1 /*
2 * KMVC decoder
3 * Copyright (c) 2006 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
24 * Karl Morton's Video Codec decoder
25 */
26
27 #include <stdio.h>
28 #include <stdlib.h>
29
30 #include "avcodec.h"
31 #include "bytestream.h"
32 #include "internal.h"
33 #include "libavutil/common.h"
34
35 #define KMVC_KEYFRAME 0x80
36 #define KMVC_PALETTE 0x40
37 #define KMVC_METHOD 0x0F
38 #define MAX_PALSIZE 256
39
40 /*
41 * Decoder context
42 */
43 typedef struct KmvcContext {
44 AVCodecContext *avctx;
45
46 int setpal;
47 int palsize;
48 uint32_t pal[MAX_PALSIZE];
49 uint8_t *cur, *prev;
50 uint8_t frm0[320 * 200], frm1[320 * 200];
51 GetByteContext g;
52 } KmvcContext;
53
54 typedef struct BitBuf {
55 int bits;
56 int bitbuf;
57 } BitBuf;
58
59 #define BLK(data, x, y) data[av_clip((x) + (y) * 320, 0, 320 * 200 -1)]
60
61 #define kmvc_init_getbits(bb, g) bb.bits = 7; bb.bitbuf = bytestream2_get_byte(g);
62
63 #define kmvc_getbit(bb, g, res) {\
64 res = 0; \
65 if (bb.bitbuf & (1 << bb.bits)) res = 1; \
66 bb.bits--; \
67 if(bb.bits == -1) { \
68 bb.bitbuf = bytestream2_get_byte(g); \
69 bb.bits = 7; \
70 } \
71 }
72
kmvc_decode_intra_8x8(KmvcContext * ctx,int w,int h)73 static int kmvc_decode_intra_8x8(KmvcContext * ctx, int w, int h)
74 {
75 BitBuf bb;
76 int res, val;
77 int i, j;
78 int bx, by;
79 int l0x, l1x, l0y, l1y;
80 int mx, my;
81
82 kmvc_init_getbits(bb, &ctx->g);
83
84 for (by = 0; by < h; by += 8)
85 for (bx = 0; bx < w; bx += 8) {
86 if (!bytestream2_get_bytes_left(&ctx->g)) {
87 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
88 return AVERROR_INVALIDDATA;
89 }
90 kmvc_getbit(bb, &ctx->g, res);
91 if (!res) { // fill whole 8x8 block
92 val = bytestream2_get_byte(&ctx->g);
93 for (i = 0; i < 64; i++)
94 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
95 } else { // handle four 4x4 subblocks
96 for (i = 0; i < 4; i++) {
97 l0x = bx + (i & 1) * 4;
98 l0y = by + (i & 2) * 2;
99 kmvc_getbit(bb, &ctx->g, res);
100 if (!res) {
101 kmvc_getbit(bb, &ctx->g, res);
102 if (!res) { // fill whole 4x4 block
103 val = bytestream2_get_byte(&ctx->g);
104 for (j = 0; j < 16; j++)
105 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
106 } else { // copy block from already decoded place
107 val = bytestream2_get_byte(&ctx->g);
108 mx = val & 0xF;
109 my = val >> 4;
110 if ((l0x-mx) + 320*(l0y-my) < 0 || (l0x-mx) + 320*(l0y-my) > 320*197 - 4) {
111 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
112 return AVERROR_INVALIDDATA;
113 }
114 for (j = 0; j < 16; j++)
115 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
116 BLK(ctx->cur, l0x + (j & 3) - mx, l0y + (j >> 2) - my);
117 }
118 } else { // descend to 2x2 sub-sub-blocks
119 for (j = 0; j < 4; j++) {
120 l1x = l0x + (j & 1) * 2;
121 l1y = l0y + (j & 2);
122 kmvc_getbit(bb, &ctx->g, res);
123 if (!res) {
124 kmvc_getbit(bb, &ctx->g, res);
125 if (!res) { // fill whole 2x2 block
126 val = bytestream2_get_byte(&ctx->g);
127 BLK(ctx->cur, l1x, l1y) = val;
