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// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef MEDIA_AUDIO_ALSA_ALSA_UTIL_H_
#define MEDIA_AUDIO_ALSA_ALSA_UTIL_H_
#include <alsa/asoundlib.h>
#include <string>
#include "media/base/media_export.h"
namespace media {
class AlsaWrapper;
}
namespace alsa_util {
// When opening ALSA devices, |period_us| is the size of a packet and
// |buffer_us| is the size of the ring buffer, which consists of multiple
// packets. In capture devices, the latency relies more on |period_us|, and thus
// one may require more details upon the value implicitly set by ALSA.
MEDIA_EXPORT snd_pcm_t* OpenCaptureDevice(media::AlsaWrapper* wrapper,
const char* device_name,
int channels,
int sample_rate,
snd_pcm_format_t pcm_format,
int buffer_us,
int period_us);
snd_pcm_t* OpenPlaybackDevice(media::AlsaWrapper* wrapper,
const char* device_name,
int channels,
int sample_rate,
snd_pcm_format_t pcm_format,
int buffer_us);
int CloseDevice(media::AlsaWrapper* wrapper, snd_pcm_t* handle);
snd_mixer_t* OpenMixer(media::AlsaWrapper* wrapper,
const std::string& device_name);
void CloseMixer(media::AlsaWrapper* wrapper,
snd_mixer_t* mixer,
const std::string& device_name);
snd_mixer_elem_t* LoadCaptureMixerElement(media::AlsaWrapper* wrapper,
snd_mixer_t* mixer);
} // namespace alsa_util
#endif // MEDIA_AUDIO_ALSA_ALSA_UTIL_H_
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