The Tor Browser: media/libvpx/vp8/common/variance

media/libvpx/vp8/common/variance_c.c@ac0c01689b40 (annotated)

media/libvpx/vp8/common/variance_c.c

Thu, 15 Jan 2015 15:59:08 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 15 Jan 2015 15:59:08 +0100
branch: TOR_BUG_9701
changeset 10: ac0c01689b40
permissions: -rw-r--r--

Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /*
  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 #include "variance.h"
 #include "filter.h"
 unsigned int vp8_get_mb_ss_c
 (
     const short *src_ptr
 )
 {
     unsigned int i = 0, sum = 0;
     do
     {
         sum += (src_ptr[i] * src_ptr[i]);
         i++;
     }
     while (i < 256);
     return sum;
 }
 static void variance(
     const unsigned char *src_ptr,
     int  source_stride,
     const unsigned char *ref_ptr,
     int  recon_stride,
     int  w,
     int  h,
     unsigned int *sse,
     int *sum)
 {
     int i, j;
     int diff;
     *sum = 0;
     *sse = 0;
     for (i = 0; i < h; i++)
     {
         for (j = 0; j < w; j++)
         {
             diff = src_ptr[j] - ref_ptr[j];
             *sum += diff;
             *sse += diff * diff;
         }
         src_ptr += source_stride;
         ref_ptr += recon_stride;
     }
 }
 unsigned int vp8_variance16x16_c(
     const unsigned char *src_ptr,
     int  source_stride,
     const unsigned char *ref_ptr,
     int  recon_stride,
     unsigned int *sse)
 {
     unsigned int var;
     int avg;
     variance(src_ptr, source_stride, ref_ptr, recon_stride, 16, 16, &var, &avg);
     *sse = var;
     return (var - (((unsigned int)avg * avg) >> 8));
 }
 unsigned int vp8_variance8x16_c(
     const unsigned char *src_ptr,
     int  source_stride,
     const unsigned char *ref_ptr,
     int  recon_stride,
     unsigned int *sse)
 {
     unsigned int var;
     int avg;
     variance(src_ptr, source_stride, ref_ptr, recon_stride, 8, 16, &var, &avg);
     *sse = var;
     return (var - (((unsigned int)avg * avg) >> 7));
 }
 unsigned int vp8_variance16x8_c(
     const unsigned char *src_ptr,
     int  source_stride,
     const unsigned char *ref_ptr,
     int  recon_stride,
     unsigned int *sse)
 {
     unsigned int var;
     int avg;
     variance(src_ptr, source_stride, ref_ptr, recon_stride, 16, 8, &var, &avg);
     *sse = var;
     return (var - (((unsigned int)avg * avg) >> 7));
 }
 unsigned int vp8_variance8x8_c(
     const unsigned char *src_ptr,
     int  source_stride,
     const unsigned char *ref_ptr,
     int  recon_stride,
     unsigned int *sse)
 {
     unsigned int var;
     int avg;
     variance(src_ptr, source_stride, ref_ptr, recon_stride, 8, 8, &var, &avg);
     *sse = var;
     return (var - (((unsigned int)avg * avg) >> 6));
 }
 unsigned int vp8_variance4x4_c(
     const unsigned char *src_ptr,
     int  source_stride,
     const unsigned char *ref_ptr,
     int  recon_stride,
     unsigned int *sse)
 {
     unsigned int var;
     int avg;
     variance(src_ptr, source_stride, ref_ptr, recon_stride, 4, 4, &var, &avg);
     *sse = var;
     return (var - (((unsigned int)avg * avg) >> 4));
 }
 unsigned int vp8_mse16x16_c(
     const unsigned char *src_ptr,
     int  source_stride,
     const unsigned char *ref_ptr,
     int  recon_stride,
     unsigned int *sse)
 {
     unsigned int var;
     int avg;
     variance(src_ptr, source_stride, ref_ptr, recon_stride, 16, 16, &var, &avg);
     *sse = var;
     return var;
 }
 /****************************************************************************
  *
  *  ROUTINE       : filter_block2d_bil_first_pass
  *
  *  INPUTS        : UINT8  *src_ptr          : Pointer to source block.
  *                  UINT32 src_pixels_per_line : Stride of input block.
  *                  UINT32 pixel_step        : Offset between filter input samples (see notes).
  *                  UINT32 output_height     : Input block height.
  *                  UINT32 output_width      : Input block width.
  *                  INT32  *vp8_filter          : Array of 2 bi-linear filter taps.
  *
  *  OUTPUTS       : INT32 *output_ptr        : Pointer to filtered block.
  *
  *  RETURNS       : void
  *
  *  FUNCTION      : Applies a 1-D 2-tap bi-linear filter to the source block in
  *                  either horizontal or vertical direction to produce the
  *                  filtered output block. Used to implement first-pass
  *                  of 2-D separable filter.
  *
  *  SPECIAL NOTES : Produces INT32 output to retain precision for next pass.
