Statistics
| Branch: | Revision:

ffmpeg / libavcodec / dfa.c @ 65daa942

History | View | Annotate | Download (11.7 KB)

1
/*
2
 * Chronomaster DFA Video Decoder
3
 * Copyright (c) 2011 Konstantin Shishkov
4
 * based on work by Vladimir "VAG" Gneushev
5
 *
6
 * This file is part of FFmpeg.
7
 *
8
 * FFmpeg is free software; you can redistribute it and/or
9
 * modify it under the terms of the GNU Lesser General Public
10
 * License as published by the Free Software Foundation; either
11
 * version 2.1 of the License, or (at your option) any later version.
12
 *
13
 * FFmpeg is distributed in the hope that it will be useful,
14
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16
 * Lesser General Public License for more details.
17
 *
18
 * You should have received a copy of the GNU Lesser General Public
19
 * License along with FFmpeg; if not, write to the Free Software
20
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21
 */
22

    
23
#include "avcodec.h"
24
#include "libavutil/intreadwrite.h"
25
#include "bytestream.h"
26
#include "libavutil/lzo.h" // for av_memcpy_backptr
27

    
28
typedef struct DfaContext {
29
    AVFrame pic;
30

    
31
    uint32_t pal[256];
32
    uint8_t *frame_buf;
33
} DfaContext;
34

    
35
static av_cold int dfa_decode_init(AVCodecContext *avctx)
36
{
37
    DfaContext *s = avctx->priv_data;
38

    
39
    avctx->pix_fmt = PIX_FMT_PAL8;
40

    
41
    s->frame_buf = av_mallocz(avctx->width * avctx->height + AV_LZO_OUTPUT_PADDING);
42
    if (!s->frame_buf)
43
        return AVERROR(ENOMEM);
44

    
45
    return 0;
46
}
47

    
48
static int decode_copy(uint8_t *frame, int width, int height,
49
                       const uint8_t *src, const uint8_t *src_end)
50
{
51
    const int size = width * height;
52

    
53
    if (src_end - src < size)
54
        return -1;
55
    bytestream_get_buffer(&src, frame, size);
56
    return 0;
57
}
58

    
59
static int decode_tsw1(uint8_t *frame, int width, int height,
60
                       const uint8_t *src, const uint8_t *src_end)
61
{
62
    const uint8_t *frame_start = frame;
63
    const uint8_t *frame_end   = frame + width * height;
64
    int mask = 0x10000, bitbuf = 0;
65
    int v, count, segments;
66
    unsigned offset;
67

    
68
    segments = bytestream_get_le32(&src);
69
    offset   = bytestream_get_le32(&src);
70
    if (frame_end - frame <= offset)
71
        return -1;
72
    frame += offset;
73
    while (segments--) {
74
        if (mask == 0x10000) {
75
            if (src >= src_end)
76
                return -1;
77
            bitbuf = bytestream_get_le16(&src);
78
            mask = 1;
79
        }
80
        if (src_end - src < 2 || frame_end - frame < 2)
81
            return -1;
82
        if (bitbuf & mask) {
83
            v = bytestream_get_le16(&src);
84
            offset = (v & 0x1FFF) << 1;
85
            count = ((v >> 13) + 2) << 1;
86
            if (frame - frame_start < offset || frame_end - frame < count)
87
                return -1;
88
            av_memcpy_backptr(frame, offset, count);
89
            frame += count;
90
        } else {
91
            *frame++ = *src++;
92
            *frame++ = *src++;
93
        }
94
        mask <<= 1;
95
    }
96

    
97
    return 0;
98
}
99

    
100
static int decode_dsw1(uint8_t *frame, int width, int height,
101
                       const uint8_t *src, const uint8_t *src_end)
102
{
103
    const uint8_t *frame_start = frame;
104
    const uint8_t *frame_end   = frame + width * height;
105
    int mask = 0x10000, bitbuf = 0;
106
    int v, offset, count, segments;
107

    
108
    segments = bytestream_get_le16(&src);
109
    while (segments--) {
110
        if (mask == 0x10000) {
111
            if (src >= src_end)
112
                return -1;
113
            bitbuf = bytestream_get_le16(&src);
114
            mask = 1;
115
        }
116
        if (src_end - src < 2 || frame_end - frame < 2)
117
            return -1;
118
        if (bitbuf & mask) {
119
            v = bytestream_get_le16(&src);
120
            offset = (v & 0x1FFF) << 1;
121
            count = ((v >> 13) + 2) << 1;
122
            if (frame - frame_start < offset || frame_end - frame < count)
123
                return -1;
124
            // can't use av_memcpy_backptr() since it can overwrite following pixels
125
            for (v = 0; v < count; v++)
126
                frame[v] = frame[v - offset];
127
            frame += count;
128
        } else if (bitbuf & (mask << 1)) {
129
            frame += bytestream_get_le16(&src);
130
        } else {
131
            *frame++ = *src++;
132
            *frame++ = *src++;
133
        }
134
        mask <<= 2;
135
    }
136

