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FFmpeg/libavcodec/dcadec.h
foo86 d1f558b362 avcodec/dca: require checked bitstream reader
Remove half-working attempt at supporting unchecked bitstream reader by
always copying input data into intermediate buffer with large amount of
padding at the end.

Convert LBR decoder to checked bitstream reader. Convert
dcadec_decode_frame() to parse input data directly if possible.

Signed-off-by: James Almer <jamrial@gmail.com>
2016-05-31 11:45:48 -03:00

98 lines
3.1 KiB
C

/*
* Copyright (C) 2016 foo86
*
* 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_DCADEC_H
#define AVCODEC_DCADEC_H
#include "libavutil/common.h"
#include "libavutil/crc.h"
#include "libavutil/float_dsp.h"
#include "avcodec.h"
#include "get_bits.h"
#include "dca.h"
#include "dcadsp.h"
#include "dca_core.h"
#include "dca_exss.h"
#include "dca_xll.h"
#include "dca_lbr.h"
#define DCA_PACKET_CORE 0x01
#define DCA_PACKET_EXSS 0x02
#define DCA_PACKET_XLL 0x04
#define DCA_PACKET_LBR 0x08
#define DCA_PACKET_MASK 0x0f
#define DCA_PACKET_RECOVERY 0x10 ///< Sync error recovery flag
#define DCA_PACKET_RESIDUAL 0x20 ///< Core valid for residual decoding
typedef struct DCAContext {
const AVClass *class; ///< class for AVOptions
AVCodecContext *avctx;
DCACoreDecoder core; ///< Core decoder context
DCAExssParser exss; ///< EXSS parser context
DCAXllDecoder xll; ///< XLL decoder context
DCALbrDecoder lbr; ///< LBR decoder context
DCADSPContext dcadsp;
const AVCRC *crctab;
uint8_t *buffer; ///< Packet buffer
unsigned int buffer_size;
int packet; ///< Packet flags
int request_channel_layout; ///< Converted from avctx.request_channel_layout
int core_only; ///< Core only decoding flag
} DCAContext;
int ff_dca_set_channel_layout(AVCodecContext *avctx, int *ch_remap, int dca_mask);
void ff_dca_downmix_to_stereo_fixed(DCADSPContext *dcadsp, int32_t **samples,
int *coeff_l, int nsamples, int ch_mask);
void ff_dca_downmix_to_stereo_float(AVFloatDSPContext *fdsp, float **samples,
int *coeff_l, int nsamples, int ch_mask);
static inline int ff_dca_check_crc(AVCodecContext *avctx, GetBitContext *s,
int p1, int p2)
{
DCAContext *dca = avctx->priv_data;
if (!(avctx->err_recognition & (AV_EF_CRCCHECK | AV_EF_CAREFUL)))
return 0;
if (((p1 | p2) & 7) || p1 < 0 || p2 > s->size_in_bits || p2 - p1 < 16)
return -1;
if (av_crc(dca->crctab, 0xffff, s->buffer + p1 / 8, (p2 - p1) / 8))
return -1;
return 0;
}
static inline int ff_dca_seek_bits(GetBitContext *s, int p)
{
if (p < s->index || p > s->size_in_bits)
return -1;
s->index = p;
return 0;
}
#endif