FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/msvideo1.c
Date: 2021-09-16 08:47:15
Exec Total Coverage
Lines: 151 159 95.0%
Branches: 74 94 78.7%

Line Branch Exec Source
1 /*
2 * Microsoft Video-1 Decoder
3 * Copyright (C) 2003 The FFmpeg project
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 * Microsoft Video-1 Decoder by Mike Melanson (melanson@pcisys.net)
25 * For more information about the MS Video-1 format, visit:
26 * http://www.pcisys.net/~melanson/codecs/
27 */
28
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32
33 #include "libavutil/internal.h"
34 #include "libavutil/intreadwrite.h"
35 #include "avcodec.h"
36 #include "decode.h"
37 #include "internal.h"
38
39 #define PALETTE_COUNT 256
40 #define CHECK_STREAM_PTR(n) \
41 if ((stream_ptr + n) > s->size ) { \
42 av_log(s->avctx, AV_LOG_ERROR, " MS Video-1 warning: stream_ptr out of bounds (%d >= %d)\n", \
43 stream_ptr + n, s->size); \
44 return; \
45 }
46
47 typedef struct Msvideo1Context {
48
49 AVCodecContext *avctx;
50 AVFrame *frame;
51
52 const unsigned char *buf;
53 int size;
54
55 int mode_8bit; /* if it's not 8-bit, it's 16-bit */
56
57 uint32_t pal[256];
58 } Msvideo1Context;
59
60 13 static av_cold int msvideo1_decode_init(AVCodecContext *avctx)
61 {
62 13 Msvideo1Context *s = avctx->priv_data;
63
64 13 s->avctx = avctx;
65
66
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13 if (avctx->width < 4 || avctx->height < 4)
67 return AVERROR_INVALIDDATA;
68
69 /* figure out the colorspace based on the presence of a palette */
70
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13 if (s->avctx->bits_per_coded_sample == 8) {
71 5 s->mode_8bit = 1;
72 5 avctx->pix_fmt = AV_PIX_FMT_PAL8;
73
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5 if (avctx->extradata_size >= AVPALETTE_SIZE)
74 5 memcpy(s->pal, avctx->extradata, AVPALETTE_SIZE);
75 } else {
76 8 s->mode_8bit = 0;
77 8 avctx->pix_fmt = AV_PIX_FMT_RGB555;
78 }
79
80 13 s->frame = av_frame_alloc();
81
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13 if (!s->frame)
82 return AVERROR(ENOMEM);
83
84 13 return 0;
85 }
86
87 147 static void msvideo1_decode_8bit(Msvideo1Context *s)
88 {
89 int block_ptr, pixel_ptr;
90 int total_blocks;
91 int pixel_x, pixel_y; /* pixel width and height iterators */
92 int block_x, block_y; /* block width and height iterators */
93 int blocks_wide, blocks_high; /* width and height in 4x4 blocks */
94 int block_inc;
95 int row_dec;
96
97 /* decoding parameters */
98 int stream_ptr;
99 unsigned char byte_a, byte_b;
100 unsigned short flags;
101 int skip_blocks;
102 unsigned char colors[8];
103 147 unsigned char *pixels = s->frame->data[0];
104 147 int stride = s->frame->linesize[0];
105
106 147 stream_ptr = 0;
107 147 skip_blocks = 0;
108 147 blocks_wide = s->avctx->width / 4;
109 147 blocks_high = s->avctx->height / 4;
110 147 total_blocks = blocks_wide * blocks_high;
111 147 block_inc = 4;
112 147 row_dec = stride + 4;
113
114
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3977 for (block_y = blocks_high; block_y > 0; block_y--) {
115 3830 block_ptr = ((block_y * 4) - 1) * stride;
116
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186030 for (block_x = blocks_wide; block_x > 0; block_x--) {
117 /* check if this block should be skipped */
118
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182200 if (skip_blocks) {
119 94392 block_ptr += block_inc;
120 94392 skip_blocks--;
121 94392 total_blocks--;
122 94392 continue;
123 }
124
125 87808 pixel_ptr = block_ptr;
126
127 /* get the next two bytes in the encoded data stream */
128
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87808 CHECK_STREAM_PTR(2);
129 87808 byte_a = s->buf[stream_ptr++];
130 87808 byte_b = s->buf[stream_ptr++];
131
132 /* check if the decode is finished */
133
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87808 if ((byte_a == 0) && (byte_b == 0) && (total_blocks == 0))
134 return;
135
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87808 else if ((byte_b & 0xFC) == 0x84) {
136 /* skip code, but don't count the current block */
137 8662 skip_blocks = ((byte_b - 0x84) << 8) + byte_a - 1;
138
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79146 } else if (byte_b < 0x80) {