    
137
    return 0;
138
}
139

    
140
static int decode_dds1(uint8_t *frame, int width, int height,
141
                       const uint8_t *src, const uint8_t *src_end)
142
{
143
    const uint8_t *frame_start = frame;
144
    const uint8_t *frame_end   = frame + width * height;
145
    int mask = 0x10000, bitbuf = 0;
146
    int i, v, offset, count, segments;
147

    
148
    segments = bytestream_get_le16(&src);
149
    while (segments--) {
150
        if (mask == 0x10000) {
151
            if (src >= src_end)
152
                return -1;
153
            bitbuf = bytestream_get_le16(&src);
154
            mask = 1;
155
        }
156
        if (src_end - src < 2 || frame_end - frame < 2)
157
            return -1;
158
        if (bitbuf & mask) {
159
            v = bytestream_get_le16(&src);
160
            offset = (v & 0x1FFF) << 2;
161
            count = ((v >> 13) + 2) << 1;
162
            if (frame - frame_start < offset || frame_end - frame < count*2 + width)
163
                return -1;
164
            for (i = 0; i < count; i++) {
165
                frame[0] = frame[1] =
166
                frame[width] = frame[width + 1] = frame[-offset];
167

    
168
                frame += 2;
169
            }
170
        } else if (bitbuf & (mask << 1)) {
171
            frame += bytestream_get_le16(&src) * 2;
172
        } else {
173
            frame[0] = frame[1] =
174
            frame[width] = frame[width + 1] =  *src++;
175
            frame += 2;
176
            frame[0] = frame[1] =
177
            frame[width] = frame[width + 1] =  *src++;
178
            frame += 2;
179
        }
180
        mask <<= 2;
181
    }
182

    
183
    return 0;
184
}
185

    
186
static int decode_bdlt(uint8_t *frame, int width, int height,
187
                       const uint8_t *src, const uint8_t *src_end)
188
{
189
    const uint8_t *frame_end = frame + width * height;
190
    uint8_t *line_ptr;
191
    int count, lines, segments;
192

    
193
    count = bytestream_get_le16(&src);
194
    if (count >= height)
195
        return -1;
196
    frame += width * count;
197
    lines = bytestream_get_le16(&src);
198
    if (count + lines > height || src >= src_end)
199
        return -1;
200

    
201
    while (lines--) {
202
        line_ptr = frame;
203
        frame += width;
204
        segments = *src++;
205
        while (segments--) {
206
            if (src_end - src < 3)
207
                return -1;
208
            if (frame - line_ptr <= *src)
209
                return -1;
210
            line_ptr += *src++;
211
            count = (int8_t)*src++;
212
            if (count >= 0) {
213
                if (frame - line_ptr < count || src_end - src < count)
214
                    return -1;
215
                bytestream_get_buffer(&src, line_ptr, count);
216
            } else {
217
                count = -count;
218
                if (frame - line_ptr < count || src >= src_end)
219
                    return -1;
220
                memset(line_ptr, *src++, count);
221
            }
222
            line_ptr += count;
223
        }
224
    }
225

    
226
    return 0;
227
}
228

    
229
static int decode_wdlt(uint8_t *frame, int width, int height,
230
                       const uint8_t *src, const uint8_t *src_end)
231
{
232
    const uint8_t *frame_end   = frame + width * height;
233
    uint8_t *line_ptr;
234
    int count, i, v, lines, segments;
235

    
236
    lines = bytestream_get_le16(&src);
237
    if (lines > height || src >= src_end)
238
        return -1;
239

    
240
    while (lines--) {
241
        segments = bytestream_get_le16(&src);
242
        while ((segments & 0xC000) == 0xC000) {
243
            unsigned delta = -((int16_t)segments * width);
244
            if (frame_end - frame <= delta)
245
                return -1;
246
            frame    += delta;
247
            segments = bytestream_get_le16(&src);
248
        }
249
        if (segments & 0x8000) {
250
            frame[width - 1] = segments & 0xFF;
251
            segments = bytestream_get_le16(&src);
252
        }
253
        line_ptr = frame;
254
        frame += width;
255
        while (segments--) {
256
            if (src_end - src < 2)
257
                return -1;
258
            if (frame - line_ptr <= *src)
259
                return -1;
260
            line_ptr += *src++;
261
            count = (int8_t)*src++;
262
            if (count >= 0) {
263
                if (frame - line_ptr < count*2 || src_end - src < count*2)
264
                    return -1;
265
                bytestream_get_buffer(&src, line_ptr, count*2);
266
                line_ptr += count * 2;
267
            } else {
268
                count = -count;
269
                if (frame - line_ptr < count*2 || src_end - src < 2)
270
                    return -1;
271
                v = bytestream_get_le16(&src);
272
                for (i = 0; i < count; i++)
273
                    bytestream_put_le16(&line_ptr, v);
274
            }
275
        }
276
    }
277

