vpx/vp9/common/vp9_scale.h
Jim Bankoski 9f37d149c1 Better validation of invalid files
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
2014-06-27 10:03:15 -07:00

66 lines
2.0 KiB
C

/*
* Copyright (c) 2013 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.
*/
#ifndef VP9_COMMON_VP9_SCALE_H_
#define VP9_COMMON_VP9_SCALE_H_
#include "vp9/common/vp9_mv.h"
#include "vp9/common/vp9_convolve.h"
#ifdef __cplusplus
extern "C" {
#endif
#define REF_SCALE_SHIFT 14
#define REF_NO_SCALE (1 << REF_SCALE_SHIFT)
#define REF_INVALID_SCALE -1
struct scale_factors {
int x_scale_fp; // horizontal fixed point scale factor
int y_scale_fp; // vertical fixed point scale factor
int x_step_q4;
int y_step_q4;
int (*scale_value_x)(int val, const struct scale_factors *sf);
int (*scale_value_y)(int val, const struct scale_factors *sf);
convolve_fn_t predict[2][2][2]; // horiz, vert, avg
};
MV32 vp9_scale_mv(const MV *mv, int x, int y, const struct scale_factors *sf);
void vp9_setup_scale_factors_for_frame(struct scale_factors *sf,
int other_w, int other_h,
int this_w, int this_h);
static INLINE int vp9_is_valid_scale(const struct scale_factors *sf) {
return sf->x_scale_fp != REF_INVALID_SCALE &&
sf->y_scale_fp != REF_INVALID_SCALE;
}
static INLINE int vp9_is_scaled(const struct scale_factors *sf) {
return vp9_is_valid_scale(sf) &&
(sf->x_scale_fp != REF_NO_SCALE || sf->y_scale_fp != REF_NO_SCALE);
}
static INLINE int valid_ref_frame_size(int ref_width, int ref_height,
int this_width, int this_height) {
return 2 * this_width >= ref_width &&
2 * this_height >= ref_height &&
this_width <= 16 * ref_width &&
this_height <= 16 * ref_height;
}
#ifdef __cplusplus
} // extern "C"
#endif
#endif // VP9_COMMON_VP9_SCALE_H_