128 BLK(ctx->cur, l1x + 1, l1y) = val;
129 BLK(ctx->cur, l1x, l1y + 1) = val;
130 BLK(ctx->cur, l1x + 1, l1y + 1) = val;
131 } else { // copy block from already decoded place
132 val = bytestream2_get_byte(&ctx->g);
133 mx = val & 0xF;
134 my = val >> 4;
135 if ((l1x-mx) + 320*(l1y-my) < 0 || (l1x-mx) + 320*(l1y-my) > 320*199 - 2) {
136 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
137 return AVERROR_INVALIDDATA;
138 }
139 BLK(ctx->cur, l1x, l1y) = BLK(ctx->cur, l1x - mx, l1y - my);
140 BLK(ctx->cur, l1x + 1, l1y) =
141 BLK(ctx->cur, l1x + 1 - mx, l1y - my);
142 BLK(ctx->cur, l1x, l1y + 1) =
143 BLK(ctx->cur, l1x - mx, l1y + 1 - my);
144 BLK(ctx->cur, l1x + 1, l1y + 1) =
145 BLK(ctx->cur, l1x + 1 - mx, l1y + 1 - my);
146 }
147 } else { // read values for block
148 BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
149 BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
150 BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
151 BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
152 }
153 }
154 }
155 }
156 }
157 }
158
159 return 0;
160 }
161
kmvc_decode_inter_8x8(KmvcContext * ctx,int w,int h)162 static int kmvc_decode_inter_8x8(KmvcContext * ctx, int w, int h)
163 {
164 BitBuf bb;
165 int res, val;
166 int i, j;
167 int bx, by;
168 int l0x, l1x, l0y, l1y;
169 int mx, my;
170
171 kmvc_init_getbits(bb, &ctx->g);
172
173 for (by = 0; by < h; by += 8)
174 for (bx = 0; bx < w; bx += 8) {
175 kmvc_getbit(bb, &ctx->g, res);
176 if (!res) {
177 kmvc_getbit(bb, &ctx->g, res);
178 if (!res) { // fill whole 8x8 block
179 if (!bytestream2_get_bytes_left(&ctx->g)) {
180 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
181 return AVERROR_INVALIDDATA;
182 }
183 val = bytestream2_get_byte(&ctx->g);
184 for (i = 0; i < 64; i++)
185 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
186 } else { // copy block from previous frame
187 for (i = 0; i < 64; i++)
188 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) =
189 BLK(ctx->prev, bx + (i & 0x7), by + (i >> 3));
190 }
191 } else { // handle four 4x4 subblocks
192 if (!bytestream2_get_bytes_left(&ctx->g)) {
193 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
194 return AVERROR_INVALIDDATA;
195 }
196 for (i = 0; i < 4; i++) {
197 l0x = bx + (i & 1) * 4;
198 l0y = by + (i & 2) * 2;
199 kmvc_getbit(bb, &ctx->g, res);
200 if (!res) {
201 kmvc_getbit(bb, &ctx->g, res);
202 if (!res) { // fill whole 4x4 block
203 val = bytestream2_get_byte(&ctx->g);
204 for (j = 0; j < 16; j++)
205 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
206 } else { // copy block
207 val = bytestream2_get_byte(&ctx->g);
208 mx = (val & 0xF) - 8;
209 my = (val >> 4) - 8;
210 if ((l0x+mx) + 320*(l0y+my) < 0 || (l0x+mx) + 320*(l0y+my) > 320*197 - 4) {
211 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
212 return AVERROR_INVALIDDATA;
213 }
214 for (j = 0; j < 16; j++)
215 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
216 BLK(ctx->prev, l0x + (j & 3) + mx, l0y + (j >> 2) + my);
