summaryrefslogtreecommitdiff
path: root/libavcodec/tiertexseqv.c
blob: 33b257954f39143f9c3c630322fbce36c4651464 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
/*
 * Tiertex Limited SEQ Video Decoder
 * Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net)
 *
 * This file is part of Libav.
 *
 * Libav 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.
 *
 * Libav 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 Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * Tiertex Limited SEQ video decoder
 */

#include "avcodec.h"
#define BITSTREAM_READER_LE
#include "get_bits.h"
#include "internal.h"


typedef struct SeqVideoContext {
    AVCodecContext *avctx;
    AVFrame *frame;
} SeqVideoContext;


static const unsigned char *seq_unpack_rle_block(const unsigned char *src,
                                                 const unsigned char *src_end,
                                                 unsigned char *dst, int dst_size)
{
    int i, len, sz;
    GetBitContext gb;
    int code_table[64];

    /* get the rle codes */
    init_get_bits(&gb, src, (src_end - src) * 8);
    for (i = 0, sz = 0; i < 64 && sz < dst_size; i++) {
        if (get_bits_left(&gb) < 4)
            return NULL;
        code_table[i] = get_sbits(&gb, 4);
        sz += FFABS(code_table[i]);
    }
    src += (get_bits_count(&gb) + 7) / 8;

    /* do the rle unpacking */
    for (i = 0; i < 64 && dst_size > 0; i++) {
        len = code_table[i];
        if (len < 0) {
            len = -len;
            if (src_end - src < 1)
                return NULL;
            memset(dst, *src++, FFMIN(len, dst_size));
        } else {
            if (src_end - src < len)
                return NULL;
            memcpy(dst, src, FFMIN(len, dst_size));
            src += len;
        }
        dst += len;
        dst_size -= len;
    }
    return src;
}

static const unsigned char *seq_decode_op1(SeqVideoContext *seq,
                                           const unsigned char *src,
                                           const unsigned char *src_end,
                                           unsigned char *dst)
{
    const unsigned char *color_table;
    int b, i, len, bits;
    GetBitContext gb;
    unsigned char block[8 * 8];

    if (src_end - src < 1)
        return NULL;
    len = *src++;
    if (len & 0x80) {
        switch (len & 3) {
        case 1:
            src = seq_unpack_rle_block(src, src_end, block, sizeof(block));
            for (b = 0; b < 8; b++) {
                memcpy(dst, &block[b * 8], 8);
                dst += seq->frame->linesize[0];
            }
            break;
        case 2:
            src = seq_unpack_rle_block(src, src_end, block, sizeof(block));
            for (i = 0; i < 8; i++) {
                for (b = 0; b < 8; b++)
                    dst[b * seq->frame->linesize[0]] = block[i * 8 + b];
                ++dst;
            }
            break;
        }
    } else {
        if (len <= 0)
            return NULL;
        bits = ff_log2_tab[len - 1] + 1;
        if (src_end - src < len + 8 * bits)
            return NULL;
        color_table = src;
        src += len;
        init_get_bits(&gb, src, bits * 8 * 8); src += bits * 8;
        for (b = 0; b < 8; b++) {
            for (i = 0; i < 8; i++)
                dst[i] = color_table[get_bits(&gb, bits)];
            dst += seq->frame->linesize[0];
        }
    }

    return src;
}

static const unsigned char *seq_decode_op2(SeqVideoContext *seq,
                                           const unsigned char *src,
                                           const unsigned char *src_end,
                                           unsigned char *dst)
{
    int i;

    if (src_end - src < 8 * 8)
        return NULL;

    for (i = 0; i < 8; i++) {
        memcpy(dst, src, 8);
        src += 8;
        dst += seq->frame->linesize[0];
    }

    return src;
}

static const unsigned char *seq_decode_op3(SeqVideoContext *seq,
                                           const unsigned char *src,
                                           const unsigned char *src_end,
                                           unsigned char *dst)
{
    int pos, offset;

    do {
        if (src_end - src < 2)
            return NULL;
        pos = *src++;
        offset = ((pos >> 3) & 7) * seq->frame->linesize[0] + (pos & 7);
        dst[offset] = *src++;
    } while (!(pos & 0x80));

    return src;
}

static int seqvideo_decode(SeqVideoContext *seq, const unsigned char *data, int data_size)
{
    const unsigned char *data_end = data + data_size;
    GetBitContext gb;
    int flags, i, j, x, y, op;
    unsigned char c[3];
    unsigned char *dst;
    uint32_t *palette;

    flags = *data++;

    if (flags & 1) {
        palette = (uint32_t *)seq->frame->data[1];
        if (data_end - data < 256 * 3)
            return AVERROR_INVALIDDATA;
        for (i = 0; i < 256; i++) {
            for (j = 0; j < 3; j++, data++)
                c[j] = (*data << 2) | (*data >> 4);
            palette[i] = AV_RB24(c);
        }
        seq->frame->palette_has_changed = 1;
    }

    if (flags & 2) {
        if (data_end - data < 128)
            return AVERROR_INVALIDDATA;
        init_get_bits(&gb, data, 128 * 8); data += 128;
        for (y = 0; y < 128; y += 8)
            for (x = 0; x < 256; x += 8) {
                dst = &seq->frame->data[0][y * seq->frame->linesize[0] + x];
                op = get_bits(&gb, 2);
                switch (op) {
                case 1:
                    data = seq_decode_op1(seq, data, data_end, dst);
                    break;
                case 2:
                    data = seq_decode_op2(seq, data, data_end, dst);
                    break;
                case 3:
                    data = seq_decode_op3(seq, data, data_end, dst);
                    break;
                }
                if (!data)
                    return AVERROR_INVALIDDATA;
            }
    }
    return 0;
}

static av_cold int seqvideo_decode_init(AVCodecContext *avctx)
{
    SeqVideoContext *seq = avctx->priv_data;

    seq->avctx = avctx;
    avctx->pix_fmt = AV_PIX_FMT_PAL8;

    seq->frame = av_frame_alloc();
    if (!seq->frame)
        return AVERROR(ENOMEM);

    return 0;
}

static int seqvideo_decode_frame(AVCodecContext *avctx,
                                 void *data, int *got_frame,
                                 AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    int ret;

    SeqVideoContext *seq = avctx->priv_data;

    if ((ret = ff_reget_buffer(avctx, seq->frame)) < 0) {
        av_log(seq->avctx, AV_LOG_ERROR, "tiertexseqvideo: reget_buffer() failed\n");
        return ret;
    }

    if (seqvideo_decode(seq, buf, buf_size))
        return AVERROR_INVALIDDATA;

    if ((ret = av_frame_ref(data, seq->frame)) < 0)
        return ret;
    *got_frame       = 1;

    return buf_size;
}

static av_cold int seqvideo_decode_end(AVCodecContext *avctx)
{
    SeqVideoContext *seq = avctx->priv_data;

    av_frame_free(&seq->frame);

    return 0;
}

AVCodec ff_tiertexseqvideo_decoder = {
    .name           = "tiertexseqvideo",
    .long_name      = NULL_IF_CONFIG_SMALL("Tiertex Limited SEQ video"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_TIERTEXSEQVIDEO,
    .priv_data_size = sizeof(SeqVideoContext),
    .init           = seqvideo_decode_init,
    .close          = seqvideo_decode_end,
    .decode         = seqvideo_decode_frame,
    .capabilities   = CODEC_CAP_DR1,
};