/*
 * libmad - MPEG audio decoder library
 * Copyright (C) 2000-2004 Underbit Technologies, Inc.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * $Id: synth.h,v 1.15 2004/01/23 09:41:33 rob Exp $
 */

#pragma once
#include "Mp3Frame.h"
#include "fixed.h"


namespace kilipili::Audio
{

struct PcmBuffer
{
	uint		samplerate {0};	  // sampling frequency (Hz)
	ushort		channels {0};	  // number of channels
	ushort		length {0};		  // number of samples per channel
	mad_fixed_t samples[2][1152]; // PCM output samples [ch][sample]
};

struct Mp3Synth
{
	Mp3Synth() noexcept { mute(); }
	~Mp3Synth() noexcept = default;

	void synthesizeFrame(const Mp3Frame*);

	mad_fixed_t filter[2][2][2][16][8]; // polyphase filterbank outputs: [ch][eo][peo][s][v]
	uint		phase {0};				// current processing phase
	PcmBuffer	pcm;					// PCM output

private:
	void mute() noexcept;
};


/* single channel PCM selector */
enum { MAD_PCM_CHANNEL_SINGLE = 0 };

/* dual channel PCM selector */
enum { MAD_PCM_CHANNEL_DUAL_1 = 0, MAD_PCM_CHANNEL_DUAL_2 = 1 };

/* stereo PCM selector */
enum { MAD_PCM_CHANNEL_STEREO_LEFT = 0, MAD_PCM_CHANNEL_STEREO_RIGHT = 1 };


} // namespace kilipili::Audio