Archipelago » qemu

/*

 * QEMU NULL audio output driver

 * 

 * Copyright (c) 2004 Vassili Karpov (malc)

 * 

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include "vl.h"

#include "audio/audio_int.h"

typedef struct NoVoice {

    HWVoice hw;

    int64_t old_ticks;

} NoVoice;

#define dolog(...) AUD_log ("noaudio", __VA_ARGS__)

#ifdef DEBUG

#define ldebug(...) dolog (__VA_ARGS__)

#else

#define ldebug(...)

#endif

static void no_hw_run (HWVoice *hw)

{

    NoVoice *no = (NoVoice *) hw;

    int rpos, live, decr, samples;

    uint8_t *dst;

    st_sample_t *src;

    int64_t now = qemu_get_clock (vm_clock);

    int64_t ticks = now - no->old_ticks;

    int64_t bytes = (ticks * hw->bytes_per_second) / ticks_per_sec;

    if (bytes > INT_MAX)

        samples = INT_MAX >> hw->shift;

    else

        samples = bytes >> hw->shift;

    live = pcm_hw_get_live (hw);

    if (live <= 0)

        return;

    no->old_ticks = now;

    decr = audio_MIN (live, samples);

    samples = decr;

    rpos = hw->rpos;

    while (samples) {

        int left_till_end_samples = hw->samples - rpos;

        int convert_samples = audio_MIN (samples, left_till_end_samples);

        src = advance (hw->mix_buf, rpos * sizeof (st_sample_t));

        memset (src, 0, convert_samples * sizeof (st_sample_t));

        rpos = (rpos + convert_samples) % hw->samples;

        samples -= convert_samples;

    }

    pcm_hw_dec_live (hw, decr);

    hw->rpos = rpos;

}

static int no_hw_write (SWVoice *sw, void *buf, int len)

{

    return pcm_hw_write (sw, buf, len);

}

static int no_hw_init (HWVoice *hw, int freq, int nchannels, audfmt_e fmt)

{

    NoVoice *no = (NoVoice *) hw;

    hw->freq = freq;

    hw->nchannels = nchannels;

    hw->fmt = fmt;

    hw->bufsize = 4096;

    return 0;

}

static void no_hw_fini (HWVoice *hw)

{

    (void) hw;

}

static int no_hw_ctl (HWVoice *hw, int cmd, ...)

{

    (void) hw;

    (void) cmd;

    return 0;

}

static void *no_audio_init (void)

{

    return &no_audio_init;

}

static void no_audio_fini (void *opaque)

{

}

struct pcm_ops no_pcm_ops = {

    no_hw_init,

    no_hw_fini,

    no_hw_run,

    no_hw_write,

    no_hw_ctl

};

struct audio_output_driver no_output_driver = {

    "none",

    no_audio_init,

    no_audio_fini,

    &no_pcm_ops,

    1,

    1,

    sizeof (NoVoice)

};