217 }
218 } else { // descend to 2x2 sub-sub-blocks
219 for (j = 0; j < 4; j++) {
220 l1x = l0x + (j & 1) * 2;
221 l1y = l0y + (j & 2);
222 kmvc_getbit(bb, &ctx->g, res);
223 if (!res) {
224 kmvc_getbit(bb, &ctx->g, res);
225 if (!res) { // fill whole 2x2 block
226 val = bytestream2_get_byte(&ctx->g);
227 BLK(ctx->cur, l1x, l1y) = val;
228 BLK(ctx->cur, l1x + 1, l1y) = val;
229 BLK(ctx->cur, l1x, l1y + 1) = val;
230 BLK(ctx->cur, l1x + 1, l1y + 1) = val;
231 } else { // copy block
232 val = bytestream2_get_byte(&ctx->g);
233 mx = (val & 0xF) - 8;
234 my = (val >> 4) - 8;
235 if ((l1x+mx) + 320*(l1y+my) < 0 || (l1x+mx) + 320*(l1y+my) > 320*199 - 2) {
236 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
237 return AVERROR_INVALIDDATA;
238 }
239 BLK(ctx->cur, l1x, l1y) = BLK(ctx->prev, l1x + mx, l1y + my);
240 BLK(ctx->cur, l1x + 1, l1y) =
241 BLK(ctx->prev, l1x + 1 + mx, l1y + my);
242 BLK(ctx->cur, l1x, l1y + 1) =
243 BLK(ctx->prev, l1x + mx, l1y + 1 + my);
244 BLK(ctx->cur, l1x + 1, l1y + 1) =
245 BLK(ctx->prev, l1x + 1 + mx, l1y + 1 + my);
246 }
247 } else { // read values for block
248 BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
249 BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
250 BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
251 BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
252 }
253 }
254 }
255 }
256 }
257 }
258
259 return 0;
260 }
261
decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)262 static int decode_frame(AVCodecContext * avctx, void *data, int *got_frame,
263 AVPacket *avpkt)
264 {
265 KmvcContext *const ctx = avctx->priv_data;
266 AVFrame *frame = data;
267 uint8_t *out, *src;
268 int i, ret;
269 int header;
270 int blocksize;
271 buffer_size_t pal_size;
272 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, &pal_size);
273
274 bytestream2_init(&ctx->g, avpkt->data, avpkt->size);
275
276 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
277 return ret;
278
279 header = bytestream2_get_byte(&ctx->g);
280
281 /* blocksize 127 is really palette change event */
282 if (bytestream2_peek_byte(&ctx->g) == 127) {
283 bytestream2_skip(&ctx->g, 3);
284 for (i = 0; i < 127; i++) {
285 ctx->pal[i + (header & 0x81)] = 0xFFU << 24 | bytestream2_get_be24(&ctx->g);
286 bytestream2_skip(&ctx->g, 1);
287 }
288 bytestream2_seek(&ctx->g, -127 * 4 - 3, SEEK_CUR);
289 }
290
291 if (header & KMVC_KEYFRAME) {
292 frame->key_frame = 1;
293 frame->pict_type = AV_PICTURE_TYPE_I;
294 } else {
295 frame->key_frame = 0;
296 frame->pict_type = AV_PICTURE_TYPE_P;
297 }
298
299 if (header & KMVC_PALETTE) {
300 frame->palette_has_changed = 1;
301 // palette starts from index 1 and has 127 entries
302 for (i = 1; i <= ctx->palsize; i++) {
303 ctx->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&ctx->g);
304 }
305 }
306
307 if (pal && pal_size == AVPALETTE_SIZE) {
308 frame->palette_has_changed = 1;
309 memcpy(ctx->pal, pal, AVPALETTE_SIZE);
310 } else if (pal) {
