aboutsummaryrefslogtreecommitdiff
path: root/video/codecs/truemotion1.cpp
blob: a0456869ab522d68cc615006894cfd2ef516c49f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $URL$
 * $Id$
 *
 */

// Based on the TrueMotion 1 decoder by Alex Beregszaszi & Mike Melanson in FFmpeg

#include "common/scummsys.h"
#include "video/codecs/truemotion1.h"

#ifdef VIDEO_CODECS_TRUEMOTION1_H

#include "video/codecs/truemotion1data.h"
#include "common/stream.h"

namespace Video {

enum {
	FLAG_SPRITE = (1 << 5),
	FLAG_KEYFRAME = (1 << 4),
	FLAG_INTERFRAME = (1 << 3),
	FLAG_INTERPOLATED = (1 << 2)
};

enum {
	ALGO_NOP = 0,
	ALGO_RGB16V = 1,
	ALGO_RGB16H = 2,
	ALGO_RGB24H = 3
};

// these are the various block sizes that can occupy a 4x4 block
enum {
	BLOCK_2x2 = 0,
	BLOCK_2x4 = 1,
	BLOCK_4x2 = 2,
	BLOCK_4x4 = 3
};

// { valid for metatype }, algorithm, num of deltas, vert res, horiz res
struct {
	int algorithm;
	int blockWidth; // vres
	int blockHeight; // hres
	int blockType;
} static const compressionTypes[17] = {
	{ ALGO_NOP,	0, 0, 0 },

	{ ALGO_RGB16V, 4, 4, BLOCK_4x4 },
	{ ALGO_RGB16H, 4, 4, BLOCK_4x4 },
	{ ALGO_RGB16V, 4, 2, BLOCK_4x2 },
	{ ALGO_RGB16H, 4, 2, BLOCK_4x2 },

	{ ALGO_RGB16V, 2, 4, BLOCK_2x4 },
	{ ALGO_RGB16H, 2, 4, BLOCK_2x4 },
	{ ALGO_RGB16V, 2, 2, BLOCK_2x2 },
	{ ALGO_RGB16H, 2, 2, BLOCK_2x2 },

	{ ALGO_NOP,	4, 4, BLOCK_4x4 },
	{ ALGO_RGB24H, 4, 4, BLOCK_4x4 },
	{ ALGO_NOP,	4, 2, BLOCK_4x2 },
	{ ALGO_RGB24H, 4, 2, BLOCK_4x2 },

	{ ALGO_NOP,	2, 4, BLOCK_2x4 },
	{ ALGO_RGB24H, 2, 4, BLOCK_2x4 },
	{ ALGO_NOP,	2, 2, BLOCK_2x2 },
	{ ALGO_RGB24H, 2, 2, BLOCK_2x2 }
};

TrueMotion1Decoder::TrueMotion1Decoder(uint16 width, uint16 height) {
	_surface = new Graphics::Surface();
	_width = width;
	_height = height;

	_surface->create(width, height, 2);

	// there is a vertical predictor for each pixel in a line; each vertical
	// predictor is 0 to start with
	_vertPred = new uint32[_width];

	_buf = _mbChangeBits = _indexStream = 0;
	_lastDeltaset = _lastVectable = -1;
}

TrueMotion1Decoder::~TrueMotion1Decoder() {
	_surface->free();
	delete _surface;
	delete[] _vertPred;
}

void TrueMotion1Decoder::selectDeltaTables(int deltaTableIndex) {
	if (deltaTableIndex > 3)
		return;
   
	for (byte i = 0; i < 8; i++) {
		_ydt[i] = ydts[deltaTableIndex][i];
		_cdt[i] = cdts[deltaTableIndex][i];

		// Y skinny deltas need to be halved for some reason; maybe the
		// skinny Y deltas should be modified
		// Drop the lsb before dividing by 2-- net effect: round down
		// when dividing a negative number (e.g., -3/2 = -2, not -1)
		_ydt[i] &= 0xFFFE;
		_ydt[i] /= 2;
	}
}

int TrueMotion1Decoder::makeYdt16Entry(int p1, int p2) {
#ifdef SCUMM_BIG_ENDIAN
	// Swap the values on BE systems. FFmpeg does this too.
	SWAP<int>(p1, p2);
#endif

	int lo = _ydt[p1];
	lo += (lo << 6) + (lo << 11);
	int hi = _ydt[p2];
	hi += (hi << 6) + (hi << 11);
	return lo + (hi << 16);
}

int TrueMotion1Decoder::makeCdt16Entry(int p1, int p2) {
	int b = _cdt[p2];
	int r = _cdt[p1] << 11;
	int lo = b + r;
	return lo + (lo << 16);
}

void TrueMotion1Decoder::genVectorTable16(const byte *selVectorTable) {
	memset(&_yPredictorTable, 0, sizeof(PredictorTableEntry) * 1024);
	memset(&_cPredictorTable, 0, sizeof(PredictorTableEntry) * 1024);

	for (int i = 0; i < 1024; i += 4) {
		int len = *selVectorTable++ / 2;
		for (int j = 0; j < len; j++) {
			byte deltaPair = *selVectorTable++;
			_yPredictorTable[i + j].color = makeYdt16Entry(deltaPair >> 4, deltaPair & 0xf);
			_cPredictorTable[i + j].color = makeCdt16Entry(deltaPair >> 4, deltaPair & 0xf);
		}

