summaryrefslogtreecommitdiffstats
path: root/libavcodec/kmvc.c
blob: a476fac7ac048b333143aa721c70074b3c2b7c52 (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
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
/*
 * KMVC decoder
 * Copyright (c) 2006 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
 * Karl Morton's Video Codec decoder
 */

#include <stdio.h>
#include <stdlib.h>

#include "avcodec.h"
#include "bytestream.h"

#define KMVC_KEYFRAME 0x80
#define KMVC_PALETTE  0x40
#define KMVC_METHOD   0x0F
#define MAX_PALSIZE   256

/*
 * Decoder context
 */
typedef struct KmvcContext {
    AVCodecContext *avctx;
    AVFrame pic;

    int setpal;
    int palsize;
    uint32_t pal[MAX_PALSIZE];
    uint8_t *cur, *prev;
    uint8_t *frm0, *frm1;
    GetByteContext g;
} KmvcContext;

typedef struct BitBuf {
    int bits;
    int bitbuf;
} BitBuf;

#define BLK(data, x, y)  data[(x) + (y) * 320]

#define kmvc_init_getbits(bb, g)  bb.bits = 7; bb.bitbuf = bytestream2_get_byte(g);

#define kmvc_getbit(bb, g, res) {\
    res = 0; \
    if (bb.bitbuf & (1 << bb.bits)) res = 1; \
    bb.bits--; \
    if(bb.bits == -1) { \
        bb.bitbuf = bytestream2_get_byte(g); \
        bb.bits = 7; \
    } \
}

static int kmvc_decode_intra_8x8(KmvcContext * ctx, int w, int h)
{
    BitBuf bb;
    int res, val;
    int i, j;
    int bx, by;
    int l0x, l1x, l0y, l1y;
    int mx, my;

    kmvc_init_getbits(bb, &ctx->g);

    for (by = 0; by < h; by += 8)
        for (bx = 0; bx < w; bx += 8) {
            if (!bytestream2_get_bytes_left(&ctx->g)) {
                av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
                return AVERROR_INVALIDDATA;
            }
            kmvc_getbit(bb, &ctx->g, res);
            if (!res) {         // fill whole 8x8 block
                val = bytestream2_get_byte(&ctx->g);
                for (i = 0; i < 64; i++)
                    BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
            } else {            // handle four 4x4 subblocks
                for (i = 0; i < 4; i++) {
                    l0x = bx + (i & 1) * 4;
                    l0y = by + (i & 2) * 2;
                    kmvc_getbit(bb, &ctx->g, res);
                    if (!res) {
                        kmvc_getbit(bb, &ctx->g, res);
                        if (!res) {     // fill whole 4x4 block
                            val = bytestream2_get_byte(&ctx->g);
                            for (j = 0; j < 16; j++)
                                BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
                        } else {        // copy block from already decoded place
                            val = bytestream2_get_byte(&ctx->g);
                            mx = val & 0xF;
                            my = val >> 4;
                            if ((l0x-mx) + 320*(l0y-my) < 0 || (l0x-mx) + 320*(l0y-my) > 316*196) {
                                av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
                                return AVERROR_INVALIDDATA;
                            }
                            for (j = 0; j < 16; j++)
                                BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
                                    BLK(ctx->cur, l0x + (j & 3) - mx, l0y + (j >> 2) - my);
                        }
                    } else {    // descend to 2x2 sub-sub-blocks
                        for (j = 0; j < 4; j++) {
                            l1x = l0x + (j & 1) * 2;
                            l1y = l0y + (j & 2);
                            kmvc_getbit(bb, &ctx->g, res);
                            if (!res) {
                                kmvc_getbit(bb, &ctx->g, res);
                                if (!res) {     // fill whole 2x2 block
                                    val = bytestream2_get_byte(&ctx->g);
                                    BLK(ctx->cur, l1x, l1y) = val;
                                    BLK(ctx->cur, l1x + 1, l1y) = val;
                                    BLK(ctx->cur, l1x, l1y + 1) = val;
                                    BLK(ctx->cur, l1x + 1, l1y + 1) = val;
                                } else {        // copy block from already decoded place
                                    val = bytestream2_get_byte(&ctx->g);
                                    mx = val & 0xF;
                                    my = val >> 4;
                                    if ((l1x-mx) + 320*(l1y-my) < 0 || (l1x-mx) + 320*(l1y-my) > 318*198) {
                                        av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
                                        return AVERROR_INVALIDDATA;
                                    }
                                    BLK(ctx->cur, l1x, l1y) = BLK(ctx->cur, l1x - mx, l1y - my);
                                    BLK(ctx->cur, l1x + 1, l1y) =
                                        BLK(ctx->cur, l1x + 1 - mx, l1y - my);
                                    BLK(ctx->cur, l1x, l1y + 1) =
                                        BLK(ctx->cur, l1x - mx, l1y + 1 - my);
                                    BLK(ctx->cur, l1x + 1, l1y + 1) =
                                        BLK(ctx->cur, l1x + 1 - mx, l1y + 1 - my);
                                }
                            } else {    // read values for block
                                BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
                                BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
                                BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
                                BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
                            }
                        }
                    }
                }
            }
        }

