1 |
/*************************************************************************** |
2 |
* * |
3 |
* LinuxSampler - modular, streaming capable sampler * |
4 |
* * |
5 |
* Copyright (C) 2003 - 2009 Christian Schoenebeck * |
6 |
* Copyright (C) 2009 Grigor Iliev * |
7 |
* * |
8 |
* This program is free software; you can redistribute it and/or modify * |
9 |
* it under the terms of the GNU General Public License as published by * |
10 |
* the Free Software Foundation; either version 2 of the License, or * |
11 |
* (at your option) any later version. * |
12 |
* * |
13 |
* This program is distributed in the hope that it will be useful, * |
14 |
* but WITHOUT ANY WARRANTY; without even the implied warranty of * |
15 |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * |
16 |
* GNU General Public License for more details. * |
17 |
* * |
18 |
* You should have received a copy of the GNU General Public License * |
19 |
* along with this program; if not, write to the Free Software * |
20 |
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, * |
21 |
* MA 02111-1307 USA * |
22 |
***************************************************************************/ |
23 |
|
24 |
#ifndef __LS_SAMPLE_H__ |
25 |
#define __LS_SAMPLE_H__ |
26 |
|
27 |
#include "../../common/global.h" |
28 |
|
29 |
namespace LinuxSampler { |
30 |
class Sample { |
31 |
public: |
32 |
|
33 |
/** Pointer address and size of a buffer. */ |
34 |
struct buffer_t { |
35 |
void* pStart; ///< Points to the beginning of the buffer. |
36 |
unsigned long Size; ///< Size of the actual data in the buffer in bytes. |
37 |
|
38 |
unsigned long NullExtensionSize; /*/< The buffer might be bigger than the actual data, if that's the case |
39 |
that unused space at the end of the buffer is filled with NULLs and NullExtensionSize reflects |
40 |
that unused buffer space in bytes. Those NULL extensions are mandatory for differential |
41 |
algorithms that have to take the following data words into account, thus have to access past |
42 |
the buffer's boundary. If you don't know what I'm talking about, just forget this variable. :) */ |
43 |
buffer_t() { |
44 |
pStart = NULL; |
45 |
Size = 0; |
46 |
NullExtensionSize = 0; |
47 |
} |
48 |
}; |
49 |
|
50 |
/** Reflects the current playback state for a sample. */ |
51 |
class PlaybackState { |
52 |
public: |
53 |
unsigned long position; ///< Current position within the sample. |
54 |
bool reverse; ///< If playback direction is currently backwards (in case there is a pingpong or reverse loop defined). |
55 |
unsigned long loop_cycles_left; ///< How many times the loop has still to be passed, this value will be decremented with each loop cycle. |
56 |
}; |
57 |
|
58 |
uint Offset; // The offset used to play the sample (in sample units) |
59 |
|
60 |
uint RAMCacheOffset; // The offset of the RAM cache from the sample start (in sample units) |
61 |
|
62 |
/* |
63 |
* Specifies the maximum offset (in frames) that can be set without |
64 |
* the need to offset the RAM cache. |
65 |
*/ |
66 |
uint MaxOffset; |
67 |
|
68 |
Sample(): MaxOffset(2000), Offset(0), RAMCacheOffset(0) { } |
69 |
virtual ~Sample() { } |
70 |
|
71 |
virtual String GetName() = 0; |
72 |
virtual int GetSampleRate() = 0; |
73 |
virtual int GetChannelCount() = 0; |
74 |
|
75 |
/** |
76 |
* @returns The frame size in bytes |
77 |
*/ |
78 |
virtual int GetFrameSize() = 0; |
79 |
|
80 |
/** |
81 |
* @returns The total number of frames in this sample |
82 |
*/ |
83 |
virtual long GetTotalFrameCount() = 0; |
84 |
|
85 |
/** |
86 |
* Loads (and uncompresses if needed) the whole sample wave into RAM. Use |
87 |
* ReleaseSampleData() to free the memory if you don't need the cached |
88 |
* sample data anymore. |
89 |
* |
90 |
* @returns buffer_t structure with start address and size of the buffer |
91 |
* in bytes |
92 |
* @see ReleaseSampleData(), Read(), SetPos() |
93 |
*/ |
94 |
virtual buffer_t LoadSampleData() = 0; |
95 |
|
96 |
/** |
97 |
