mpd/src/pcm/SoxrResampler.cxx
2015-06-20 15:25:00 +02:00

173 lines
4.3 KiB
C++

/*
* Copyright (C) 2003-2015 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 "SoxrResampler.hxx"
#include "AudioFormat.hxx"
#include "config/Block.hxx"
#include "util/ASCII.hxx"
#include "util/Error.hxx"
#include "util/Domain.hxx"
#include "Log.hxx"
#include <soxr.h>
#include <assert.h>
#include <string.h>
static constexpr Domain soxr_domain("soxr");
static constexpr unsigned long SOXR_DEFAULT_RECIPE = SOXR_HQ;
/**
* Special value for "invalid argument".
*/
static constexpr unsigned long SOXR_INVALID_RECIPE = -1;
static soxr_quality_spec_t soxr_quality;
static soxr_runtime_spec_t soxr_runtime;
static constexpr struct {
unsigned long recipe;
const char *name;
} soxr_quality_table[] = {
{ SOXR_VHQ, "very high" },
{ SOXR_HQ, "high" },
{ SOXR_MQ, "medium" },
{ SOXR_LQ, "low" },
{ SOXR_QQ, "quick" },
{ SOXR_INVALID_RECIPE, nullptr }
};
gcc_const
static const char *
soxr_quality_name(unsigned long recipe)
{
for (const auto *i = soxr_quality_table;; ++i) {
assert(i->name != nullptr);
if (i->recipe == recipe)
return i->name;
}
}
gcc_pure
static unsigned long
soxr_parse_quality(const char *quality)
{
if (quality == nullptr)
return SOXR_DEFAULT_RECIPE;
for (const auto *i = soxr_quality_table; i->name != nullptr; ++i)
if (strcmp(i->name, quality) == 0)
return i->recipe;
return SOXR_INVALID_RECIPE;
}
bool
pcm_resample_soxr_global_init(const ConfigBlock &block, Error &error)
{
const char *quality_string = block.GetBlockValue("quality");
unsigned long recipe = soxr_parse_quality(quality_string);
if (recipe == SOXR_INVALID_RECIPE) {
assert(quality_string != nullptr);
error.Format(soxr_domain,
"unknown quality setting '%s' in line %d",
quality_string, block.line);
return false;
}
soxr_quality = soxr_quality_spec(recipe, 0);
FormatDebug(soxr_domain,
"soxr converter '%s'",
soxr_quality_name(recipe));
const unsigned n_threads = block.GetBlockValue("threads", 1);
soxr_runtime = soxr_runtime_spec(n_threads);
return true;
}
AudioFormat
SoxrPcmResampler::Open(AudioFormat &af, unsigned new_sample_rate,
Error &error)
{
assert(af.IsValid());
assert(audio_valid_sample_rate(new_sample_rate));
soxr_error_t e;
soxr = soxr_create(af.sample_rate, new_sample_rate,
af.channels, &e,
nullptr, &soxr_quality, &soxr_runtime);
if (soxr == nullptr) {
error.Format(soxr_domain,
"soxr initialization has failed: %s", e);
return AudioFormat::Undefined();
}
FormatDebug(soxr_domain, "soxr engine '%s'", soxr_engine(soxr));
channels = af.channels;
ratio = float(new_sample_rate) / float(af.sample_rate);
FormatDebug(soxr_domain,
"samplerate conversion ratio to %.2lf",
ratio);
/* libsoxr works with floating point samples */
af.format = SampleFormat::FLOAT;
AudioFormat result = af;
result.sample_rate = new_sample_rate;
return result;
}
void
SoxrPcmResampler::Close()
{
soxr_delete(soxr);
}
ConstBuffer<void>
SoxrPcmResampler::Resample(ConstBuffer<void> src, Error &error)
{
const size_t frame_size = channels * sizeof(float);
assert(src.size % frame_size == 0);
const size_t n_frames = src.size / frame_size;
/* always round up: worst case output buffer size */
const size_t o_frames = size_t(n_frames * ratio) + 1;
float *output_buffer = (float *)buffer.Get(o_frames * frame_size);
size_t i_done, o_done;
soxr_error_t e = soxr_process(soxr, src.data, n_frames, &i_done,
output_buffer, o_frames, &o_done);
if (e != nullptr) {
error.Format(soxr_domain, "soxr error: %s", e);
return nullptr;
}
return { output_buffer, o_done * frame_size };
}