Imported Debian version 2.5.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / msvideo1.c
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
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 #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 static av_cold int msvideo1_decode_init(AVCodecContext *avctx)
61 {
62 Msvideo1Context *s = avctx->priv_data;
63
64 s->avctx = avctx;
65
66 /* figure out the colorspace based on the presence of a palette */
67 if (s->avctx->bits_per_coded_sample == 8) {
68 s->mode_8bit = 1;
69 avctx->pix_fmt = AV_PIX_FMT_PAL8;
70 if (avctx->extradata_size >= AVPALETTE_SIZE)
71 memcpy(s->pal, avctx->extradata, AVPALETTE_SIZE);
72 } else {
73 s->mode_8bit = 0;
74 avctx->pix_fmt = AV_PIX_FMT_RGB555;
75 }
76
77 s->frame = av_frame_alloc();
78 if (!s->frame)
79 return AVERROR(ENOMEM);
80
81 return 0;
82 }
83
84 static void msvideo1_decode_8bit(Msvideo1Context *s)
85 {
86 int block_ptr, pixel_ptr;
87 int total_blocks;
88 int pixel_x, pixel_y; /* pixel width and height iterators */
89 int block_x, block_y; /* block width and height iterators */
90 int blocks_wide, blocks_high; /* width and height in 4x4 blocks */
91 int block_inc;
92 int row_dec;
93
94 /* decoding parameters */
95 int stream_ptr;
96 unsigned char byte_a, byte_b;
97 unsigned short flags;
98 int skip_blocks;
99 unsigned char colors[8];
100 unsigned char *pixels = s->frame->data[0];
101 int stride = s->frame->linesize[0];
102
103 stream_ptr = 0;
104 skip_blocks = 0;
105 blocks_wide = s->avctx->width / 4;
106 blocks_high = s->avctx->height / 4;
107 total_blocks = blocks_wide * blocks_high;
108 block_inc = 4;
109 row_dec = stride + 4;
110
111 for (block_y = blocks_high; block_y > 0; block_y--) {
112 block_ptr = ((block_y * 4) - 1) * stride;
113 for (block_x = blocks_wide; block_x > 0; block_x--) {
114 /* check if this block should be skipped */
115 if (skip_blocks) {
116 block_ptr += block_inc;
117 skip_blocks--;
118 total_blocks--;
119 continue;
120 }
121
122 pixel_ptr = block_ptr;
123
124 /* get the next two bytes in the encoded data stream */
125 CHECK_STREAM_PTR(2);
126 byte_a = s->buf[stream_ptr++];
127 byte_b = s->buf[stream_ptr++];
128
129 /* check if the decode is finished */
130 if ((byte_a == 0) && (byte_b == 0) && (total_blocks == 0))
131 return;
132 else if ((byte_b & 0xFC) == 0x84) {
133 /* skip code, but don't count the current block */
134 skip_blocks = ((byte_b - 0x84) << 8) + byte_a - 1;
135 } else if (byte_b < 0x80) {
136 /* 2-color encoding */
137 flags = (byte_b << 8) | byte_a;
138
139 CHECK_STREAM_PTR(2);
140 colors[0] = s->buf[stream_ptr++];
141 colors[1] = s->buf[stream_ptr++];
142
143 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
144 for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
145 pixels[pixel_ptr++] = colors[(flags & 0x1) ^ 1];
146 pixel_ptr -= row_dec;
147 }
148 } else if (byte_b >= 0x90) {
149 /* 8-color encoding */
150 flags = (byte_b << 8) | byte_a;
151
152 CHECK_STREAM_PTR(8);
153 memcpy(colors, &s->buf[stream_ptr], 8);
154 stream_ptr += 8;
155
156 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
157 for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
158 pixels[pixel_ptr++] =
159 colors[((pixel_y & 0x2) << 1) +
160 (pixel_x & 0x2) + ((flags & 0x1) ^ 1)];
161 pixel_ptr -= row_dec;
162 }
163 } else {
164 /* 1-color encoding */
165 colors[0] = byte_a;
166
167 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
168 for (pixel_x = 0; pixel_x < 4; pixel_x++)
169 pixels[pixel_ptr++] = colors[0];
170 pixel_ptr -= row_dec;
171 }
172 }
173
174 block_ptr += block_inc;
175 total_blocks--;
176 }
177 }
178
179 /* make the palette available on the way out */
180 if (s->avctx->pix_fmt == AV_PIX_FMT_PAL8)
181 memcpy(s->frame->data[1], s->pal, AVPALETTE_SIZE);
182 }
183
184 static void msvideo1_decode_16bit(Msvideo1Context *s)
185 {
186 int block_ptr, pixel_ptr;
187 int total_blocks;
188 int pixel_x, pixel_y; /* pixel width and height iterators */
189 int block_x, block_y; /* block width and height iterators */
190 int blocks_wide, blocks_high; /* width and height in 4x4 blocks */
191 int block_inc;
192 int row_dec;
193
194 /* decoding parameters */
195 int stream_ptr;
196 unsigned char byte_a, byte_b;
