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FFmpeg/libavcodec/cavsdec.c
Stefano Sabatini 72415b2adb Define AVMediaType enum, and use it instead of enum CodecType, which 
is deprecated and will be dropped at the next major bump.

Originally committed as revision 22735 to svn://svn.ffmpeg.org/ffmpeg/trunk
2010-03-30 23:30:55 +00:00

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/*
* Chinese AVS video (AVS1-P2, JiZhun profile) decoder.
* Copyright (c) 2006 Stefan Gehrer <stefan.gehrer@gmx.de>
*
* 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 libavcodec/cavsdec.c
* Chinese AVS video (AVS1-P2, JiZhun profile) decoder
* @author Stefan Gehrer <stefan.gehrer@gmx.de>
*/
#include "avcodec.h"
#include "get_bits.h"
#include "golomb.h"
#include "cavs.h"
static const uint8_t mv_scan[4] = {
MV_FWD_X0,MV_FWD_X1,
MV_FWD_X2,MV_FWD_X3
};
static const uint8_t cbp_tab[64][2] = {
{63, 0},{15,15},{31,63},{47,31},{ 0,16},{14,32},{13,47},{11,13},
{ 7,14},{ 5,11},{10,12},{ 8, 5},{12,10},{61, 7},{ 4,48},{55, 3},
{ 1, 2},{ 2, 8},{59, 4},{ 3, 1},{62,61},{ 9,55},{ 6,59},{29,62},
{45,29},{51,27},{23,23},{39,19},{27,30},{46,28},{53, 9},{30, 6},
{43,60},{37,21},{60,44},{16,26},{21,51},{28,35},{19,18},{35,20},
{42,24},{26,53},{44,17},{32,37},{58,39},{24,45},{20,58},{17,43},
{18,42},{48,46},{22,36},{33,33},{25,34},{49,40},{40,52},{36,49},
{34,50},{50,56},{52,25},{54,22},{41,54},{56,57},{38,41},{57,38}
};
/*****************************************************************************
*
* motion vector prediction
*
****************************************************************************/
static inline void store_mvs(AVSContext *h) {
h->col_mv[h->mbidx*4 + 0] = h->mv[MV_FWD_X0];
h->col_mv[h->mbidx*4 + 1] = h->mv[MV_FWD_X1];
h->col_mv[h->mbidx*4 + 2] = h->mv[MV_FWD_X2];
h->col_mv[h->mbidx*4 + 3] = h->mv[MV_FWD_X3];
}
static inline void mv_pred_direct(AVSContext *h, cavs_vector *pmv_fw,
cavs_vector *col_mv) {
cavs_vector *pmv_bw = pmv_fw + MV_BWD_OFFS;
int den = h->direct_den[col_mv->ref];
int m = col_mv->x >> 31;
pmv_fw->dist = h->dist[1];
pmv_bw->dist = h->dist[0];
pmv_fw->ref = 1;
pmv_bw->ref = 0;
/* scale the co-located motion vector according to its temporal span */
pmv_fw->x = (((den+(den*col_mv->x*pmv_fw->dist^m)-m-1)>>14)^m)-m;
pmv_bw->x = m-(((den+(den*col_mv->x*pmv_bw->dist^m)-m-1)>>14)^m);
m = col_mv->y >> 31;
pmv_fw->y = (((den+(den*col_mv->y*pmv_fw->dist^m)-m-1)>>14)^m)-m;
pmv_bw->y = m-(((den+(den*col_mv->y*pmv_bw->dist^m)-m-1)>>14)^m);
}
static inline void mv_pred_sym(AVSContext *h, cavs_vector *src, enum cavs_block size) {
cavs_vector *dst = src + MV_BWD_OFFS;
/* backward mv is the scaled and negated forward mv */
dst->x = -((src->x * h->sym_factor + 256) >> 9);
dst->y = -((src->y * h->sym_factor + 256) >> 9);
dst->ref = 0;
dst->dist = h->dist[0];
set_mvs(dst, size);
}
/*****************************************************************************
*
* residual data decoding
*
