2 Copyright (C) 2012-2021 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/>.
23 #include "audio_buffers.h"
24 #include "dcpomatic_assert.h"
32 using std::shared_ptr;
33 using std::make_shared;
36 /** Construct an AudioBuffers. Audio data is undefined after this constructor.
37 * @param channels Number of channels.
38 * @param frames Number of frames to reserve space for.
40 AudioBuffers::AudioBuffers (int channels, int32_t frames)
42 allocate (channels, frames);
47 * @param other Other AudioBuffers; data is copied.
49 AudioBuffers::AudioBuffers (AudioBuffers const & other)
51 allocate (other._channels, other._frames);
52 copy_from (&other, other._frames, 0, 0);
56 AudioBuffers::AudioBuffers (std::shared_ptr<const AudioBuffers> other)
58 allocate (other->_channels, other->_frames);
59 copy_from (other.get(), other->_frames, 0, 0);
63 AudioBuffers::AudioBuffers (std::shared_ptr<const AudioBuffers> other, int32_t frames_to_copy, int32_t read_offset)
65 allocate (other->_channels, frames_to_copy);
66 copy_from (other.get(), frames_to_copy, read_offset, 0);
71 AudioBuffers::operator= (AudioBuffers const & other)
78 allocate (other._channels, other._frames);
79 copy_from (&other, other._frames, 0, 0);
85 /** AudioBuffers destructor */
86 AudioBuffers::~AudioBuffers ()
93 AudioBuffers::allocate (int channels, int32_t frames)
95 DCPOMATIC_ASSERT (frames >= 0);
96 DCPOMATIC_ASSERT (channels >= 0);
100 _allocated_frames = frames;
102 _data = static_cast<float**> (malloc(_channels * sizeof(float *)));
107 for (int i = 0; i < _channels; ++i) {
108 _data[i] = static_cast<float*> (malloc(frames * sizeof(float)));
117 AudioBuffers::deallocate ()
119 for (int i = 0; i < _channels; ++i) {
127 /** @param c Channel index.
128 * @return Buffer for this channel.
131 AudioBuffers::data (int c) const
133 DCPOMATIC_ASSERT (c >= 0 && c < _channels);
138 /** Set the number of frames that these AudioBuffers will report themselves
139 * as having. If we reduce the number of frames, the `lost' frames will
141 * @param f Frames; must be less than or equal to the number of allocated frames.
144 AudioBuffers::set_frames (int32_t f)
146 DCPOMATIC_ASSERT (f <= _allocated_frames);
149 make_silent (f, _frames - f);
155 /** Make all frames silent */
157 AudioBuffers::make_silent ()
159 for (int i = 0; i < _channels; ++i) {
165 /** Make all samples on a given channel silent.
169 AudioBuffers::make_silent (int c)
171 DCPOMATIC_ASSERT (c >= 0 && c < _channels);
173 /* This isn't really allowed, as all-bits-0 is not guaranteed to mean a 0 float,
174 but it seems that we can get away with it.
176 memset (_data[c], 0, _frames * sizeof(float));
180 /** Make some frames.
181 * @param from Start frame.
182 * @param frames Number of frames to silence.
185 AudioBuffers::make_silent (int32_t from, int32_t frames)
187 DCPOMATIC_ASSERT ((from + frames) <= _allocated_frames);
189 for (int c = 0; c < _channels; ++c) {
190 /* This isn't really allowed, as all-bits-0 is not guaranteed to mean a 0 float,
191 but it seems that we can get away with it.
193 memset (_data[c] + from, 0, frames * sizeof(float));
198 /** Copy data from another AudioBuffers to this one. All channels are copied.
199 * @param from AudioBuffers to copy from; must have the same number of channels as this.
200 * @param frames_to_copy Number of frames to copy.
201 * @param read_offset Offset to read from in `from'.
202 * @param write_offset Offset to write to in `to'.
205 AudioBuffers::copy_from (AudioBuffers const * from, int32_t frames_to_copy, int32_t read_offset, int32_t write_offset)
207 if (frames_to_copy == 0) {
208 /* Prevent the asserts from firing if there is nothing to do */
212 DCPOMATIC_ASSERT (from);
213 DCPOMATIC_ASSERT (from->channels() == channels());
214 DCPOMATIC_ASSERT (read_offset >= 0 && (read_offset + frames_to_copy) <= from->_allocated_frames);
215 DCPOMATIC_ASSERT (write_offset >= 0 && (write_offset + frames_to_copy) <= _allocated_frames);
217 for (int i = 0; i < _channels; ++i) {
218 memcpy (_data[i] + write_offset, from->_data[i] + read_offset, frames_to_copy * sizeof(float));
223 /** Move audio data around.
224 * @param from Offset to move from.
225 * @param to Offset to move to.
226 * @param frames Number of frames to move.
