470 lines
12 KiB
C
470 lines
12 KiB
C
/*
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* PCM Interface - misc routines
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* Copyright (c) 1998 by Jaroslav Kysela <perex@perex.cz>
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*
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*
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* This library is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Library General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <linux/time.h>
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#include <sound/core.h>
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#include <sound/pcm.h>
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#define SND_PCM_FORMAT_UNKNOWN (-1)
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/* NOTE: "signed" prefix must be given below since the default char is
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* unsigned on some architectures!
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*/
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struct pcm_format_data {
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unsigned char width; /* bit width */
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unsigned char phys; /* physical bit width */
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signed char le; /* 0 = big-endian, 1 = little-endian, -1 = others */
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signed char signd; /* 0 = unsigned, 1 = signed, -1 = others */
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unsigned char silence[8]; /* silence data to fill */
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};
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static struct pcm_format_data pcm_formats[SNDRV_PCM_FORMAT_LAST+1] = {
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[SNDRV_PCM_FORMAT_S8] = {
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.width = 8, .phys = 8, .le = -1, .signd = 1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_U8] = {
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.width = 8, .phys = 8, .le = -1, .signd = 0,
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.silence = { 0x80 },
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},
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[SNDRV_PCM_FORMAT_S16_LE] = {
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.width = 16, .phys = 16, .le = 1, .signd = 1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_S16_BE] = {
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.width = 16, .phys = 16, .le = 0, .signd = 1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_U16_LE] = {
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.width = 16, .phys = 16, .le = 1, .signd = 0,
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.silence = { 0x00, 0x80 },
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},
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[SNDRV_PCM_FORMAT_U16_BE] = {
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.width = 16, .phys = 16, .le = 0, .signd = 0,
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.silence = { 0x80, 0x00 },
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},
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[SNDRV_PCM_FORMAT_S24_LE] = {
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.width = 24, .phys = 32, .le = 1, .signd = 1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_S24_BE] = {
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.width = 24, .phys = 32, .le = 0, .signd = 1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_U24_LE] = {
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.width = 24, .phys = 32, .le = 1, .signd = 0,
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.silence = { 0x00, 0x00, 0x80 },
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},
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[SNDRV_PCM_FORMAT_U24_BE] = {
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.width = 24, .phys = 32, .le = 0, .signd = 0,
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.silence = { 0x00, 0x80, 0x00, 0x00 },
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},
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[SNDRV_PCM_FORMAT_S32_LE] = {
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.width = 32, .phys = 32, .le = 1, .signd = 1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_S32_BE] = {
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.width = 32, .phys = 32, .le = 0, .signd = 1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_U32_LE] = {
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.width = 32, .phys = 32, .le = 1, .signd = 0,
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.silence = { 0x00, 0x00, 0x00, 0x80 },
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},
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[SNDRV_PCM_FORMAT_U32_BE] = {
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.width = 32, .phys = 32, .le = 0, .signd = 0,
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.silence = { 0x80, 0x00, 0x00, 0x00 },
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},
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[SNDRV_PCM_FORMAT_FLOAT_LE] = {
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.width = 32, .phys = 32, .le = 1, .signd = -1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_FLOAT_BE] = {
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.width = 32, .phys = 32, .le = 0, .signd = -1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_FLOAT64_LE] = {
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.width = 64, .phys = 64, .le = 1, .signd = -1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_FLOAT64_BE] = {
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.width = 64, .phys = 64, .le = 0, .signd = -1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE] = {
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.width = 32, .phys = 32, .le = 1, .signd = -1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE] = {
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.width = 32, .phys = 32, .le = 0, .signd = -1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_MU_LAW] = {
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.width = 8, .phys = 8, .le = -1, .signd = -1,
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.silence = { 0x7f },
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},
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[SNDRV_PCM_FORMAT_A_LAW] = {
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.width = 8, .phys = 8, .le = -1, .signd = -1,
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.silence = { 0x55 },
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},
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[SNDRV_PCM_FORMAT_IMA_ADPCM] = {
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.width = 4, .phys = 4, .le = -1, .signd = -1,
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.silence = {},
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},
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/* FIXME: the following three formats are not defined properly yet */
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[SNDRV_PCM_FORMAT_MPEG] = {
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.le = -1, .signd = -1,
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},
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[SNDRV_PCM_FORMAT_GSM] = {
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.le = -1, .signd = -1,
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},
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[SNDRV_PCM_FORMAT_SPECIAL] = {
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.le = -1, .signd = -1,
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},
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[SNDRV_PCM_FORMAT_S24_3LE] = {
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.width = 24, .phys = 24, .le = 1, .signd = 1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_S24_3BE] = {
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.width = 24, .phys = 24, .le = 0, .signd = 1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_U24_3LE] = {
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.width = 24, .phys = 24, .le = 1, .signd = 0,
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.silence = { 0x00, 0x00, 0x80 },
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},
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[SNDRV_PCM_FORMAT_U24_3BE] = {
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.width = 24, .phys = 24, .le = 0, .signd = 0,
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.silence = { 0x80, 0x00, 0x00 },
