2 Copyright (C) 2012-2020 Carl Hetherington <cth@carlh.net>
4 This file is part of DCP-o-matic.
6 DCP-o-matic is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 DCP-o-matic is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with DCP-o-matic. If not, see <http://www.gnu.org/licenses/>.
22 #include "audio_buffers.h"
23 #include "dcpomatic_assert.h"
30 using std::shared_ptr;
32 /** Construct an AudioBuffers. Audio data is undefined after this constructor.
33 * @param channels Number of channels.
34 * @param frames Number of frames to reserve space for.
36 AudioBuffers::AudioBuffers (int channels, int32_t frames)
38 allocate (channels, frames);
42 * @param other Other AudioBuffers; data is copied.
44 AudioBuffers::AudioBuffers (AudioBuffers const & other)
46 allocate (other._channels, other._frames);
47 copy_from (&other, other._frames, 0, 0);
50 AudioBuffers::AudioBuffers (std::shared_ptr<const AudioBuffers> other)
52 allocate (other->_channels, other->_frames);
53 copy_from (other.get(), other->_frames, 0, 0);
56 AudioBuffers::AudioBuffers (std::shared_ptr<const AudioBuffers> other, int32_t frames_to_copy, int32_t read_offset)
58 allocate (other->_channels, frames_to_copy);
59 copy_from (other.get(), frames_to_copy, read_offset, 0);
63 AudioBuffers::operator= (AudioBuffers const & other)
70 allocate (other._channels, other._frames);
71 copy_from (&other, other._frames, 0, 0);
76 /** AudioBuffers destructor */
77 AudioBuffers::~AudioBuffers ()
83 AudioBuffers::allocate (int channels, int32_t frames)
85 DCPOMATIC_ASSERT (frames >= 0);
86 DCPOMATIC_ASSERT (channels >= 0);
90 _allocated_frames = frames;
92 _data = static_cast<float**> (malloc (_channels * sizeof (float *)));
97 for (int i = 0; i < _channels; ++i) {
98 _data[i] = static_cast<float*> (malloc (frames * sizeof (float)));
106 AudioBuffers::deallocate ()
108 for (int i = 0; i < _channels; ++i) {
115 /** @param c Channel index.
116 * @return Buffer for this channel.
119 AudioBuffers::data (int c) const
121 DCPOMATIC_ASSERT (c >= 0 && c < _channels);
125 /** Set the number of frames that these AudioBuffers will report themselves
126 * as having. If we reduce the number of frames, the `lost' frames will
128 * @param f Frames; must be less than or equal to the number of allocated frames.
131 AudioBuffers::set_frames (int32_t f)
133 DCPOMATIC_ASSERT (f <= _allocated_frames);
136 make_silent (f, _frames - f);
141 /** Make all frames silent */
143 AudioBuffers::make_silent ()
145 for (int i = 0; i < _channels; ++i) {
150 /** Make all samples on a given channel silent.
154 AudioBuffers::make_silent (int c)
156 DCPOMATIC_ASSERT (c >= 0 && c < _channels);
158 /* This isn't really allowed, as all-bits-0 is not guaranteed to mean a 0 float,
159 but it seems that we can get away with it.
161 memset (_data[c], 0, _frames * sizeof(float));
164 /** Make some frames.
165 * @param from Start frame.
166 * @param frames Number of frames to silence.
169 AudioBuffers::make_silent (int32_t from, int32_t frames)
171 DCPOMATIC_ASSERT ((from + frames) <= _allocated_frames);
173 for (int c = 0; c < _channels; ++c) {
174 /* This isn't really allowed, as all-bits-0 is not guaranteed to mean a 0 float,
175 but it seems that we can get away with it.
177 memset (_data[c] + from, 0, frames * sizeof(float));
181 /** Copy data from another AudioBuffers to this one. All channels are copied.
182 * @param from AudioBuffers to copy from; must have the same number of channels as this.
183 * @param frames_to_copy Number of frames to copy.
184 * @param read_offset Offset to read from in `from'.
185 * @param write_offset Offset to write to in `to'.
188 AudioBuffers::copy_from (AudioBuffers const * from, int32_t frames_to_copy, int32_t read_offset, int32_t write_offset)
190 if (frames_to_copy == 0) {
191 /* Prevent the asserts from firing if there is nothing to do */
195 DCPOMATIC_ASSERT (from);
196 DCPOMATIC_ASSERT (from->channels() == channels());
197 DCPOMATIC_ASSERT (read_offset >= 0 && (read_offset + frames_to_copy) <= from->_allocated_frames);
198 DCPOMATIC_ASSERT (write_offset >= 0 && (write_offset + frames_to_copy) <= _allocated_frames);
200 for (int i = 0; i < _channels; ++i) {
201 memcpy (_data[i] + write_offset, from->_data[i] + read_offset, frames_to_copy * sizeof(float));
205 /** Move audio data around.
206 * @param from Offset to move from.
207 * @param to Offset to move to.
208 * @param frames Number of frames to move.