****************************************************************************/
/** kth-order exponential golomb code */
static inline int get_ue_code(GetBitContext *gb, int order) {
if(order) {
int ret = get_ue_golomb(gb) << order;
return ret + get_bits(gb,order);
}
return get_ue_golomb(gb);
}
/**
* decode coefficients from one 8x8 block, dequantize, inverse transform
* and add them to sample block
* @param r pointer to 2D VLC table
* @param esc_golomb_order escape codes are k-golomb with this order k
* @param qp quantizer
* @param dst location of sample block
* @param stride line stride in frame buffer
*/
static int decode_residual_block(AVSContext *h, GetBitContext *gb,
const struct dec_2dvlc *r, int esc_golomb_order,
int qp, uint8_t *dst, int stride) {
int i, level_code, esc_code, level, run, mask;
DCTELEM level_buf[65];
uint8_t run_buf[65];
DCTELEM *block = h->block;
for(i=0;i<65;i++) {
level_code = get_ue_code(gb,r->golomb_order);
if(level_code >= ESCAPE_CODE) {
run = ((level_code - ESCAPE_CODE) >> 1) + 1;
esc_code = get_ue_code(gb,esc_golomb_order);
level = esc_code + (run > r->max_run ? 1 : r->level_add[run]);
while(level > r->inc_limit)
r++;
mask = -(level_code & 1);
level = (level^mask) - mask;
} else {
level = r->rltab[level_code][0];
if(!level) //end of block signal
break;
run = r->rltab[level_code][1];
r += r->rltab[level_code][2];
}
level_buf[i] = level;
run_buf[i] = run;
}
if(dequant(h,level_buf, run_buf, block, ff_cavs_dequant_mul[qp],
ff_cavs_dequant_shift[qp], i))
return -1;
h->s.dsp.cavs_idct8_add(dst,block,stride);
h->s.dsp.clear_block(block);
return 0;
}
static inline void decode_residual_chroma(AVSContext *h) {
if(h->cbp & (1<<4))
decode_residual_block(h,&h->s.gb,ff_cavs_chroma_dec,0,
ff_cavs_chroma_qp[h->qp],h->cu,h->c_stride);
if(h->cbp & (1<<5))
decode_residual_block(h,&h->s.gb,ff_cavs_chroma_dec,0,
ff_cavs_chroma_qp[h->qp],h->cv,h->c_stride);
}
static inline int decode_residual_inter(AVSContext *h) {
int block;
/* get coded block pattern */
int cbp= get_ue_golomb(&h->s.gb);
if(cbp > 63){
av_log(h->s.avctx, AV_LOG_ERROR, "illegal inter cbp\n");
return -1;
}
h->cbp = cbp_tab[cbp][1];
/* get quantizer */
if(h->cbp && !h->qp_fixed)
h->qp = (h->qp + get_se_golomb(&h->s.gb)) & 63;
for(block=0;block<4;block++)
if(h->cbp & (1<<block))
decode_residual_block(h,&h->s.gb,ff_cavs_inter_dec,0,h->qp,
h->cy + h->luma_scan[block], h->l_stride);
decode_residual_chroma(h);
return 0;
}
/*****************************************************************************
*
* macroblock level
*
****************************************************************************/
static int decode_mb_i(AVSContext *h, int cbp_code) {
GetBitContext *gb = &h->s.gb;
int block, pred_mode_uv;
uint8_t top[18];
uint8_t *left = NULL;
uint8_t *d;
ff_cavs_init_mb(h);
/* get intra prediction modes from stream */
for(block=0;block<4;block++) {
int nA,nB,predpred;
int pos = ff_cavs_scan3x3[block];
nA = h->pred_mode_Y[pos-1];
nB = h->pred_mode_Y[pos-3];