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},
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[SNDRV_PCM_FORMAT_S20_3LE] = {
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.width = 20, .phys = 24, .le = 1, .signd = 1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_S20_3BE] = {
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.width = 20, .phys = 24, .le = 0, .signd = 1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_U20_3LE] = {
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.width = 20, .phys = 24, .le = 1, .signd = 0,
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.silence = { 0x00, 0x00, 0x08 },
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},
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[SNDRV_PCM_FORMAT_U20_3BE] = {
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.width = 20, .phys = 24, .le = 0, .signd = 0,
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.silence = { 0x08, 0x00, 0x00 },
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},
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[SNDRV_PCM_FORMAT_S18_3LE] = {
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.width = 18, .phys = 24, .le = 1, .signd = 1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_S18_3BE] = {
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.width = 18, .phys = 24, .le = 0, .signd = 1,
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.silence = {},
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},
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[SNDRV_PCM_FORMAT_U18_3LE] = {
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.width = 18, .phys = 24, .le = 1, .signd = 0,
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.silence = { 0x00, 0x00, 0x02 },
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},
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[SNDRV_PCM_FORMAT_U18_3BE] = {
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.width = 18, .phys = 24, .le = 0, .signd = 0,
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.silence = { 0x02, 0x00, 0x00 },
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},
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};
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/**
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* snd_pcm_format_signed - Check the PCM format is signed linear
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* @format: the format to check
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*
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* Returns 1 if the given PCM format is signed linear, 0 if unsigned
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* linear, and a negative error code for non-linear formats.
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*/
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int snd_pcm_format_signed(snd_pcm_format_t format)
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{
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int val;
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if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
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return -EINVAL;
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if ((val = pcm_formats[format].signd) < 0)
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return -EINVAL;
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return val;
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}
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EXPORT_SYMBOL(snd_pcm_format_signed);
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/**
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* snd_pcm_format_unsigned - Check the PCM format is unsigned linear
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* @format: the format to check
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*
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* Returns 1 if the given PCM format is unsigned linear, 0 if signed
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* linear, and a negative error code for non-linear formats.
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*/
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int snd_pcm_format_unsigned(snd_pcm_format_t format)
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{
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int val;
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val = snd_pcm_format_signed(format);
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if (val < 0)
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return val;
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return !val;
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}
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EXPORT_SYMBOL(snd_pcm_format_unsigned);
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/**
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* snd_pcm_format_linear - Check the PCM format is linear
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* @format: the format to check
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*
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* Returns 1 if the given PCM format is linear, 0 if not.
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*/
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int snd_pcm_format_linear(snd_pcm_format_t format)
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{
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return snd_pcm_format_signed(format) >= 0;
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}
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EXPORT_SYMBOL(snd_pcm_format_linear);
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/**
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* snd_pcm_format_little_endian - Check the PCM format is little-endian
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* @format: the format to check
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*
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* Returns 1 if the given PCM format is little-endian, 0 if
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* big-endian, or a negative error code if endian not specified.
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*/
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int snd_pcm_format_little_endian(snd_pcm_format_t format)
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{
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int val;
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if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
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return -EINVAL;
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if ((val = pcm_formats[format].le) < 0)
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return -EINVAL;
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return val;
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}
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EXPORT_SYMBOL(snd_pcm_format_little_endian);
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/**
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* snd_pcm_format_big_endian - Check the PCM format is big-endian
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* @format: the format to check
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*
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* Returns 1 if the given PCM format is big-endian, 0 if
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* little-endian, or a negative error code if endian not specified.
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*/
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int snd_pcm_format_big_endian(snd_pcm_format_t format)
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{
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int val;
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val = snd_pcm_format_little_endian(format);
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if (val < 0)
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return val;
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return !val;
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}
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EXPORT_SYMBOL(snd_pcm_format_big_endian);
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/**
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* snd_pcm_format_width - return the bit-width of the format
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* @format: the format to check
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*
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* Returns the bit-width of the format, or a negative error code
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* if unknown format.
