dolphin/Source/Plugins/Plugin_DSP_LLE/Src/gdsp_aram.cpp

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// Copyright (C) 2003-2008 Dolphin Project.
// 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, version 2.0.
// 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 2.0 for more details.
// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/
// Official SVN repository and contact information can be found at
// http://code.google.com/p/dolphin-emu/
#include "Globals.h"
#include "gdsp_interface.h"
extern uint16 dsp_swap16(uint16 x);
// The hardware adpcm decoder :)
sint16 ADPCM_Step(uint32& _rSamplePos, uint32 _BaseAddress)
{
sint16* pCoefTable = (sint16*)&gdsp_ifx_regs[DSP_COEF_A1_0];
if (((_rSamplePos) & 15) == 0)
{
gdsp_ifx_regs[DSP_PRED_SCALE] = g_dspInitialize.pARAM_Read_U8((_rSamplePos & ~15) >> 1);
_rSamplePos += 2;
}
int scale = 1 << (gdsp_ifx_regs[DSP_PRED_SCALE] & 0xF);
int coef_idx = gdsp_ifx_regs[DSP_PRED_SCALE] >> 4;
sint32 coef1 = pCoefTable[coef_idx * 2 + 0];
sint32 coef2 = pCoefTable[coef_idx * 2 + 1];
int temp = (_rSamplePos & 1) ?
(g_dspInitialize.pARAM_Read_U8(_rSamplePos >> 1) & 0xF) :
(g_dspInitialize.pARAM_Read_U8(_rSamplePos >> 1) >> 4);
if (temp >= 8)
temp -= 16;
// 0x400 = 0.5 in 11-bit fixed point
int val = (scale * temp) + ((0x400 + coef1 * (sint16)gdsp_ifx_regs[DSP_YN1] + coef2 * (sint16)gdsp_ifx_regs[DSP_YN2]) >> 11);
// Clamp values.
if (val > 0x7FFF)
val = 0x7FFF;
else if (val < -0x7FFF)
val = -0x7FFF;
gdsp_ifx_regs[DSP_YN2] = gdsp_ifx_regs[DSP_YN1];
gdsp_ifx_regs[DSP_YN1] = val;
_rSamplePos++;
// The advanced interpolation (linear, polyphase,...) is done by the UCode, so we don't
// need to bother with it here.
return val;
}
extern void gdsp_generate_exception(uint8 level);
uint16 dsp_read_aram()
{
// uint32 BaseAddress = (gdsp_ifx_regs[DSP_ACSAH] << 16) | gdsp_ifx_regs[DSP_ACSAL];
uint32 EndAddress = (gdsp_ifx_regs[DSP_ACEAH] << 16) | gdsp_ifx_regs[DSP_ACEAL];
uint32 Address = (gdsp_ifx_regs[DSP_ACCAH] << 16) | gdsp_ifx_regs[DSP_ACCAL];
uint16 val;
// lets the "hardware" decode
switch (gdsp_ifx_regs[DSP_FORMAT])
{
case 0x00:
val = ADPCM_Step(Address, EndAddress);
break;
case 0x0A:
val = (g_dspInitialize.pARAM_Read_U8(Address) << 8) | g_dspInitialize.pARAM_Read_U8(Address + 1);
gdsp_ifx_regs[DSP_YN2] = gdsp_ifx_regs[DSP_YN1];
gdsp_ifx_regs[DSP_YN1] = val;
Address += 2;
break;
default:
val = (g_dspInitialize.pARAM_Read_U8(Address) << 8) | g_dspInitialize.pARAM_Read_U8(Address + 1);
Address += 2;
ErrorLog("Unknown DSP Format %i", gdsp_ifx_regs[DSP_FORMAT]);
break;
}
// check for loop
if (Address > EndAddress)
{
Address = (gdsp_ifx_regs[DSP_ACSAH] << 16) | gdsp_ifx_regs[DSP_ACSAL];
gdsp_generate_exception(3);
gdsp_generate_exception(5);
// Somehow, YN1 and YN2 must be initialized with their "loop" values, so yeah,
// it seems likely that we should raise an exception to let the DSP program do that,
// at least if DSP_FORMAT == 0x0A.
}
gdsp_ifx_regs[DSP_ACCAH] = Address >> 16;
gdsp_ifx_regs[DSP_ACCAL] = Address & 0xffff;
return(val);
}