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/*
* Copyright 2003-2018 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 "AoOutputPlugin.hxx"
#include "../OutputAPI.hxx"
#include "thread/SafeSingleton.hxx"
#include "system/Error.hxx"
#include "util/DivideString.hxx"
#include "util/SplitString.hxx"
#include "util/RuntimeError.hxx"
#include "util/Domain.hxx"
#include "Log.hxx"
#include <ao/ao.h>
#include <string.h>
/* An ao_sample_format, with all fields set to zero: */
static ao_sample_format OUR_AO_FORMAT_INITIALIZER;
class AoInit {
public:
AoInit() {
ao_initialize();
}
~AoInit() noexcept {
ao_shutdown();
}
};
class AoOutput final : AudioOutput, SafeSingleton<AoInit> {
const size_t write_size;
int driver;
ao_option *options = nullptr;
ao_device *device;
size_t frame_size;
AoOutput(const ConfigBlock &block);
~AoOutput();
public:
static AudioOutput *Create(EventLoop &, const ConfigBlock &block) {
return new AoOutput(block);
}
void Open(AudioFormat &audio_format) override;
void Close() noexcept override;
size_t Play(const void *chunk, size_t size) override;
};
static constexpr Domain ao_output_domain("ao_output");
static std::system_error
MakeAoError()
{
const char *error = "Unknown libao failure";
switch (errno) {
case AO_ENODRIVER:
error = "No such libao driver";
break;
case AO_ENOTLIVE:
error = "This driver is not a libao live device";
break;
case AO_EBADOPTION:
error = "Invalid libao option";
break;
case AO_EOPENDEVICE:
error = "Cannot open the libao device";
break;
case AO_EFAIL:
error = "Generic libao failure";
break;
}
return MakeErrno(errno, error);
}
AoOutput::AoOutput(const ConfigBlock &block)
:AudioOutput(0),
write_size(block.GetPositiveValue("write_size", 1024u))
{
const char *value = block.GetBlockValue("driver", "default");
if (0 == strcmp(value, "default"))
driver = ao_default_driver_id();
else
driver = ao_driver_id(value);
if (driver < 0)
throw FormatRuntimeError("\"%s\" is not a valid ao driver",
value);
ao_info *ai = ao_driver_info(driver);
if (ai == nullptr)
throw std::runtime_error("problems getting driver info");
FormatDebug(ao_output_domain, "using ao driver \"%s\" for \"%s\"\n",
ai->short_name, block.GetBlockValue("name", nullptr));
value = block.GetBlockValue("options", nullptr);
if (value != nullptr) {
for (const auto &i : SplitString(value, ';')) {
const DivideString ss(i.c_str(), '=', true);
if (!ss.IsDefined())
throw FormatRuntimeError("problems parsing options \"%s\"",
i.c_str());
ao_append_option(&options, ss.GetFirst(), ss.GetSecond());
}
}
}
AoOutput::~AoOutput()
{
ao_free_options(options);
}
void
AoOutput::Open(AudioFormat &audio_format)
{
ao_sample_format format = OUR_AO_FORMAT_INITIALIZER;
switch (audio_format.format) {
case SampleFormat::S8:
format.bits = 8;
break;
case SampleFormat::S16:
format.bits = 16;
break;
default:
/* support for 24 bit samples in libao is currently
dubious, and until we have sorted that out,
convert everything to 16 bit */
audio_format.format = SampleFormat::S16;
format.bits = 16;
break;
}
frame_size = audio_format.GetFrameSize();
format.rate = audio_format.sample_rate;
format.byte_format = AO_FMT_NATIVE;
format.channels = audio_format.channels;
device = ao_open_live(driver, &format, options);
if (device == nullptr)
throw MakeAoError();
}
void
AoOutput::Close() noexcept
{
ao_close(device);
}
size_t
AoOutput::Play(const void *chunk, size_t size)
{
assert(size % frame_size == 0);
if (size > write_size) {
/* round down to a multiple of the frame size */
size = (write_size / frame_size) * frame_size;
if (size < frame_size)
/* no matter how small "write_size" was
configured, we must pass at least one frame
to libao */
size = frame_size;
}
/* For whatever reason, libao wants a non-const pointer.
Let's hope it does not write to the buffer, and use the
union deconst hack to * work around this API misdesign. */
char *data = const_cast<char *>((const char *)chunk);
if (ao_play(device, data, size) == 0)
throw MakeAoError();
return size;
}
const struct AudioOutputPlugin ao_output_plugin = {
"ao",
nullptr,
&AoOutput::Create,
nullptr,
};
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