139 /* 2-color encoding */
140 11480 flags = (byte_b << 8) | byte_a;
141
142
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11480 CHECK_STREAM_PTR(2);
143 11480 colors[0] = s->buf[stream_ptr++];
144 11480 colors[1] = s->buf[stream_ptr++];
145
146
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57400 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
147
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229600 for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
148 183680 pixels[pixel_ptr++] = colors[(flags & 0x1) ^ 1];
149 45920 pixel_ptr -= row_dec;
150 }
151
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67666 } else if (byte_b >= 0x90) {
152 /* 8-color encoding */
153 56844 flags = (byte_b << 8) | byte_a;
154
155
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56844 CHECK_STREAM_PTR(8);
156 56844 memcpy(colors, &s->buf[stream_ptr], 8);
157 56844 stream_ptr += 8;
158
159
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284220 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
160
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1136880 for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
161 909504 pixels[pixel_ptr++] =
162 909504 colors[((pixel_y & 0x2) << 1) +
163 909504 (pixel_x & 0x2) + ((flags & 0x1) ^ 1)];
164 227376 pixel_ptr -= row_dec;
165 }
166 } else {
167 /* 1-color encoding */
168 10822 colors[0] = byte_a;
169
170
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54110 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
171
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216440 for (pixel_x = 0; pixel_x < 4; pixel_x++)
172 173152 pixels[pixel_ptr++] = colors[0];
173 43288 pixel_ptr -= row_dec;
174 }
175 }
176
177 87808 block_ptr += block_inc;
178 87808 total_blocks--;
179 }
180 }
181
182 /* make the palette available on the way out */
183
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147 if (s->avctx->pix_fmt == AV_PIX_FMT_PAL8)
184 147 memcpy(s->frame->data[1], s->pal, AVPALETTE_SIZE);
185 }
186
187 180 static void msvideo1_decode_16bit(Msvideo1Context *s)
188 {
189 int block_ptr, pixel_ptr;
190 int total_blocks;
191 int pixel_x, pixel_y; /* pixel width and height iterators */
192 int block_x, block_y; /* block width and height iterators */
193 int blocks_wide, blocks_high; /* width and height in 4x4 blocks */
194 int block_inc;
195 int row_dec;
196
197 /* decoding parameters */
198 int stream_ptr;
199 unsigned char byte_a, byte_b;
200 unsigned short flags;
201 int skip_blocks;
202 unsigned short colors[8];
203 180 unsigned short *pixels = (unsigned short *)s->frame->data[0];
204 180 int stride = s->frame->linesize[0] / 2;
205
206 180 stream_ptr = 0;
207 180 skip_blocks = 0;
208 180 blocks_wide = s->avctx->width / 4;
209 180 blocks_high = s->avctx->height / 4;
210 180 total_blocks = blocks_wide * blocks_high;
211 180 block_inc = 4;
212 180 row_dec = stride + 4;
213
214
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12090 for (block_y = blocks_high; block_y > 0; block_y--) {
215 11910 block_ptr = ((block_y * 4) - 1) * stride;
216
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1003380 for (block_x = blocks_wide; block_x > 0; block_x--) {
217 /* check if this block should be skipped */
218
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991470 if (skip_blocks) {
219 281140 block_ptr += block_inc;
220 281140 skip_blocks--;
221 281140 total_blocks--;
222 281140 continue;
223 }
224
225 710330 pixel_ptr = block_ptr;
226
227 /* get the next two bytes in the encoded data stream */
228
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710330 CHECK_STREAM_PTR(2);
229 710330 byte_a = s->buf[stream_ptr++];
230 710330 byte_b = s->buf[stream_ptr++];
231
232 /* check if the decode is finished */
233
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710330 if ((byte_a == 0) && (byte_b == 0) && (total_blocks == 0)) {
234 return;
235
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710330 } else if ((byte_b & 0xFC) == 0x84) {
236 /* skip code, but don't count the current block */
237 108271 skip_blocks = ((byte_b - 0x84) << 8) + byte_a - 1;
238
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602059 } else if (byte_b < 0x80) {