229 AudioBuffers::move (int32_t frames, int32_t from, int32_t to)
235 DCPOMATIC_ASSERT (from >= 0);
236 DCPOMATIC_ASSERT (from < _frames);
237 DCPOMATIC_ASSERT (to >= 0);
238 DCPOMATIC_ASSERT (to < _frames);
239 DCPOMATIC_ASSERT (frames > 0);
240 DCPOMATIC_ASSERT (frames <= _frames);
241 DCPOMATIC_ASSERT ((from + frames) <= _frames);
242 DCPOMATIC_ASSERT ((to + frames) <= _allocated_frames);
244 for (int i = 0; i < _channels; ++i) {
245 memmove (_data[i] + to, _data[i] + from, frames * sizeof(float));
250 /** Add data from from `from', `from_channel' to our channel `to_channel'.
251 * @param from Buffers to copy data from.
252 * @param from_channel Channel index to read in \p from.
253 * @param to_channel Channel index to accumulate into.
254 * @param gain Linear gain to apply to the data before it is added.
257 AudioBuffers::accumulate_channel (AudioBuffers const * from, int from_channel, int to_channel, float gain)
259 int const N = frames ();
260 DCPOMATIC_ASSERT (from->frames() == N);
261 DCPOMATIC_ASSERT (to_channel <= _channels);
263 auto s = from->data (from_channel);
264 auto d = _data[to_channel];
266 for (int i = 0; i < N; ++i) {
267 *d++ += (*s++) * gain;
272 /** Ensure we have space for at least a certain number of frames. If we extend
273 * the buffers, fill the new space with silence.
276 AudioBuffers::ensure_size (int32_t frames)
278 if (_allocated_frames >= frames) {
282 /* Round up frames to the next power of 2 to reduce the number
283 of realloc()s that are necessary.
286 frames |= frames >> 1;
287 frames |= frames >> 2;
288 frames |= frames >> 4;
289 frames |= frames >> 8;
290 frames |= frames >> 16;
293 for (int i = 0; i < _channels; ++i) {
294 _data[i] = static_cast<float*> (realloc(_data[i], frames * sizeof(float)));
300 auto const old_allocated = _allocated_frames;
301 _allocated_frames = frames;
302 if (old_allocated < _allocated_frames) {
303 make_silent (old_allocated, _allocated_frames - old_allocated);
308 /** Mix some other buffers with these ones. The AudioBuffers must have the same number of channels.
309 * @param from Audio buffers to get data from.
310 * @param frames Number of frames to mix.
311 * @param read_offset Offset within `from' to read from.
312 * @param write_offset Offset within this to mix into.
315 AudioBuffers::accumulate_frames (AudioBuffers const * from, int32_t frames, int32_t read_offset, int32_t write_offset)
317 DCPOMATIC_ASSERT (_channels == from->channels ());
318 DCPOMATIC_ASSERT (read_offset >= 0);
319 DCPOMATIC_ASSERT (write_offset >= 0);
321 auto from_data = from->data ();
322 for (int i = 0; i < _channels; ++i) {
323 for (int j = 0; j < frames; ++j) {
324 _data[i][j + write_offset] += from_data[i][j + read_offset];
330 /** @param dB gain in dB */
332 AudioBuffers::apply_gain (float dB)
334 auto const linear = db_to_linear (dB);
336 for (int i = 0; i < _channels; ++i) {
337 for (int j = 0; j < _frames; ++j) {
338 _data[i][j] *= linear;
344 /** @param c Channel index.
345 * @return AudioBuffers object containing only channel `c' from this AudioBuffers.
347 shared_ptr<AudioBuffers>
348 AudioBuffers::channel (int c) const
350 auto o = make_shared<AudioBuffers>(1, frames());
351 o->copy_channel_from (this, c, 0);
356 /** Copy all the samples from a channel on another AudioBuffers to a channel on this one.
357 * @param from AudioBuffers to copy from.
358 * @param from_channel Channel index in `from' to copy from.
359 * @param to_channel Channel index in this to copy into, overwriting what's already there.
362 AudioBuffers::copy_channel_from (AudioBuffers const * from, int from_channel, int to_channel)
364 DCPOMATIC_ASSERT (from->frames() == frames());
365 memcpy (data(to_channel), from->data(from_channel), frames() * sizeof (float));
369 /** Make a copy of these AudioBuffers */
370 shared_ptr<AudioBuffers>
371 AudioBuffers::clone () const
373 auto b = make_shared<AudioBuffers>(channels(), frames());
374 b->copy_from (this, frames(), 0, 0);
379 /** Extend these buffers with the data from another. The AudioBuffers must have the same number of channels. */
381 AudioBuffers::append (shared_ptr<const AudioBuffers> other)
383 DCPOMATIC_ASSERT (channels() == other->channels());
384 ensure_size (_frames + other->frames());
385 copy_from (other.get(), other->frames(), 0, _frames);
386 _frames += other->frames();
390 /** Remove some frames from the start of these AudioBuffers */
392 AudioBuffers::trim_start (int32_t frames)
394 DCPOMATIC_ASSERT (frames <= _frames);
395 move (_frames - frames, frames, 0);
396 set_frames (_frames - frames);