winamp SDK 를 받으면 sample 로 있는 dspecho 에 대한 분석.
기본 뼈대 프로그램은 다음과 같다.
~cpp
// Winamp test dsp library 0.9 for Winamp 2
// Copyright (C) 1997, Justin Frankel/Nullsoft
// Feel free to base any plugins on this "framework"...
#include <windows.h>
#include <commctrl.h>
#include "dsp.h"
#include "resource.h"
// avoid stupid CRT silliness
BOOL WINAPI _DllMainCRTStartup(HANDLE hInst, ULONG ul_reason_for_call, LPVOID lpReserved)
{
return TRUE;
}
// pitch value
int g_pitch=100;
int delta = 1;
// pitch control window
HWND pitch_control_hwnd;
// auxilary pitch buffer (for resampling from)
short *pitch_buffer=NULL;
int pitch_buffer_len=0;
int quit_pitch=0;
// module getter.
winampDSPModule *getModule(int which);
void config(struct winampDSPModule *this_mod);
int init(struct winampDSPModule *this_mod);
void quit(struct winampDSPModule *this_mod);
void initpitch(struct winampDSPModule *this_mod);
void quitpitch(struct winampDSPModule *this_mod);
// 실제로 DSP 관련 처리시 호출되는 함수들.
int modify_samples1(struct winampDSPModule *this_mod, short int *samples, int numsamples, int bps, int nch, int srate);
int modify_samples2(struct winampDSPModule *this_mod, short int *samples, int numsamples, int bps, int nch, int srate);
// 이 부분은 [1002] 가 장난삼아 수정. ^^;
int modify_samples3(struct winampDSPModule *this_mod, short int *samples, int numsamples, int bps, int nch, int srate);
int modify_samples4(struct winampDSPModule *this_mod, short int *samples, int numsamples, int bps, int nch, int srate);
int modify_samples5(struct winampDSPModule *this_mod, short int *samples, int numsamples, int bps, int nch, int srate);
// samples3-5 번 관련. pitch control 를 보여주기 위한 윈도우.
// DSP 처리만을 위해서라면 별 필요 없다.
static BOOL CALLBACK pitchProc(HWND hwndDlg, UINT uMsg, WPARAM wParam,LPARAM lParam);
// Module header, includes version, description, and address of the module retriever function
winampDSPHeader hdr = { DSP_HDRVER, "Nullsoft DSP demo v0.3 for Winamp 2", getModule };
// first module
// DLL 당 여러개의 모듈들이 들어갈 수 있다.
winampDSPModule mod =
{
"Nullsoft Echo v0.2",
NULL, // hwndParent
NULL, // hDllInstance
config, // config 시 호출 함수.
init, // init 시 호출 함수
modify_samples1, // DSP 처리시 호출 함수
quit // quit 시 호출 함수
};
// second module
winampDSPModule mod2 =
{
"Nullsoft Stereo Voice Removal v0.2",
NULL, // hwndParent
NULL, // hDllInstance
config,
init,
modify_samples2,
quit
};
winampDSPModule mod3 =
{
"Nullsoft Pitch/Tempo Control v0.2",
NULL, // hwndParent
NULL, // hDllInstance
config,
initpitch,
modify_samples3,
quitpitch
};
winampDSPModule mod4 =
{
"Nullsoft Pitch/Tempo Control v0.3 - lower",
NULL, // hwndParent
NULL, // hDllInstance
config,
initpitch,
modify_samples4,
quitpitch
};
winampDSPModule mod5 =
{
"Nullsoft Pitch/Tempo Control v0.3 - higher",
NULL, // hwndParent
NULL, // hDllInstance
config,
initpitch,
modify_samples5,
quitpitch
};
#ifdef __cplusplus
extern "C" {
#endif
// this is the only exported symbol. returns our main header.
