2 Copyright (C) 2012-2013 Carl Hetherington <cth@carlh.net>
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 #include "audio_buffers.h"
27 using boost::shared_ptr;
29 /** Construct an AudioBuffers. Audio data is undefined after this constructor.
30 * @param channels Number of channels.
31 * @param frames Number of frames to reserve space for.
33 AudioBuffers::AudioBuffers (int channels, int frames)
35 allocate (channels, frames);
39 * @param other Other AudioBuffers; data is copied.
41 AudioBuffers::AudioBuffers (AudioBuffers const & other)
43 allocate (other._channels, other._frames);
44 copy_from (&other, other._frames, 0, 0);
47 AudioBuffers::AudioBuffers (boost::shared_ptr<const AudioBuffers> other)
49 allocate (other->_channels, other->_frames);
50 copy_from (other.get(), other->_frames, 0, 0);
54 AudioBuffers::operator= (AudioBuffers const & other)
61 allocate (other._channels, other._frames);
62 copy_from (&other, other._frames, 0, 0);
67 /** AudioBuffers destructor */
68 AudioBuffers::~AudioBuffers ()
74 AudioBuffers::allocate (int channels, int frames)
77 assert (channels >= 0);
81 _allocated_frames = frames;
83 _data = static_cast<float**> (malloc (_channels * sizeof (float *)));
88 for (int i = 0; i < _channels; ++i) {
89 _data[i] = static_cast<float*> (malloc (frames * sizeof (float)));
97 AudioBuffers::deallocate ()
99 for (int i = 0; i < _channels; ++i) {
106 /** @param c Channel index.
107 * @return Buffer for this channel.
110 AudioBuffers::data (int c) const
112 assert (c >= 0 && c < _channels);
116 /** Set the number of frames that these AudioBuffers will report themselves
117 * as having. If we reduce the number of frames, the `lost' frames will
119 * @param f Frames; must be less than or equal to the number of allocated frames.
122 AudioBuffers::set_frames (int f)
124 assert (f <= _allocated_frames);
126 for (int c = 0; c < _channels; ++c) {
127 for (int i = f; i < _frames; ++i) {
135 /** Make all samples on all channels silent */
137 AudioBuffers::make_silent ()
139 for (int i = 0; i < _channels; ++i) {
144 /** Make all samples on a given channel silent.
148 AudioBuffers::make_silent (int c)
150 assert (c >= 0 && c < _channels);
152 for (int i = 0; i < _frames; ++i) {
158 AudioBuffers::make_silent (int from, int frames)
160 assert ((from + frames) <= _allocated_frames);
162 for (int c = 0; c < _channels; ++c) {
163 for (int i = from; i < (from + frames); ++i) {
169 /** Copy data from another AudioBuffers to this one. All channels are copied.
170 * @param from AudioBuffers to copy from; must have the same number of channels as this.
171 * @param frames_to_copy Number of frames to copy.
172 * @param read_offset Offset to read from in `from'.
173 * @param write_offset Offset to write to in `to'.
176 AudioBuffers::copy_from (AudioBuffers const * from, int frames_to_copy, int read_offset, int write_offset)
178 if (frames_to_copy == 0) {
179 /* Prevent the asserts from firing if there is nothing to do */
183 assert (from->channels() == channels());
186 assert (read_offset >= 0 && (read_offset + frames_to_copy) <= from->_allocated_frames);
187 assert (write_offset >= 0 && (write_offset + frames_to_copy) <= _allocated_frames);
189 for (int i = 0; i < _channels; ++i) {
190 memcpy (_data[i] + write_offset, from->_data[i] + read_offset, frames_to_copy * sizeof(float));
194 /** Move audio data around.
195 * @param from Offset to move from.
196 * @param to Offset to move to.
197 * @param frames Number of frames to move.
201 AudioBuffers::move (int from, int to, int frames)
208 assert (from < _frames);
210 assert (to < _frames);
212 assert (frames <= _frames);
213 assert ((from + frames) <= _frames);
214 assert ((to + frames) <= _allocated_frames);
216 for (int i = 0; i < _channels; ++i) {
217 memmove (_data[i] + to, _data[i] + from, frames * sizeof(float));
221 /** Add data from from `from', `from_channel' to our channel `to_channel'.
222 * @param gain Linear gain to apply to the data before it is added.
225 AudioBuffers::accumulate_channel (AudioBuffers const * from, int from_channel, int to_channel, float gain)
227 int const N = frames ();
228 assert (from->frames() == N);
229 assert (to_channel <= _channels);
231 float* s = from->data (from_channel);
232 float* d = _data[to_channel];
234 for (int i = 0; i < N; ++i) {
235 *d++ += (*s++) * gain;
239 /** Ensure we have space for at least a certain number of frames. If we extend
240 * the buffers, fill the new space with silence.
243 AudioBuffers::ensure_size (int frames)
245 if (_allocated_frames >= frames) {
249 for (int i = 0; i < _channels; ++i) {
250 _data[i] = static_cast<float*> (realloc (_data[i], frames * sizeof (float)));
254 for (int j = _allocated_frames; j < frames; ++j) {
259 _allocated_frames = frames;
263 AudioBuffers::accumulate_frames (AudioBuffers const * from, int read_offset, int write_offset, int frames)
265 assert (_channels == from->channels ());
266 assert (read_offset >= 0);
267 assert (write_offset >= 0);
269 for (int i = 0; i < _channels; ++i) {
270 for (int j = 0; j < frames; ++j) {
271 _data[i][j + write_offset] += from->data()[i][j + read_offset];
276 /** @param dB gain in dB */
278 AudioBuffers::apply_gain (float dB)
280 float const linear = pow (10, dB / 20);
282 for (int i = 0; i < _channels; ++i) {
283 for (int j = 0; j < _frames; ++j) {
284 _data[i][j] *= linear;
289 /** @param c Channel index.
290 * @return AudioBuffers object containing only channel `c' from this AudioBuffers.
292 shared_ptr<AudioBuffers>
293 AudioBuffers::channel (int c) const
295 shared_ptr<AudioBuffers> o (new AudioBuffers (1, frames ()));
296 o->copy_channel_from (this, c, 0);
301 AudioBuffers::copy_channel_from (AudioBuffers const * from, int from_channel, int to_channel)
303 assert (from->frames() == frames());
304 memcpy (data(to_channel), from->data(from_channel), frames() * sizeof (float));
307 shared_ptr<AudioBuffers>
308 AudioBuffers::clone () const
310 shared_ptr<AudioBuffers> b (new AudioBuffers (channels (), frames ()));
311 b->copy_from (this, frames (), 0, 0);