* Reads (uncompresses if needed) and caches the first \a FrameCount |
98 |
* numbers of SamplePoints in RAM. Use ReleaseSampleData() to free the |
99 |
* memory space if you don't need the cached samples anymore. There is no |
100 |
* guarantee that exactly \a SampleCount samples will be cached; this is |
101 |
* not an error. The size will be eventually truncated e.g. to the |
102 |
* beginning of a frame of a compressed sample. This is done for |
103 |
* efficiency reasons while streaming the wave by your sampler engine |
104 |
* later. Read the <i>Size</i> member of the <i>buffer_t</i> structure |
105 |
* that will be returned to determine the actual cached samples, but note |
106 |
* that the size is given in bytes! You get the number of actually cached |
107 |
* samples by dividing it by the frame size of the sample: |
108 |
* @code |
109 |
* buffer_t buf = pSample->LoadSampleData(acquired_samples); |
110 |
* long cachedsamples = buf.Size / pSample->FrameSize; |
111 |
* @endcode |
112 |
* |
113 |
* @param FrameCount - number of sample points to load into RAM |
114 |
* @returns buffer_t structure with start address and size of |
115 |
* the cached sample data in bytes |
116 |
* @see ReleaseSampleData(), Read(), SetPos() |
117 |
*/ |
118 |
virtual buffer_t LoadSampleData(unsigned long FrameCount) = 0; |
119 |
|
120 |
/** |
121 |
* Loads (and uncompresses if needed) the whole sample wave into RAM. Use |
122 |
* ReleaseSampleData() to free the memory if you don't need the cached |
123 |
* sample data anymore. |
124 |
* The method will add \a NullSamplesCount silence samples past the |
125 |
* official buffer end (this won't affect the 'Size' member of the |
126 |
* buffer_t structure, that means 'Size' always reflects the size of the |
127 |
* actual sample data, the buffer might be bigger though). Silence |
128 |
* samples past the official buffer are needed for differential |
129 |
* algorithms that always have to take subsequent samples into account |
130 |
* (resampling/interpolation would be an important example) and avoids |
131 |
* memory access faults in such cases. |
132 |
* |
133 |
* @param NullSamplesCount - number of silence samples the buffer should |
134 |
* be extended past it's data end |
135 |
* @returns buffer_t structure with start address and |
136 |
* size of the buffer in bytes |
137 |
* @see ReleaseSampleData(), Read(), SetPos() |
138 |
*/ |
139 |
virtual buffer_t LoadSampleDataWithNullSamplesExtension(uint NullFrameCount) = 0; |
140 |
|
141 |
/** |
142 |
* Reads (uncompresses if needed) and caches the first \a SampleCount |
143 |
* numbers of SamplePoints in RAM. Use ReleaseSampleData() to free the |
144 |
* memory space if you don't need the cached samples anymore. There is no |
145 |
* guarantee that exactly \a SampleCount samples will be cached; this is |
146 |
* not an error. The size will be eventually truncated e.g. to the |
147 |
* beginning of a frame of a compressed sample. This is done for |
148 |
* efficiency reasons while streaming the wave by your sampler engine |
149 |
* later. Read the <i>Size</i> member of the <i>buffer_t</i> structure |
150 |
* that will be returned to determine the actual cached samples, but note |
151 |
* that the size is given in bytes! You get the number of actually cached |
152 |
* samples by dividing it by the frame size of the sample: |
153 |
* @code |
154 |
* buffer_t buf = pSample->LoadSampleDataWithNullSamplesExtension(acquired_samples, null_samples); |
155 |
* long cachedsamples = buf.Size / pSample->FrameSize; |
156 |
* @endcode |
157 |
* The method will add \a NullSamplesCount silence samples past the |
158 |
* official buffer end (this won't affect the 'Size' member of the |
159 |
* buffer_t structure, that means 'Size' always reflects the size of the |
160 |
* actual sample data, the buffer might be bigger though). Silence |
161 |
* samples past the official buffer are needed for differential |
162 |
