FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/kmvc.c
Date: 2022-07-04 19:11:22
Exec Total Coverage
Lines: 123 209 58.9%
Branches: 90 156 57.7%

Line Branch Exec Source
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 "codec_internal.h"
33 #include "decode.h"
34 #include "internal.h"
35 #include "libavutil/common.h"
36
37 #define KMVC_KEYFRAME 0x80
38 #define KMVC_PALETTE 0x40
39 #define KMVC_METHOD 0x0F
40 #define MAX_PALSIZE 256
41
42 /*
43 * Decoder context
44 */
45 typedef struct KmvcContext {
46 AVCodecContext *avctx;
47
48 GetByteContext g;
49 uint8_t *cur, *prev;
50 int setpal;
51 int palsize;
52 uint32_t pal[MAX_PALSIZE];
53 uint8_t frm0[320 * 200], frm1[320 * 200];
54 } KmvcContext;
55
56 typedef struct BitBuf {
57 int bits;
58 int bitbuf;
59 } BitBuf;
60
61 #define BLK(data, x, y) data[av_clip((x) + (y) * 320, 0, 320 * 200 -1)]
62
63 #define kmvc_init_getbits(bb, g) bb.bits = 7; bb.bitbuf = bytestream2_get_byte(g);
64
65 #define kmvc_getbit(bb, g, res) {\
66 res = 0; \
67 if (bb.bitbuf & (1 << bb.bits)) res = 1; \
68 bb.bits--; \
69 if(bb.bits == -1) { \
70 bb.bitbuf = bytestream2_get_byte(g); \
71 bb.bits = 7; \
72 } \
73 }
74
75 1 static int kmvc_decode_intra_8x8(KmvcContext * ctx, int w, int h)
76 {
77 BitBuf bb;
78 int res, val;
79 int i, j;
80 int bx, by;
81 int l0x, l1x, l0y, l1y;
82 int mx, my;
83
84 1 kmvc_init_getbits(bb, &ctx->g);
85
86
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21 for (by = 0; by < h; by += 8)
87
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820 for (bx = 0; bx < w; bx += 8) {
88
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800 if (!bytestream2_get_bytes_left(&ctx->g)) {
89 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
90 return AVERROR_INVALIDDATA;
91 }
92
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800 kmvc_getbit(bb, &ctx->g, res);
93
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800 if (!res) { // fill whole 8x8 block
94 800 val = bytestream2_get_byte(&ctx->g);
95
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52000 for (i = 0; i < 64; i++)
96 51200 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
97 } else { // handle four 4x4 subblocks
98 for (i = 0; i < 4; i++) {
99 l0x = bx + (i & 1) * 4;
100 l0y = by + (i & 2) * 2;
101 kmvc_getbit(bb, &ctx->g, res);
102 if (!res) {
103 kmvc_getbit(bb, &ctx->g, res);
104 if (!res) { // fill whole 4x4 block
105 val = bytestream2_get_byte(&ctx->g);
106 for (j = 0; j < 16; j++)
107 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
108 } else { // copy block from already decoded place
109 val = bytestream2_get_byte(&ctx->g);
110 mx = val & 0xF;
111 my = val >> 4;
112 if ((l0x-mx) + 320*(l0y-my) < 0 || (l0x-mx) + 320*(l0y-my) > 320*197 - 4) {
113 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
114 return AVERROR_INVALIDDATA;
115 }
116 for (j = 0; j < 16; j++)
117 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
118 BLK(ctx->cur, l0x + (j & 3) - mx, l0y + (j >> 2) - my);
119 }
120 } else { // descend to 2x2 sub-sub-blocks
121 for (j = 0; j < 4; j++) {
122 l1x = l0x + (j & 1) * 2;
123 l1y = l0y + (j & 2);
124 kmvc_getbit(bb, &ctx->g, res);
125 if (!res) {
126 kmvc_getbit(bb, &ctx->g, res);
127 if (!res) { // fill whole 2x2 block
128 val = bytestream2_get_byte(&ctx->g);
129 BLK(ctx->cur, l1x, l1y) = val;
130 BLK(ctx->cur, l1x + 1, l1y) = val;
131 BLK(ctx->cur, l1x, l1y + 1) = val;
132 BLK(ctx->cur, l1x + 1, l1y + 1) = val;
133 } else { // copy block from already decoded place
134 val = bytestream2_get_byte(&ctx->g);
135 mx = val & 0xF;
136 my = val >> 4;
