ffmpeg/libavcodec/rv30.c

148 lines
4.1 KiB
C

/*
* RV30 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 rv30.c
* RV30 decoder
*/
#include "avcodec.h"
#include "dsputil.h"
#include "mpegvideo.h"
#include "golomb.h"
#include "rv34.h"
#include "rv30data.h"
static int rv30_parse_slice_header(RV34DecContext *r, GetBitContext *gb, SliceInfo *si)
{
int mb_bits;
int w = r->s.width, h = r->s.height;
int mb_size;
memset(si, 0, sizeof(SliceInfo));
skip_bits(gb, 3);
si->type = get_bits(gb, 2);
if(si->type == 1) si->type = 0;
if(get_bits1(gb))
return -1;
si->quant = get_bits(gb, 5);
skip_bits1(gb);
skip_bits(gb, 13); // timestamp
skip_bits(gb, r->rpr);
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);
skip_bits1(gb);
return 0;
}
/**
* Decode 4x4 intra types array.
*/
static int rv30_decode_intra_types(RV34DecContext *r, GetBitContext *gb, int8_t *dst)
{
int i, j, k;
for(i = 0; i < 4; i++, dst += r->s.b4_stride - 4){
for(j = 0; j < 4; j+= 2){
int code = svq3_get_ue_golomb(gb) << 1;
if(code >= 81*2){
av_log(r->s.avctx, AV_LOG_ERROR, "Incorrect intra prediction code\n");
return -1;
}
for(k = 0; k < 2; k++){
int A = dst[-r->s.b4_stride] + 1;
int B = dst[-1] + 1;
*dst++ = rv30_itype_from_context[A * 90 + B * 9 + rv30_itype_code[code + k]];
if(dst[-1] == 9){
av_log(r->s.avctx, AV_LOG_ERROR, "Incorrect intra prediction mode\n");
return -1;
}
}
}
}
return 0;
}
/**
* Decode macroblock information.
*/
static int rv30_decode_mb_info(RV34DecContext *r)
{
static const int rv30_p_types[6] = { RV34_MB_SKIP, RV34_MB_P_16x16, RV34_MB_P_8x8, -1, RV34_MB_TYPE_INTRA, RV34_MB_TYPE_INTRA16x16 };
static const int rv30_b_types[6] = { RV34_MB_SKIP, RV34_MB_B_DIRECT, RV34_MB_B_FORWARD, RV34_MB_B_BACKWARD, RV34_MB_TYPE_INTRA, RV34_MB_TYPE_INTRA16x16 };
MpegEncContext *s = &r->s;
GetBitContext *gb = &s->gb;
int code = svq3_get_ue_golomb(gb);
if(code > 11){
av_log(s->avctx, AV_LOG_ERROR, "Incorrect MB type code\n");
return -1;
}
if(code > 5){
av_log(s->avctx, AV_LOG_ERROR, "dquant needed\n");
code -= 6;
}
if(s->pict_type != B_TYPE)
return rv30_p_types[code];
else
return rv30_b_types[code];
}
/**
* Initialize decoder.
*/
static int rv30_decode_init(AVCodecContext *avctx)
{
RV34DecContext *r = avctx->priv_data;
r->rv30 = 1;
ff_rv34_decode_init(avctx);
if(avctx->extradata_size < 2){
av_log(avctx, AV_LOG_ERROR, "Extradata is too small.\n");
return -1;
}
r->rpr = (avctx->extradata[1] & 7) >> 1;
r->rpr = FFMIN(r->rpr + 1, 3);
r->parse_slice_header = rv30_parse_slice_header;
r->decode_intra_types = rv30_decode_intra_types;
r->decode_mb_info = rv30_decode_mb_info;
r->luma_dc_quant_i = rv30_luma_dc_quant;
r->luma_dc_quant_p = rv30_luma_dc_quant;
return 0;
}
AVCodec rv30_decoder = {
"rv30",
CODEC_TYPE_VIDEO,
CODEC_ID_RV30,
sizeof(RV34DecContext),
rv30_decode_init,
NULL,
ff_rv34_decode_end,
ff_rv34_decode_frame,
CODEC_CAP_DR1 | CODEC_CAP_DELAY,
};