Statistics
| Branch: | Revision:

ffmpeg / libavcodec / tiertexseqv.c @ 2029f312

History | View | Annotate | Download (6.17 KB)

1
/*
2
 * Tiertex Limited SEQ Video Decoder
3
 * Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net)
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 tiertexseqv.c
24
 * Tiertex Limited SEQ video decoder
25
 */
26

    
27
#include "avcodec.h"
28
#define ALT_BITSTREAM_READER_LE
29
#include "bitstream.h"
30

    
31

    
32
typedef struct SeqVideoContext {
33
    AVCodecContext *avctx;
34
    AVFrame frame;
35
    unsigned int palette[256];
36
    unsigned char block[8 * 8];
37
} SeqVideoContext;
38

    
39

    
40
static unsigned char *seq_unpack_rle_block(unsigned char *src, unsigned char *dst, int dst_size)
41
{
42
    int i, len, sz;
43
    GetBitContext gb;
44
    int code_table[64];
45

    
46
    /* get the rle codes (at most 64 bytes) */
47
    init_get_bits(&gb, src, 64 * 8);
48
    for (i = 0, sz = 0; i < 64 && sz < dst_size; i++) {
49
        code_table[i] = get_sbits(&gb, 4);
50
        sz += FFABS(code_table[i]);
51
    }
52
    src += (get_bits_count(&gb) + 7) / 8;
53

    
54
    /* do the rle unpacking */
55
    for (i = 0; i < 64 && dst_size > 0; i++) {
56
        len = code_table[i];
57
        if (len < 0) {
58
            len = -len;
59
            memset(dst, *src++, FFMIN(len, dst_size));
60
        } else {
61
            memcpy(dst, src, FFMIN(len, dst_size));
62
            src += len;
63
        }
64
        dst += len;
65
        dst_size -= len;
66
    }
67
    return src;
68
}
69

    
70
static unsigned char *seq_decode_op1(SeqVideoContext *seq, unsigned char *src, unsigned char *dst)
71
{
72
    unsigned char *color_table;
73
    int b, i, len, bits;
74
    GetBitContext gb;
75

    
76
    len = *src++;
77
    if (len & 0x80) {
78
        switch (len & 3) {
79
        case 1:
80
            src = seq_unpack_rle_block(src, seq->block, sizeof(seq->block));
81
            for (b = 0; b < 8; b++) {
82
                memcpy(dst, &seq->block[b * 8], 8);
83
                dst += seq->frame.linesize[0];
84
            }
85
            break;
86
        case 2:
87
            src = seq_unpack_rle_block(src, seq->block, sizeof(seq->block));
88
            for (i = 0; i < 8; i++) {
89
                for (b = 0; b < 8; b++)
90
                    dst[b * seq->frame.linesize[0]] = seq->block[i * 8 + b];
91
                ++dst;
92
            }
93
            break;
94
        }
95
    } else {
96
        color_table = src;
97
        src += len;
98
        bits = ff_log2_tab[len - 1] + 1;
99
        init_get_bits(&gb, src, bits * 8 * 8); src += bits * 8;
100
        for (b = 0; b < 8; b++) {
101
            for (i = 0; i < 8; i++)
102
                dst[i] = color_table[get_bits(&gb, bits)];
103
            dst += seq->frame.linesize[0];
104
        }
105
    }
106

    
107
    return src;
108
}
109

    
110
static unsigned char *seq_decode_op2(SeqVideoContext *seq, unsigned char *src, unsigned char *dst)
111
{
112
    int i;
113

    
114
    for (i = 0; i < 8; i++) {
115
        memcpy(dst, src, 8);
116
        src += 8;
117
        dst += seq->frame.linesize[0];
118
    }
119

    
120
    return src;
121
}
122

    
123
static unsigned char *seq_decode_op3(SeqVideoContext *seq, unsigned char *src, unsigned char *dst)
124
{
125
    int pos, offset;
126

    
127
    do {
128
        pos = *src++;
129
        offset = ((pos >> 3) & 7) * seq->frame.linesize[0] + (pos & 7);
130
        dst[offset] = *src++;
131
    } while (!(pos & 0x80));
132

    
133
    return src;
134
}
135

    
136
static void seqvideo_decode(SeqVideoContext *seq, unsigned char *data, int data_size)
137
{
138
    GetBitContext gb;
139
    int flags, i, j, x, y, op;
140
    unsigned char c[3];
141
    unsigned char *dst;
142

    
143
    flags = *data++;
144

    
145
    if (flags & 1) {
146
        for (i = 0; i < 256; i++) {
147
            for (j = 0; j < 3; j++, data++)
148
                c[j] = (*data << 2) | (*data >> 4);
149
            seq->palette[i] = (c[0] << 16) | (c[1] << 8) | c[2];
150
        }
151
        memcpy(seq->frame.data[1], seq->palette, sizeof(seq->palette));
152
        seq->frame.palette_has_changed = 1;
153
    }
154

    
155
    if (flags & 2) {
156
        init_get_bits(&gb, data, 128 * 8); data += 128;
157
        for (y = 0; y < 128; y += 8)
158
            for (x = 0; x < 256; x += 8) {
159
                dst = &seq->frame.data[0][y * seq->frame.linesize[0] + x];
160
                op = get_bits(&gb, 2);
161
                switch (op) {
162
                case 1:
163
                    data = seq_decode_op1(seq, data, dst);
164
                    break;
165
                case 2:
166
                    data = seq_decode_op2(seq, data, dst);
167
                    break;
168
                case 3:
169
                    data = seq_decode_op3(seq, data, dst);
170
                    break;
171
                }
172
            }
173
    }
174
}
175

    
176
static int seqvideo_decode_init(AVCodecContext *avctx)
177
{
178
    SeqVideoContext *seq = avctx->priv_data;
179

    
180
    seq->avctx = avctx;
181
    avctx->pix_fmt = PIX_FMT_PAL8;
182

    
183
    seq->frame.data[0] = NULL;
184

    
185
    return 0;
186
}
187

    
188
static int seqvideo_decode_frame(AVCodecContext *avctx,
189
                                 void *data, int *data_size,
190
                                 uint8_t *buf, int buf_size)
191
{
192

    
193
    SeqVideoContext *seq = avctx->priv_data;
194

    
195
    seq->frame.reference = 1;
196
    seq->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
197
    if (avctx->reget_buffer(avctx, &seq->frame)) {
198
        av_log(seq->avctx, AV_LOG_ERROR, "tiertexseqvideo: reget_buffer() failed\n");
199
        return -1;
200
    }
201

    
202
    seqvideo_decode(seq, buf, buf_size);
203

    
204
    *data_size = sizeof(AVFrame);
205
    *(AVFrame *)data = seq->frame;
206

    
207
    return buf_size;
208
}
209

    
210
static int seqvideo_decode_end(AVCodecContext *avctx)
211
{
212
    SeqVideoContext *seq = avctx->priv_data;
213

    
214
    if (seq->frame.data[0])
215
        avctx->release_buffer(avctx, &seq->frame);
216

    
217
    return 0;
218
}
219

    
220
AVCodec tiertexseqvideo_decoder = {
221
    "tiertexseqvideo",
222
    CODEC_TYPE_VIDEO,
223
    CODEC_ID_TIERTEXSEQVIDEO,
224
    sizeof(SeqVideoContext),
225
    seqvideo_decode_init,
226
    NULL,
227
    seqvideo_decode_end,
228
    seqvideo_decode_frame,
229
    CODEC_CAP_DR1,
230
};