137 if ((l1x-mx) + 320*(l1y-my) < 0 || (l1x-mx) + 320*(l1y-my) > 320*199 - 2) {
138 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
139 return AVERROR_INVALIDDATA;
140 }
141 BLK(ctx->cur, l1x, l1y) = BLK(ctx->cur, l1x - mx, l1y - my);
142 BLK(ctx->cur, l1x + 1, l1y) =
143 BLK(ctx->cur, l1x + 1 - mx, l1y - my);
144 BLK(ctx->cur, l1x, l1y + 1) =
145 BLK(ctx->cur, l1x - mx, l1y + 1 - my);
146 BLK(ctx->cur, l1x + 1, l1y + 1) =
147 BLK(ctx->cur, l1x + 1 - mx, l1y + 1 - my);
148 }
149 } else { // read values for block
150 BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
151 BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
152 BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
153 BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
154 }
155 }
156 }
157 }
158 }
159 }
160
161 1 return 0;
162 }
163
164 75 static int kmvc_decode_inter_8x8(KmvcContext * ctx, int w, int h)
165 {
166 BitBuf bb;
167 int res, val;
168 int i, j;
169 int bx, by;
170 int l0x, l1x, l0y, l1y;
171 int mx, my;
172
173 75 kmvc_init_getbits(bb, &ctx->g);
174
175
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1575 for (by = 0; by < h; by += 8)
176
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61500 for (bx = 0; bx < w; bx += 8) {
177
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60000 kmvc_getbit(bb, &ctx->g, res);
178
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60000 if (!res) {
179
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40230 kmvc_getbit(bb, &ctx->g, res);
180
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40230 if (!res) { // fill whole 8x8 block
181
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39003 if (!bytestream2_get_bytes_left(&ctx->g)) {
182 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
183 return AVERROR_INVALIDDATA;
184 }
185 39003 val = bytestream2_get_byte(&ctx->g);
186
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2535195 for (i = 0; i < 64; i++)
187 2496192 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
188 } else { // copy block from previous frame
189
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79755 for (i = 0; i < 64; i++)
190 78528 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) =
191 78528 BLK(ctx->prev, bx + (i & 0x7), by + (i >> 3));
192 }
193 } else { // handle four 4x4 subblocks
194
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19770 if (!bytestream2_get_bytes_left(&ctx->g)) {
195 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
196 return AVERROR_INVALIDDATA;
197 }
198
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98850 for (i = 0; i < 4; i++) {
199 79080 l0x = bx + (i & 1) * 4;
200 79080 l0y = by + (i & 2) * 2;
201
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79080 kmvc_getbit(bb, &ctx->g, res);
202
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79080 if (!res) {
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15620 kmvc_getbit(bb, &ctx->g, res);
204
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15620 if (!res) { // fill whole 4x4 block
205 6017 val = bytestream2_get_byte(&ctx->g);
206
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102289 for (j = 0; j < 16; j++)
207 96272 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
208 } else { // copy block
209 9603 val = bytestream2_get_byte(&ctx->g);
210 9603 mx = (val & 0xF) - 8;
211 9603 my = (val >> 4) - 8;
212
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9603 if ((l0x+mx) + 320*(l0y+my) < 0 || (l0x+mx) + 320*(l0y+my) > 320*197 - 4) {
213 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
214 return AVERROR_INVALIDDATA;
