pcm_misc.c

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/*
 *  PCM Interface - misc routines
 *  Copyright (c) 1998 by Jaroslav Kysela <[email protected]>
 *
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Library 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 Library General Public License for more details.
 *
 *   You should have received a copy of the GNU Library General Public
 *   License along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */
  
#include <linux/time.h>
#include <linux/export.h>
#include <sound/core.h>
#include <sound/pcm.h>
#define SND_PCM_FORMAT_UNKNOWN (-1)

/* NOTE: "signed" prefix must be given below since the default char is
 *       unsigned on some architectures!
 */
struct pcm_format_data {
    unsigned char width;    /* bit width */
    unsigned char phys; /* physical bit width */
    signed char le; /* 0 = big-endian, 1 = little-endian, -1 = others */
    signed char signd;  /* 0 = unsigned, 1 = signed, -1 = others */
    unsigned char silence[8];   /* silence data to fill */
};

/* we do lots of calculations on snd_pcm_format_t; shut up sparse */
#define INT __force int

static struct pcm_format_data pcm_formats[(INT)SNDRV_PCM_FORMAT_LAST+1] = {
    [SNDRV_PCM_FORMAT_S8] = {
        .width = 8, .phys = 8, .le = -1, .signd = 1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_U8] = {
        .width = 8, .phys = 8, .le = -1, .signd = 0,
        .silence = { 0x80 },
    },
    [SNDRV_PCM_FORMAT_S16_LE] = {
        .width = 16, .phys = 16, .le = 1, .signd = 1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_S16_BE] = {
        .width = 16, .phys = 16, .le = 0, .signd = 1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_U16_LE] = {
        .width = 16, .phys = 16, .le = 1, .signd = 0,
        .silence = { 0x00, 0x80 },
    },
    [SNDRV_PCM_FORMAT_U16_BE] = {
        .width = 16, .phys = 16, .le = 0, .signd = 0,
        .silence = { 0x80, 0x00 },
    },
    [SNDRV_PCM_FORMAT_S24_LE] = {
        .width = 24, .phys = 32, .le = 1, .signd = 1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_S24_BE] = {
        .width = 24, .phys = 32, .le = 0, .signd = 1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_U24_LE] = {
        .width = 24, .phys = 32, .le = 1, .signd = 0,
        .silence = { 0x00, 0x00, 0x80 },
    },
    [SNDRV_PCM_FORMAT_U24_BE] = {
        .width = 24, .phys = 32, .le = 0, .signd = 0,
        .silence = { 0x00, 0x80, 0x00, 0x00 },
    },
    [SNDRV_PCM_FORMAT_S32_LE] = {
        .width = 32, .phys = 32, .le = 1, .signd = 1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_S32_BE] = {
        .width = 32, .phys = 32, .le = 0, .signd = 1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_U32_LE] = {
        .width = 32, .phys = 32, .le = 1, .signd = 0,
        .silence = { 0x00, 0x00, 0x00, 0x80 },
    },
    [SNDRV_PCM_FORMAT_U32_BE] = {
        .width = 32, .phys = 32, .le = 0, .signd = 0,
        .silence = { 0x80, 0x00, 0x00, 0x00 },
    },
    [SNDRV_PCM_FORMAT_FLOAT_LE] = {
        .width = 32, .phys = 32, .le = 1, .signd = -1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_FLOAT_BE] = {
        .width = 32, .phys = 32, .le = 0, .signd = -1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_FLOAT64_LE] = {
        .width = 64, .phys = 64, .le = 1, .signd = -1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_FLOAT64_BE] = {
        .width = 64, .phys = 64, .le = 0, .signd = -1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE] = {
        .width = 32, .phys = 32, .le = 1, .signd = -1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE] = {