		_yPredictorTable[i + (len - 1)].getNextIndex = true;
		_cPredictorTable[i + (len - 1)].getNextIndex = true;
	}
}

void TrueMotion1Decoder::decodeHeader(Common::SeekableReadStream *stream) {
	_buf = new byte[stream->size()];
	stream->read(_buf, stream->size());

	byte headerBuffer[128];  // logical maximum size of the header
	const byte *selVectorTable;

	// There is 1 change bit per 4 pixels, so each change byte represents
	// 32 pixels; divide width by 4 to obtain the number of change bits and
	// then round up to the nearest byte.
	_mbChangeBitsRowSize = ((_width >> 2) + 7) >> 3;

	_header.headerSize = ((_buf[0] >> 5) | (_buf[0] << 3)) & 0x7f;

	if (_buf[0] < 0x10)
		error("Invalid TrueMotion1 header size %d", _header.headerSize);

	// unscramble the header bytes with a XOR operation
	memset(headerBuffer, 0, 128);
	for (int i = 1; i < _header.headerSize; i++)
		headerBuffer[i - 1] = _buf[i] ^ _buf[i + 1];

	_header.compression = headerBuffer[0];
	_header.deltaset = headerBuffer[1];
	_header.vectable = headerBuffer[2];
	_header.ysize = READ_LE_UINT16(&headerBuffer[3]);
	_header.xsize = READ_LE_UINT16(&headerBuffer[5]);
	_header.checksum = READ_LE_UINT16(&headerBuffer[7]);
	_header.version = headerBuffer[9];
	_header.headerType = headerBuffer[10];
	_header.flags = headerBuffer[11];
	_header.control = headerBuffer[12];

	// Version 2
	if (_header.version >= 2) {
		if (_header.headerType > 3) {
			error("Invalid header type %d", _header.headerType);
		} else if (_header.headerType == 2 || _header.headerType == 3) {
			_flags = _header.flags;
			if (!(_flags & FLAG_INTERFRAME))
				_flags |= FLAG_KEYFRAME;
		} else
			_flags = FLAG_KEYFRAME;
	} else // Version 1
		_flags = FLAG_KEYFRAME;

	if (_flags & FLAG_SPRITE) {
		error("SPRITE frame found, please report the sample to the developers");
	} else if (_header.headerType < 2 && _header.xsize < 213 && _header.ysize >= 176) {
		_flags |= FLAG_INTERPOLATED;
		error("INTERPOLATION selected, please report the sample to the developers");
	}

	if (_header.compression >= 17)
		error("Invalid TrueMotion1 compression type %d", _header.compression);

	if (_header.deltaset != _lastDeltaset || _header.vectable != _lastVectable)
		selectDeltaTables(_header.deltaset);

	if ((_header.compression & 1) && _header.headerType)
		selVectorTable = pc_tbl2;
	else if (_header.vectable < 4)
		selVectorTable = tables[_header.vectable - 1];
	else
		error("Invalid vector table id %d", _header.vectable);

	if (_header.deltaset != _lastDeltaset || _header.vectable != _lastVectable)
		genVectorTable16(selVectorTable);

	// set up pointers to the other key data chunks
	_mbChangeBits = _buf + _header.headerSize;

	if (_flags & FLAG_KEYFRAME) {
		// no change bits specified for a keyframe; only index bytes
		_indexStream = _mbChangeBits;
	} else {
		// one change bit per 4x4 block
		_indexStream = _mbChangeBits + _mbChangeBitsRowSize * (_height >> 2);
	}

	_indexStreamSize = stream->size() - (_indexStream - _buf);

	_lastDeltaset = _header.deltaset;
	_lastVectable = _header.vectable;
	_blockWidth = compressionTypes[_header.compression].blockWidth;
	_blockHeight = compressionTypes[_header.compression].blockHeight;
	_blockType = compressionTypes[_header.compression].blockType;
}

#define GET_NEXT_INDEX() \
do { \
	if (indexStreamIndex >= _indexStreamSize) \
		error("TrueMotion1 decoder went out of bounds"); \
	index = _indexStream[indexStreamIndex++] * 4; \
} while (0) \

#define APPLY_C_PREDICTOR() \
	predictor_pair = _cPredictorTable[index].color; \
	horizPred += predictor_pair; \
	if (_cPredictorTable[index].getNextIndex) { \
		GET_NEXT_INDEX(); \
		if (!index) { \
			GET_NEXT_INDEX(); \
			predictor_pair = _cPredictorTable[index].color; \
			horizPred += predictor_pair * 5; \
			if (_cPredictorTable[index].getNextIndex) \
				GET_NEXT_INDEX(); \
			else \
				index++; \
		} \
	} else \
		index++

