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• x86 : Remove X264_CPU_SSE_MISALIGN functions

  5 juillet 2013, par Henrik Gramner

  x86 : Remove X264_CPU_SSE_MISALIGN functions
  Prevents a crash if the misaligned exception mask bit is cleared for some reason.
  Misaligned SSE functions are only used on AMD Phenom CPUs and the benefit is miniscule.
  
  They also require modifying the MXCSR control register and by removing those functions
  
  we can get rid of that complexity altogether.
  VEX-encoded instructions also supports unaligned memory operands. I tried adding AVX
  
  implementations of all removed functions but there were no performance improvements on
  
  Ivy Bridge. pixel_sad_x3 and pixel_sad_x4 had significant code size reductions though
  
  so I kept them and added some minor cosmetics fixes and tweaks.
  

  • [DH] common/cpu.c
  • [DH] common/cpu.h
  • [DH] common/pixel.c
  • [DH] common/x86/cpu-a.asm
  • [DH] common/x86/mc-a.asm
  • [DH] common/x86/mc-a2.asm
  • [DH] common/x86/mc-c.c
  • [DH] common/x86/pixel.h
  • [DH] common/x86/sad-a.asm
  • [DH] common/x86/x86inc.asm
  • [DH] encoder/encoder.c
  • [DH] encoder/lookahead.c
  • [DH] tools/checkasm.c
  • [DH] x264.h

• avcodec/mips/aaccoder_mips : Remove MIPS-specific aaccoder

  15 mars 2024, par Andreas Rheinhardt

  avcodec/mips/aaccoder_mips : Remove MIPS-specific aaccoder
  ff_aac_coder_init_mips() modifies a static const structure of
  
  function pointers. This will crash if the binary uses relro
  
  and is a data race in any case.
  Furthermore it points to a maintainability issue : The
  
  AACCoefficientsEncoder structures have been constified
  
  in commit fd9212f2edfe9b107c3c08ba2df5fd2cba5ab9e3,
  
  a Libav commit merged in 318778de9ebec276cb9dfc65509231ca56590d13.
  
  Libav did not have the MIPS-specific AAC code and so this was
  
  fine for them ; yet FFmpeg had them, but this was not recognized.
  Commit 75a099fc734a4ee2b1347d0a3d8c53d883b95174 points to another
  
  maintainability issue : Contrary to ordinary DSP code, this code
  
  here is way more complex and needs to be constantly kept in sync
  
  with the ordinary code which it mimicks and replaces. Said commit
  
  is the only commit actually changing aaccoder.c in the last few
  
  years and the same change has not been performed for the MIPS
  
  clone ; before that, it even happened several times that the mips
  
  code was broken due to changes of the generic code (see commits
  
  97437bd17a8c5d4135b2f3b1b299bd7bb72ce02c and
  
  de262d018d7d7d9c967af1dfd1b861c4b9eb2a60 or
  
  860dbe0275e57cbf4228f3f653f872ff66ca596b or
  
  933309a6ca0f18bf1d40e917fff455221f57fb4b or
  
  b65ffa316e377213c29736929beba584d0d80d7c). This might even lead
  
  to scenarios where someone changing non-dsp aacenc code would
  
  have to modify mips inline asm in order to keep them in sync.
  
  This is obviously a significant burden (if the AAC encoder were
  
  actively developed).
  Finally, the code does not even compile here due to errors like
  
  "Error : float register should be even, was 1".
  Reviewed-by : Lynne <dev@lynne.ee>
  
  Reviewed-by : Jean-Baptiste Kempf <jb@videolan.org>
  
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] libavcodec/aacenc.c
  • [DH] libavcodec/aacenc.h
  • [DH] libavcodec/mips/Makefile
  • [DH] libavcodec/mips/aaccoder_mips.c

• lavd : add new API for iterating input and output devices

  2 janvier 2018, par Josh de Kock

  lavd : add new API for iterating input and output devices
  This also adds an avpriv function to register devices in
  
  libavformat
  

  • [DH] Makefile
  • [DH] configure
  • [DH] libavdevice/.gitignore
  • [DH] libavdevice/alldevices.c
  • [DH] libavdevice/avdevice.c
  • [DH] libavdevice/avdevice.h
  • [DH] libavdevice/version.h
  • [DH] libavformat/allformats.c
  • [DH] libavformat/format.c
  • [DH] libavformat/internal.h