aboutsummaryrefslogtreecommitdiff
path: root/video/video_decoder.h
blob: aa88dda4a457714b360b86d15abeee7f17e1daa0 (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
/* 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.
 *
 * $URL$
 * $Id$
 *
 */

#ifndef VIDEO_DECODER_H
#define VIDEO_DECODER_H

#include "common/events.h"
#include "common/list.h"
#include "common/rational.h"

#include "graphics/surface.h"
#include "graphics/pixelformat.h"

namespace Common {
	class SeekableReadStream;
}

namespace Video {

/**
 * Implementation of a generic video decoder
 */
class VideoDecoder {
public:
	VideoDecoder();
	virtual ~VideoDecoder() {}

	/**
	 * Returns the width of the video
	 * @return the width of the video
	 */
	virtual uint16 getWidth() const = 0;

	/**
	 * Returns the height of the video
	 * @return the height of the video
	 */
	virtual uint16 getHeight() const = 0;

	/**
	 * Returns the current frame number of the video
	 * @return the last frame decoded by the video
	 */
	virtual int32 getCurFrame() const { return _curFrame; }

	/**
	 * Returns the amount of frames in the video
	 * @return the amount of frames in the video
	 */
	virtual uint32 getFrameCount() const = 0;

	/**
	 * Returns the time (in ms) that the video has been running
	 */
	virtual uint32 getElapsedTime() const;

	/**
	 * Returns whether a frame should be decoded or not
	 * @return whether a frame should be decoded or not
	 */
	virtual bool needsUpdate() const;

	/**
	 * Load a video file
	 * @param filename	the filename to load
	 */
	virtual bool loadFile(const Common::String &filename);

	/**
	 * Load a video file
	 * @param stream  the stream to load
	 */
	virtual bool load(Common::SeekableReadStream *stream) = 0;

	/**
	 * Close a video file
	 */
	virtual void close() = 0;

	/**
	 * Returns if a video file is loaded or not
	 */
	virtual bool isVideoLoaded() const = 0;

	/**
	 * Decode the next frame and return the frame's surface
	 * @note the return surface should *not* be freed
	 * @note this may return 0, in which case the last frame should be kept on screen
	 */
	virtual const Graphics::Surface *decodeNextFrame() = 0;

	/**
	 * Get the pixel format of the video
	 */
	virtual Graphics::PixelFormat getPixelFormat() const = 0;

	/**
	 * Get the palette for the video in RGB format (if 8bpp or less)
	 */
	virtual const byte *getPalette() { return 0; }

	/**
	 * Returns if the palette is dirty or not
	 */
	virtual bool hasDirtyPalette() const { return false; }

	/**
	 * Returns if the video is finished or not
	 */
	virtual bool endOfVideo() const;

	/**
	 * Set the current palette to the system palette
	 */
	void setSystemPalette();

	/**
	 * Return the time until the next frame (in ms)
	 */
	virtual uint32 getTimeToNextFrame() const = 0;

	/**
	 * Pause or resume the video. This should stop/resume any audio playback
	 * and other stuff. The initial pause time is kept so that any timing
	 * variables can be updated appropriately.
	 *
	 * This is a convenience tracker which automatically keeps track on how
	 * often the video has been paused, ensuring that after pausing an video
	 * e.g. twice, it has to be unpaused twice before actuallying resuming.
	 *
	 * @param pause		true to pause the video, false to resume it
	 */
	void pauseVideo(bool pause);

	/**
	 * Return whether the video is currently paused or not.
	 */
	bool isPaused() const { return _pauseLevel != 0; }

protected:
	/**
	 * Resets _curFrame and _startTime. Should be called from every close() function.
	 */
	void reset();

	/**
	 * Actual implementation of pause by subclasses. See pause()
	 * for details.
	 */
	virtual void pauseVideoIntern(bool pause) {}

	/**
	 * Add the time the video has been paused to maintain sync
	 */
	virtual void addPauseTime(uint32 ms) { _startTime += ms; }

	/**
	 * Reset the pause start time (which should be called when seeking)
	 */
	void resetPauseStartTime();

	int32 _curFrame;
	int32 _startTime;

private:
	uint32 _pauseLevel;
	uint32 _pauseStartTime;
};

/**
 * A VideoDecoder wrapper that implements getTimeToNextFrame() based on getFrameRate().
 */
class FixedRateVideoDecoder : public virtual VideoDecoder {
public:
	uint32 getTimeToNextFrame() const;

protected:
	/**
	 * Return the frame rate in frames per second
	 * This returns a Rational because videos can have rates that are not integers and
	 * there are some videos with frame rates < 1.
	 */
	virtual Common::Rational getFrameRate() const = 0;

private:
	uint32 getFrameBeginTime(uint32 frame) const;
};

/**
 * A VideoDecoder that can rewind back to the beginning.
 */
class RewindableVideoDecoder : public virtual VideoDecoder {
public:
	/**
	 * Rewind to the beginning of the video.
	 */
	virtual void rewind() = 0;
};

/**
 * A simple video timestamp that holds time according to a specific scale.
 *
 * The scale is in terms of 1/x. For example, if you set units to 1 and the scale to 
 * 1000, the timestamp will hold the value of 1/1000s or 1ms.
 */
class VideoTimestamp {
public:
	VideoTimestamp();
	VideoTimestamp(uint units, uint scale = 1000);

	/**
	 * Get the units in terms of _scale
	 */
	uint getUnits() const { return _units; }

	/**
	 * Get the scale of this timestamp
	 */
	uint getScale() const { return _scale; }

	/**
	 * Get the value of the units in terms of the specified scale
	 */
	uint getUnitsInScale(uint scale) const;

	// TODO: Simple comparisons (<, <=, >, >=, ==, !=)

private:
	uint _units, _scale;
};

/**
 * A VideoDecoder that can seek to a frame or point in time.
 */
class SeekableVideoDecoder : public virtual RewindableVideoDecoder {
public:
	/**
	 * Seek to the frame specified
	 * If seekToFrame(0) is called, frame 0 will be decoded next in decodeNextFrame()
	 */
	virtual void seekToFrame(uint32 frame) = 0;

	/**
	 * Seek to the time specified
	 *
	 * This will round to the previous frame showing. If the time would happen to
	 * land while a frame is showing, this function will seek to the beginning of that
	 * frame. In other words, there is *no* subframe accuracy. This may change in a
	 * later revision of the API.
	 */
	virtual void seekToTime(VideoTimestamp time) = 0;

	/**
	 * Seek to the frame specified (in ms)
	 *
	 * See seekToTime(VideoTimestamp)
	 */
	void seekToTime(uint32 time) { seekToTime(VideoTimestamp(time)); }

	/**
	 * Implementation of RewindableVideoDecoder::rewind()
	 */
	virtual void rewind() { seekToTime(0); }
};

} // End of namespace Video

#endif