  *                  Two filter taps should sum to VP8_FILTER_WEIGHT.
  *                  pixel_step defines whether the filter is applied
  *                  horizontally (pixel_step=1) or vertically (pixel_step=stride).
  *                  It defines the offset required to move from one input
  *                  to the next.
  *
  ****************************************************************************/
 static void var_filter_block2d_bil_first_pass
 (
     const unsigned char *src_ptr,
     unsigned short *output_ptr,
     unsigned int src_pixels_per_line,
     int pixel_step,
     unsigned int output_height,
     unsigned int output_width,
     const short *vp8_filter
 )
 {
     unsigned int i, j;
     for (i = 0; i < output_height; i++)
     {
         for (j = 0; j < output_width; j++)
         {
             /* Apply bilinear filter */
             output_ptr[j] = (((int)src_ptr[0]          * vp8_filter[0]) +
                              ((int)src_ptr[pixel_step] * vp8_filter[1]) +
                              (VP8_FILTER_WEIGHT / 2)) >> VP8_FILTER_SHIFT;
             src_ptr++;
         }
         /* Next row... */
         src_ptr    += src_pixels_per_line - output_width;
         output_ptr += output_width;
     }
 }
 /****************************************************************************
  *
  *  ROUTINE       : filter_block2d_bil_second_pass
  *
  *  INPUTS        : INT32  *src_ptr          : Pointer to source block.
  *                  UINT32 src_pixels_per_line : Stride of input block.
  *                  UINT32 pixel_step        : Offset between filter input samples (see notes).
  *                  UINT32 output_height     : Input block height.
  *                  UINT32 output_width      : Input block width.
  *                  INT32  *vp8_filter          : Array of 2 bi-linear filter taps.
  *
  *  OUTPUTS       : UINT16 *output_ptr       : Pointer to filtered block.
  *
  *  RETURNS       : void
  *
  *  FUNCTION      : Applies a 1-D 2-tap bi-linear filter to the source block in
  *                  either horizontal or vertical direction to produce the
  *                  filtered output block. Used to implement second-pass
  *                  of 2-D separable filter.
  *
  *  SPECIAL NOTES : Requires 32-bit input as produced by filter_block2d_bil_first_pass.
  *                  Two filter taps should sum to VP8_FILTER_WEIGHT.
  *                  pixel_step defines whether the filter is applied
  *                  horizontally (pixel_step=1) or vertically (pixel_step=stride).
  *                  It defines the offset required to move from one input
  *                  to the next.
  *
  ****************************************************************************/
 static void var_filter_block2d_bil_second_pass
 (
     const unsigned short *src_ptr,
     unsigned char  *output_ptr,
     unsigned int  src_pixels_per_line,
     unsigned int  pixel_step,
     unsigned int  output_height,
     unsigned int  output_width,
     const short *vp8_filter
 )
 {
     unsigned int  i, j;
     int  Temp;
     for (i = 0; i < output_height; i++)
     {
         for (j = 0; j < output_width; j++)
         {
             /* Apply filter */
             Temp = ((int)src_ptr[0]          * vp8_filter[0]) +
                    ((int)src_ptr[pixel_step] * vp8_filter[1]) +
                    (VP8_FILTER_WEIGHT / 2);
             output_ptr[j] = (unsigned int)(Temp >> VP8_FILTER_SHIFT);
             src_ptr++;
         }
         /* Next row... */
         src_ptr    += src_pixels_per_line - output_width;
         output_ptr += output_width;
     }
 }
 unsigned int vp8_sub_pixel_variance4x4_c
 (
     const unsigned char  *src_ptr,
     int  src_pixels_per_line,
     int  xoffset,
     int  yoffset,
     const unsigned char *dst_ptr,
     int dst_pixels_per_line,
     unsigned int *sse
 )
 {
     unsigned char  temp2[20*16];
     const short *HFilter, *VFilter;
     unsigned short FData3[5*4]; /* Temp data bufffer used in filtering */
     HFilter = vp8_bilinear_filters[xoffset];
     VFilter = vp8_bilinear_filters[yoffset];
     /* First filter 1d Horizontal */
     var_filter_block2d_bil_first_pass(src_ptr, FData3, src_pixels_per_line, 1, 5, 4, HFilter);
     /* Now filter Verticaly */
     var_filter_block2d_bil_second_pass(FData3, temp2, 4,  4,  4,  4, VFilter);
     return vp8_variance4x4_c(temp2, 4, dst_ptr, dst_pixels_per_line, sse);
 }
 unsigned int vp8_sub_pixel_variance8x8_c
