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Diffstat (limited to 'src/pcm/SoxrResampler.cxx')
| -rw-r--r-- | src/pcm/SoxrResampler.cxx | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/src/pcm/SoxrResampler.cxx b/src/pcm/SoxrResampler.cxx new file mode 100644 index 000000000..2508e816e --- /dev/null +++ b/src/pcm/SoxrResampler.cxx @@ -0,0 +1,162 @@ +/* + * 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 "SoxrResampler.hxx" +#include "AudioFormat.hxx" +#include "util/ASCII.hxx" +#include "util/Error.hxx" +#include "util/Domain.hxx" +#include "Log.hxx" + +#include <soxr.h> + +#include <assert.h> + +static constexpr Domain soxr_domain("soxr"); + +static unsigned long soxr_quality_recipe = SOXR_HQ; + +static const char * +soxr_quality_name(unsigned long recipe) +{ + switch (recipe) { + case SOXR_VHQ: + return "Very High Quality"; + case SOXR_HQ: + return "High Quality"; + case SOXR_MQ: + return "Medium Quality"; + case SOXR_LQ: + return "Low Quality"; + case SOXR_QQ: + return "Quick"; + } + + gcc_unreachable(); +} + +static bool +soxr_parse_converter(const char *converter) +{ + assert(converter != nullptr); + + assert(memcmp(converter, "soxr", 4) == 0); + if (converter[4] == '\0') + return true; + if (converter[4] != ' ') + return false; + + // converter example is "soxr very high", we want the "very high" part + const char *quality = converter + 5; + if (strcmp(quality, "very high") == 0) + soxr_quality_recipe = SOXR_VHQ; + else if (strcmp(quality, "high") == 0) + soxr_quality_recipe = SOXR_HQ; + else if (strcmp(quality, "medium") == 0) + soxr_quality_recipe = SOXR_MQ; + else if (strcmp(quality, "low") == 0) + soxr_quality_recipe = SOXR_LQ; + else if (strcmp(quality, "quick") == 0) + soxr_quality_recipe = SOXR_QQ; + else + return false; + + return true; +} + +bool +pcm_resample_soxr_global_init(const char *converter, Error &error) +{ + if (!soxr_parse_converter(converter)) { + error.Format(soxr_domain, + "unknown samplerate converter '%s'", converter); + return false; + } + + FormatDebug(soxr_domain, + "soxr converter '%s'", + soxr_quality_name(soxr_quality_recipe)); + + 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_quality_spec_t quality = soxr_quality_spec(soxr_quality_recipe, 0); + soxr = soxr_create(af.sample_rate, new_sample_rate, + af.channels, &e, + nullptr, &quality, nullptr); + 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; + + const size_t o_frames = size_t(n_frames * ratio + 0.5); + + 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 }; +} |