    
278
    return 0;
279
}
280

    
281
static int decode_unk6(uint8_t *frame, int width, int height,
282
                       const uint8_t *src, const uint8_t *src_end)
283
{
284
    return -1;
285
}
286

    
287
static int decode_blck(uint8_t *frame, int width, int height,
288
                       const uint8_t *src, const uint8_t *src_end)
289
{
290
    memset(frame, 0, width * height);
291
    return 0;
292
}
293

    
294

    
295
typedef int (*chunk_decoder)(uint8_t *frame, int width, int height,
296
                             const uint8_t *src, const uint8_t *src_end);
297

    
298
static const chunk_decoder decoder[8] = {
299
    decode_copy, decode_tsw1, decode_bdlt, decode_wdlt,
300
    decode_unk6, decode_dsw1, decode_blck, decode_dds1,
301
};
302

    
303
static const char* chunk_name[8] = {
304
    "COPY", "TSW1", "BDLT", "WDLT", "????", "DSW1", "BLCK", "DDS1"
305
};
306

    
307
static int dfa_decode_frame(AVCodecContext *avctx,
308
                            void *data, int *data_size,
309
                            AVPacket *avpkt)
310
{
311
    DfaContext *s = avctx->priv_data;
312
    const uint8_t *buf = avpkt->data;
313
    const uint8_t *buf_end = avpkt->data + avpkt->size;
314
    const uint8_t *tmp_buf;
315
    uint32_t chunk_type, chunk_size;
316
    uint8_t *dst;
317
    int ret;
318
    int i, pal_elems;
319

    
320
    if (s->pic.data[0])
321
        avctx->release_buffer(avctx, &s->pic);
322

    
323
    if ((ret = avctx->get_buffer(avctx, &s->pic))) {
324
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
325
        return ret;
326
    }
327

    
328
    while (buf < buf_end) {
329
        chunk_size = AV_RL32(buf + 4);
330
        chunk_type = AV_RL32(buf + 8);
331
        buf += 12;
332
        if (buf_end - buf < chunk_size) {
333
            av_log(avctx, AV_LOG_ERROR, "Chunk size is too big (%d bytes)\n", chunk_size);
334
            return -1;
335
        }
336
        if (!chunk_type)
337
            break;
338
        if (chunk_type == 1) {
339
            pal_elems = FFMIN(chunk_size / 3, 256);
340
            tmp_buf = buf;
341
            for (i = 0; i < pal_elems; i++) {
342
                s->pal[i] = bytestream_get_be24(&tmp_buf) << 2;
343
                s->pal[i] |= (s->pal[i] >> 6) & 0x333;
344
            }
345
            s->pic.palette_has_changed = 1;
346
        } else if (chunk_type <= 9) {
347
            if (decoder[chunk_type - 2](s->frame_buf, avctx->width, avctx->height,
348
                                        buf, buf + chunk_size)) {
349
                av_log(avctx, AV_LOG_ERROR, "Error decoding %s chunk\n",
350
                       chunk_name[chunk_type - 2]);
351
                return -1;
352
            }
353
        } else {
354
            av_log(avctx, AV_LOG_WARNING, "Ignoring unknown chunk type %d\n",
355
                   chunk_type);
356
        }
357
        buf += chunk_size;
358
    }
359

    
360
    buf = s->frame_buf;
361
    dst = s->pic.data[0];
362
    for (i = 0; i < avctx->height; i++) {
363
        memcpy(dst, buf, avctx->width);
364
        dst += s->pic.linesize[0];
365
        buf += avctx->width;
366
    }
367
    memcpy(s->pic.data[1], s->pal, sizeof(s->pal));
368

    
369
    *data_size = sizeof(AVFrame);
370
    *(AVFrame*)data = s->pic;
371

    
372
    return avpkt->size;
373
}
374

    
375
static av_cold int dfa_decode_end(AVCodecContext *avctx)
376
{
377
    DfaContext *s = avctx->priv_data;
378

    
379
    if (s->pic.data[0])
380
        avctx->release_buffer(avctx, &s->pic);
381

    
382
    av_freep(&s->frame_buf);
383

    
384
    return 0;
385
}
386

    
387
AVCodec ff_dfa_decoder = {
388
    "dfa",
389
    AVMEDIA_TYPE_VIDEO,
390
    CODEC_ID_DFA,
391
    sizeof(DfaContext),
392
    dfa_decode_init,
393
    NULL,
394
    dfa_decode_end,
395
    dfa_decode_frame,
396
    CODEC_CAP_DR1,
397
    .long_name = NULL_IF_CONFIG_SMALL("Chronomaster DFA"),
398
};