197 unsigned short flags;
198 int skip_blocks;
199 unsigned short colors[8];
200 unsigned short *pixels = (unsigned short *)s->frame->data[0];
201 int stride = s->frame->linesize[0] / 2;
202
203 stream_ptr = 0;
204 skip_blocks = 0;
205 blocks_wide = s->avctx->width / 4;
206 blocks_high = s->avctx->height / 4;
207 total_blocks = blocks_wide * blocks_high;
208 block_inc = 4;
209 row_dec = stride + 4;
210
211 for (block_y = blocks_high; block_y > 0; block_y--) {
212 block_ptr = ((block_y * 4) - 1) * stride;
213 for (block_x = blocks_wide; block_x > 0; block_x--) {
214 /* check if this block should be skipped */
215 if (skip_blocks) {
216 block_ptr += block_inc;
217 skip_blocks--;
218 total_blocks--;
219 continue;
220 }
221
222 pixel_ptr = block_ptr;
223
224 /* get the next two bytes in the encoded data stream */
225 CHECK_STREAM_PTR(2);
226 byte_a = s->buf[stream_ptr++];
227 byte_b = s->buf[stream_ptr++];
228
229 /* check if the decode is finished */
230 if ((byte_a == 0) && (byte_b == 0) && (total_blocks == 0)) {
231 return;
232 } else if ((byte_b & 0xFC) == 0x84) {
233 /* skip code, but don't count the current block */
234 skip_blocks = ((byte_b - 0x84) << 8) + byte_a - 1;
235 } else if (byte_b < 0x80) {
236 /* 2- or 8-color encoding modes */
237 flags = (byte_b << 8) | byte_a;
238
239 CHECK_STREAM_PTR(4);
240 colors[0] = AV_RL16(&s->buf[stream_ptr]);
241 stream_ptr += 2;
242 colors[1] = AV_RL16(&s->buf[stream_ptr]);
243 stream_ptr += 2;
244
245 if (colors[0] & 0x8000) {
246 /* 8-color encoding */
247 CHECK_STREAM_PTR(12);
248 colors[2] = AV_RL16(&s->buf[stream_ptr]);
249 stream_ptr += 2;
250 colors[3] = AV_RL16(&s->buf[stream_ptr]);
251 stream_ptr += 2;
252 colors[4] = AV_RL16(&s->buf[stream_ptr]);
253 stream_ptr += 2;
254 colors[5] = AV_RL16(&s->buf[stream_ptr]);
255 stream_ptr += 2;
256 colors[6] = AV_RL16(&s->buf[stream_ptr]);
257 stream_ptr += 2;
258 colors[7] = AV_RL16(&s->buf[stream_ptr]);
259 stream_ptr += 2;
260
261 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
262 for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
263 pixels[pixel_ptr++] =
264 colors[((pixel_y & 0x2) << 1) +
265 (pixel_x & 0x2) + ((flags & 0x1) ^ 1)];
266 pixel_ptr -= row_dec;
267 }
268 } else {
269 /* 2-color encoding */
270 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
271 for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
272 pixels[pixel_ptr++] = colors[(flags & 0x1) ^ 1];
273 pixel_ptr -= row_dec;
274 }
275 }
276 } else {
277 /* otherwise, it's a 1-color block */
278 colors[0] = (byte_b << 8) | byte_a;
279
280 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
281 for (pixel_x = 0; pixel_x < 4; pixel_x++)
282 pixels[pixel_ptr++] = colors[0];
283 pixel_ptr -= row_dec;
284 }
285 }
286
287 block_ptr += block_inc;
288 total_blocks--;
289 }
290 }
291 }
292
293 static int msvideo1_decode_frame(AVCodecContext *avctx,
294 void *data, int *got_frame,
295 AVPacket *avpkt)
296 {
297 const uint8_t *buf = avpkt->data;
298 int buf_size = avpkt->size;
299 Msvideo1Context *s = avctx->priv_data;
300 int ret;
301
302 s->buf = buf;
303 s->size = buf_size;
304
305 if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
306 return ret;
307
308 if (s->mode_8bit) {
309 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
310
311 if (pal) {
312 memcpy(s->pal, pal, AVPALETTE_SIZE);
313 s->frame->palette_has_changed = 1;
314 }
315 }
316
317 if (s->mode_8bit)
318 msvideo1_decode_8bit(s);
319 else
320 msvideo1_decode_16bit(s);
321
322 if ((ret = av_frame_ref(data, s->frame)) < 0)
323 return ret;
324
325 *got_frame = 1;
326
327 /* report that the buffer was completely consumed */
328 return buf_size;
329 }
330
331 static av_cold int msvideo1_decode_end(AVCodecContext *avctx)
332 {
333 Msvideo1Context *s = avctx->priv_data;
334
335 av_frame_free(&s->frame);
336
337 return 0;
338 }
339
340 AVCodec ff_msvideo1_decoder = {
341 .name = "msvideo1",
342 .long_name = NULL_IF_CONFIG_SMALL("Microsoft Video 1"),
343 .type = AVMEDIA_TYPE_VIDEO,
344 .id = AV_CODEC_ID_MSVIDEO1,
345 .priv_data_size = sizeof(Msvideo1Context),
346 .init = msvideo1_decode_init,
347 .close = msvideo1_decode_end,
348 .decode = msvideo1_decode_frame,
349 .capabilities = CODEC_CAP_DR1,
350 };