ffmpeg/libavcodec/vc2enc_dwt.h
Rostislav Pehlivanov 3228ac730c vc2enc_dwt: pad the temporary buffer by the slice size
Since non-Haar wavelets need to look into pixels outside the frame, we
need to pad the buffer. The old factor of two seemed to be a workaround
that fact and only padded to the left and bottom. This correctly pads
by the slice size and as such reduces memory usage and potential
exploits.
Reported by Liu Bingchang.

Ideally, there should be no temporary buffer but the encoder is designed
to deinterleave the coefficients into the classical wavelet structure
with the lower frequency values in the top left corner.

Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
2017-11-09 00:05:48 +00:00

55 lines
2.0 KiB
C

/*
* Copyright (C) 2016 Open Broadcast Systems Ltd.
* Author 2016 Rostislav Pehlivanov <atomnuker@gmail.com>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVCODEC_VC2ENC_DWT_H
#define AVCODEC_VC2ENC_DWT_H
#include <stddef.h>
#include <stdint.h>
typedef int32_t dwtcoef;
enum VC2TransformType {
VC2_TRANSFORM_9_7 = 0, /* Deslauriers-Dubuc (9,7) */
VC2_TRANSFORM_5_3 = 1, /* LeGall (5,3) */
VC2_TRANSFORM_13_7 = 2, /* Deslauriers-Dubuc (13,7) */
VC2_TRANSFORM_HAAR = 3, /* Haar without shift */
VC2_TRANSFORM_HAAR_S = 4, /* Haar with 1 shift/lvl */
VC2_TRANSFORM_FIDEL = 5, /* Fidelity filter */
VC2_TRANSFORM_9_7_I = 6, /* Daubechies (9,7) */
VC2_TRANSFORMS_NB
};
typedef struct VC2TransformContext {
dwtcoef *buffer;
int padding;
void (*vc2_subband_dwt[VC2_TRANSFORMS_NB])(struct VC2TransformContext *t,
dwtcoef *data, ptrdiff_t stride,
int width, int height);
} VC2TransformContext;
int ff_vc2enc_init_transforms(VC2TransformContext *t, int p_stride, int p_height,
int slice_w, int slice_h);
void ff_vc2enc_free_transforms(VC2TransformContext *t);
#endif /* AVCODEC_VC2ENC_DWT_H */