spice/client/x11/playback.cpp

/*
   Copyright (C) 2009 Red Hat, Inc.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   This library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include "playback.h"
#include "utils.h"
#include "debug.h"

#define REING_SIZE_MS 300

WavePlayer::WavePlayer(uint32_t sampels_per_sec, uint32_t bits_per_sample, uint32_t channels)
    : _pcm (NULL)
    , _hw_params (NULL)
    , _sw_params (NULL)
{
    if (!init(sampels_per_sec, bits_per_sample, channels)) {
        cleanup();
        THROW("failed");
    }
}

void WavePlayer::cleanup()
{
    if (_pcm) {
        snd_pcm_close(_pcm);
    }

    if (_hw_params) {
        snd_pcm_hw_params_free(_hw_params);
    }

    if (_sw_params) {
        snd_pcm_sw_params_free(_sw_params);
    }
}

WavePlayer::~WavePlayer()
{
    cleanup();
}

bool WavePlayer::init(uint32_t sampels_per_sec,
                      uint32_t bits_per_sample,
                      uint32_t channels)
{
    const int frame_size = WavePlaybackAbstract::FRAME_SIZE;
    const char* pcm_device = "default";
    snd_pcm_format_t format;
    int err;

    switch (bits_per_sample) {
    case 8:
        format = SND_PCM_FORMAT_S8;
        break;
    case 16:
        format = SND_PCM_FORMAT_S16_LE;
        break;
    default:
        return false;
    }
    _sampels_per_ms = sampels_per_sec / 1000;

    if ((err = snd_pcm_open(&_pcm, pcm_device, SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK)) < 0) {
        LOG_ERROR("cannot open audio playback device %s %s", pcm_device, snd_strerror(err));
        return false;
    }

    if ((err = snd_pcm_hw_params_malloc(&_hw_params)) < 0) {
        LOG_ERROR("cannot allocate hardware parameter structure %s", snd_strerror(err));
        return false;
    }

    if ((err = snd_pcm_sw_params_malloc(&_sw_params)) < 0) {
        LOG_ERROR("cannot allocate software parameter structure %s", snd_strerror(err));
        return false;
    }

    if ((err = snd_pcm_hw_params_any(_pcm, _hw_params)) < 0) {
        LOG_ERROR("cannot initialize hardware parameter structure %s", snd_strerror(err));
        return false;
    }

    if ((err = snd_pcm_hw_params_set_rate_resample(_pcm, _hw_params, 1)) < 0) {
        LOG_ERROR("cannot set rate resample %s", snd_strerror(err));
        return false;
    }

    if ((err = snd_pcm_hw_params_set_access(_pcm, _hw_params,
                                            SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) {
        LOG_ERROR("cannot set access type %s", snd_strerror(err));
        return false;
    }

    if ((err = snd_pcm_hw_params_set_rate(_pcm, _hw_params, sampels_per_sec, 0)) < 0) {
        LOG_ERROR("cannot set sample rate %s", snd_strerror(err));
        return false;
    }

    if ((err = snd_pcm_hw_params_set_channels(_pcm, _hw_params, channels)) < 0) {
        LOG_ERROR("cannot set channel count %s", snd_strerror(err));
        return false;
    }

    if ((err = snd_pcm_hw_params_set_format(_pcm, _hw_params, format)) < 0) {
        LOG_ERROR("cannot set sample format %s", snd_strerror(err));
        return false;
    }

    snd_pcm_uframes_t buffer_size;
    buffer_size = (sampels_per_sec * REING_SIZE_MS / 1000) / frame_size * frame_size;

    if ((err = snd_pcm_hw_params_set_buffer_size_near(_pcm, _hw_params, &buffer_size)) < 0) {
        LOG_ERROR("cannot set buffer size %s", snd_strerror(err));
        return false;
    }

    int direction = 1;
    snd_pcm_uframes_t period_size = (sampels_per_sec * 20 / 1000) / frame_size * frame_size;
    if ((err = snd_pcm_hw_params_set_period_size_near(_pcm, _hw_params, &period_size,
                                                      &direction)) < 0) {
        LOG_ERROR("cannot set period size %s", snd_strerror(err));
        return false;
    }

    if ((err = snd_pcm_hw_params(_pcm, _hw_params)) < 0) {
        LOG_ERROR("cannot set parameters %s", snd_strerror(err));
        return false;
    }

    if ((err = snd_pcm_sw_params_current(_pcm, _sw_params)) < 0) {
        LOG_ERROR("cannot obtain sw parameters %s", snd_strerror(err));
        return false;
    }

    err = snd_pcm_hw_params_get_buffer_size(_hw_params, &buffer_size);
    if (err < 0) {
        LOG_ERROR("unable to get buffer size for playback: %s", snd_strerror(err));
        return false;
    }

    direction = 0;
    err = snd_pcm_hw_params_get_period_size(_hw_params, &period_size, &direction);
    if (err < 0) {
        LOG_ERROR("unable to get period size for playback: %s", snd_strerror(err));
        return false;
    }

    err = snd_pcm_sw_params_set_start_threshold(_pcm, _sw_params,
                                                (buffer_size / period_size) * period_size);
    if (err < 0) {
        LOG_ERROR("unable to set start threshold mode for playback: %s", snd_strerror(err));
        return false;
    }

    if ((err = snd_pcm_sw_params(_pcm, _sw_params)) < 0) {
        LOG_ERROR("cannot set software parameters %s", snd_strerror(err));
        return false;
    }

    if ((err = snd_pcm_prepare(_pcm)) < 0) {
        LOG_ERROR("cannot prepare pcm device %s", snd_strerror(err));
        return false;
    }

    return true;
}

bool WavePlayer::write(uint8_t* frame)
{
    snd_pcm_sframes_t ret = snd_pcm_writei(_pcm, frame, WavePlaybackAbstract::FRAME_SIZE);
    if (ret < 0) {
        if (ret == -EAGAIN) {
            return false;
        }
        DBG(0, "err %s", snd_strerror(-ret));
        if (snd_pcm_recover(_pcm, ret, 1) == 0) {
            snd_pcm_writei(_pcm, frame, WavePlaybackAbstract::FRAME_SIZE);
        }
    }
    return true;
}

void WavePlayer::stop()
{
    snd_pcm_drain(_pcm);
    snd_pcm_prepare(_pcm);
}

bool WavePlayer::abort()
{
    return true;
}

uint32_t WavePlayer::get_delay_ms()
{
    ASSERT(_pcm);

    snd_pcm_sframes_t delay;

    if (snd_pcm_delay(_pcm, &delay) < 0) {
        return 0;
    }
    return delay / _sampels_per_ms;
}