predpred = FFMIN(nA,nB);
if(predpred == NOT_AVAIL) // if either is not available
predpred = INTRA_L_LP;
if(!get_bits1(gb)){
int rem_mode= get_bits(gb, 2);
predpred = rem_mode + (rem_mode >= predpred);
}
h->pred_mode_Y[pos] = predpred;
}
pred_mode_uv = get_ue_golomb(gb);
if(pred_mode_uv > 6) {
av_log(h->s.avctx, AV_LOG_ERROR, "illegal intra chroma pred mode\n");
return -1;
}
ff_cavs_modify_mb_i(h, &pred_mode_uv);
/* get coded block pattern */
if(h->pic_type == FF_I_TYPE)
cbp_code = get_ue_golomb(gb);
if(cbp_code > 63){
av_log(h->s.avctx, AV_LOG_ERROR, "illegal intra cbp\n");
return -1;
}
h->cbp = cbp_tab[cbp_code][0];
if(h->cbp && !h->qp_fixed)
h->qp = (h->qp + get_se_golomb(gb)) & 63; //qp_delta
/* luma intra prediction interleaved with residual decode/transform/add */
for(block=0;block<4;block++) {
d = h->cy + h->luma_scan[block];
ff_cavs_load_intra_pred_luma(h, top, &left, block);
h->intra_pred_l[h->pred_mode_Y[ff_cavs_scan3x3[block]]]
(d, top, left, h->l_stride);
if(h->cbp & (1<<block))
decode_residual_block(h,gb,ff_cavs_intra_dec,1,h->qp,d,h->l_stride);
}
/* chroma intra prediction */
ff_cavs_load_intra_pred_chroma(h);
h->intra_pred_c[pred_mode_uv](h->cu, &h->top_border_u[h->mbx*10],
h->left_border_u, h->c_stride);
h->intra_pred_c[pred_mode_uv](h->cv, &h->top_border_v[h->mbx*10],
h->left_border_v, h->c_stride);
decode_residual_chroma(h);
ff_cavs_filter(h,I_8X8);
set_mv_intra(h);
return 0;
}
static void decode_mb_p(AVSContext *h, enum cavs_mb mb_type) {
GetBitContext *gb = &h->s.gb;
int ref[4];
ff_cavs_init_mb(h);
switch(mb_type) {
case P_SKIP:
ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_PSKIP, BLK_16X16, 0);
break;
case P_16X16:
ref[0] = h->ref_flag ? 0 : get_bits1(gb);
ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_MEDIAN, BLK_16X16,ref[0]);
break;
case P_16X8:
ref[0] = h->ref_flag ? 0 : get_bits1(gb);
ref[2] = h->ref_flag ? 0 : get_bits1(gb);
ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_TOP, BLK_16X8, ref[0]);
ff_cavs_mv(h, MV_FWD_X2, MV_FWD_A1, MV_PRED_LEFT, BLK_16X8, ref[2]);
break;
case P_8X16:
ref[0] = h->ref_flag ? 0 : get_bits1(gb);
ref[1] = h->ref_flag ? 0 : get_bits1(gb);
ff_cavs_mv(h, MV_FWD_X0, MV_FWD_B3, MV_PRED_LEFT, BLK_8X16, ref[0]);
ff_cavs_mv(h, MV_FWD_X1, MV_FWD_C2, MV_PRED_TOPRIGHT,BLK_8X16, ref[1]);
break;
case P_8X8:
ref[0] = h->ref_flag ? 0 : get_bits1(gb);
ref[1] = h->ref_flag ? 0 : get_bits1(gb);
ref[2] = h->ref_flag ? 0 : get_bits1(gb);
ref[3] = h->ref_flag ? 0 : get_bits1(gb);
ff_cavs_mv(h, MV_FWD_X0, MV_FWD_B3, MV_PRED_MEDIAN, BLK_8X8, ref[0]);
ff_cavs_mv(h, MV_FWD_X1, MV_FWD_C2, MV_PRED_MEDIAN, BLK_8X8, ref[1]);
ff_cavs_mv(h, MV_FWD_X2, MV_FWD_X1, MV_PRED_MEDIAN, BLK_8X8, ref[2]);
ff_cavs_mv(h, MV_FWD_X3, MV_FWD_X0, MV_PRED_MEDIAN, BLK_8X8, ref[3]);
}
ff_cavs_inter(h, mb_type);
set_intra_mode_default(h);
store_mvs(h);
if(mb_type != P_SKIP)
decode_residual_inter(h);
ff_cavs_filter(h,mb_type);
h->col_type_base[h->mbidx] = mb_type;
}
