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/*
* Copyright 2003-2017 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 "LameEncoderPlugin.hxx"
#include "../EncoderAPI.hxx"
#include "AudioFormat.hxx"
#include "config/Domain.hxx"
#include "util/NumberParser.hxx"
#include "util/ReusableArray.hxx"
#include "util/RuntimeError.hxx"
#include <lame/lame.h>
#include <stdexcept>
#include <assert.h>
#include <string.h>
class LameEncoder final : public Encoder {
const AudioFormat audio_format;
lame_global_flags *const gfp;
ReusableArray<unsigned char, 32768> output_buffer;
unsigned char *output_begin = nullptr, *output_end = nullptr;
public:
LameEncoder(const AudioFormat _audio_format,
lame_global_flags *_gfp)
:Encoder(false),
audio_format(_audio_format), gfp(_gfp) {}
~LameEncoder() override;
/* virtual methods from class Encoder */
void Write(const void *data, size_t length) override;
size_t Read(void *dest, size_t length) override;
};
class PreparedLameEncoder final : public PreparedEncoder {
float quality;
int bitrate;
public:
PreparedLameEncoder(const ConfigBlock &block);
/* virtual methods from class PreparedEncoder */
Encoder *Open(AudioFormat &audio_format) override;
const char *GetMimeType() const override {
return "audio/mpeg";
}
};
PreparedLameEncoder::PreparedLameEncoder(const ConfigBlock &block)
{
const char *value;
char *endptr;
value = block.GetBlockValue("quality");
if (value != nullptr) {
/* a quality was configured (VBR) */
quality = ParseDouble(value, &endptr);
if (*endptr != '\0' || quality < -1.0 || quality > 10.0)
throw FormatRuntimeError("quality \"%s\" is not a number in the "
"range -1 to 10",
value);
if (block.GetBlockValue("bitrate") != nullptr)
throw std::runtime_error("quality and bitrate are both defined");
} else {
/* a bit rate was configured */
value = block.GetBlockValue("bitrate");
if (value == nullptr)
throw std::runtime_error("neither bitrate nor quality defined");
quality = -2.0;
bitrate = ParseInt(value, &endptr);
if (*endptr != '\0' || bitrate <= 0)
throw std::runtime_error("bitrate should be a positive integer");
}
}
static PreparedEncoder *
lame_encoder_init(const ConfigBlock &block)
{
return new PreparedLameEncoder(block);
}
static void
lame_encoder_setup(lame_global_flags *gfp, float quality, int bitrate,
const AudioFormat &audio_format)
{
if (quality >= -1.0) {
/* a quality was configured (VBR) */
if (0 != lame_set_VBR(gfp, vbr_rh))
throw std::runtime_error("error setting lame VBR mode");
if (0 != lame_set_VBR_q(gfp, quality))
throw std::runtime_error("error setting lame VBR quality");
} else {
/* a bit rate was configured */
if (0 != lame_set_brate(gfp, bitrate))
throw std::runtime_error("error setting lame bitrate");
}
if (0 != lame_set_num_channels(gfp, audio_format.channels))
throw std::runtime_error("error setting lame num channels");
if (0 != lame_set_in_samplerate(gfp, audio_format.sample_rate))
throw std::runtime_error("error setting lame sample rate");
if (0 != lame_set_out_samplerate(gfp, audio_format.sample_rate))
throw std::runtime_error("error setting lame out sample rate");
if (0 > lame_init_params(gfp))
throw std::runtime_error("error initializing lame params");
}
Encoder *
PreparedLameEncoder::Open(AudioFormat &audio_format)
{
audio_format.format = SampleFormat::S16;
audio_format.channels = 2;
auto gfp = lame_init();
if (gfp == nullptr)
throw std::runtime_error("lame_init() failed");
try {
lame_encoder_setup(gfp, quality, bitrate, audio_format);
} catch (...) {
lame_close(gfp);
throw;
}
return new LameEncoder(audio_format, gfp);
}
LameEncoder::~LameEncoder()
{
lame_close(gfp);
}
void
LameEncoder::Write(const void *data, size_t length)
{
const int16_t *src = (const int16_t*)data;
assert(output_begin == output_end);
const unsigned num_frames = length / audio_format.GetFrameSize();
const unsigned num_samples = length / audio_format.GetSampleSize();
/* worst-case formula according to LAME documentation */
const size_t output_buffer_size = 5 * num_samples / 4 + 7200;
const auto dest = output_buffer.Get(output_buffer_size);
/* this is for only 16-bit audio */
int bytes_out = lame_encode_buffer_interleaved(gfp,
const_cast<short *>(src),
num_frames,
dest, output_buffer_size);
if (bytes_out < 0)
throw std::runtime_error("lame encoder failed");
output_begin = dest;
output_end = dest + bytes_out;
}
size_t
LameEncoder::Read(void *dest, size_t length)
{
const auto begin = output_begin;
assert(begin <= output_end);
const size_t remainning = output_end - begin;
if (length > remainning)
length = remainning;
memcpy(dest, begin, length);
output_begin = begin + length;
return length;
}
const EncoderPlugin lame_encoder_plugin = {
"lame",
lame_encoder_init,
};
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