211 AudioBuffers::move (int32_t frames, int32_t from, int32_t to)
217 DCPOMATIC_ASSERT (from >= 0);
218 DCPOMATIC_ASSERT (from < _frames);
219 DCPOMATIC_ASSERT (to >= 0);
220 DCPOMATIC_ASSERT (to < _frames);
221 DCPOMATIC_ASSERT (frames > 0);
222 DCPOMATIC_ASSERT (frames <= _frames);
223 DCPOMATIC_ASSERT ((from + frames) <= _frames);
224 DCPOMATIC_ASSERT ((to + frames) <= _allocated_frames);
226 for (int i = 0; i < _channels; ++i) {
227 memmove (_data[i] + to, _data[i] + from, frames * sizeof(float));
231 /** Add data from from `from', `from_channel' to our channel `to_channel'.
232 * @param from Buffers to copy data from.
233 * @param from_channel Channel index to read in \p from.
234 * @param to_channel Channel index to accumulate into.
235 * @param gain Linear gain to apply to the data before it is added.
238 AudioBuffers::accumulate_channel (AudioBuffers const * from, int from_channel, int to_channel, float gain)
240 int const N = frames ();
241 DCPOMATIC_ASSERT (from->frames() == N);
242 DCPOMATIC_ASSERT (to_channel <= _channels);
244 float* s = from->data (from_channel);
245 float* d = _data[to_channel];
247 for (int i = 0; i < N; ++i) {
248 *d++ += (*s++) * gain;
252 /** Ensure we have space for at least a certain number of frames. If we extend
253 * the buffers, fill the new space with silence.
256 AudioBuffers::ensure_size (int32_t frames)
258 if (_allocated_frames >= frames) {
262 /* Round up frames to the next power of 2 to reduce the number
263 of realloc()s that are necessary.
266 frames |= frames >> 1;
267 frames |= frames >> 2;
268 frames |= frames >> 4;
269 frames |= frames >> 8;
270 frames |= frames >> 16;
273 for (int i = 0; i < _channels; ++i) {
274 _data[i] = static_cast<float*> (realloc (_data[i], frames * sizeof (float)));
280 int32_t const old_allocated = _allocated_frames;
281 _allocated_frames = frames;
282 if (old_allocated < _allocated_frames) {
283 make_silent (old_allocated, _allocated_frames - old_allocated);
287 /** Mix some other buffers with these ones. The AudioBuffers must have the same number of channels.
288 * @param from Audio buffers to get data from.
289 * @param frames Number of frames to mix.
290 * @param read_offset Offset within `from' to read from.
291 * @param write_offset Offset within this to mix into.
294 AudioBuffers::accumulate_frames (AudioBuffers const * from, int32_t frames, int32_t read_offset, int32_t write_offset)
296 DCPOMATIC_ASSERT (_channels == from->channels ());
297 DCPOMATIC_ASSERT (read_offset >= 0);
298 DCPOMATIC_ASSERT (write_offset >= 0);
300 float** from_data = from->data ();
301 for (int i = 0; i < _channels; ++i) {
302 for (int j = 0; j < frames; ++j) {
303 _data[i][j + write_offset] += from_data[i][j + read_offset];
308 /** @param dB gain in dB */
310 AudioBuffers::apply_gain (float dB)
312 float const linear = db_to_linear (dB);
314 for (int i = 0; i < _channels; ++i) {
315 for (int j = 0; j < _frames; ++j) {
316 _data[i][j] *= linear;
321 /** @param c Channel index.
322 * @return AudioBuffers object containing only channel `c' from this AudioBuffers.
324 shared_ptr<AudioBuffers>
325 AudioBuffers::channel (int c) const
327 shared_ptr<AudioBuffers> o (new AudioBuffers (1, frames ()));
328 o->copy_channel_from (this, c, 0);
332 /** Copy all the samples from a channel on another AudioBuffers to a channel on this one.
333 * @param from AudioBuffers to copy from.
334 * @param from_channel Channel index in `from' to copy from.
335 * @param to_channel Channel index in this to copy into, overwriting what's already there.
338 AudioBuffers::copy_channel_from (AudioBuffers const * from, int from_channel, int to_channel)
340 DCPOMATIC_ASSERT (from->frames() == frames());
341 memcpy (data(to_channel), from->data(from_channel), frames() * sizeof (float));
344 /** Make a copy of these AudioBuffers */
345 shared_ptr<AudioBuffers>
346 AudioBuffers::clone () const
348 shared_ptr<AudioBuffers> b (new AudioBuffers (channels (), frames ()));
349 b->copy_from (this, frames (), 0, 0);
353 /** Extend these buffers with the data from another. The AudioBuffers must have the same number of channels. */
355 AudioBuffers::append (shared_ptr<const AudioBuffers> other)
357 DCPOMATIC_ASSERT (channels() == other->channels());
358 ensure_size (_frames + other->frames());
359 copy_from (other.get(), other->frames(), 0, _frames);
360 _frames += other->frames();
363 /** Remove some frames from the start of these AudioBuffers */
365 AudioBuffers::trim_start (int32_t frames)
367 DCPOMATIC_ASSERT (frames <= _frames);
368 move (_frames - frames, frames, 0);
369 set_frames (_frames - frames);