static void decode_mb_b(AVSContext *h, enum cavs_mb mb_type) {
int block;
enum cavs_sub_mb sub_type[4];
int flags;
ff_cavs_init_mb(h);
/* reset all MVs */
h->mv[MV_FWD_X0] = ff_cavs_dir_mv;
set_mvs(&h->mv[MV_FWD_X0], BLK_16X16);
h->mv[MV_BWD_X0] = ff_cavs_dir_mv;
set_mvs(&h->mv[MV_BWD_X0], BLK_16X16);
switch(mb_type) {
case B_SKIP:
case B_DIRECT:
if(!h->col_type_base[h->mbidx]) {
/* intra MB at co-location, do in-plane prediction */
ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_BSKIP, BLK_16X16, 1);
ff_cavs_mv(h, MV_BWD_X0, MV_BWD_C2, MV_PRED_BSKIP, BLK_16X16, 0);
} else
/* direct prediction from co-located P MB, block-wise */
for(block=0;block<4;block++)
mv_pred_direct(h,&h->mv[mv_scan[block]],
&h->col_mv[h->mbidx*4 + block]);
break;
case B_FWD_16X16:
ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_MEDIAN, BLK_16X16, 1);
break;
case B_SYM_16X16:
ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_MEDIAN, BLK_16X16, 1);
mv_pred_sym(h, &h->mv[MV_FWD_X0], BLK_16X16);
break;
case B_BWD_16X16:
ff_cavs_mv(h, MV_BWD_X0, MV_BWD_C2, MV_PRED_MEDIAN, BLK_16X16, 0);
break;
case B_8X8:
for(block=0;block<4;block++)
sub_type[block] = get_bits(&h->s.gb,2);
for(block=0;block<4;block++) {
switch(sub_type[block]) {
case B_SUB_DIRECT:
if(!h->col_type_base[h->mbidx]) {
/* intra MB at co-location, do in-plane prediction */
ff_cavs_mv(h, mv_scan[block], mv_scan[block]-3,
MV_PRED_BSKIP, BLK_8X8, 1);
ff_cavs_mv(h, mv_scan[block]+MV_BWD_OFFS,
mv_scan[block]-3+MV_BWD_OFFS,
MV_PRED_BSKIP, BLK_8X8, 0);
} else
mv_pred_direct(h,&h->mv[mv_scan[block]],
&h->col_mv[h->mbidx*4 + block]);
break;
case B_SUB_FWD:
ff_cavs_mv(h, mv_scan[block], mv_scan[block]-3,
MV_PRED_MEDIAN, BLK_8X8, 1);
break;
case B_SUB_SYM:
ff_cavs_mv(h, mv_scan[block], mv_scan[block]-3,
MV_PRED_MEDIAN, BLK_8X8, 1);
mv_pred_sym(h, &h->mv[mv_scan[block]], BLK_8X8);
break;
}
}
for(block=0;block<4;block++) {
if(sub_type[block] == B_SUB_BWD)
ff_cavs_mv(h, mv_scan[block]+MV_BWD_OFFS,
mv_scan[block]+MV_BWD_OFFS-3,
MV_PRED_MEDIAN, BLK_8X8, 0);
}
break;
default:
assert((mb_type > B_SYM_16X16) && (mb_type < B_8X8));
flags = ff_cavs_partition_flags[mb_type];
if(mb_type & 1) { /* 16x8 macroblock types */
if(flags & FWD0)
ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_TOP, BLK_16X8, 1);
if(flags & SYM0)
mv_pred_sym(h, &h->mv[MV_FWD_X0], BLK_16X8);
if(flags & FWD1)
ff_cavs_mv(h, MV_FWD_X2, MV_FWD_A1, MV_PRED_LEFT, BLK_16X8, 1);
if(flags & SYM1)
mv_pred_sym(h, &h->mv[MV_FWD_X2], BLK_16X8);
if(flags & BWD0)
ff_cavs_mv(h, MV_BWD_X0, MV_BWD_C2, MV_PRED_TOP, BLK_16X8, 0);
if(flags & BWD1)
ff_cavs_mv(h, MV_BWD_X2, MV_BWD_A1, MV_PRED_LEFT, BLK_16X8, 0);
} else { /* 8x16 macroblock types */
if(flags & FWD0)
ff_cavs_mv(h, MV_FWD_X0, MV_FWD_B3, MV_PRED_LEFT, BLK_8X16, 1);
if(flags & SYM0)
mv_pred_sym(h, &h->mv[MV_FWD_X0], BLK_8X16);
if(flags & FWD1)
ff_cavs_mv(h,MV_FWD_X1,MV_FWD_C2,MV_PRED_TOPRIGHT,BLK_8X16,1);
if(flags & SYM1)
mv_pred_sym(h, &h->mv[MV_FWD_X1], BLK_8X16);