__declspec( dllexport ) winampDSPHeader *winampDSPGetHeader2()
{
return &hdr;
}
#ifdef __cplusplus
}
#endif
// getmodule routine from the main header. Returns NULL if an invalid module was requested,
// otherwise returns either mod1 or mod2 depending on 'which'.
winampDSPModule *getModule(int which)
{
switch (which)
{
case 0: return &mod;
case 1: return &mod2;
case 2: return &mod3;
case 3: return &mod4;
case 4: return &mod5;
default:return NULL;
}
}
// configuration. Passed this_mod, as a "this" parameter. Allows you to make one configuration
// function that shares code for all your modules (you don't HAVE to use it though, you can make
// config1(), config2(), etc...)
void config(struct winampDSPModule *this_mod)
{
MessageBox(this_mod->hwndParent,"This module is Copyright(C) 1997, Justin Frankel/Nullsoft\n"
"Notes:\n"
" * 8 bit samples aren't supported.\n"
" * Pitch control rules!\n"
" * Voice removal sucks (works about 10% of the time)!\n"
" * Echo isn't very good!\n"
"etc... this is really just a test of the new\n"
"DSP plug-in system. Nothing more.",
"Configuration",MB_OK);
}
int init(struct winampDSPModule *this_mod)
{
return 0;
}
void initpitch(struct winampDSPModule *this_mod)
{
pitch_buffer_len=0;
pitch_buffer=NULL;
quit_pitch=0;
ShowWindow((pitch_control_hwnd=CreateDialog(this_mod->hDllInstance,MAKEINTRESOURCE(IDD_DIALOG1),this_mod->hwndParent,pitchProc)),SW_SHOW);
}
// cleanup (opposite of init()). Destroys the window, unregisters the window class
void quit(struct winampDSPModule *this_mod)
{
}
void quitpitch(struct winampDSPModule *this_mod)
{
if (this_mod == &mod3 || this_mod == &mod4 || this_mod == &mod5)
{
if (pitch_buffer) GlobalFree(pitch_buffer);
pitch_buffer_len=0;
pitch_buffer=NULL;
quit_pitch=1;
if (pitch_control_hwnd)
{
DestroyWindow(pitch_control_hwnd);
pitch_control_hwnd=0;
}
}
}
short echo_buf[65536], echo_buf2[65536];
// 실질적인 callback 함수.
// this_mod 는 일종의 this pointer 라고 생각해도 좋을듯 하다. 해당 모듈(위의 mod1~5) 의 포인터이다.
// samples 는 output 쪽으로 나갈 데이터이며 이 데이터를 수정해주면 된다.
// echo plugin.
int modify_samples1(struct winampDSPModule *this_mod, short int *samples, int numsamples, int bps, int nch, int srate)
{
// echo doesn't support 8 bit right now cause I'm lazy.
if (bps==16)
{
int x,s;
s = numsamples*nch;
memcpy(echo_buf2, echo_buf, s*2);
memcpy(echo_buf, echo_buf+s, s*2);
memcpy(echo_buf+s, echo_buf+s*2, s*2);
memcpy(echo_buf+s*2,echo_buf+s*3, s*2);
memcpy(echo_buf+s*3,samples, s*2);
for (x = 0; x < s; x ++)
{
int s = samples[x]/2+echo_buf2[x]/2;
samples[x] = (s>32767?32767:s<-32768?-32768:s);
}
}
return numsamples;
}
// pitch 를 올렸다 낮췄다 함.
int modify_samples3(struct winampDSPModule *this_mod, short int *samples, int numsamples, int bps, int nch, int srate)
{
int pitch=g_pitch;
int rlen =numsamples*bps/8*nch;
int index=0, x;
int n;
int dindex;
g_pitch += delta;
if (quit_pitch || g_pitch==100) return numsamples;
if (g_pitch > 200) {
g_pitch=200;
delta = -delta;
}
if (g_pitch < 50) {
g_pitch=50;
delta = -delta;
}
pitch = g_pitch;
pitch = 100000/pitch;
n=(numsamples*pitch)/1000;
dindex=(numsamples<<14)/n;
if (pitch_buffer_len < rlen)
{
pitch_buffer_len = rlen;
GlobalFree(pitch_buffer);
pitch_buffer=GlobalAlloc(GMEM_FIXED,rlen);
}
if (bps == 16 && nch == 2)
{
short *buf=pitch_buffer;
memcpy(buf,samples,rlen);
for (x = 0; x < n; x ++)
{
int p=(index>>14)<<1;
index+=dindex;
samples[0] = buf[p];
samples[1] = buf[p+1];
samples+=2;
}
return n;
}
else if (bps == 16 && nch == 1)
{
short *buf=pitch_buffer;
memcpy(buf,samples,rlen);
for (x = 0; x < n; x ++)
{
int p=(index>>14);
index+=dindex;
*samples++ = buf[p];
}
return n;
}
return numsamples;
}
// pitch 를 낮춘 결과를 출력하는 플러그인.