215 }
216
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163251 for (j = 0; j < 16; j++)
217 153648 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
218 153648 BLK(ctx->prev, l0x + (j & 3) + mx, l0y + (j >> 2) + my);
219 }
220 } else { // descend to 2x2 sub-sub-blocks
221
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317300 for (j = 0; j < 4; j++) {
222 253840 l1x = l0x + (j & 1) * 2;
223 253840 l1y = l0y + (j & 2);
224
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253840 kmvc_getbit(bb, &ctx->g, res);
225
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253840 if (!res) {
226
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126609 kmvc_getbit(bb, &ctx->g, res);
227
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126609 if (!res) { // fill whole 2x2 block
228 21343 val = bytestream2_get_byte(&ctx->g);
229 21343 BLK(ctx->cur, l1x, l1y) = val;
230 21343 BLK(ctx->cur, l1x + 1, l1y) = val;
231 21343 BLK(ctx->cur, l1x, l1y + 1) = val;
232 21343 BLK(ctx->cur, l1x + 1, l1y + 1) = val;
233 } else { // copy block
234 105266 val = bytestream2_get_byte(&ctx->g);
235 105266 mx = (val & 0xF) - 8;
236 105266 my = (val >> 4) - 8;
237
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105266 if ((l1x+mx) + 320*(l1y+my) < 0 || (l1x+mx) + 320*(l1y+my) > 320*199 - 2) {
238 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
239 return AVERROR_INVALIDDATA;
240 }
241 105266 BLK(ctx->cur, l1x, l1y) = BLK(ctx->prev, l1x + mx, l1y + my);
242 105266 BLK(ctx->cur, l1x + 1, l1y) =
243 105266 BLK(ctx->prev, l1x + 1 + mx, l1y + my);
244 105266 BLK(ctx->cur, l1x, l1y + 1) =
245 105266 BLK(ctx->prev, l1x + mx, l1y + 1 + my);
246 105266 BLK(ctx->cur, l1x + 1, l1y + 1) =
247 105266 BLK(ctx->prev, l1x + 1 + mx, l1y + 1 + my);
248 }
249 } else { // read values for block
250 127231 BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
251 127231 BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
252 127231 BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
253 127231 BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
254 }
255 }
256 }
257 }
258 }
259 }
260
261 75 return 0;
262 }
263
264 76 static int decode_frame(AVCodecContext * avctx, AVFrame *frame,
265 int *got_frame, AVPacket *avpkt)
266 {
267 76 KmvcContext *const ctx = avctx->priv_data;
268 uint8_t *out, *src;
269 int i, ret;
270 int header;
271 int blocksize;
272
273 76 bytestream2_init(&ctx->g, avpkt->data, avpkt->size);
274
275
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76 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
276 return ret;
277
278 76 frame->palette_has_changed = ff_copy_palette(ctx->pal, avpkt, avctx);
279
280 76 header = bytestream2_get_byte(&ctx->g);
281
282 /* blocksize 127 is really palette change event */
283
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76 if (bytestream2_peek_byte(&ctx->g) == 127) {
284 bytestream2_skip(&ctx->g, 3);
285 for (i = 0; i < 127; i++) {
286 ctx->pal[i + (header & 0x81)] = 0xFFU << 24 | bytestream2_get_be24(&ctx->g);
287 bytestream2_skip(&ctx->g, 1);
288 }
289 bytestream2_seek(&ctx->g, -127 * 4 - 3, SEEK_CUR);
290 }
291
292
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76 if (header & KMVC_KEYFRAME) {
293 1 frame->key_frame = 1;
294 1 frame->pict_type = AV_PICTURE_TYPE_I;
295 } else {
296 75 frame->key_frame = 0;
297 75 frame->pict_type = AV_PICTURE_TYPE_P;
298 }
299
300
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76 if (header & KMVC_PALETTE) {
301 1 frame->palette_has_changed = 1;
302 // palette starts from index 1 and has 127 entries
303