if(flags & BWD0)
ff_cavs_mv(h, MV_BWD_X0, MV_BWD_B3, MV_PRED_LEFT, BLK_8X16, 0);
if(flags & BWD1)
ff_cavs_mv(h,MV_BWD_X1,MV_BWD_C2,MV_PRED_TOPRIGHT,BLK_8X16,0);
}
}
ff_cavs_inter(h, mb_type);
set_intra_mode_default(h);
if(mb_type != B_SKIP)
decode_residual_inter(h);
ff_cavs_filter(h,mb_type);
}
/*****************************************************************************
*
* slice level
*
****************************************************************************/
static inline int decode_slice_header(AVSContext *h, GetBitContext *gb) {
if(h->stc > 0xAF)
av_log(h->s.avctx, AV_LOG_ERROR, "unexpected start code 0x%02x\n", h->stc);
h->mby = h->stc;
h->mbidx = h->mby*h->mb_width;
/* mark top macroblocks as unavailable */
h->flags &= ~(B_AVAIL|C_AVAIL);
if((h->mby == 0) && (!h->qp_fixed)){
h->qp_fixed = get_bits1(gb);
h->qp = get_bits(gb,6);
}
/* inter frame or second slice can have weighting params */
if((h->pic_type != FF_I_TYPE) || (!h->pic_structure && h->mby >= h->mb_width/2))
if(get_bits1(gb)) { //slice_weighting_flag
av_log(h->s.avctx, AV_LOG_ERROR,
"weighted prediction not yet supported\n");
}
return 0;
}
static inline int check_for_slice(AVSContext *h) {
GetBitContext *gb = &h->s.gb;
int align;
if(h->mbx)
return 0;
align = (-get_bits_count(gb)) & 7;
/* check for stuffing byte */
if(!align && (show_bits(gb,8) == 0x80))
align = 8;
if((show_bits_long(gb,24+align) & 0xFFFFFF) == 0x000001) {
skip_bits_long(gb,24+align);
h->stc = get_bits(gb,8);
decode_slice_header(h,gb);
return 1;
}
return 0;
}
/*****************************************************************************
*
* frame level
*
****************************************************************************/
static int decode_pic(AVSContext *h) {
MpegEncContext *s = &h->s;
int skip_count = -1;
enum cavs_mb mb_type;
if (!s->context_initialized) {
s->avctx->idct_algo = FF_IDCT_CAVS;
if (MPV_common_init(s) < 0)
return -1;
ff_init_scantable(s->dsp.idct_permutation,&h->scantable,ff_zigzag_direct);
}
skip_bits(&s->gb,16);//bbv_dwlay
if(h->stc == PIC_PB_START_CODE) {
h->pic_type = get_bits(&s->gb,2) + FF_I_TYPE;
if(h->pic_type > FF_B_TYPE) {
av_log(s->avctx, AV_LOG_ERROR, "illegal picture type\n");
return -1;
}
/* make sure we have the reference frames we need */
if(!h->DPB[0].data[0] ||
(!h->DPB[1].data[0] && h->pic_type == FF_B_TYPE))
return -1;
} else {
h->pic_type = FF_I_TYPE;
if(get_bits1(&s->gb))
skip_bits(&s->gb,24);//time_code
/* old sample clips were all progressive and no low_delay,
bump stream revision if detected otherwise */
if((s->low_delay) || !(show_bits(&s->gb,9) & 1))
h->stream_revision = 1;
/* similarly test top_field_first and repeat_first_field */
else if(show_bits(&s->gb,11) & 3)
h->stream_revision = 1;
if(h->stream_revision > 0)
skip_bits(&s->gb,1); //marker_bit
}
/* release last B frame */
if(h->picture.data[0])
s->avctx->release_buffer(s->avctx, (AVFrame *)&h->picture);
s->avctx->get_buffer(s->avctx, (AVFrame *)&h->picture);
