aboutsummaryrefslogtreecommitdiff
path: root/engines/sci/video/seq_decoder.cpp
blob: 2c117ae329db9163c0c8dc0c4ef70796ad3a10fb (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
/* 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.
 *
 * $URL$
 * $Id$
 *
 */

#include "common/debug.h"
#include "common/endian.h"
#include "common/archive.h"
#include "common/system.h"
#include "common/util.h"

#include "graphics/surface.h"

#include "sci/video/seq_decoder.h"

namespace Sci {

enum seqPalTypes {
	kSeqPalVariable = 0,
	kSeqPalConstant = 1
};

enum seqFrameTypes {
	kSeqFrameFull = 0,
	kSeqFrameDiff = 1
};

SeqDecoder::SeqDecoder() {
	_fileStream = 0;
	_surface = 0;
	_dirtyPalette = false;
}

SeqDecoder::~SeqDecoder() {
	close();
}

bool SeqDecoder::load(Common::SeekableReadStream &stream) {
	close();

	_fileStream = &stream;
	_surface = new Graphics::Surface();
	_surface->create(SEQ_SCREEN_WIDTH, SEQ_SCREEN_HEIGHT, 1);

	_frameCount = _fileStream->readUint16LE();

	// Set palette
	int paletteSize = _fileStream->readUint32LE();

	byte *paletteData = new byte[paletteSize];
	_fileStream->read(paletteData, paletteSize);

	// SCI1.1 palette
	byte palFormat = paletteData[32];
	uint16 palColorStart = READ_LE_UINT16(paletteData + 25);
	uint16 palColorCount = READ_LE_UINT16(paletteData + 29);

	int palOffset = 37;

	for (uint16 colorNo = palColorStart; colorNo < palColorStart + palColorCount; colorNo++) {
		if (palFormat == kSeqPalVariable)
			palOffset++;
		_palette[colorNo * 3 + 0] = paletteData[palOffset++];
		_palette[colorNo * 3 + 1] = paletteData[palOffset++];
		_palette[colorNo * 3 + 2] = paletteData[palOffset++];
	}

	_dirtyPalette = true;
	delete[] paletteData;
	return true;
}

void SeqDecoder::close() {
	if (!_fileStream)
		return;

	_frameDelay = 0;

	delete _fileStream;
	_fileStream = 0;

	_surface->free();
	delete _surface;
	_surface = 0;

	reset();
}

Graphics::Surface *SeqDecoder::decodeNextFrame() {
	int16 frameWidth = _fileStream->readUint16LE();
	int16 frameHeight = _fileStream->readUint16LE();
	int16 frameLeft = _fileStream->readUint16LE();
	int16 frameTop = _fileStream->readUint16LE();
	byte colorKey = _fileStream->readByte();
	byte frameType = _fileStream->readByte();
	_fileStream->skip(2);
	uint16 frameSize = _fileStream->readUint16LE();
	_fileStream->skip(2);
	uint16 rleSize = _fileStream->readUint16LE();
	_fileStream->skip(6);
	uint32 offset = _fileStream->readUint32LE();

	_fileStream->seek(offset);

	if (frameType == kSeqFrameFull) {
		byte *dst = (byte *)_surface->pixels + frameTop * SEQ_SCREEN_WIDTH + frameLeft;

		byte *linebuf = new byte[frameWidth];

		do {
			_fileStream->read(linebuf, frameWidth);
			memcpy(dst, linebuf, frameWidth);
			dst += SEQ_SCREEN_WIDTH;
		} while (--frameHeight);

		delete[] linebuf;
	} else {
		byte *buf = new byte[frameSize];
		_fileStream->read(buf, frameSize);
		decodeFrame(buf, rleSize, buf + rleSize, frameSize - rleSize, (byte *)_surface->pixels + SEQ_SCREEN_WIDTH * frameTop, frameLeft, frameWidth, frameHeight, colorKey);
		delete[] buf;
	}

	if (_curFrame == -1)
		_startTime = g_system->getMillis();

	_curFrame++;
	return _surface;
}

#define WRITE_TO_BUFFER(n) \
	if (writeRow * SEQ_SCREEN_WIDTH + writeCol + (n) > SEQ_SCREEN_WIDTH * height) { \
		warning("SEQ player: writing out of bounds, aborting"); \
		return false; \
	} \
	if (litPos + (n) > litSize) { \
		warning("SEQ player: reading out of bounds, aborting"); \
	} \
	memcpy(dest + writeRow * SEQ_SCREEN_WIDTH + writeCol, litData + litPos, n);

bool SeqDecoder::decodeFrame(byte *rleData, int rleSize, byte *litData, int litSize, byte *dest, int left, int width, int height, int colorKey) {
	int writeRow = 0;
	int writeCol = left;
	int litPos = 0;
	int rlePos = 0;

	while (rlePos < rleSize) {
		int op = rleData[rlePos++];

		if ((op & 0xc0) == 0xc0) {
			op &= 0x3f;
			if (op == 0) {
				// Go to next line in target buffer
				writeRow++;
				writeCol = left;
			} else {
				// Skip bytes on current line
				writeCol += op;
			}
		} else if (op & 0x80) {
			op &= 0x3f;
			if (op == 0) {
				// Copy remainder of current line
				int rem = width - (writeCol - left);

				WRITE_TO_BUFFER(rem);
				writeRow++;
				writeCol = left;
				litPos += rem;
			} else {
				// Copy bytes
				WRITE_TO_BUFFER(op);
				writeCol += op;
				litPos += op;
			}
		} else {
			uint16 count = ((op & 7) << 8) | rleData[rlePos++];

			switch (op >> 3) {
			case 2:
				// Skip bytes
				writeCol += count;
				break;
			case 3:
				// Copy bytes
				WRITE_TO_BUFFER(count);
				writeCol += count;
				litPos += count;
				break;
			case 6: {
				// Copy rows
				if (count == 0)
					count = height - writeRow;

				for (int i = 0; i < count; i++) {
					WRITE_TO_BUFFER(width);
					litPos += width;
					writeRow++;
				}
				break;
			}
			case 7:
				// Skip rows
				if (count == 0)
					count = height - writeRow;

				writeRow += count;
				break;
			default:
				warning("Unsupported operation %i encountered", op >> 3);
				return false;
			}
		}
	}

	return true;
}

} // End of namespace Sci