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/*
* Copyright (C) 2003-2013 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 PCM_EXPORT_HXX
#define PCM_EXPORT_HXX
#include "check.h"
#include "pcm_buffer.h"
#include "audio_format.h"
struct audio_format;
/**
* An object that handles export of PCM samples to some instance
* outside of MPD. It has a few more options to tweak the binary
* representation which are not supported by the pcm_convert library.
*/
struct PcmExport {
/**
* The buffer is used to convert DSD samples to the
* DSD-over-USB format.
*
* @see #dsd_usb
*/
struct pcm_buffer dsd_buffer;
/**
* The buffer is used to pack samples, removing padding.
*
* @see #pack24
*/
struct pcm_buffer pack_buffer;
/**
* The buffer is used to reverse the byte order.
*
* @see #reverse_endian
*/
struct pcm_buffer reverse_buffer;
/**
* The number of channels.
*/
uint8_t channels;
/**
* Convert DSD to DSD-over-USB? Input format must be
* SAMPLE_FORMAT_DSD and output format must be
* SAMPLE_FORMAT_S24_P32.
*/
bool dsd_usb;
/**
* Convert (padded) 24 bit samples to 32 bit by shifting 8
* bits to the left?
*/
bool shift8;
/**
* Pack 24 bit samples?
*/
bool pack24;
/**
* Export the samples in reverse byte order? A non-zero value
* means the option is enabled and represents the size of each
* sample (2 or bigger).
*/
uint8_t reverse_endian;
PcmExport() {
pcm_buffer_init(&reverse_buffer);
pcm_buffer_init(&pack_buffer);
pcm_buffer_init(&dsd_buffer);
}
~PcmExport() {
pcm_buffer_deinit(&reverse_buffer);
pcm_buffer_deinit(&pack_buffer);
pcm_buffer_deinit(&dsd_buffer);
}
/**
* Open the #pcm_export_state object.
*
* There is no "close" method. This function may be called multiple
* times to reuse the object, until pcm_export_deinit() is called.
*
* This function cannot fail.
*
* @param channels the number of channels; ignored unless dsd_usb is set
*/
void Open(enum sample_format sample_format, unsigned channels,
bool dsd_usb, bool shift8, bool pack, bool reverse_endian);
/**
* Calculate the size of one output frame.
*/
gcc_pure
size_t GetFrameSize(const struct audio_format &audio_format) const;
/**
* Export a PCM buffer.
*
* @param state an initialized and open pcm_export_state object
* @param src the source PCM buffer
* @param src_size the size of #src in bytes
* @param dest_size_r returns the number of bytes of the destination buffer
* @return the destination buffer (may be a pointer to the source buffer)
*/
const void *Export(const void *src, size_t src_size,
size_t &dest_size_r);
/**
* Converts the number of consumed bytes from the pcm_export()
* destination buffer to the according number of bytes from the
* pcm_export() source buffer.
*/
gcc_pure
size_t CalcSourceSize(size_t dest_size) const;
};
#endif
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