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• arm : vp9 : Add NEON optimizations of VP9 MC functions

  3 novembre 2016, par Martin Storsjö

  arm : vp9 : Add NEON optimizations of VP9 MC functions
  This work is sponsored by, and copyright, Google.
  The filter coefficients are signed values, where the product of the
  
  multiplication with one individual filter coefficient doesn’t
  
  overflow a 16 bit signed value (the largest filter coefficient is
  
  127). But when the products are accumulated, the resulting sum can
  
  overflow the 16 bit signed range. Instead of accumulating in 32 bit,
  
  we accumulate the largest product (either index 3 or 4) last with a
  
  saturated addition.
  (The VP8 MC asm does something similar, but slightly simpler, by
  
  accumulating each half of the filter separately. In the VP9 MC
  
  filters, each half of the filter can also overflow though, so the
  
  largest component has to be handled individually.)
  Examples of relative speedup compared to the C version, from checkasm :
  
                         Cortex      A7     A8     A9    A53
  
  vp9_avg4_neon :                   1.71   1.15   1.42   1.49
  
  vp9_avg8_neon :                   2.51   3.63   3.14   2.58
  
  vp9_avg16_neon :                  2.95   6.76   3.01   2.84
  
  vp9_avg32_neon :                  3.29   6.64   2.85   3.00
  
  vp9_avg64_neon :                  3.47   6.67   3.14   2.80
  
  vp9_avg_8tap_smooth_4h_neon :     3.22   4.73   2.76   4.67
  
  vp9_avg_8tap_smooth_4hv_neon :    3.67   4.76   3.28   4.71
  
  vp9_avg_8tap_smooth_4v_neon :     5.52   7.60   4.60   6.31
  
  vp9_avg_8tap_smooth_8h_neon :     6.22   9.04   5.12   9.32
  
  vp9_avg_8tap_smooth_8hv_neon :    6.38   8.21   5.72   8.17
  
  vp9_avg_8tap_smooth_8v_neon :     9.22  12.66   8.15  11.10
  
  vp9_avg_8tap_smooth_64h_neon :    7.02  10.23   5.54  11.58
  
  vp9_avg_8tap_smooth_64hv_neon :   6.76   9.46   5.93   9.40
  
  vp9_avg_8tap_smooth_64v_neon :   10.76  14.13   9.46  13.37
  
  vp9_put4_neon :                   1.11   1.47   1.00   1.21
  
  vp9_put8_neon :                   1.23   2.17   1.94   1.48
  
  vp9_put16_neon :                  1.63   4.02   1.73   1.97
  
  vp9_put32_neon :                  1.56   4.92   2.00   1.96
  
  vp9_put64_neon :                  2.10   5.28   2.03   2.35
  
  vp9_put_8tap_smooth_4h_neon :     3.11   4.35   2.63   4.35
  
  vp9_put_8tap_smooth_4hv_neon :    3.67   4.69   3.25   4.71
  
  vp9_put_8tap_smooth_4v_neon :     5.45   7.27   4.49   6.52
  
  vp9_put_8tap_smooth_8h_neon :     5.97   8.18   4.81   8.56
  
  vp9_put_8tap_smooth_8hv_neon :    6.39   7.90   5.64   8.15
  
  vp9_put_8tap_smooth_8v_neon :     9.03  11.84   8.07  11.51
  
  vp9_put_8tap_smooth_64h_neon :    6.78   9.48   4.88  10.89
  
  vp9_put_8tap_smooth_64hv_neon :   6.99   8.87   5.94   9.56
  
  vp9_put_8tap_smooth_64v_neon :   10.69  13.30   9.43  14.34
  For the larger 8tap filters, the speedup vs C code is around 5-14x.
  This is significantly faster than libvpx’s implementation of the same
  
  functions, at least when comparing the put_8tap_smooth_64 functions
  
  (compared to vpx_convolve8_horiz_neon and vpx_convolve8_vert_neon from
  
  libvpx).
  Absolute runtimes from checkasm :
  
                            Cortex      A7        A8        A9       A53
  
  vp9_put_8tap_smooth_64h_neon :    20150.3   14489.4   19733.6   10863.7
  
  libvpx vpx_convolve8_horiz_neon : 52623.3   19736.4   21907.7   25027.7
  vp9_put_8tap_smooth_64v_neon :    14455.0   12303.9   13746.4    9628.9
  
  libvpx vpx_convolve8_vert_neon :  42090.0   17706.2   17659.9   16941.2
  Thus, on the A9, the horizontal filter is only marginally faster than
  
  libvpx, while our version is significantly faster on the other cores,
  
  and the vertical filter is significantly faster on all cores. The
  
  difference is especially large on the A7.
  The libvpx implementation does the accumulation in 32 bit, which
  
  probably explains most of the differences.
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DBH] libavcodec/arm/Makefile
  • [DBH] libavcodec/arm/vp9dsp_init_arm.c
  • [DBH] libavcodec/arm/vp9mc_neon.S
  • [DBH] libavcodec/vp9.h
  • [DBH] libavcodec/vp9block.c
  • [DBH] libavcodec/vp9dsp.c

• FFMPEG using wrong arguements when refering to image files

  14 août 2013, par Chad Marmon

  I am creating a bat file that will use FFMPEG to convert Real Media files to .MP4 files. I am looping though the current folder and finding files with the .rm extension adding several pictures to the video files to create a slide show effect in the final product.

  With this code here it works except it only shows one static image :

  for %%a in ("*.rm") do ffmpeg -f image2 -r 1/5 -i "img00.jpg" -i "%%a" -c:v libx264 -r 30 -preset slow -crf 20 -c:a libvo_aacenc -b:a 48k -b:v 16k "newfiles\%%~na.mp4"

  With this code it should show a series of photos. However it does not :

  for %%a in ("*.rm") do ffmpeg -f image2 -r 1/5 -i "img%02d.jpg" -i "%%a" -c:v libx264 -r 30 -preset slow -crf 20 -c:a libvo_aacenc -b:a 48k -b:v 16k "newfiles\%%~na.mp4"

  I get this error when I run the second piece of code :

  Could find no file with with path 'imgC :\Data\RealtoMP\FFMPEG_JPG\ffmpegA48V16_AudOnly' and index in the range 0-4
  imgC :\Data\RealtoMP\FFMPEG_JPG\ffmpegA48V16_AudOnly : No such file or directory

  It appears to me that it is somehow instead of getting the range argument like it should, it's injecting the path to the file that I am running. Any ideas of what is causing this ?

  EDIT :

  I fixed my problem by escaping the %02 with another %. The result is %%02 for it to act correctly in the script.

• lavc/flacdsp : R-V V LPC16 function

  15 novembre 2023, par Rémi Denis-Courmont

  lavc/flacdsp : R-V V LPC16 function
  In this case, the inner loop computing the scalar product can be reduced
  
  to just one multiplication and one sum even with 128-bit vectors. The
  
  result is a lot simpler, but also brings more modest performance gains :
  flac_lpc_16_13_c :       15241.0
  
  flac_lpc_16_13_rvv_i32 : 11230.0
  
  flac_lpc_16_16_c :       17884.0
  
  flac_lpc_16_16_rvv_i32 : 12125.7
  
  flac_lpc_16_29_c :       27847.7
  
  flac_lpc_16_29_rvv_i32 : 10494.0
  
  flac_lpc_16_32_c :       30051.5
  
  flac_lpc_16_32_rvv_i32 : 10355.0
  

  • [DH] libavcodec/riscv/flacdsp_init.c
  • [DH] libavcodec/riscv/flacdsp_rvv.S