Statistics
| Branch: | Revision:

ffmpeg / libavcodec / rv30.c @ 39902a8c

History | View | Annotate | Download (4.18 KB)

1
/*
2
 * RV30 decoder
3
 * Copyright (c) 2007 Konstantin Shishkov
4
 *
5
 * This file is part of FFmpeg.
6
 *
7
 * FFmpeg is free software; you can redistribute it and/or
8
 * modify it under the terms of the GNU Lesser General Public
9
 * License as published by the Free Software Foundation; either
10
 * version 2.1 of the License, or (at your option) any later version.
11
 *
12
 * FFmpeg is distributed in the hope that it will be useful,
13
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15
 * Lesser General Public License for more details.
16
 *
17
 * You should have received a copy of the GNU Lesser General Public
18
 * License along with FFmpeg; if not, write to the Free Software
19
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20
 */
21

    
22
/**
23
 * @file rv30.c
24
 * RV30 decoder
25
 */
26

    
27
#include "avcodec.h"
28
#include "dsputil.h"
29
#include "mpegvideo.h"
30
#include "golomb.h"
31

    
32
#include "rv34.h"
33
#include "rv30data.h"
34

    
35

    
36
static int rv30_parse_slice_header(RV34DecContext *r, GetBitContext *gb, SliceInfo *si)
37
{
38
    int mb_bits;
39
    int w = r->s.width, h = r->s.height;
40
    int mb_size;
41

    
42
    memset(si, 0, sizeof(SliceInfo));
43
    skip_bits(gb, 3);
44
    si->type = get_bits(gb, 2);
45
    if(si->type == 1) si->type = 0;
46
    if(get_bits1(gb))
47
        return -1;
48
    si->quant = get_bits(gb, 5);
49
    skip_bits1(gb);
50
    si->pts = get_bits(gb, 13);
51
    skip_bits(gb, r->rpr);
52
    si->width  = w;
53
    si->height = h;
54
    mb_size = ((w + 15) >> 4) * ((h + 15) >> 4);
55
    mb_bits = ff_rv34_get_start_offset(gb, mb_size);
56
    si->start = get_bits(gb, mb_bits);
57
    skip_bits1(gb);
58
    return 0;
59
}
60

    
61
/**
62
 * Decode 4x4 intra types array.
63
 */
64
static int rv30_decode_intra_types(RV34DecContext *r, GetBitContext *gb, int8_t *dst)
65
{
66
    int i, j, k;
67

    
68
    for(i = 0; i < 4; i++, dst += r->s.b4_stride - 4){
69
        for(j = 0; j < 4; j+= 2){
70
            int code = svq3_get_ue_golomb(gb) << 1;
71
            if(code >= 81*2){
72
                av_log(r->s.avctx, AV_LOG_ERROR, "Incorrect intra prediction code\n");
73
                return -1;
74
            }
75
            for(k = 0; k < 2; k++){
76
                int A = dst[-r->s.b4_stride] + 1;
77
                int B = dst[-1] + 1;
78
                *dst++ = rv30_itype_from_context[A * 90 + B * 9 + rv30_itype_code[code + k]];
79
                if(dst[-1] == 9){
80
                    av_log(r->s.avctx, AV_LOG_ERROR, "Incorrect intra prediction mode\n");
81
                    return -1;
82
                }
83
            }
84
        }
85
    }
86
    return 0;
87
}
88

    
89
/**
90
 * Decode macroblock information.
91
 */
92
static int rv30_decode_mb_info(RV34DecContext *r)
93
{
94
    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 };
95
    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 };
96
    MpegEncContext *s = &r->s;
97
    GetBitContext *gb = &s->gb;
98
    int code = svq3_get_ue_golomb(gb);
99

    
100
    if(code > 11){
101
        av_log(s->avctx, AV_LOG_ERROR, "Incorrect MB type code\n");
102
        return -1;
103
    }
104
    if(code > 5){
105
        av_log(s->avctx, AV_LOG_ERROR, "dquant needed\n");
106
        code -= 6;
107
    }
108
    if(s->pict_type != FF_B_TYPE)
109
        return rv30_p_types[code];
110
    else
111
        return rv30_b_types[code];
112
}
113

    
114
/**
115
 * Initialize decoder.
116
 */
117
static av_cold int rv30_decode_init(AVCodecContext *avctx)
118
{
119
    RV34DecContext *r = avctx->priv_data;
120

    
121
    r->rv30 = 1;
122
    ff_rv34_decode_init(avctx);
123
    if(avctx->extradata_size < 2){
124
        av_log(avctx, AV_LOG_ERROR, "Extradata is too small.\n");
125
        return -1;
126
    }
127
    r->rpr = (avctx->extradata[1] & 7) >> 1;
128
    r->rpr = FFMIN(r->rpr + 1, 3);
129
    r->parse_slice_header = rv30_parse_slice_header;
130
    r->decode_intra_types = rv30_decode_intra_types;
131
    r->decode_mb_info     = rv30_decode_mb_info;
132
    r->luma_dc_quant_i = rv30_luma_dc_quant;
133
    r->luma_dc_quant_p = rv30_luma_dc_quant;
134
    return 0;
135
}
136

    
137
AVCodec rv30_decoder = {
138
    "rv30",
139
    CODEC_TYPE_VIDEO,
140
    CODEC_ID_RV30,
141
    sizeof(RV34DecContext),
142
    rv30_decode_init,
143
    NULL,
144
    ff_rv34_decode_end,
145
    ff_rv34_decode_frame,
146
    CODEC_CAP_DR1 | CODEC_CAP_DELAY,
147
    .long_name = "RealVideo 3.0",
148
};