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256 for (i = 1; i <= ctx->palsize; i++) {
304 255 ctx->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&ctx->g);
305 }
306 }
307
308
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76 if (ctx->setpal) {
309 ctx->setpal = 0;
310 frame->palette_has_changed = 1;
311 }
312
313 /* make the palette available on the way out */
314 76 memcpy(frame->data[1], ctx->pal, 1024);
315
316 76 blocksize = bytestream2_get_byte(&ctx->g);
317
318
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76 if (blocksize != 8 && blocksize != 127) {
319 av_log(avctx, AV_LOG_ERROR, "Block size = %i\n", blocksize);
320 return AVERROR_INVALIDDATA;
321 }
322 76 memset(ctx->cur, 0, 320 * 200);
323
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76 switch (header & KMVC_METHOD) {
324 case 0:
325 case 1: // used in palette changed event
326 memcpy(ctx->cur, ctx->prev, 320 * 200);
327 break;
328 1 case 3:
329 1 kmvc_decode_intra_8x8(ctx, avctx->width, avctx->height);
330 1 break;
331 75 case 4:
332 75 kmvc_decode_inter_8x8(ctx, avctx->width, avctx->height);
333 75 break;
334 default:
335 av_log(avctx, AV_LOG_ERROR, "Unknown compression method %i\n", header & KMVC_METHOD);
336 return AVERROR_INVALIDDATA;
337 }
338
339 76 out = frame->data[0];
340 76 src = ctx->cur;
341
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12236 for (i = 0; i < avctx->height; i++) {
342 12160 memcpy(out, src, avctx->width);
343 12160 src += 320;
344 12160 out += frame->linesize[0];
345 }
346
347 /* flip buffers */
348 76 FFSWAP(uint8_t *, ctx->cur, ctx->prev);
349
350 76 *got_frame = 1;
351
352 /* always report that the buffer was completely consumed */
353 76 return avpkt->size;
354 }
355
356
357
358 /*
359 * Init kmvc decoder
360 */
361 2 static av_cold int decode_init(AVCodecContext * avctx)
362 {
363 2 KmvcContext *const c = avctx->priv_data;
364 int i;
365
366 2 c->avctx = avctx;
367
368
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2 if (avctx->width > 320 || avctx->height > 200) {
369 av_log(avctx, AV_LOG_ERROR, "KMVC supports frames <= 320x200\n");
370 return AVERROR(EINVAL);
371 }
372
373 2 c->cur = c->frm0;
374 2 c->prev = c->frm1;
375
376
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514 for (i = 0; i < 256; i++) {
377 512 c->pal[i] = 0xFFU << 24 | i * 0x10101;
378 }
379
380
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2 if (avctx->extradata_size < 12) {
381 av_log(avctx, AV_LOG_WARNING,
382 "Extradata missing, decoding may not work properly...\n");
383 c->palsize = 127;
384 } else {
385 2 c->palsize = AV_RL16(avctx->extradata + 10);
386
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2 if (c->palsize >= (unsigned)MAX_PALSIZE) {
387 c->palsize = 127;
388 av_log(avctx, AV_LOG_ERROR, "KMVC palette too large\n");
389 return AVERROR_INVALIDDATA;
390 }
391 }
392
393
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2 if (avctx->extradata_size == 1036) { // palette in extradata
394 uint8_t *src = avctx->extradata + 12;
395 for (i = 0; i < 256; i++) {
396 c->pal[i] = AV_RL32(src);
397 src += 4;
398 }
399 c->setpal = 1;
400 }
401
402 2 avctx->pix_fmt = AV_PIX_FMT_PAL8;
403
404 2 return 0;
405 }
406
407 const FFCodec ff_kmvc_decoder = {
408 .p.name = "kmvc",
409 .p.long_name = NULL_IF_CONFIG_SMALL("Karl Morton's video codec"),
410 .p.type = AVMEDIA_TYPE_VIDEO,
411 .p.id = AV_CODEC_ID_KMVC,
412 .priv_data_size = sizeof(KmvcContext),
413 .init = decode_init,
414 FF_CODEC_DECODE_CB(decode_frame),
415 .p.capabilities = AV_CODEC_CAP_DR1,
416 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
417 };
418