* algorithms that always have to take subsequent samples into account |
163 |
* (resampling/interpolation would be an important example) and avoids |
164 |
* memory access faults in such cases. |
165 |
* |
166 |
* @param FrameCount - number of sample points to load into RAM |
167 |
* @param NullFramesCount - number of silence samples the buffer should |
168 |
* be extended past it's data end |
169 |
* @returns buffer_t structure with start address and |
170 |
* size of the cached sample data in bytes |
171 |
* @see ReleaseSampleData(), Read() |
172 |
*/ |
173 |
virtual buffer_t LoadSampleDataWithNullSamplesExtension(unsigned long FrameCount, uint NullFramesCount) = 0; |
174 |
|
175 |
/** |
176 |
* Frees the cached sample from RAM if loaded with |
177 |
* <i>LoadSampleData()</i> previously. |
178 |
* |
179 |
* @see LoadSampleData(); |
180 |
*/ |
181 |
virtual void ReleaseSampleData() = 0; |
182 |
|
183 |
/** |
184 |
* Returns current cached sample points. A buffer_t structure will be |
185 |
* returned which contains address pointer to the begin of the cache and |
186 |
* the size of the cached sample data in bytes. Use |
187 |
* <i>LoadSampleData()</i> to cache a specific amount of sample points in |
188 |
* RAM. |
189 |
* |
190 |
* @returns buffer_t structure with current cached sample points |
191 |
* @see LoadSampleData(); |
192 |
*/ |
193 |
virtual buffer_t GetCache() = 0; |
194 |
|
195 |
/** |
196 |
* Reads \a FrameCount number of frames from the current |
197 |
* position into the buffer pointed by \a pBuffer and increments the |
198 |
* position within the sample. Use this method |
199 |
* and <i>SetPos()</i> if you don't want to load the sample into RAM, |
200 |
* thus for disk streaming. |
201 |
* |
202 |
* For 16 bit samples, the data in the buffer will be int16_t |
203 |
* (using native endianness). For 24 bit, the buffer will |
204 |
* contain 4 bytes per sample. |
205 |
* |
206 |
* @param pBuffer destination buffer |
207 |
* @param SampleCount number of sample points to read |
208 |
* @returns number of successfully read sample points |
209 |
*/ |
210 |
virtual long Read(void* pBuffer, unsigned long FrameCount) = 0; |
211 |
|
212 |
/** |
213 |
* Reads \a SampleCount number of sample points from the position stored |
214 |
* in \a pPlaybackState into the buffer pointed by \a pBuffer and moves |
215 |
* the position within the sample respectively, this method honors the |
216 |
* looping informations of the sample (if any). Use this |
217 |
* method if you don't want to load the sample into RAM, thus for disk |
218 |
* streaming. All this methods needs to know to proceed with streaming |
219 |
* for the next time you call this method is stored in \a pPlaybackState. |
220 |
* You have to allocate and initialize the playback_state_t structure by |
221 |
* yourself before you use it to stream a sample: |
222 |
* @code |
223 |
* PlaybackState playbackstate; |
224 |
* playbackstate.position = 0; |
225 |
* playbackstate.reverse = false; |
226 |
* playbackstate.loop_cycles_left = pSample->LoopPlayCount; |
227 |
* @endcode |
228 |
* You don't have to take care of things like if there is actually a loop |
229 |
* defined or if the current read position is located within a loop area. |
230 |
* The method already handles such cases by itself. |
231 |
* |
232 |
* @param pBuffer destination buffer |
233 |
* @param FrameCount number of sample points to read |
234 |
* @param pPlaybackState will be used to store and reload the playback |
235 |
* state for the next ReadAndLoop() call |
236 |
* @returns number of successfully read sample points |
237 |
*/ |
238 |
virtual unsigned long ReadAndLoop ( |
239 |
void* pBuffer, |
240 |
unsigned long FrameCount, |
241 |
PlaybackState* pPlaybackState |
242 |
) = 0; |
243 |
|
244 |
virtual long SetPos(unsigned long FrameOffset) = 0; |
245 |
virtual long GetPos() = 0; |
246 |
}; |
247 |
} // namespace LinuxSampler |
248 |
|
249 |
#endif // __LS_SAMPLE_H__ |