311 av_log(avctx, AV_LOG_ERROR, "Palette size %d is wrong\n", pal_size);
312 }
313
314 if (ctx->setpal) {
315 ctx->setpal = 0;
316 frame->palette_has_changed = 1;
317 }
318
319 /* make the palette available on the way out */
320 memcpy(frame->data[1], ctx->pal, 1024);
321
322 blocksize = bytestream2_get_byte(&ctx->g);
323
324 if (blocksize != 8 && blocksize != 127) {
325 av_log(avctx, AV_LOG_ERROR, "Block size = %i\n", blocksize);
326 return AVERROR_INVALIDDATA;
327 }
328 memset(ctx->cur, 0, 320 * 200);
329 switch (header & KMVC_METHOD) {
330 case 0:
331 case 1: // used in palette changed event
332 memcpy(ctx->cur, ctx->prev, 320 * 200);
333 break;
334 case 3:
335 kmvc_decode_intra_8x8(ctx, avctx->width, avctx->height);
336 break;
337 case 4:
338 kmvc_decode_inter_8x8(ctx, avctx->width, avctx->height);
339 break;
340 default:
341 av_log(avctx, AV_LOG_ERROR, "Unknown compression method %i\n", header & KMVC_METHOD);
342 return AVERROR_INVALIDDATA;
343 }
344
345 out = frame->data[0];
346 src = ctx->cur;
347 for (i = 0; i < avctx->height; i++) {
348 memcpy(out, src, avctx->width);
349 src += 320;
350 out += frame->linesize[0];
351 }
352
353 /* flip buffers */
354 if (ctx->cur == ctx->frm0) {
355 ctx->cur = ctx->frm1;
356 ctx->prev = ctx->frm0;
357 } else {
358 ctx->cur = ctx->frm0;
359 ctx->prev = ctx->frm1;
360 }
361
362 *got_frame = 1;
363
364 /* always report that the buffer was completely consumed */
365 return avpkt->size;
366 }
367
368
369
370 /*
371 * Init kmvc decoder
372 */
decode_init(AVCodecContext * avctx)373 static av_cold int decode_init(AVCodecContext * avctx)
374 {
375 KmvcContext *const c = avctx->priv_data;
376 int i;
377
378 c->avctx = avctx;
379
380 if (avctx->width > 320 || avctx->height > 200) {
381 av_log(avctx, AV_LOG_ERROR, "KMVC supports frames <= 320x200\n");
382 return AVERROR(EINVAL);
383 }
384
385 c->cur = c->frm0;
386 c->prev = c->frm1;
387
388 for (i = 0; i < 256; i++) {
389 c->pal[i] = 0xFFU << 24 | i * 0x10101;
390 }
391
392 if (avctx->extradata_size < 12) {
393 av_log(avctx, AV_LOG_WARNING,
394 "Extradata missing, decoding may not work properly...\n");
395 c->palsize = 127;
396 } else {
397 c->palsize = AV_RL16(avctx->extradata + 10);
398 if (c->palsize >= (unsigned)MAX_PALSIZE) {
399 c->palsize = 127;
400 av_log(avctx, AV_LOG_ERROR, "KMVC palette too large\n");
401 return AVERROR_INVALIDDATA;
402 }
403 }
404
405 if (avctx->extradata_size == 1036) { // palette in extradata
406 uint8_t *src = avctx->extradata + 12;
407 for (i = 0; i < 256; i++) {
408 c->pal[i] = AV_RL32(src);
409 src += 4;
410 }
411 c->setpal = 1;
412 }
413
414 avctx->pix_fmt = AV_PIX_FMT_PAL8;
415
416 return 0;
417 }
418
419 AVCodec ff_kmvc_decoder = {
420 .name = "kmvc",
421 .long_name = NULL_IF_CONFIG_SMALL("Karl Morton's video codec"),
422 .type = AVMEDIA_TYPE_VIDEO,
423 .id = AV_CODEC_ID_KMVC,
424 .priv_data_size = sizeof(KmvcContext),
425 .init = decode_init,
426 .decode = decode_frame,
427 .capabilities = AV_CODEC_CAP_DR1,
428 };
429