644fecf66b708e1d99eca66096dfc3fdf8a30160
[libav.git] / libavcodec / msvideo1.c
1 /*
2 * Microsoft Video-1 Decoder
3 * Copyright (C) 2003 the ffmpeg project
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33
34 #include "libavutil/internal.h"
35 #include "libavutil/intreadwrite.h"
36 #include "avcodec.h"
37
38 #define PALETTE_COUNT 256
39 #define CHECK_STREAM_PTR(n) \
40 if ((stream_ptr + n) > s->size ) { \
41 av_log(s->avctx, AV_LOG_ERROR, " MS Video-1 warning: stream_ptr out of bounds (%d >= %d)\n", \
42 stream_ptr + n, s->size); \
43 return; \
44 }
45
46 typedef struct Msvideo1Context {
47
48 AVCodecContext *avctx;
49 AVFrame frame;
50
51 const unsigned char *buf;
52 int size;
53
54 int mode_8bit; /* if it's not 8-bit, it's 16-bit */
55
56 uint32_t pal[256];
57 } Msvideo1Context;
58
59 static av_cold int msvideo1_decode_init(AVCodecContext *avctx)
60 {
61 Msvideo1Context *s = avctx->priv_data;
62
63 s->avctx = avctx;
64
65 /* figure out the colorspace based on the presence of a palette */
66 if (s->avctx->bits_per_coded_sample == 8) {
67 s->mode_8bit = 1;
68 avctx->pix_fmt = AV_PIX_FMT_PAL8;
69 } else {
70 s->mode_8bit = 0;
71 avctx->pix_fmt = AV_PIX_FMT_RGB555;
72 }
73
74 s->frame.data[0] = NULL;
75
76 return 0;
77 }
78
79 static void msvideo1_decode_8bit(Msvideo1Context *s)
80 {
81 int block_ptr, pixel_ptr;
82 int total_blocks;
83 int pixel_x, pixel_y; /* pixel width and height iterators */
84 int block_x, block_y; /* block width and height iterators */
85 int blocks_wide, blocks_high; /* width and height in 4x4 blocks */
86 int block_inc;
87 int row_dec;
88
89 /* decoding parameters */
90 int stream_ptr;
91 unsigned char byte_a, byte_b;
92 unsigned short flags;
93 int skip_blocks;
94 unsigned char colors[8];
95 unsigned char *pixels = s->frame.data[0];
96 int stride = s->frame.linesize[0];
97
98 stream_ptr = 0;
99 skip_blocks = 0;
100 blocks_wide = s->avctx->width / 4;
101 blocks_high = s->avctx->height / 4;
102 total_blocks = blocks_wide * blocks_high;
103 block_inc = 4;
104 row_dec = stride + 4;
105
106 for (block_y = blocks_high; block_y > 0; block_y--) {
107 block_ptr = ((block_y * 4) - 1) * stride;
108 for (block_x = blocks_wide; block_x > 0; block_x--) {
109 /* check if this block should be skipped */
110 if (skip_blocks) {
111 block_ptr += block_inc;
112 skip_blocks--;
113 total_blocks--;
114 continue;
115 }
116
117 pixel_ptr = block_ptr;
118
119 /* get the next two bytes in the encoded data stream */
120 CHECK_STREAM_PTR(2);
121 byte_a = s->buf[stream_ptr++];
122 byte_b = s->buf[stream_ptr++];
123
124 /* check if the decode is finished */
125 if ((byte_a == 0) && (byte_b == 0) && (total_blocks == 0))
126 return;
127 else if ((byte_b & 0xFC) == 0x84) {
128 /* skip code, but don't count the current block */
129 skip_blocks = ((byte_b - 0x84) << 8) + byte_a - 1;
130 } else if (byte_b < 0x80) {
131 /* 2-color encoding */
132 flags = (byte_b << 8) | byte_a;
133
134 CHECK_STREAM_PTR(2);
135 colors[0] = s->buf[stream_ptr++];
136 colors[1] = s->buf[stream_ptr++];
137
138 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
139 for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
140 pixels[pixel_ptr++] = colors[(flags & 0x1) ^ 1];
141 pixel_ptr -= row_dec;
142 }
143 } else if (byte_b >= 0x90) {
144 /* 8-color encoding */
145 flags = (byte_b << 8) | byte_a;
146
147 CHECK_STREAM_PTR(8);
148 memcpy(colors, &s->buf[stream_ptr], 8);
149 stream_ptr += 8;
150
151 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
152 for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
153 pixels[pixel_ptr++] =
154 colors[((pixel_y & 0x2) << 1) +
155 (pixel_x & 0x2) + ((flags & 0x1) ^ 1)];
156 pixel_ptr -= row_dec;
157 }
158 } else {
159 /* 1-color encoding */
160 colors[0] = byte_a;
161
162 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
163 for (pixel_x = 0; pixel_x < 4; pixel_x++)
164 pixels[pixel_ptr++] = colors[0];
165 pixel_ptr -= row_dec;
166 }
167 }
168
169 block_ptr += block_inc;
170 total_blocks--;
171 }
172 }
173
174 /* make the palette available on the way out */
175 if (s->avctx->pix_fmt == AV_PIX_FMT_PAL8)
176 memcpy(s->frame.data[1], s->pal, AVPALETTE_SIZE);
177 }
178
179 static void msvideo1_decode_16bit(Msvideo1Context *s)
180 {
181 int block_ptr, pixel_ptr;
182 int total_blocks;
183 int pixel_x, pixel_y; /* pixel width and height iterators */
184 int block_x, block_y; /* block width and height iterators */
185 int blocks_wide, blocks_high; /* width and height in 4x4 blocks */