        .width = 32, .phys = 32, .le = 0, .signd = -1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_MU_LAW] = {
        .width = 8, .phys = 8, .le = -1, .signd = -1,
        .silence = { 0x7f },
    },
    [SNDRV_PCM_FORMAT_A_LAW] = {
        .width = 8, .phys = 8, .le = -1, .signd = -1,
        .silence = { 0x55 },
    },
    [SNDRV_PCM_FORMAT_IMA_ADPCM] = {
        .width = 4, .phys = 4, .le = -1, .signd = -1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_G723_24] = {
        .width = 3, .phys = 3, .le = -1, .signd = -1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_G723_40] = {
        .width = 5, .phys = 5, .le = -1, .signd = -1,
        .silence = {},
    },
    /* FIXME: the following three formats are not defined properly yet */
    [SNDRV_PCM_FORMAT_MPEG] = {
        .le = -1, .signd = -1,
    },
    [SNDRV_PCM_FORMAT_GSM] = {
        .le = -1, .signd = -1,
    },
    [SNDRV_PCM_FORMAT_SPECIAL] = {
        .le = -1, .signd = -1,
    },
    [SNDRV_PCM_FORMAT_S24_3LE] = {
        .width = 24, .phys = 24, .le = 1, .signd = 1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_S24_3BE] = {
        .width = 24, .phys = 24, .le = 0, .signd = 1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_U24_3LE] = {
        .width = 24, .phys = 24, .le = 1, .signd = 0,
        .silence = { 0x00, 0x00, 0x80 },
    },
    [SNDRV_PCM_FORMAT_U24_3BE] = {
        .width = 24, .phys = 24, .le = 0, .signd = 0,
        .silence = { 0x80, 0x00, 0x00 },
    },
    [SNDRV_PCM_FORMAT_S20_3LE] = {
        .width = 20, .phys = 24, .le = 1, .signd = 1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_S20_3BE] = {
        .width = 20, .phys = 24, .le = 0, .signd = 1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_U20_3LE] = {
        .width = 20, .phys = 24, .le = 1, .signd = 0,
        .silence = { 0x00, 0x00, 0x08 },
    },
    [SNDRV_PCM_FORMAT_U20_3BE] = {
        .width = 20, .phys = 24, .le = 0, .signd = 0,
        .silence = { 0x08, 0x00, 0x00 },
    },
    [SNDRV_PCM_FORMAT_S18_3LE] = {
        .width = 18, .phys = 24, .le = 1, .signd = 1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_S18_3BE] = {
        .width = 18, .phys = 24, .le = 0, .signd = 1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_U18_3LE] = {
        .width = 18, .phys = 24, .le = 1, .signd = 0,
        .silence = { 0x00, 0x00, 0x02 },
    },
    [SNDRV_PCM_FORMAT_U18_3BE] = {
        .width = 18, .phys = 24, .le = 0, .signd = 0,
        .silence = { 0x02, 0x00, 0x00 },
    },
    [SNDRV_PCM_FORMAT_G723_24_1B] = {
        .width = 3, .phys = 8, .le = -1, .signd = -1,
        .silence = {},
    },
    [SNDRV_PCM_FORMAT_G723_40_1B] = {
        .width = 5, .phys = 8, .le = -1, .signd = -1,
        .silence = {},
    },
};


int snd_pcm_format_signed(snd_pcm_format_t format)
{
    int val;
    if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
        return -EINVAL;
    if ((val = pcm_formats[(INT)format].signd) < 0)
        return -EINVAL;
    return val;
}

EXPORT_SYMBOL(snd_pcm_format_signed);

int snd_pcm_format_unsigned(snd_pcm_format_t format)
{
    int val;

    val = snd_pcm_format_signed(format);
    if (val < 0)
        return val;
    return !val;
}

EXPORT_SYMBOL(snd_pcm_format_unsigned);

int snd_pcm_format_linear(snd_pcm_format_t format)
{
    return snd_pcm_format_signed(format) >= 0;
}

EXPORT_SYMBOL(snd_pcm_format_linear);

int snd_pcm_format_little_endian(snd_pcm_format_t format)
{
    int val;
    if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
        return -EINVAL;
    if ((val = pcm_formats[(INT)format].le) < 0)
        return -EINVAL;
    return val;
}

