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ffmpeg/libavcodec/rv40.c

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/*
* RV40 decoder
* Copyright (c) 2007 Konstantin Shishkov
*
* 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
*/
/**
* @file rv40.c
* RV40 decoder
*/
#include "avcodec.h"
#include "dsputil.h"
#include "mpegvideo.h"
#include "golomb.h"
#include "rv34.h"
#include "rv40vlc2.h"
#include "rv40data.h"
static VLC aic_top_vlc;
static VLC aic_mode1_vlc[AIC_MODE1_NUM], aic_mode2_vlc[AIC_MODE2_NUM];
static VLC ptype_vlc[NUM_PTYPE_VLCS], btype_vlc[NUM_BTYPE_VLCS];
/**
* Initialize all tables.
*/
static void rv40_init_tables()
{
int i;
init_vlc(&aic_top_vlc, AIC_TOP_BITS, AIC_TOP_SIZE,
rv40_aic_top_vlc_bits, 1, 1,
rv40_aic_top_vlc_codes, 1, 1, INIT_VLC_USE_STATIC);
for(i = 0; i < AIC_MODE1_NUM; i++){
// Every tenth VLC table is empty
if((i % 10) == 9) continue;
init_vlc(&aic_mode1_vlc[i], AIC_MODE1_BITS, AIC_MODE1_SIZE,
aic_mode1_vlc_bits[i], 1, 1,
aic_mode1_vlc_codes[i], 1, 1, INIT_VLC_USE_STATIC);
}
for(i = 0; i < AIC_MODE2_NUM; i++){
init_vlc(&aic_mode2_vlc[i], AIC_MODE2_BITS, AIC_MODE2_SIZE,
aic_mode2_vlc_bits[i], 1, 1,
aic_mode2_vlc_codes[i], 2, 2, INIT_VLC_USE_STATIC);
}
for(i = 0; i < NUM_PTYPE_VLCS; i++)
init_vlc_sparse(&ptype_vlc[i], PTYPE_VLC_BITS, PTYPE_VLC_SIZE,
ptype_vlc_bits[i], 1, 1,
ptype_vlc_codes[i], 1, 1,
ptype_vlc_syms, 1, 1, INIT_VLC_USE_STATIC);
for(i = 0; i < NUM_BTYPE_VLCS; i++)
init_vlc_sparse(&btype_vlc[i], BTYPE_VLC_BITS, BTYPE_VLC_SIZE,
btype_vlc_bits[i], 1, 1,
btype_vlc_codes[i], 1, 1,
btype_vlc_syms, 1, 1, INIT_VLC_USE_STATIC);
}
/**
* Get stored dimension from bitstream.
*
* If the width/height is the standard one then it's coded as a 3-bit index.
* Otherwise it is coded as escaped 8-bit portions.
*/
static int get_dimension(GetBitContext *gb, const int *dim)
{
int t = get_bits(gb, 3);
int val = dim[t];
if(val < 0)
val = dim[get_bits1(gb) - val];
if(!val){
do{
t = get_bits(gb, 8);
val += t << 2;
}while(t == 0xFF);
}
return val;
}
/**
* Get encoded picture size - usually this is called from rv40_parse_slice_header.
*/
static void rv40_parse_picture_size(GetBitContext *gb, int *w, int *h)
{
*w = get_dimension(gb, rv40_standard_widths);
*h = get_dimension(gb, rv40_standard_heights);
}
static int rv40_parse_slice_header(RV34DecContext *r, GetBitContext *gb, SliceInfo *si)
{
int t, mb_bits;
int w = r->s.width, h = r->s.height;
int mb_size;
memset(si, 0, sizeof(SliceInfo));
if(get_bits1(gb))
return -1;
si->type = get_bits(gb, 2);
if(si->type == 1) si->type = 0;
si->quant = get_bits(gb, 5);
if(get_bits(gb, 2))
return -1;
si->vlc_set = get_bits(gb, 2);
skip_bits1(gb);
t = get_bits(gb, 13); /// ???
if(!si->type || !get_bits1(gb))
rv40_parse_picture_size(gb, &w, &h);
if(avcodec_check_dimensions(r->s.avctx, w, h) < 0)
return -1;
si->width = w;
si->height = h;
mb_size = ((w + 15) >> 4) * ((h + 15) >> 4);
mb_bits = ff_rv34_get_start_offset(gb, mb_size);
si->start = get_bits(gb, mb_bits);
return 0;
}
/**
* Decode 4x4 intra types array.