239 /* 2- or 8-color encoding modes */
240 280291 flags = (byte_b << 8) | byte_a;
241
242
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280291 CHECK_STREAM_PTR(4);
243 280291 colors[0] = AV_RL16(&s->buf[stream_ptr]);
244 280291 stream_ptr += 2;
245 280291 colors[1] = AV_RL16(&s->buf[stream_ptr]);
246 280291 stream_ptr += 2;
247
248
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280291 if (colors[0] & 0x8000) {
249 /* 8-color encoding */
250
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145448 CHECK_STREAM_PTR(12);
251 145448 colors[2] = AV_RL16(&s->buf[stream_ptr]);
252 145448 stream_ptr += 2;
253 145448 colors[3] = AV_RL16(&s->buf[stream_ptr]);
254 145448 stream_ptr += 2;
255 145448 colors[4] = AV_RL16(&s->buf[stream_ptr]);
256 145448 stream_ptr += 2;
257 145448 colors[5] = AV_RL16(&s->buf[stream_ptr]);
258 145448 stream_ptr += 2;
259 145448 colors[6] = AV_RL16(&s->buf[stream_ptr]);
260 145448 stream_ptr += 2;
261 145448 colors[7] = AV_RL16(&s->buf[stream_ptr]);
262 145448 stream_ptr += 2;
263
264
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727240 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
265
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2908960 for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
266 2327168 pixels[pixel_ptr++] =
267 2327168 colors[((pixel_y & 0x2) << 1) +
268 2327168 (pixel_x & 0x2) + ((flags & 0x1) ^ 1)];
269 581792 pixel_ptr -= row_dec;
270 }
271 } else {
272 /* 2-color encoding */
273
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674215 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
274
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2696860 for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
275 2157488 pixels[pixel_ptr++] = colors[(flags & 0x1) ^ 1];
276 539372 pixel_ptr -= row_dec;
277 }
278 }
279 } else {
280 /* otherwise, it's a 1-color block */
281 321768 colors[0] = (byte_b << 8) | byte_a;
282
283
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284
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6435360 for (pixel_x = 0; pixel_x < 4; pixel_x++)
285 5148288 pixels[pixel_ptr++] = colors[0];
286 1287072 pixel_ptr -= row_dec;
287 }
288 }
289
290 710330 block_ptr += block_inc;
291 710330 total_blocks--;
292 }
293 }
294 }
295
296 327 static int msvideo1_decode_frame(AVCodecContext *avctx,
297 void *data, int *got_frame,
298 AVPacket *avpkt)
299 {
300 327 const uint8_t *buf = avpkt->data;
301 327 int buf_size = avpkt->size;
302 327 Msvideo1Context *s = avctx->priv_data;
303 int ret;
304
305 327 s->buf = buf;
306 327 s->size = buf_size;
307
308 // Discard frame if its smaller than the minimum frame size
309
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327 if (buf_size < (avctx->width/4) * (avctx->height/4) / 512) {
310 av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
311 return AVERROR_INVALIDDATA;
312 }
313
314
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327 if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)
315 return ret;
316
317
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327 if (s->mode_8bit) {
318 147 s->frame->palette_has_changed = ff_copy_palette(s->pal, avpkt, avctx);
319 }
320
321
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327 if (s->mode_8bit)
322 147 msvideo1_decode_8bit(s);
323 else
324 180 msvideo1_decode_16bit(s);
325
326
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327 if ((ret = av_frame_ref(data, s->frame)) < 0)
327 return ret;
328
329 327 *got_frame = 1;
330
331 /* report that the buffer was completely consumed */
332 327 return buf_size;
333 }
334
335 13 static av_cold int msvideo1_decode_end(AVCodecContext *avctx)
336 {
337 13 Msvideo1Context *s = avctx->priv_data;
338
339 13 av_frame_free(&s->frame);
340
341 13 return 0;
342 }
343
344 const AVCodec ff_msvideo1_decoder = {
345 .name = "msvideo1",
346 .long_name = NULL_IF_CONFIG_SMALL("Microsoft Video 1"),
347 .type = AVMEDIA_TYPE_VIDEO,
348 .id = AV_CODEC_ID_MSVIDEO1,
349 .priv_data_size = sizeof(Msvideo1Context),
350 .init = msvideo1_decode_init,
351 .close = msvideo1_decode_end,
352 .decode = msvideo1_decode_frame,
353 .capabilities = AV_CODEC_CAP_DR1,
354 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
355 };
356