EXPORT_SYMBOL(snd_pcm_format_little_endian);

int snd_pcm_format_big_endian(snd_pcm_format_t format)
{
    int val;

    val = snd_pcm_format_little_endian(format);
    if (val < 0)
        return val;
    return !val;
}

EXPORT_SYMBOL(snd_pcm_format_big_endian);

int snd_pcm_format_width(snd_pcm_format_t format)
{
    int val;
    if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
        return -EINVAL;
    if ((val = pcm_formats[(INT)format].width) == 0)
        return -EINVAL;
    return val;
}

EXPORT_SYMBOL(snd_pcm_format_width);

int snd_pcm_format_physical_width(snd_pcm_format_t format)
{
    int val;
    if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
        return -EINVAL;
    if ((val = pcm_formats[(INT)format].phys) == 0)
        return -EINVAL;
    return val;
}

EXPORT_SYMBOL(snd_pcm_format_physical_width);

ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples)
{
    int phys_width = snd_pcm_format_physical_width(format);
    if (phys_width < 0)
        return -EINVAL;
    return samples * phys_width / 8;
}

EXPORT_SYMBOL(snd_pcm_format_size);

const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format)
{
    if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
        return NULL;
    if (! pcm_formats[(INT)format].phys)
        return NULL;
    return pcm_formats[(INT)format].silence;
}

EXPORT_SYMBOL(snd_pcm_format_silence_64);

int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples)
{
    int width;
    unsigned char *dst, *pat;

    if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
        return -EINVAL;
    if (samples == 0)
        return 0;
    width = pcm_formats[(INT)format].phys; /* physical width */
    pat = pcm_formats[(INT)format].silence;
    if (! width)
        return -EINVAL;
    /* signed or 1 byte data */
    if (pcm_formats[(INT)format].signd == 1 || width <= 8) {
        unsigned int bytes = samples * width / 8;
        memset(data, *pat, bytes);
        return 0;
    }
    /* non-zero samples, fill using a loop */
    width /= 8;
    dst = data;
#if 0
    while (samples--) {
        memcpy(dst, pat, width);
        dst += width;
    }
#else
    /* a bit optimization for constant width */
    switch (width) {
    case 2:
        while (samples--) {
            memcpy(dst, pat, 2);
            dst += 2;
        }
        break;
    case 3:
        while (samples--) {
            memcpy(dst, pat, 3);
            dst += 3;
        }
        break;
    case 4:
        while (samples--) {
            memcpy(dst, pat, 4);
            dst += 4;
        }
        break;
    case 8:
        while (samples--) {
            memcpy(dst, pat, 8);
            dst += 8;
        }
        break;
    }
#endif
    return 0;
}

EXPORT_SYMBOL(snd_pcm_format_set_silence);

int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime)
{
    int i;
    for (i = 0; i < (int)snd_pcm_known_rates.count; i++) {
        if (runtime->hw.rates & (1 << i)) {
            runtime->hw.rate_min = snd_pcm_known_rates.list[i];
            break;
        }
    }
    for (i = (int)snd_pcm_known_rates.count - 1; i >= 0; i--) {
        if (runtime->hw.rates & (1 << i)) {
            runtime->hw.rate_max = snd_pcm_known_rates.list[i];
            break;
        }
    }
    return 0;
}

EXPORT_SYMBOL(snd_pcm_limit_hw_rates);

unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate)
{
    unsigned int i;

    for (i = 0; i < snd_pcm_known_rates.count; i++)
        if (snd_pcm_known_rates.list[i] == rate)
            return 1u << i;
    return SNDRV_PCM_RATE_KNOT;
}
EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit);

unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit)
{
    unsigned int i;

    for (i = 0; i < snd_pcm_known_rates.count; i++)
        if ((1u << i) == rate_bit)
            return snd_pcm_known_rates.list[i];
    return 0;
}
EXPORT_SYMBOL(snd_pcm_rate_bit_to_rate);