forked from len0rd/rockbox
e8135fea5a
Plain import of the library parts first. Adaptions to Rockbox will follow. A *lot* of kudos go to Mihaly Horvath for creating this library from his already lightweight cSID-light, mainly for Rockbox. Besides a lot of other things, he made his algorithms integer-only and significantly improved the C64 emulation, so finally RSIDs could be played as well as PSIDs. TinySID was nice for what it is, but this is a quantum leap in SID playback quality for Rockbox. Check for example: https://hvsc.csdb.dk/MUSICIANS/P/Page_Jason/Eighth.sid https://hvsc.csdb.dk/MUSICIANS/J/Jeff/Blowing.sid Change-Id: I353e12fbfd7cd8696b834616e55743e7b844a73e
134 lines
5 KiB
C
134 lines
5 KiB
C
// cRSID lightweight (integer-only) RealSID library (with API-calls) by Hermit (Mihaly Horvath), Year 2022
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// License: WTF - do what the fuck you want with the code, but please mention me as the original author
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#include <stdlib.h>
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//#include <stdint.h>
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#ifdef CRSID_PLATFORM_PC
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#include <stdio.h>
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#endif
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#include "libcRSID.h"
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#include "C64/C64.c"
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#include "host/file.c"
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#include "host/audio.c"
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cRSID_C64instance* cRSID_init (unsigned short samplerate, unsigned short buflen) {
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static cRSID_C64instance* C64 = &cRSID_C64;
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C64 = cRSID_createC64 (C64, samplerate);
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#ifdef CRSID_PLATFORM_PC
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if ( cRSID_initSound (C64, samplerate,buflen) == NULL) return NULL;
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#else
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if (buflen) return C64; //this is here just to eliminate unused 'buflen' variable warning
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#endif
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return C64;
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}
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void cRSID_initSIDtune (cRSID_C64instance* C64, cRSID_SIDheader* SIDheader, char subtune) { //subtune: 1..255
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static const unsigned char PowersOf2[] = {0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80};
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unsigned int InitTimeout=10000000; //allowed instructions, value should be selected to allow for long-running memory-copiers in init-routines (e.g. Synth Sample)
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if (subtune==0) subtune = 1;
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else if (subtune > SIDheader->SubtuneAmount) subtune = SIDheader->SubtuneAmount;
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C64->SubTune = subtune;
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cRSID_setC64(C64); cRSID_initC64(C64); //cRSID_writeMemC64(C64,0xD418,0xF); //set C64 hardware and init (reset) it
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//determine init-address:
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C64->InitAddress = ((SIDheader->InitAddressH)<<8) + (SIDheader->InitAddressL); //get info from BASIC-startupcode for some tunes
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if (C64->RAMbank[1] == 0x37) { //are there SIDs with routine under IO area? some PSIDs don't set bank-registers themselves
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if ( (0xA000 <= C64->InitAddress && C64->InitAddress < 0xC000)
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|| (C64->LoadAddress < 0xC000 && C64->EndAddress >= 0xA000) ) C64->RAMbank[1] = 0x36;
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else if (C64->InitAddress >= 0xE000 || C64->EndAddress >=0xE000) C64->RAMbank[1] = 0x35;
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}
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cRSID_initCPU( &C64->CPU, C64->InitAddress ); //prepare init-routine call
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C64->CPU.A = subtune - 1;
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if (!C64->RealSIDmode) {
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//call init-routine:
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for (InitTimeout=10000000; InitTimeout>0; InitTimeout--) { if ( cRSID_emulateCPU()>=0xFE ) break; } //give error when timed out?
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}
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//determine timing-source, if CIA, replace FrameCycles previouisly set to VIC-timing
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if (subtune>32) C64->TimerSource = C64->SIDheader->SubtuneTimeSources[0] & 0x80; //subtunes above 32 should use subtune32's timing
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else C64->TimerSource = C64->SIDheader->SubtuneTimeSources[(32-subtune)>>3] & PowersOf2[(subtune-1)&7];
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if (C64->TimerSource || C64->IObankWR[0xDC05]!=0x40 || C64->IObankWR[0xDC04]!=0x24) { //CIA1-timing (probably multispeed tune)
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C64->FrameCycles = ( ( C64->IObankWR[0xDC04] + (C64->IObankWR[0xDC05]<<8) ) ); //<< 4) / C64->ClockRatio;
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C64->TimerSource = 1; //if init-routine changed DC04 or DC05, assume CIA-timing
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}
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//determine playaddress:
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C64->PlayAddress = (SIDheader->PlayAddressH<<8) + SIDheader->PlayAddressL;
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if (C64->PlayAddress) { //normal play-address called with JSR
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if (C64->RAMbank[1] == 0x37) { //are there SIDs with routine under IO area?
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if (0xA000 <= C64->PlayAddress && C64->PlayAddress < 0xC000) C64->RAMbank[1] = 0x36;
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}
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else if (C64->PlayAddress >= 0xE000) C64->RAMbank[1] = 0x35; //player under KERNAL (e.g. Crystal Kingdom Dizzy)
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}
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else { //IRQ-playaddress for multispeed-tunes set by init-routine (some tunes turn off KERNAL ROM but doesn't set IRQ-vector!)
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C64->PlayAddress = (C64->RAMbank[1] & 3) < 2 ? cRSID_readMemC64(C64,0xFFFE) + (cRSID_readMemC64(C64,0xFFFF)<<8) //for PSID
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: cRSID_readMemC64(C64,0x314) + (cRSID_readMemC64(C64,0x315)<<8);
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if (C64->PlayAddress==0) { //if 0, still try with RSID-mode fallback
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cRSID_initCPU( &C64->CPU, C64->PlayAddress ); //point CPU to play-routine
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C64->Finished=1; C64->Returned=1; return;
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}
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}
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if (!C64->RealSIDmode) { //prepare (PSID) play-routine playback:
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cRSID_initCPU( &C64->CPU, C64->PlayAddress ); //point CPU to play-routine
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C64->FrameCycleCnt=0; C64->Finished=1; C64->SampleCycleCnt=0; //C64->CIAisSet=0;
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}
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else { C64->Finished=0; C64->Returned=0; }
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}
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#ifdef CRSID_PLATFORM_PC
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char cRSID_playSIDfile(cRSID_C64instance* C64, char* filename, char subtune) {
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static cRSID_SIDheader* SIDheader;
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SIDheader = cRSID_loadSIDtune(C64,filename);
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if (SIDheader==NULL) return CRSID_ERROR_LOAD;
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cRSID_initSIDtune (C64 , SIDheader , subtune);
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cRSID_playSIDtune ();
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return CRSID_STATUS_OK;
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}
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cRSID_SIDheader* cRSID_loadSIDtune(cRSID_C64instance* C64, char* filename) {
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enum SIDspecs { CRSID_FILESIZE_MAX = 100000 };
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int FileSize;
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static unsigned char SIDfileData [CRSID_FILESIZE_MAX]; //use memset?
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FileSize = cRSID_loadSIDfile( SIDfileData, filename, CRSID_FILESIZE_MAX);
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if ( FileSize == CRSID_ERROR_LOAD ) return NULL;
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return cRSID_processSIDfile ( C64, SIDfileData, FileSize );
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}
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void cRSID_close() {
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cRSID_closeSound();
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}
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void cRSID_playSIDtune (void) {
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cRSID_startSound();
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}
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void cRSID_pauseSIDtune (void) {
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cRSID_stopSound();
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}
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#endif
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