ff_cavs_init_pic(h);
h->picture.poc = get_bits(&s->gb,8)*2;
/* get temporal distances and MV scaling factors */
if(h->pic_type != FF_B_TYPE) {
h->dist[0] = (h->picture.poc - h->DPB[0].poc + 512) % 512;
} else {
h->dist[0] = (h->DPB[0].poc - h->picture.poc + 512) % 512;
}
h->dist[1] = (h->picture.poc - h->DPB[1].poc + 512) % 512;
h->scale_den[0] = h->dist[0] ? 512/h->dist[0] : 0;
h->scale_den[1] = h->dist[1] ? 512/h->dist[1] : 0;
if(h->pic_type == FF_B_TYPE) {
h->sym_factor = h->dist[0]*h->scale_den[1];
} else {
h->direct_den[0] = h->dist[0] ? 16384/h->dist[0] : 0;
h->direct_den[1] = h->dist[1] ? 16384/h->dist[1] : 0;
}
if(s->low_delay)
get_ue_golomb(&s->gb); //bbv_check_times
h->progressive = get_bits1(&s->gb);
h->pic_structure = 1;
if(!h->progressive)
h->pic_structure = get_bits1(&s->gb);
if(!h->pic_structure && h->stc == PIC_PB_START_CODE)
skip_bits1(&s->gb); //advanced_pred_mode_disable
skip_bits1(&s->gb); //top_field_first
skip_bits1(&s->gb); //repeat_first_field
h->qp_fixed = get_bits1(&s->gb);
h->qp = get_bits(&s->gb,6);
if(h->pic_type == FF_I_TYPE) {
if(!h->progressive && !h->pic_structure)
skip_bits1(&s->gb);//what is this?
skip_bits(&s->gb,4); //reserved bits
} else {
if(!(h->pic_type == FF_B_TYPE && h->pic_structure == 1))
h->ref_flag = get_bits1(&s->gb);
skip_bits(&s->gb,4); //reserved bits
h->skip_mode_flag = get_bits1(&s->gb);
}
h->loop_filter_disable = get_bits1(&s->gb);
if(!h->loop_filter_disable && get_bits1(&s->gb)) {
h->alpha_offset = get_se_golomb(&s->gb);
h->beta_offset = get_se_golomb(&s->gb);
} else {
h->alpha_offset = h->beta_offset = 0;
}
if(h->pic_type == FF_I_TYPE) {
do {
check_for_slice(h);
decode_mb_i(h, 0);
} while(ff_cavs_next_mb(h));
} else if(h->pic_type == FF_P_TYPE) {
do {
if(check_for_slice(h))
skip_count = -1;
if(h->skip_mode_flag && (skip_count < 0))
skip_count = get_ue_golomb(&s->gb);
if(h->skip_mode_flag && skip_count--) {
decode_mb_p(h,P_SKIP);
} else {
mb_type = get_ue_golomb(&s->gb) + P_SKIP + h->skip_mode_flag;
if(mb_type > P_8X8)
decode_mb_i(h, mb_type - P_8X8 - 1);
else
decode_mb_p(h,mb_type);
}
} while(ff_cavs_next_mb(h));
} else { /* FF_B_TYPE */
do {
if(check_for_slice(h))
skip_count = -1;
if(h->skip_mode_flag && (skip_count < 0))
skip_count = get_ue_golomb(&s->gb);
if(h->skip_mode_flag && skip_count--) {
decode_mb_b(h,B_SKIP);
} else {
mb_type = get_ue_golomb(&s->gb) + B_SKIP + h->skip_mode_flag;
if(mb_type > B_8X8)
decode_mb_i(h, mb_type - B_8X8 - 1);
else
decode_mb_b(h,mb_type);
}
} while(ff_cavs_next_mb(h));
}
if(h->pic_type != FF_B_TYPE) {
if(h->DPB[1].data[0])
s->avctx->release_buffer(s->avctx, (AVFrame *)&h->DPB[1]);
h->DPB[1] = h->DPB[0];
h->DPB[0] = h->picture;
memset(&h->picture,0,sizeof(Picture));
}
return 0;
}
/*****************************************************************************
*
* headers and interface
*
****************************************************************************/
static int decode_seq_header(AVSContext *h) {
