9f37d149c1
This patch checks that a decoder never tries to reference frame that's outside the range of 2x to 1/16th the size of this frame. Any attempt to do so causes a failure. Change-Id: I5c98fa7bb95ac4f29146f29dd92b62fe96164e4c
115 lines
4.4 KiB
C
115 lines
4.4 KiB
C
/*
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* Copyright (c) 2013 The WebM project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "./vp9_rtcd.h"
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#include "vp9/common/vp9_filter.h"
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#include "vp9/common/vp9_scale.h"
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static INLINE int scaled_x(int val, const struct scale_factors *sf) {
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return (int)((int64_t)val * sf->x_scale_fp >> REF_SCALE_SHIFT);
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}
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static INLINE int scaled_y(int val, const struct scale_factors *sf) {
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return (int)((int64_t)val * sf->y_scale_fp >> REF_SCALE_SHIFT);
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}
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static int unscaled_value(int val, const struct scale_factors *sf) {
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(void) sf;
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return val;
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}
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static int get_fixed_point_scale_factor(int other_size, int this_size) {
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// Calculate scaling factor once for each reference frame
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// and use fixed point scaling factors in decoding and encoding routines.
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// Hardware implementations can calculate scale factor in device driver
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// and use multiplication and shifting on hardware instead of division.
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return (other_size << REF_SCALE_SHIFT) / this_size;
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}
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MV32 vp9_scale_mv(const MV *mv, int x, int y, const struct scale_factors *sf) {
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const int x_off_q4 = scaled_x(x << SUBPEL_BITS, sf) & SUBPEL_MASK;
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const int y_off_q4 = scaled_y(y << SUBPEL_BITS, sf) & SUBPEL_MASK;
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const MV32 res = {
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scaled_y(mv->row, sf) + y_off_q4,
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scaled_x(mv->col, sf) + x_off_q4
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};
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return res;
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}
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void vp9_setup_scale_factors_for_frame(struct scale_factors *sf,
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int other_w, int other_h,
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int this_w, int this_h) {
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if (!valid_ref_frame_size(other_w, other_h, this_w, this_h)) {
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sf->x_scale_fp = REF_INVALID_SCALE;
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sf->y_scale_fp = REF_INVALID_SCALE;
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return;
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}
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sf->x_scale_fp = get_fixed_point_scale_factor(other_w, this_w);
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sf->y_scale_fp = get_fixed_point_scale_factor(other_h, this_h);
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sf->x_step_q4 = scaled_x(16, sf);
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sf->y_step_q4 = scaled_y(16, sf);
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if (vp9_is_scaled(sf)) {
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sf->scale_value_x = scaled_x;
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sf->scale_value_y = scaled_y;
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} else {
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sf->scale_value_x = unscaled_value;
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sf->scale_value_y = unscaled_value;
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}
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// TODO(agrange): Investigate the best choice of functions to use here
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// for EIGHTTAP_SMOOTH. Since it is not interpolating, need to choose what
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// to do at full-pel offsets. The current selection, where the filter is
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// applied in one direction only, and not at all for 0,0, seems to give the
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// best quality, but it may be worth trying an additional mode that does
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// do the filtering on full-pel.
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if (sf->x_step_q4 == 16) {
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if (sf->y_step_q4 == 16) {
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// No scaling in either direction.
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sf->predict[0][0][0] = vp9_convolve_copy;
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sf->predict[0][0][1] = vp9_convolve_avg;
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sf->predict[0][1][0] = vp9_convolve8_vert;
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sf->predict[0][1][1] = vp9_convolve8_avg_vert;
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sf->predict[1][0][0] = vp9_convolve8_horiz;
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sf->predict[1][0][1] = vp9_convolve8_avg_horiz;
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} else {
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// No scaling in x direction. Must always scale in the y direction.
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sf->predict[0][0][0] = vp9_convolve8_vert;
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sf->predict[0][0][1] = vp9_convolve8_avg_vert;
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sf->predict[0][1][0] = vp9_convolve8_vert;
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sf->predict[0][1][1] = vp9_convolve8_avg_vert;
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sf->predict[1][0][0] = vp9_convolve8;
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sf->predict[1][0][1] = vp9_convolve8_avg;
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}
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} else {
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if (sf->y_step_q4 == 16) {
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// No scaling in the y direction. Must always scale in the x direction.
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sf->predict[0][0][0] = vp9_convolve8_horiz;
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sf->predict[0][0][1] = vp9_convolve8_avg_horiz;
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sf->predict[0][1][0] = vp9_convolve8;
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sf->predict[0][1][1] = vp9_convolve8_avg;
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sf->predict[1][0][0] = vp9_convolve8_horiz;
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sf->predict[1][0][1] = vp9_convolve8_avg_horiz;
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} else {
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// Must always scale in both directions.
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sf->predict[0][0][0] = vp9_convolve8;
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sf->predict[0][0][1] = vp9_convolve8_avg;
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sf->predict[0][1][0] = vp9_convolve8;
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sf->predict[0][1][1] = vp9_convolve8_avg;
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sf->predict[1][0][0] = vp9_convolve8;
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sf->predict[1][0][1] = vp9_convolve8_avg;
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}
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}
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// 2D subpel motion always gets filtered in both directions
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sf->predict[1][1][0] = vp9_convolve8;
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sf->predict[1][1][1] = vp9_convolve8_avg;
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}
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