    return 0;
}

static int kmvc_decode_inter_8x8(KmvcContext * ctx, int w, int h)
{
    BitBuf bb;
    int res, val;
    int i, j;
    int bx, by;
    int l0x, l1x, l0y, l1y;
    int mx, my;

    kmvc_init_getbits(bb, &ctx->g);

    for (by = 0; by < h; by += 8)
        for (bx = 0; bx < w; bx += 8) {
            kmvc_getbit(bb, &ctx->g, res);
            if (!res) {
                kmvc_getbit(bb, &ctx->g, res);
                if (!res) {     // fill whole 8x8 block
                    if (!bytestream2_get_bytes_left(&ctx->g)) {
                        av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
                        return AVERROR_INVALIDDATA;
                    }
                    val = bytestream2_get_byte(&ctx->g);
                    for (i = 0; i < 64; i++)
                        BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
                } else {        // copy block from previous frame
                    for (i = 0; i < 64; i++)
                        BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) =
                            BLK(ctx->prev, bx + (i & 0x7), by + (i >> 3));
                }
            } else {            // handle four 4x4 subblocks
                if (!bytestream2_get_bytes_left(&ctx->g)) {
                    av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
                    return AVERROR_INVALIDDATA;
                }
                for (i = 0; i < 4; i++) {
                    l0x = bx + (i & 1) * 4;
                    l0y = by + (i & 2) * 2;
                    kmvc_getbit(bb, &ctx->g, res);
                    if (!res) {
                        kmvc_getbit(bb, &ctx->g, res);
                        if (!res) {     // fill whole 4x4 block
                            val = bytestream2_get_byte(&ctx->g);
                            for (j = 0; j < 16; j++)
                                BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
                        } else {        // copy block
                            val = bytestream2_get_byte(&ctx->g);
                            mx = (val & 0xF) - 8;
                            my = (val >> 4) - 8;
                            if ((l0x+mx) + 320*(l0y+my) < 0 || (l0x+mx) + 320*(l0y+my) > 318*198) {
                                av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
                                return AVERROR_INVALIDDATA;
                            }
                            for (j = 0; j < 16; j++)
                                BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
                                    BLK(ctx->prev, l0x + (j & 3) + mx, l0y + (j >> 2) + my);
                        }
                    } else {    // descend to 2x2 sub-sub-blocks
                        for (j = 0; j < 4; j++) {
                            l1x = l0x + (j & 1) * 2;
                            l1y = l0y + (j & 2);
                            kmvc_getbit(bb, &ctx->g, res);
                            if (!res) {
                                kmvc_getbit(bb, &ctx->g, res);
                                if (!res) {     // fill whole 2x2 block
                                    val = bytestream2_get_byte(&ctx->g);
                                    BLK(ctx->cur, l1x, l1y) = val;
                                    BLK(ctx->cur, l1x + 1, l1y) = val;
                                    BLK(ctx->cur, l1x, l1y + 1) = val;
                                    BLK(ctx->cur, l1x + 1, l1y + 1) = val;
                                } else {        // copy block
                                    val = bytestream2_get_byte(&ctx->g);
                                    mx = (val & 0xF) - 8;
                                    my = (val >> 4) - 8;
                                    if ((l1x+mx) + 320*(l1y+my) < 0 || (l1x+mx) + 320*(l1y+my) > 318*198) {
                                        av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
                                        return AVERROR_INVALIDDATA;
                                    }
                                    BLK(ctx->cur, l1x, l1y) = BLK(ctx->prev, l1x + mx, l1y + my);
                                    BLK(ctx->cur, l1x + 1, l1y) =
                                        BLK(ctx->prev, l1x + 1 + mx, l1y + my);
                                    BLK(ctx->cur, l1x, l1y + 1) =
                                        BLK(ctx->prev, l1x + mx, l1y + 1 + my);
                                    BLK(ctx->cur, l1x + 1, l1y + 1) =
                                        BLK(ctx->prev, l1x + 1 + mx, l1y + 1 + my);
                                }
                            } else {    // read values for block
                                BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
                                BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
                                BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
                                BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
                            }
                        }
                    }
                }
            }
        }

    return 0;
}

static int decode_frame(AVCodecContext * avctx, void *data, int *data_size, AVPacket *avpkt)
{
    KmvcContext *const ctx = avctx->priv_data;
    uint8_t *out, *src;
    int i;
    int header;
    int blocksize;
    const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);

    bytestream2_init(&ctx->g, avpkt->data, avpkt->size);
    if (ctx->pic.data[0])
        avctx->release_buffer(avctx, &ctx->pic);

    ctx->pic.reference = 3;
    ctx->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
    if (avctx->get_buffer(avctx, &ctx->pic) < 0) {
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return -1;
    }

    header = bytestream2_get_byte(&ctx->g);

