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/*
* Copyright 2003-2021 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef MPD_ALSA_FORMAT_HXX
#define MPD_ALSA_FORMAT_HXX
#include "pcm/SampleFormat.hxx"
#include "util/Compiler.h"
#include "config.h"
#include <alsa/asoundlib.h>
#include <cassert>
#if SND_LIB_VERSION >= 0x1001c
/* alsa-lib supports DSD since version 1.0.27.1 */
#define HAVE_ALSA_DSD
#endif
#if SND_LIB_VERSION >= 0x1001d
/* alsa-lib supports DSD_U32 since version 1.0.29 */
#define HAVE_ALSA_DSD_U32
#endif
/**
* Convert MPD's #SampleFormat enum to libasound's snd_pcm_format_t
* enum. Returns SND_PCM_FORMAT_UNKNOWN if there is no according ALSA
* PCM format.
*/
[[gnu::const]]
inline snd_pcm_format_t
ToAlsaPcmFormat(SampleFormat sample_format) noexcept
{
switch (sample_format) {
case SampleFormat::UNDEFINED:
return SND_PCM_FORMAT_UNKNOWN;
case SampleFormat::DSD:
#ifdef HAVE_ALSA_DSD
return SND_PCM_FORMAT_DSD_U8;
#else
return SND_PCM_FORMAT_UNKNOWN;
#endif
case SampleFormat::S8:
return SND_PCM_FORMAT_S8;
case SampleFormat::S16:
return SND_PCM_FORMAT_S16;
case SampleFormat::S24_P32:
return SND_PCM_FORMAT_S24;
case SampleFormat::S32:
return SND_PCM_FORMAT_S32;
case SampleFormat::FLOAT:
return SND_PCM_FORMAT_FLOAT;
}
assert(false);
gcc_unreachable();
}
/**
* Determine the byte-swapped PCM format. Returns
* SND_PCM_FORMAT_UNKNOWN if the format cannot be byte-swapped.
*/
[[gnu::const]]
inline snd_pcm_format_t
ByteSwapAlsaPcmFormat(snd_pcm_format_t fmt) noexcept
{
switch (fmt) {
case SND_PCM_FORMAT_S16_LE: return SND_PCM_FORMAT_S16_BE;
case SND_PCM_FORMAT_S24_LE: return SND_PCM_FORMAT_S24_BE;
case SND_PCM_FORMAT_S32_LE: return SND_PCM_FORMAT_S32_BE;
case SND_PCM_FORMAT_S16_BE: return SND_PCM_FORMAT_S16_LE;
case SND_PCM_FORMAT_S24_BE: return SND_PCM_FORMAT_S24_LE;
case SND_PCM_FORMAT_S24_3BE:
return SND_PCM_FORMAT_S24_3LE;
case SND_PCM_FORMAT_S24_3LE:
return SND_PCM_FORMAT_S24_3BE;
case SND_PCM_FORMAT_S32_BE: return SND_PCM_FORMAT_S32_LE;
#ifdef HAVE_ALSA_DSD_U32
case SND_PCM_FORMAT_DSD_U16_LE:
return SND_PCM_FORMAT_DSD_U16_BE;
case SND_PCM_FORMAT_DSD_U16_BE:
return SND_PCM_FORMAT_DSD_U16_LE;
case SND_PCM_FORMAT_DSD_U32_LE:
return SND_PCM_FORMAT_DSD_U32_BE;
case SND_PCM_FORMAT_DSD_U32_BE:
return SND_PCM_FORMAT_DSD_U32_LE;
#endif
default: return SND_PCM_FORMAT_UNKNOWN;
}
}
/**
* Check if there is a "packed" version of the give PCM format.
* Returns SND_PCM_FORMAT_UNKNOWN if not.
*/
constexpr snd_pcm_format_t
PackAlsaPcmFormat(snd_pcm_format_t fmt) noexcept
{
switch (fmt) {
case SND_PCM_FORMAT_S24_LE:
return SND_PCM_FORMAT_S24_3LE;
case SND_PCM_FORMAT_S24_BE:
return SND_PCM_FORMAT_S24_3BE;
default:
return SND_PCM_FORMAT_UNKNOWN;
}
}
#endif