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*/
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int snd_pcm_format_width(snd_pcm_format_t format)
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{
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int val;
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if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
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return -EINVAL;
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if ((val = pcm_formats[format].width) == 0)
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return -EINVAL;
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return val;
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}
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EXPORT_SYMBOL(snd_pcm_format_width);
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/**
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* snd_pcm_format_physical_width - return the physical bit-width of the format
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* @format: the format to check
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*
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* Returns the physical bit-width of the format, or a negative error code
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* if unknown format.
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*/
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int snd_pcm_format_physical_width(snd_pcm_format_t format)
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{
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int val;
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if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
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return -EINVAL;
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if ((val = pcm_formats[format].phys) == 0)
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return -EINVAL;
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return val;
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}
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EXPORT_SYMBOL(snd_pcm_format_physical_width);
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/**
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* snd_pcm_format_size - return the byte size of samples on the given format
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* @format: the format to check
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*
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* Returns the byte size of the given samples for the format, or a
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* negative error code if unknown format.
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*/
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ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples)
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{
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int phys_width = snd_pcm_format_physical_width(format);
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if (phys_width < 0)
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return -EINVAL;
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return samples * phys_width / 8;
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}
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EXPORT_SYMBOL(snd_pcm_format_size);
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/**
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* snd_pcm_format_silence_64 - return the silent data in 8 bytes array
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* @format: the format to check
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*
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* Returns the format pattern to fill or NULL if error.
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*/
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const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format)
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{
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if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
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return NULL;
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if (! pcm_formats[format].phys)
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return NULL;
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return pcm_formats[format].silence;
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}
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EXPORT_SYMBOL(snd_pcm_format_silence_64);
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/**
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* snd_pcm_format_set_silence - set the silence data on the buffer
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* @format: the PCM format
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* @data: the buffer pointer
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* @samples: the number of samples to set silence
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*
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* Sets the silence data on the buffer for the given samples.
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*
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* Returns zero if successful, or a negative error code on failure.
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*/
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int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples)
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{
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int width;
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unsigned char *dst, *pat;
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if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
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return -EINVAL;
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if (samples == 0)
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return 0;
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width = pcm_formats[format].phys; /* physical width */
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pat = pcm_formats[format].silence;
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if (! width)
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return -EINVAL;
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/* signed or 1 byte data */
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if (pcm_formats[format].signd == 1 || width <= 8) {
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unsigned int bytes = samples * width / 8;
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memset(data, *pat, bytes);
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return 0;
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}
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/* non-zero samples, fill using a loop */
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width /= 8;
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dst = data;
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#if 0
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while (samples--) {
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memcpy(dst, pat, width);
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dst += width;
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}
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#else
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/* a bit optimization for constant width */
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switch (width) {
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case 2:
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while (samples--) {
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memcpy(dst, pat, 2);
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dst += 2;
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}
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break;
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case 3:
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while (samples--) {
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memcpy(dst, pat, 3);
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dst += 3;
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}
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break;
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case 4:
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while (samples--) {
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memcpy(dst, pat, 4);
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dst += 4;
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}
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break;
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case 8:
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while (samples--) {
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memcpy(dst, pat, 8);
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dst += 8;
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}
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break;
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}
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#endif
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return 0;
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}
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EXPORT_SYMBOL(snd_pcm_format_set_silence);
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/**
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* snd_pcm_limit_hw_rates - determine rate_min/rate_max fields
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* @runtime: the runtime instance
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*
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* Determines the rate_min and rate_max fields from the rates bits of
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* the given runtime->hw.
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*
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* Returns zero if successful.
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*/
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int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime)
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{
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int i;
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for (i = 0; i < (int)snd_pcm_known_rates.count; i++) {
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if (runtime->hw.rates & (1 << i)) {
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runtime->hw.rate_min = snd_pcm_known_rates.list[i];
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break;
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}
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}
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for (i = (int)snd_pcm_known_rates.count - 1; i >= 0; i--) {
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if (runtime->hw.rates & (1 << i)) {
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runtime->hw.rate_max = snd_pcm_known_rates.list[i];
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break;
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}
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}
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return 0;
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}
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EXPORT_SYMBOL(snd_pcm_limit_hw_rates);
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/**
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* snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit
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* @rate: the sample rate to convert
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*
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* Returns the SNDRV_PCM_RATE_xxx flag that corresponds to the given rate, or
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* SNDRV_PCM_RATE_KNOT for an unknown rate.
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*/
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unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate)
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{
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unsigned int i;
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for (i = 0; i < snd_pcm_known_rates.count; i++)
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if (snd_pcm_known_rates.list[i] == rate)
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return 1u << i;
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return SNDRV_PCM_RATE_KNOT;
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}
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EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit);
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