    /* blocksize 127 is really palette change event */
    if (bytestream2_peek_byte(&ctx->g) == 127) {
        bytestream2_skip(&ctx->g, 3);
        for (i = 0; i < 127; i++) {
            ctx->pal[i + (header & 0x81)] = 0xFFU << 24 | bytestream2_get_be24(&ctx->g);
            bytestream2_skip(&ctx->g, 1);
        }
        bytestream2_seek(&ctx->g, -127 * 4 - 3, SEEK_CUR);
    }

    if (header & KMVC_KEYFRAME) {
        ctx->pic.key_frame = 1;
        ctx->pic.pict_type = AV_PICTURE_TYPE_I;
    } else {
        ctx->pic.key_frame = 0;
        ctx->pic.pict_type = AV_PICTURE_TYPE_P;
    }

    if (header & KMVC_PALETTE) {
        ctx->pic.palette_has_changed = 1;
        // palette starts from index 1 and has 127 entries
        for (i = 1; i <= ctx->palsize; i++) {
            ctx->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&ctx->g);
        }
    }

    if (pal) {
        ctx->pic.palette_has_changed = 1;
        memcpy(ctx->pal, pal, AVPALETTE_SIZE);
    }

    if (ctx->setpal) {
        ctx->setpal = 0;
        ctx->pic.palette_has_changed = 1;
    }

    /* make the palette available on the way out */
    memcpy(ctx->pic.data[1], ctx->pal, 1024);

    blocksize = bytestream2_get_byte(&ctx->g);

    if (blocksize != 8 && blocksize != 127) {
        av_log(avctx, AV_LOG_ERROR, "Block size = %i\n", blocksize);
        return -1;
    }
    memset(ctx->cur, 0, 320 * 200);
    switch (header & KMVC_METHOD) {
    case 0:
    case 1: // used in palette changed event
        memcpy(ctx->cur, ctx->prev, 320 * 200);
        break;
    case 3:
        kmvc_decode_intra_8x8(ctx, avctx->width, avctx->height);
        break;
    case 4:
        kmvc_decode_inter_8x8(ctx, avctx->width, avctx->height);
        break;
    default:
        av_log(avctx, AV_LOG_ERROR, "Unknown compression method %i\n", header & KMVC_METHOD);
        return -1;
    }

    out = ctx->pic.data[0];
    src = ctx->cur;
    for (i = 0; i < avctx->height; i++) {
        memcpy(out, src, avctx->width);
        src += 320;
        out += ctx->pic.linesize[0];
    }

    /* flip buffers */
    if (ctx->cur == ctx->frm0) {
        ctx->cur = ctx->frm1;
        ctx->prev = ctx->frm0;
    } else {
        ctx->cur = ctx->frm0;
        ctx->prev = ctx->frm1;
    }

    *data_size = sizeof(AVFrame);
    *(AVFrame *) data = ctx->pic;

    /* always report that the buffer was completely consumed */
    return avpkt->size;
}



/*
 * Init kmvc decoder
 */
static av_cold int decode_init(AVCodecContext * avctx)
{
    KmvcContext *const c = avctx->priv_data;
    int i;

    c->avctx = avctx;

    if (avctx->width > 320 || avctx->height > 200) {
        av_log(avctx, AV_LOG_ERROR, "KMVC supports frames <= 320x200\n");
        return -1;
    }

    c->frm0 = av_mallocz(320 * 200);
    c->frm1 = av_mallocz(320 * 200);
    c->cur = c->frm0;
    c->prev = c->frm1;

    for (i = 0; i < 256; i++) {
        c->pal[i] = 0xFF << 24 | i * 0x10101;
    }

    if (avctx->extradata_size < 12) {
        av_log(avctx, AV_LOG_WARNING,
               "Extradata missing, decoding may not work properly...\n");
        c->palsize = 127;
    } else {
        c->palsize = AV_RL16(avctx->extradata + 10);
        if (c->palsize >= (unsigned)MAX_PALSIZE) {
            c->palsize = 127;
            av_log(avctx, AV_LOG_ERROR, "KMVC palette too large\n");
            return AVERROR_INVALIDDATA;
        }
    }

    if (avctx->extradata_size == 1036) {        // palette in extradata
        uint8_t *src = avctx->extradata + 12;
        for (i = 0; i < 256; i++) {
            c->pal[i] = AV_RL32(src);
            src += 4;
        }
        c->setpal = 1;
    }

    avcodec_get_frame_defaults(&c->pic);
    avctx->pix_fmt = PIX_FMT_PAL8;

    return 0;
}



/*
 * Uninit kmvc decoder
 */
static av_cold int decode_end(AVCodecContext * avctx)
{
    KmvcContext *const c = avctx->priv_data;

    av_freep(&c->frm0);
    av_freep(&c->frm1);
    if (c->pic.data[0])
        avctx->release_buffer(avctx, &c->pic);

    return 0;
}

AVCodec ff_kmvc_decoder = {
    .name           = "kmvc",
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = CODEC_ID_KMVC,
    .priv_data_size = sizeof(KmvcContext),
    .init           = decode_init,
    .close          = decode_end,
    .decode         = decode_frame,
    .capabilities   = CODEC_CAP_DR1,
    .long_name      = NULL_IF_CONFIG_SMALL("Karl Morton's video codec"),
};
OpenPOWER on IntegriCloud