141 lines
3.9 KiB
C++
141 lines
3.9 KiB
C++
/*
|
|
* Copyright (C) 2003-2014 The Music Player Daemon Project
|
|
* http://www.musicpd.org
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#include "config.h"
|
|
#include "CrossFade.hxx"
|
|
#include "Chrono.hxx"
|
|
#include "MusicChunk.hxx"
|
|
#include "AudioFormat.hxx"
|
|
#include "util/NumberParser.hxx"
|
|
#include "util/Domain.hxx"
|
|
#include "Log.hxx"
|
|
|
|
#include <assert.h>
|
|
|
|
static constexpr Domain cross_fade_domain("cross_fade");
|
|
|
|
gcc_pure
|
|
static float
|
|
mixramp_interpolate(const char *ramp_list, float required_db)
|
|
{
|
|
float last_db = 0, last_secs = 0;
|
|
bool have_last = false;
|
|
|
|
/* ramp_list is a string of pairs of dBs and seconds that describe the
|
|
* volume profile. Delimiters are semi-colons between pairs and spaces
|
|
* between the dB and seconds of a pair.
|
|
* The dB values must be monotonically increasing for this to work. */
|
|
|
|
while (1) {
|
|
/* Parse the dB value. */
|
|
char *endptr;
|
|
const float db = ParseFloat(ramp_list, &endptr);
|
|
if (endptr == ramp_list || *endptr != ' ')
|
|
break;
|
|
|
|
ramp_list = endptr + 1;
|
|
|
|
/* Parse the time. */
|
|
float secs = ParseFloat(ramp_list, &endptr);
|
|
if (endptr == ramp_list || (*endptr != ';' && *endptr != 0))
|
|
break;
|
|
|
|
ramp_list = endptr;
|
|
if (*ramp_list == ';')
|
|
++ramp_list;
|
|
|
|
/* Check for exact match. */
|
|
if (db == required_db) {
|
|
return secs;
|
|
}
|
|
|
|
/* Save if too quiet. */
|
|
if (db < required_db) {
|
|
last_db = db;
|
|
last_secs = secs;
|
|
have_last = true;
|
|
continue;
|
|
}
|
|
|
|
/* If required db < any stored value, use the least. */
|
|
if (!have_last)
|
|
return secs;
|
|
|
|
/* Finally, interpolate linearly. */
|
|
secs = last_secs + (required_db - last_db) * (secs - last_secs) / (db - last_db);
|
|
return secs;
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
unsigned
|
|
CrossFadeSettings::Calculate(SignedSongTime total_time,
|
|
float replay_gain_db, float replay_gain_prev_db,
|
|
const char *mixramp_start, const char *mixramp_prev_end,
|
|
const AudioFormat af,
|
|
const AudioFormat old_format,
|
|
unsigned max_chunks) const
|
|
{
|
|
unsigned int chunks = 0;
|
|
float chunks_f;
|
|
|
|
if (total_time.IsNegative() ||
|
|
duration < 0 || duration >= total_time.ToDoubleS() ||
|
|
/* we can't crossfade when the audio formats are different */
|
|
af != old_format)
|
|
return 0;
|
|
|
|
assert(duration >= 0);
|
|
assert(af.IsValid());
|
|
|
|
chunks_f = (float)af.GetTimeToSize() / (float)CHUNK_SIZE;
|
|
|
|
if (mixramp_delay <= 0 || !mixramp_start || !mixramp_prev_end) {
|
|
chunks = (chunks_f * duration + 0.5);
|
|
} else {
|
|
/* Calculate mixramp overlap. */
|
|
const float mixramp_overlap_current =
|
|
mixramp_interpolate(mixramp_start,
|
|
mixramp_db - replay_gain_db);
|
|
const float mixramp_overlap_prev =
|
|
mixramp_interpolate(mixramp_prev_end,
|
|
mixramp_db - replay_gain_prev_db);
|
|
const float mixramp_overlap =
|
|
mixramp_overlap_current + mixramp_overlap_prev;
|
|
|
|
if (mixramp_overlap_current >= 0 &&
|
|
mixramp_overlap_prev >= 0 &&
|
|
mixramp_delay <= mixramp_overlap) {
|
|
chunks = (chunks_f * (mixramp_overlap - mixramp_delay));
|
|
FormatDebug(cross_fade_domain,
|
|
"will overlap %d chunks, %fs", chunks,
|
|
mixramp_overlap - mixramp_delay);
|
|
}
|
|
}
|
|
|
|
if (chunks > max_chunks) {
|
|
chunks = max_chunks;
|
|
LogWarning(cross_fade_domain,
|
|
"audio_buffer_size too small for computed MixRamp overlap");
|
|
}
|
|
|
|
return chunks;
|
|
}
|