MpegEncContext *s = &h->s;
int frame_rate_code;
h->profile = get_bits(&s->gb,8);
h->level = get_bits(&s->gb,8);
skip_bits1(&s->gb); //progressive sequence
s->width = get_bits(&s->gb,14);
s->height = get_bits(&s->gb,14);
skip_bits(&s->gb,2); //chroma format
skip_bits(&s->gb,3); //sample_precision
h->aspect_ratio = get_bits(&s->gb,4);
frame_rate_code = get_bits(&s->gb,4);
skip_bits(&s->gb,18);//bit_rate_lower
skip_bits1(&s->gb); //marker_bit
skip_bits(&s->gb,12);//bit_rate_upper
s->low_delay = get_bits1(&s->gb);
h->mb_width = (s->width + 15) >> 4;
h->mb_height = (s->height + 15) >> 4;
h->s.avctx->time_base.den = ff_frame_rate_tab[frame_rate_code].num;
h->s.avctx->time_base.num = ff_frame_rate_tab[frame_rate_code].den;
h->s.avctx->width = s->width;
h->s.avctx->height = s->height;
if(!h->top_qp)
ff_cavs_init_top_lines(h);
return 0;
}
static void cavs_flush(AVCodecContext * avctx) {
AVSContext *h = avctx->priv_data;
h->got_keyframe = 0;
}
static int cavs_decode_frame(AVCodecContext * avctx,void *data, int *data_size,
AVPacket *avpkt) {
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
AVSContext *h = avctx->priv_data;
MpegEncContext *s = &h->s;
int input_size;
const uint8_t *buf_end;
const uint8_t *buf_ptr;
AVFrame *picture = data;
uint32_t stc = -1;
s->avctx = avctx;
if (buf_size == 0) {
if(!s->low_delay && h->DPB[0].data[0]) {
*data_size = sizeof(AVPicture);
*picture = *(AVFrame *) &h->DPB[0];
}
return 0;
}
buf_ptr = buf;
buf_end = buf + buf_size;
for(;;) {
buf_ptr = ff_find_start_code(buf_ptr,buf_end, &stc);
if(stc & 0xFFFFFE00)
return FFMAX(0, buf_ptr - buf - s->parse_context.last_index);
input_size = (buf_end - buf_ptr)*8;
switch(stc) {
case CAVS_START_CODE:
init_get_bits(&s->gb, buf_ptr, input_size);
decode_seq_header(h);
break;
case PIC_I_START_CODE:
if(!h->got_keyframe) {
if(h->DPB[0].data[0])
avctx->release_buffer(avctx, (AVFrame *)&h->DPB[0]);
if(h->DPB[1].data[0])
avctx->release_buffer(avctx, (AVFrame *)&h->DPB[1]);
h->got_keyframe = 1;
}
case PIC_PB_START_CODE:
*data_size = 0;
if(!h->got_keyframe)
break;
init_get_bits(&s->gb, buf_ptr, input_size);
h->stc = stc;
if(decode_pic(h))
break;
*data_size = sizeof(AVPicture);
if(h->pic_type != FF_B_TYPE) {
if(h->DPB[1].data[0]) {
*picture = *(AVFrame *) &h->DPB[1];
} else {
*data_size = 0;
}
} else
*picture = *(AVFrame *) &h->picture;
break;
case EXT_START_CODE:
//mpeg_decode_extension(avctx,buf_ptr, input_size);
break;
case USER_START_CODE:
//mpeg_decode_user_data(avctx,buf_ptr, input_size);
break;
default:
if (stc <= SLICE_MAX_START_CODE) {
init_get_bits(&s->gb, buf_ptr, input_size);
decode_slice_header(h, &s->gb);
}
break;
}
}
}
AVCodec cavs_decoder = {
"cavs",
AVMEDIA_TYPE_VIDEO,
CODEC_ID_CAVS,
sizeof(AVSContext),
ff_cavs_init,
NULL,
ff_cavs_end,
cavs_decode_frame,
CODEC_CAP_DR1 | CODEC_CAP_DELAY,
.flush= cavs_flush,
.long_name= NULL_IF_CONFIG_SMALL("Chinese AVS video (AVS1-P2, JiZhun profile)"),
};
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