 (
     const unsigned char  *src_ptr,
     int  src_pixels_per_line,
     int  xoffset,
     int  yoffset,
     const unsigned char *dst_ptr,
     int dst_pixels_per_line,
     unsigned int *sse
 )
 {
     unsigned short FData3[9*8]; /* Temp data bufffer used in filtering */
     unsigned char  temp2[20*16];
     const short *HFilter, *VFilter;
     HFilter = vp8_bilinear_filters[xoffset];
     VFilter = vp8_bilinear_filters[yoffset];
     var_filter_block2d_bil_first_pass(src_ptr, FData3, src_pixels_per_line, 1, 9, 8, HFilter);
     var_filter_block2d_bil_second_pass(FData3, temp2, 8, 8, 8, 8, VFilter);
     return vp8_variance8x8_c(temp2, 8, dst_ptr, dst_pixels_per_line, sse);
 }
 unsigned int vp8_sub_pixel_variance16x16_c
 (
     const unsigned char  *src_ptr,
     int  src_pixels_per_line,
     int  xoffset,
     int  yoffset,
     const unsigned char *dst_ptr,
     int dst_pixels_per_line,
     unsigned int *sse
 )
 {
     unsigned short FData3[17*16];   /* Temp data bufffer used in filtering */
     unsigned char  temp2[20*16];
     const short *HFilter, *VFilter;
     HFilter = vp8_bilinear_filters[xoffset];
     VFilter = vp8_bilinear_filters[yoffset];
     var_filter_block2d_bil_first_pass(src_ptr, FData3, src_pixels_per_line, 1, 17, 16, HFilter);
     var_filter_block2d_bil_second_pass(FData3, temp2, 16, 16, 16, 16, VFilter);
     return vp8_variance16x16_c(temp2, 16, dst_ptr, dst_pixels_per_line, sse);
 }
 unsigned int vp8_variance_halfpixvar16x16_h_c(
     const unsigned char *src_ptr,
     int  source_stride,
     const unsigned char *ref_ptr,
     int  recon_stride,
     unsigned int *sse)
 {
     return vp8_sub_pixel_variance16x16_c(src_ptr, source_stride, 4, 0,
                                          ref_ptr, recon_stride, sse);
 }
 unsigned int vp8_variance_halfpixvar16x16_v_c(
     const unsigned char *src_ptr,
     int  source_stride,
     const unsigned char *ref_ptr,
     int  recon_stride,
     unsigned int *sse)
 {
     return vp8_sub_pixel_variance16x16_c(src_ptr, source_stride, 0, 4,
                                          ref_ptr, recon_stride, sse);
 }
 unsigned int vp8_variance_halfpixvar16x16_hv_c(
     const unsigned char *src_ptr,
     int  source_stride,
     const unsigned char *ref_ptr,
     int  recon_stride,
     unsigned int *sse)
 {
     return vp8_sub_pixel_variance16x16_c(src_ptr, source_stride, 4, 4,
                                          ref_ptr, recon_stride, sse);
 }
 unsigned int vp8_sub_pixel_mse16x16_c
 (
     const unsigned char  *src_ptr,
     int  src_pixels_per_line,
     int  xoffset,
     int  yoffset,
     const unsigned char *dst_ptr,
     int dst_pixels_per_line,
     unsigned int *sse
 )
 {
     vp8_sub_pixel_variance16x16_c(src_ptr, src_pixels_per_line, xoffset, yoffset, dst_ptr, dst_pixels_per_line, sse);
     return *sse;
 }
 unsigned int vp8_sub_pixel_variance16x8_c
 (
     const unsigned char  *src_ptr,
     int  src_pixels_per_line,
     int  xoffset,
     int  yoffset,
     const unsigned char *dst_ptr,
     int dst_pixels_per_line,
     unsigned int *sse
 )
 {
     unsigned short FData3[16*9];    /* Temp data bufffer used in filtering */
     unsigned char  temp2[20*16];
     const short *HFilter, *VFilter;
     HFilter = vp8_bilinear_filters[xoffset];
     VFilter = vp8_bilinear_filters[yoffset];
     var_filter_block2d_bil_first_pass(src_ptr, FData3, src_pixels_per_line, 1, 9, 16, HFilter);
     var_filter_block2d_bil_second_pass(FData3, temp2, 16, 16, 8, 16, VFilter);
     return vp8_variance16x8_c(temp2, 16, dst_ptr, dst_pixels_per_line, sse);
 }
 unsigned int vp8_sub_pixel_variance8x16_c
 (
     const unsigned char  *src_ptr,
     int  src_pixels_per_line,
     int  xoffset,
     int  yoffset,
     const unsigned char *dst_ptr,
     int dst_pixels_per_line,
     unsigned int *sse
 )
 {
     unsigned short FData3[9*16];    /* Temp data bufffer used in filtering */
     unsigned char  temp2[20*16];
     const short *HFilter, *VFilter;
     HFilter = vp8_bilinear_filters[xoffset];
     VFilter = vp8_bilinear_filters[yoffset];
     var_filter_block2d_bil_first_pass(src_ptr, FData3, src_pixels_per_line, 1, 17, 8, HFilter);
     var_filter_block2d_bil_second_pass(FData3, temp2, 8, 8, 16, 8, VFilter);
     return vp8_variance8x16_c(temp2, 8, dst_ptr, dst_pixels_per_line, sse);
 }

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media/libvpx/vp8/common/variance_c.c@ac0c01689b40 (annotated)

media/libvpx/vp8/common/variance_c.c