*/
static int rv40_decode_intra_types(RV34DecContext *r, GetBitContext *gb, int8_t *dst)
{
MpegEncContext *s = &r->s;
int i, j, k, v;
int A, B, C;
int pattern;
int8_t *ptr;
for(i = 0; i < 4; i++, dst += s->b4_stride){
if(!i && s->first_slice_line){
pattern = get_vlc2(gb, aic_top_vlc.table, AIC_TOP_BITS, 1);
dst[0] = (pattern >> 2) & 2;
dst[1] = (pattern >> 1) & 2;
dst[2] = pattern & 2;
dst[3] = (pattern << 1) & 2;
continue;
}
ptr = dst;
for(j = 0; j < 4; j++){
/* Coefficients are read using VLC chosen by the prediction pattern
* The first one (used for retrieving a pair of coefficients) is
* constructed from the top, top right and left coefficients
* The second one (used for retrieving only one coefficient) is
* top + 10 * left.
*/
A = ptr[-s->b4_stride + 1]; // it won't be used for the last coefficient in a row
B = ptr[-s->b4_stride];
C = ptr[-1];
pattern = A + (B << 4) + (C << 8);
for(k = 0; k < MODE2_PATTERNS_NUM; k++)
if(pattern == rv40_aic_table_index[k])
break;
if(j < 3 && k < MODE2_PATTERNS_NUM){ //pattern is found, decoding 2 coefficients
v = get_vlc2(gb, aic_mode2_vlc[k].table, AIC_MODE2_BITS, 2);
*ptr++ = v/9;
*ptr++ = v%9;
j++;
}else{
if(B != -1 && C != -1)
v = get_vlc2(gb, aic_mode1_vlc[B + C*10].table, AIC_MODE1_BITS, 1);
else{ // tricky decoding
v = 0;
switch(C){
case -1: // code 0 -> 1, 1 -> 0
if(B < 2)
v = get_bits1(gb) ^ 1;
break;
case 0:
case 2: // code 0 -> 2, 1 -> 0
v = (get_bits1(gb) ^ 1) << 1;
break;
}
}
*ptr++ = v;
}
}
}
return 0;
}
/**
* Decode macroblock information.
*/
static int rv40_decode_mb_info(RV34DecContext *r)
{
MpegEncContext *s = &r->s;
GetBitContext *gb = &s->gb;
int q, i;
int prev_type = 0;
int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
int blocks[RV34_MB_TYPES] = {0};
int count = 0;
if(!r->s.mb_skip_run)
r->s.mb_skip_run = svq3_get_ue_golomb(gb) + 1;
if(--r->s.mb_skip_run)
return RV34_MB_SKIP;
if(r->avail_cache[5-1])
blocks[r->mb_type[mb_pos - 1]]++;
if(r->avail_cache[5-4]){
blocks[r->mb_type[mb_pos - s->mb_stride]]++;
if(r->avail_cache[5-2])
blocks[r->mb_type[mb_pos - s->mb_stride + 1]]++;
if(r->avail_cache[5-5])
blocks[r->mb_type[mb_pos - s->mb_stride - 1]]++;
}
for(i = 0; i < RV34_MB_TYPES; i++){
if(blocks[i] > count){
count = blocks[i];
prev_type = i;
}
}
if(s->pict_type == P_TYPE){
prev_type = block_num_to_ptype_vlc_num[prev_type];
q = get_vlc2(gb, ptype_vlc[prev_type].table, PTYPE_VLC_BITS, 1);
if(q < PBTYPE_ESCAPE)
return q;
q = get_vlc2(gb, ptype_vlc[prev_type].table, PTYPE_VLC_BITS, 1);
av_log(s->avctx, AV_LOG_ERROR, "Dquant for P-frame\n");
}else{
prev_type = block_num_to_btype_vlc_num[prev_type];
q = get_vlc2(gb, btype_vlc[prev_type].table, BTYPE_VLC_BITS, 1);
if(q < PBTYPE_ESCAPE)
return q;
q = get_vlc2(gb, btype_vlc[prev_type].table, BTYPE_VLC_BITS, 1);
av_log(s->avctx, AV_LOG_ERROR, "Dquant for B-frame\n");
}
return 0;
}
/**
* Initialize decoder.
*/
static int rv40_decode_init(AVCodecContext *avctx)
{
RV34DecContext *r = avctx->priv_data;
r->rv30 = 0;
ff_rv34_decode_init(avctx);
if(!aic_top_vlc.bits)
rv40_init_tables();
r->parse_slice_header = rv40_parse_slice_header;
r->decode_intra_types = rv40_decode_intra_types;
r->decode_mb_info = rv40_decode_mb_info;
r->luma_dc_quant_i = rv40_luma_dc_quant[0];
r->luma_dc_quant_p = rv40_luma_dc_quant[1];
return 0;
}
AVCodec rv40_decoder = {
"rv40",
CODEC_TYPE_VIDEO,
CODEC_ID_RV40,
sizeof(RV34DecContext),
rv40_decode_init,
NULL,
ff_rv34_decode_end,
ff_rv34_decode_frame,
CODEC_CAP_DR1 | CODEC_CAP_DELAY,
};
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