-linux-androideabi-4.4.3/prebuilt/windows --target=arm-linux-androideabi --host=i586-mingw32msvc --build=x86_64-linux-gnu --with-gnu-as --with-gnu-ld --enable-languages=c,c++ --with-gmp=/tmp/ndk-digit/build/toolchain/temp-install --with-mpfr=/tmp/ndk-digit/build/toolchain/temp-install --disable-libssp --enable-threads --disable-nls --disable-libmudflap --disable
  
  -libgomp --disable-libstdc__-v3 --disable-sjlj-exceptions --disable-shared --disable-tls --with-float=soft --with-fpu=vfp --with-arch=armv5te --enable-target-optspace --enable-initfini-array --disable-nls --prefix=/usr/local/google/digit/repo/opensource/ndk/toolchains/arm-linux-androideabi-4.4.3/prebuilt/windows --with-sysroot=/usr/local/google/digit/repo/opensource/ndk/toolchains/arm-linux-androideabi-4.4.3/prebuilt/windows/sysroot --with-binutils-version=2.20.1 --with-mpfr-version=2.4.1 --with
  
  -gmp-version=4.2.4 --with-gcc-version=4.4.3 --with-gdb-version=6.6 --with-arch=armv5te --program-transform-name='s,^,arm-linux-androideabi-,'
  
  Thread model: posix
  
  gcc version 4.4.3 (GCC)    

  Goal is to utilize neon enabled ARM processor to boost x264 encoder performance...

• Video Processing via Bluetooth

  16 juillet 2012, par kerim yucel

  The application I am currently developing processes each frames using a native code and it should record the video as well. I tried SDK for this purpose but certain restrictions didn't allow me to do so, so I switched to NDK for a video recording code piece.

  Apparently, my algorithm seriously uses CPU, upto %70 percent in the worst case. Before I actually start working on a video recorder, I wanted to try the following approach.

  I will process the preview frames using an android phone and send it to another phone (which uses same application and same model) for recording. My questions are :

  1.Should I try WiFi instead of Bluetooth ? I am developing the application for API 8 so I don't have WiFi-Direct, therefore I should do some socket programming, which would possibly complicate things a bit for me since Bluetooth can easily be set up using SDK.

  2- Will I be available to record the frames as a video at the receiving end ? I will receive each frame with certain metadata embedded to it and should record them using the other phone. I doubt I will be able to do it using SDK, so NDK along with ffmpeg seems to be the best choice ? Any suggestions related to this question will be more than welcome.

  3-Here comes the best part. I am recording the video with the lowest resolution that,after compressed, takes no more than 14mb space for a 10 minute long video. I have to reach the raw frames to send it to other end, encode and compress it. Any ideas related to possible flooding of Bluetooth/Wi-Fi because of big-sized raw frames ?

  Any other approaches and answers will be much appreciated. Thanks.

• AAC encoder : Fix rate control on twoloop.

  4 mai 2013, par Claudio Freire

  AAC encoder : Fix rate control on twoloop.
  Fixes a case where multichannel bitrate isn’t accurately
  
  targetted by psy model alone, never achieving the target bitrate.
  
  Now fixed.
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] libavcodec/aaccoder.c