FFmpeg/libavcodec/intrax8.h
Andreas Rheinhardt 900ce6f8c3 avcodec/intrax8: Avoid indirection when accessing VLC table
To do so, store the pointer to the VLC table and not to the VLC.
This is possible, because all the VLCs of the same type use
the same number of bits.
Also use a const VLCElem*, because the target is static and must
therefore not be modified after its initialization.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-08-03 21:23:35 +02:00

117 lines
3.6 KiB
C

/*
* 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_INTRAX8_H
#define AVCODEC_INTRAX8_H
#include "blockdsp.h"
#include "get_bits.h"
#include "idctdsp.h"
#include "intrax8dsp.h"
#include "wmv2dsp.h"
#include "mpegpicture.h"
typedef struct IntraX8Context {
const VLCElem *j_ac_vlc_table[4]; // they point to the static j_mb_vlc.table
const VLCElem *j_orient_vlc_table;
const VLCElem *j_dc_vlc_table[3];
int use_quant_matrix;
// set by ff_intrax8_common_init
uint8_t *prediction_table; // 2 * (mb_w * 2)
ScanTable scantable[3];
WMV2DSPContext wdsp;
uint8_t idct_permutation[64];
AVCodecContext *avctx;
int *block_last_index; ///< last nonzero coefficient in block
int16_t (*block)[64];
// set by the caller codec
IntraX8DSPContext dsp;
BlockDSPContext bdsp;
int quant;
int dquant;
int qsum;
int loopfilter;
AVFrame *frame;
GetBitContext *gb;
// calculated per frame
int quant_dc_chroma;
int divide_quant_dc_luma;
int divide_quant_dc_chroma;
uint8_t *dest[3];
uint8_t scratchpad[42]; // size of the block is fixed (8x8 plus padding)
// changed per block
int edges;
int flat_dc;
int predicted_dc;
int raw_orient;
int chroma_orient;
int orient;
int est_run;
// block props
int mb_x, mb_y;
int mb_width, mb_height;
} IntraX8Context;
/**
* Initialize IntraX8 frame decoder.
* @param avctx pointer to AVCodecContext
* @param w pointer to IntraX8Context
* @param idsp pointer to IDCTDSPContext
* @param block pointer to block array
* @param block_last_index pointer to index array
* @param mb_width macroblock width
* @param mb_height macroblock height
* @return 0 on success, a negative AVERROR value on error
*/
int ff_intrax8_common_init(AVCodecContext *avctx,
IntraX8Context *w,
int16_t (*block)[64],
int block_last_index[12],
int mb_width, int mb_height);
/**
* Destroy IntraX8 frame structure.
* @param w pointer to IntraX8Context
*/
void ff_intrax8_common_end(IntraX8Context *w);
/**
* Decode single IntraX8 frame.
* lowres decoding is theoretically impossible.
* @param w pointer to IntraX8Context
* @param pict the output Picture containing an AVFrame
* @param gb open bitstream reader
* @param mb_x pointer to the x coordinate of the current macroblock
* @param mb_y pointer to the y coordinate of the current macroblock
* @param dquant doubled quantizer, it would be odd in case of VC-1 halfpq==1.
* @param quant_offset offset away from zero
* @param loopfilter enable filter after decoding a block
*/
int ff_intrax8_decode_picture(IntraX8Context *w, Picture *pict,
GetBitContext *gb, int *mb_x, int *mb_y,
int quant, int halfpq,
int loopfilter, int lowdelay);
#endif /* AVCODEC_INTRAX8_H */