186 int block_inc;
187 int row_dec;
188
189 /* decoding parameters */
190 int stream_ptr;
191 unsigned char byte_a, byte_b;
192 unsigned short flags;
193 int skip_blocks;
194 unsigned short colors[8];
195 unsigned short *pixels = (unsigned short *)s->frame.data[0];
196 int stride = s->frame.linesize[0] / 2;
197
198 stream_ptr = 0;
199 skip_blocks = 0;
200 blocks_wide = s->avctx->width / 4;
201 blocks_high = s->avctx->height / 4;
202 total_blocks = blocks_wide * blocks_high;
203 block_inc = 4;
204 row_dec = stride + 4;
205
206 for (block_y = blocks_high; block_y > 0; block_y--) {
207 block_ptr = ((block_y * 4) - 1) * stride;
208 for (block_x = blocks_wide; block_x > 0; block_x--) {
209 /* check if this block should be skipped */
210 if (skip_blocks) {
211 block_ptr += block_inc;
212 skip_blocks--;
213 total_blocks--;
214 continue;
215 }
216
217 pixel_ptr = block_ptr;
218
219 /* get the next two bytes in the encoded data stream */
220 CHECK_STREAM_PTR(2);
221 byte_a = s->buf[stream_ptr++];
222 byte_b = s->buf[stream_ptr++];
223
224 /* check if the decode is finished */
225 if ((byte_a == 0) && (byte_b == 0) && (total_blocks == 0)) {
226 return;
227 } else if ((byte_b & 0xFC) == 0x84) {
228 /* skip code, but don't count the current block */
229 skip_blocks = ((byte_b - 0x84) << 8) + byte_a - 1;
230 } else if (byte_b < 0x80) {
231 /* 2- or 8-color encoding modes */
232 flags = (byte_b << 8) | byte_a;
233
234 CHECK_STREAM_PTR(4);
235 colors[0] = AV_RL16(&s->buf[stream_ptr]);
236 stream_ptr += 2;
237 colors[1] = AV_RL16(&s->buf[stream_ptr]);
238 stream_ptr += 2;
239
240 if (colors[0] & 0x8000) {
241 /* 8-color encoding */
242 CHECK_STREAM_PTR(12);
243 colors[2] = AV_RL16(&s->buf[stream_ptr]);
244 stream_ptr += 2;
245 colors[3] = AV_RL16(&s->buf[stream_ptr]);
246 stream_ptr += 2;
247 colors[4] = AV_RL16(&s->buf[stream_ptr]);
248 stream_ptr += 2;
249 colors[5] = AV_RL16(&s->buf[stream_ptr]);
250 stream_ptr += 2;
251 colors[6] = AV_RL16(&s->buf[stream_ptr]);
252 stream_ptr += 2;
253 colors[7] = AV_RL16(&s->buf[stream_ptr]);
254 stream_ptr += 2;
255
256 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
257 for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
258 pixels[pixel_ptr++] =
259 colors[((pixel_y & 0x2) << 1) +
260 (pixel_x & 0x2) + ((flags & 0x1) ^ 1)];
261 pixel_ptr -= row_dec;
262 }
263 } else {
264 /* 2-color encoding */
265 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
266 for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
267 pixels[pixel_ptr++] = colors[(flags & 0x1) ^ 1];
268 pixel_ptr -= row_dec;
269 }
270 }
271 } else {
272 /* otherwise, it's a 1-color block */
273 colors[0] = (byte_b << 8) | byte_a;
274
275 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
276 for (pixel_x = 0; pixel_x < 4; pixel_x++)
277 pixels[pixel_ptr++] = colors[0];
278 pixel_ptr -= row_dec;
279 }
280 }
281
282 block_ptr += block_inc;
283 total_blocks--;
284 }
285 }
286 }
287
288 static int msvideo1_decode_frame(AVCodecContext *avctx,
289 void *data, int *data_size,
290 AVPacket *avpkt)
291 {
292 const uint8_t *buf = avpkt->data;
293 int buf_size = avpkt->size;
294 Msvideo1Context *s = avctx->priv_data;
295
296 s->buf = buf;
297 s->size = buf_size;
298
299 s->frame.reference = 1;
300 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
301 if (avctx->reget_buffer(avctx, &s->frame)) {
302 av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
303 return -1;
304 }
305
306 if (s->mode_8bit) {
307 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
308
309 if (pal) {
310 memcpy(s->pal, pal, AVPALETTE_SIZE);
311 s->frame.palette_has_changed = 1;
312 }
313 }
314
315 if (s->mode_8bit)
316 msvideo1_decode_8bit(s);
317 else
318 msvideo1_decode_16bit(s);
319
320 *data_size = sizeof(AVFrame);
321 *(AVFrame*)data = s->frame;
322
323 /* report that the buffer was completely consumed */
324 return buf_size;
325 }
326
327 static av_cold int msvideo1_decode_end(AVCodecContext *avctx)
328 {
329 Msvideo1Context *s = avctx->priv_data;
330
331 if (s->frame.data[0])
332 avctx->release_buffer(avctx, &s->frame);
333
334 return 0;
335 }
336
337 AVCodec ff_msvideo1_decoder = {
338 .name = "msvideo1",
339 .type = AVMEDIA_TYPE_VIDEO,
340 .id = AV_CODEC_ID_MSVIDEO1,
341 .priv_data_size = sizeof(Msvideo1Context),
342 .init = msvideo1_decode_init,
343 .close = msvideo1_decode_end,
344 .decode = msvideo1_decode_frame,
345 .capabilities = CODEC_CAP_DR1,
346 .long_name = NULL_IF_CONFIG_SMALL("Microsoft Video 1"),
347 };