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#include <algorithm>
#include <string>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <alsa/asoundlib.h>
#include "device_alsa.h"
#include "debug.h"
namespace audiere {
ALSAAudioDevice*
ALSAAudioDevice::create(const ParameterList& parameters) {
std::string devices[] = {
"default", "plughw:0,0", "hw:0,0", ""
};
std::string default_device = parameters.getValue("device", devices[0].c_str());
if (default_device != devices[0])
devices[0] = default_device;
int status = 0;
snd_pcm_t* pcm_handle = 0;
for (int i = 0; devices[i].length() > 0; i++) {
status = snd_pcm_open(&pcm_handle, devices[i].c_str (),
SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
if (status >= 0)
break;
}
if (status < 0) {
ADR_LOG("Coudn't open haredware.");
return 0;
}
int rate = 48000;
status = snd_pcm_set_params(pcm_handle,
SND_PCM_FORMAT_S16_LE,
SND_PCM_ACCESS_RW_INTERLEAVED,
2, rate, 1, 0);
if (status < 0) {
rate = 441000;
status = snd_pcm_set_params(pcm_handle,
SND_PCM_FORMAT_S16_LE,
SND_PCM_ACCESS_RW_INTERLEAVED,
2, rate, 1, 0);
if (status < 0) {
ADR_LOG("Couldn't set audio device parameters.");
snd_pcm_close(pcm_handle);
return 0;
}
}
snd_pcm_uframes_t buffer_size;
snd_pcm_uframes_t period_size;
status = snd_pcm_get_params(pcm_handle, &buffer_size, &period_size);
if (status) {
ADR_LOG("Couldn't get audio device parameters.");
snd_pcm_close(pcm_handle);
return 0;
}
int chunk_size = period_size;
int bits_per_sample = snd_pcm_format_physical_width(SND_PCM_FORMAT_S16_LE);
int bits_per_frame = bits_per_sample * 2;
int chunk_bytes = chunk_size * bits_per_frame / 8;
return new ALSAAudioDevice(pcm_handle, rate, chunk_bytes);
}
ALSAAudioDevice::ALSAAudioDevice(snd_pcm_t* pcm_handle,
int rate,
int buffer_size)
: MixerDevice(rate)
{
m_pcm_handle = pcm_handle;
m_buffer_size = buffer_size;
m_buffer = new char [buffer_size];
}
ALSAAudioDevice::~ALSAAudioDevice() {
ADR_GUARD("ALSAAudioDevice::~ALSAAudioDevice");
snd_pcm_drain(m_pcm_handle);
snd_pcm_close(m_pcm_handle);
delete [] m_buffer;
}
void ADR_CALL
ALSAAudioDevice::update() {
int ret;
int sample_len;
int sample_left;
char* sample_buf;
sample_buf = m_buffer;
sample_len = m_buffer_size / 4;
sample_left = read(sample_len, sample_buf);
while (sample_len > 0) {
ret = snd_pcm_writei(m_pcm_handle, sample_buf, sample_len);
if (ret == -EAGAIN || (ret > 0 && ret < sample_len)) {
snd_pcm_wait(m_pcm_handle, 10);
} else if (ret == -ESTRPIPE) {
do {
snd_pcm_wait(m_pcm_handle, 10);
ret = snd_pcm_resume(m_pcm_handle);
} while (ret == -EAGAIN);
snd_pcm_prepare(m_pcm_handle);
} else if (ret == -EPIPE) {
snd_pcm_prepare(m_pcm_handle);
} else if (ret == -EINTR) {
// nothing to do.
} else if (ret < 0) {
fprintf(stderr, "alsa error: %s\n", snd_strerror(ret));
return;
}
if (ret > 0) {
sample_buf += ret * 4;
sample_len -= ret;
}
}
}
const char* ADR_CALL
ALSAAudioDevice::getName() {
return "alsa";
}
}
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