aboutsummaryrefslogtreecommitdiff
path: root/sound/audiostream.cpp
blob: 26e2de48b4e1fa8ae3ecd05c5b29e607aa0f60e1 (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
/* ScummVM - Scumm Interpreter
 * Copyright (C) 2001-2006 The ScummVM project
 *
 * 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/stdafx.h"
#include "common/file.h"
#include "common/util.h"
#include "sound/audiostream.h"
#include "sound/mixer.h"
#include "sound/mp3.h"
#include "sound/vorbis.h"
#include "sound/flac.h"

struct StreamFileFormat {
	/** Decodername */
	const char* decoderName;
	const char* fileExtension;
	/**
	 * Pointer to a function which tries to open a file of type StreamFormat.
	 * Return NULL in case of an error (invalid/nonexisting file).
	 */
	AudioStream* (*openStreamFile)(Common::File *file, uint32 size);
};

static const StreamFileFormat STREAM_FILEFORMATS[] = {
	/* decoderName,		fileExt, openStreamFuntion */
#ifdef USE_FLAC
	{ "Flac",			"flac", makeFlacStream },
	{ "Flac",			"fla",  makeFlacStream },
#endif
#ifdef USE_VORBIS
	{ "Ogg Vorbis",		"ogg",  makeVorbisStream },
#endif
#ifdef USE_MAD
	{ "MPEG Layer 3",	"mp3",  makeMP3Stream },
#endif

	{ NULL, NULL, NULL } // Terminator
};

AudioStream* AudioStream::openStreamFile(const char *filename)
{
	char buffer[1024];
	const uint len = strlen(filename);
	assert(len+6 < sizeof(buffer)); // we need a bigger buffer if wrong

	memcpy(buffer, filename, len);
	buffer[len] = '.';
	char *ext = &buffer[len+1];

	AudioStream* stream = NULL;
	Common::File *fileHandle = new Common::File();

	for (int i = 0; i < ARRAYSIZE(STREAM_FILEFORMATS)-1 && stream == NULL; ++i) {
		strcpy(ext, STREAM_FILEFORMATS[i].fileExtension);
		fileHandle->open(buffer);
		if (fileHandle->isOpen())
			stream = STREAM_FILEFORMATS[i].openStreamFile(fileHandle, fileHandle->size());
	}

	// Do not reference the file anymore. If the stream didn't incRef the file,
	// the object will be deleted (and the file be closed).
	fileHandle->decRef();

	if (stream == NULL) {
		debug(1, "AudioStream: Could not open compressed AudioFile %s", filename);
	}

	return stream;
}

#pragma mark -
#pragma mark --- LinearMemoryStream ---
#pragma mark -


/**
 * A simple raw audio stream, purely memory based. It operates on a single
 * block of data, which is passed to it upon creation.
 * Optionally supports looping the sound.
 *
 * Design note: This code tries to be as optimized as possible (without
 * resorting to assembly, that is). To this end, it is written as a template
 * class. This way the compiler can actually create optimized code for each
 * special code. This results in a total of 12 versions of the code being
 * generated.
 */
template<bool stereo, bool is16Bit, bool isUnsigned, bool isLE>
class LinearMemoryStream : public AudioStream {
protected:
	const byte *_ptr;
	const byte *_end;
	const byte *_loopPtr;
	const byte *_loopEnd;
	const int _rate;
	const byte *_origPtr;

	inline bool eosIntern() const	{ return _ptr >= _end; };
public:
	LinearMemoryStream(int rate, const byte *ptr, uint len, uint loopOffset, uint loopLen, bool autoFreeMemory)
		: _ptr(ptr), _end(ptr+len), _loopPtr(0), _loopEnd(0), _rate(rate) {

		// Verify the buffer sizes are sane
		if (is16Bit && stereo)
			assert((len & 3) == 0 && (loopLen & 3) == 0);
		else if (is16Bit || stereo)
			assert((len & 1) == 0 && (loopLen & 1) == 0);

		if (loopLen) {
			_loopPtr = _ptr + loopOffset;
			_loopEnd = _loopPtr + loopLen;
		}
		if (stereo)	// Stereo requires even sized data
			assert(len % 2 == 0);

		_origPtr = autoFreeMemory ? ptr : 0;
	}
	~LinearMemoryStream() {
		free(const_cast<byte *>(_origPtr));
	}
	int readBuffer(int16 *buffer, const int numSamples);

	bool isStereo() const		{ return stereo; }
	bool endOfData() const		{ return eosIntern(); }

	int getRate() const			{ return _rate; }
};

template<bool stereo, bool is16Bit, bool isUnsigned, bool isLE>
int LinearMemoryStream<stereo, is16Bit, isUnsigned, isLE>::readBuffer(int16 *buffer, const int numSamples) {
	int samples = 0;
	while (samples < numSamples && !eosIntern()) {
		const int len = MIN(numSamples, samples + (int)(_end - _ptr) / (is16Bit ? 2 : 1));
		while (samples < len) {
			*buffer++ = READ_ENDIAN_SAMPLE(is16Bit, isUnsigned, _ptr, isLE);
			_ptr += (is16Bit ? 2 : 1);
			samples++;
		}
		// Loop, if looping was specified
		if (_loopPtr && eosIntern()) {
			_ptr = _loopPtr;
			_end = _loopEnd;
		}
	}
	return samples;
}


#pragma mark -
#pragma mark --- Input stream factory ---
#pragma mark -

/* In the following, we use preprocessor / macro tricks to simplify the code
 * which instantiates the input streams. We used to use template functions for
 * this, but MSVC6 / EVC 3-4 (used for WinCE builds) are extremely buggy when it
 * comes to this feature of C++... so as a compromise we use macros to cut down
 * on the (source) code duplication a bit.
 * So while normally macro tricks are said to make maintenance harder, in this
 * particular case it should actually help it :-)
 */

#define MAKE_LINEAR(STEREO, UNSIGNED) \
		if (is16Bit) { \
			if (isLE) \
				return new LinearMemoryStream<STEREO, true, UNSIGNED, true>(rate, ptr, len, loopOffset, loopLen, autoFree); \
			else  \
				return new LinearMemoryStream<STEREO, true, UNSIGNED, false>(rate, ptr, len, loopOffset, loopLen, autoFree); \
		} else \
			return new LinearMemoryStream<STEREO, false, UNSIGNED, false>(rate, ptr, len, loopOffset, loopLen, autoFree)

AudioStream *makeLinearInputStream(int rate, byte flags, const byte *ptr, uint32 len, uint loopOffset, uint loopLen) {
	const bool isStereo   = (flags & Audio::Mixer::FLAG_STEREO) != 0;
	const bool is16Bit    = (flags & Audio::Mixer::FLAG_16BITS) != 0;
	const bool isUnsigned = (flags & Audio::Mixer::FLAG_UNSIGNED) != 0;
	const bool isLE       = (flags & Audio::Mixer::FLAG_LITTLE_ENDIAN) != 0;
	const bool autoFree   = (flags & Audio::Mixer::FLAG_AUTOFREE) != 0;

	if (isStereo) {
		if (isUnsigned) {
			MAKE_LINEAR(true, true);
		} else {
			MAKE_LINEAR(true, false);
		}
	} else {
		if (isUnsigned) {
			MAKE_LINEAR(false, true);
		} else {
			MAKE_LINEAR(false, false);
		}
	}
}