#define APPLY_Y_PREDICTOR() \
	predictor_pair = _yPredictorTable[index].color; \
	horizPred += predictor_pair; \
	if (_yPredictorTable[index].getNextIndex) { \
		GET_NEXT_INDEX(); \
		if (!index) { \
			GET_NEXT_INDEX(); \
			predictor_pair = _yPredictorTable[index].color; \
			horizPred += predictor_pair * 5; \
			if (_yPredictorTable[index].getNextIndex) \
				GET_NEXT_INDEX(); \
			else \
				index++; \
		} \
	} else \
		index++

#define OUTPUT_PIXEL_PAIR() \
	*currentPixelPair = *vertPred + horizPred; \
	*vertPred++ = *currentPixelPair++

void TrueMotion1Decoder::decode16() {
	uint32 predictor_pair;
	bool keyframe = _flags & FLAG_KEYFRAME;
	int indexStreamIndex = 0;

	// these variables are for managing the main index stream
	int index;

	// clean out the line buffer
	memset(_vertPred, 0, _width * 4);

	GET_NEXT_INDEX();

	for (int y = 0; y < _height; y++) {
		// re-init variables for the next line iteration
		uint32 horizPred = 0;
		uint32 *currentPixelPair = (uint32 *)_surface->getBasePtr(0, y);
		uint32 *vertPred = _vertPred;
		int mbChangeIndex = 0;
		byte mbChangeByte = _mbChangeBits[mbChangeIndex++];
		byte mbChangeByteMask = 1;

		for (int pixelsLeft = _width; pixelsLeft > 0; pixelsLeft -= 4) {
			if (keyframe || (mbChangeByte & mbChangeByteMask) == 0) {
				switch (y & 3) {
				case 0:
					// if macroblock width is 2, apply C-Y-C-Y; else
					// apply C-Y-Y
					if (_blockWidth == 2) {
						APPLY_C_PREDICTOR();
						APPLY_Y_PREDICTOR();
						OUTPUT_PIXEL_PAIR();
						APPLY_C_PREDICTOR();
						APPLY_Y_PREDICTOR();
						OUTPUT_PIXEL_PAIR();
					} else {
						APPLY_C_PREDICTOR();
						APPLY_Y_PREDICTOR();
						OUTPUT_PIXEL_PAIR();
						APPLY_Y_PREDICTOR();
						OUTPUT_PIXEL_PAIR();
					}
					break;
				case 1:
				case 3:
					// always apply 2 Y predictors on these iterations
					APPLY_Y_PREDICTOR();
					OUTPUT_PIXEL_PAIR();
					APPLY_Y_PREDICTOR();
					OUTPUT_PIXEL_PAIR();
					break;
				case 2:
					// this iteration might be C-Y-C-Y, Y-Y, or C-Y-Y
					// depending on the macroblock type
					if (_blockType == BLOCK_2x2) {
						APPLY_C_PREDICTOR();
						APPLY_Y_PREDICTOR();
						OUTPUT_PIXEL_PAIR();
						APPLY_C_PREDICTOR();
						APPLY_Y_PREDICTOR();
						OUTPUT_PIXEL_PAIR();
					} else if (_blockType == BLOCK_4x2) {
						APPLY_C_PREDICTOR();
						APPLY_Y_PREDICTOR();
						OUTPUT_PIXEL_PAIR();
						APPLY_Y_PREDICTOR();
						OUTPUT_PIXEL_PAIR();
					} else {
						APPLY_Y_PREDICTOR();
						OUTPUT_PIXEL_PAIR();
						APPLY_Y_PREDICTOR();
						OUTPUT_PIXEL_PAIR();
					}
					break;
				}
			} else {
				// skip (copy) four pixels, but reassign the horizontal
				// predictor
				*vertPred++ = *currentPixelPair++;
				horizPred = *currentPixelPair - *vertPred;
				*vertPred++ = *currentPixelPair++;
			}

			if (!keyframe) {
				mbChangeByteMask <<= 1;

				// next byte
				if (!mbChangeByteMask) {
					mbChangeByte = _mbChangeBits[mbChangeIndex++];
					mbChangeByteMask = 1;
				}
			}
		}

		// next change row
		if (((y + 1) & 3) == 0)
			_mbChangeBits += _mbChangeBitsRowSize;
	}
}

const Graphics::Surface *TrueMotion1Decoder::decodeImage(Common::SeekableReadStream *stream) {
	decodeHeader(stream);

	if (compressionTypes[_header.compression].algorithm == ALGO_NOP)
		return 0;

	if (compressionTypes[_header.compression].algorithm == ALGO_RGB24H) {
		warning("Unhandled TrueMotion1 24bpp frame");
		return 0;
	} else
		decode16();

	delete[] _buf;

	return _surface;
}

} // End of namespace Video

#endif