int modify_samples4(struct winampDSPModule *this_mod, short int *samples, int numsamples, int bps, int nch, int srate)
{
int pitch=60;
int rlen =numsamples*bps/8*nch;
int index=0, x;
int n;
int dindex;
pitch = 100000/pitch;
n=(numsamples*pitch)/1000;
dindex=(numsamples<<14)/n;
if (pitch_buffer_len < rlen)
{
pitch_buffer_len = rlen;
GlobalFree(pitch_buffer);
pitch_buffer=GlobalAlloc(GMEM_FIXED,rlen);
}
if (bps == 16 && nch == 2)
{
short *buf=pitch_buffer;
memcpy(buf,samples,rlen);
for (x = 0; x < n; x ++)
{
int p=(index>>14)<<1;
index+=dindex;
samples[0] = buf[p];
samples[1] = buf[p+1];
samples+=2;
}
return n;
}
else if (bps == 16 && nch == 1)
{
short *buf=pitch_buffer;
memcpy(buf,samples,rlen);
for (x = 0; x < n; x ++)
{
int p=(index>>14);
index+=dindex;
*samples++ = buf[p];
}
return n;
}
return numsamples;
}
// pitch 를 올리는 결과를 출력하는 플러그인
int modify_samples5(struct winampDSPModule *this_mod, short int *samples, int numsamples, int bps, int nch, int srate)
{
int pitch=180;
int rlen =numsamples*bps/8*nch;
int index=0, x;
int n;
int dindex;
pitch = 100000/pitch;
n=(numsamples*pitch)/1000;
dindex=(numsamples<<14)/n;
if (pitch_buffer_len < rlen)
{
pitch_buffer_len = rlen;
GlobalFree(pitch_buffer);
pitch_buffer=GlobalAlloc(GMEM_FIXED,rlen);
}
if (bps == 16 && nch == 2)
{
short *buf=pitch_buffer;
memcpy(buf,samples,rlen);
for (x = 0; x < n; x ++)
{
int p=(index>>14)<<1;
index+=dindex;
samples[0] = buf[p];
samples[1] = buf[p+1];
samples+=2;
}
return n;
}
else if (bps == 16 && nch == 1)
{
short *buf=pitch_buffer;
memcpy(buf,samples,rlen);
for (x = 0; x < n; x ++)
{
int p=(index>>14);
index+=dindex;
*samples++ = buf[p];
}
return n;
}
return numsamples;
}
// 이 플러그인은 voice removal.
int modify_samples2(struct winampDSPModule *this_mod, short int *samples, int numsamples, int bps, int nch, int srate)
{
int x = numsamples;
if (bps == 16)
{
short *a = samples;
if (nch == 2) while (x--)
{
int l, r;
l = a[1]-a[0];
r = a[0]-a[1];
if (l < -32768) l = -32768;
if (l > 32767) l = 32767;
if (r < -32768) r = -32768;
if (r > 32767) r = 32767;
a[0] = l;
a[1] = r;
a+=2;
}
}
return numsamples;
}
static BOOL CALLBACK pitchProc(HWND hwndDlg, UINT uMsg, WPARAM wParam,LPARAM lParam)
{
if (uMsg == WM_INITDIALOG)
{
SendDlgItemMessage(hwndDlg,IDC_SLIDER1,TBM_SETRANGEMAX,0,18);
SendDlgItemMessage(hwndDlg,IDC_SLIDER1,TBM_SETRANGEMIN,0,-18);
SendDlgItemMessage(hwndDlg,IDC_SLIDER1,TBM_SETPOS,1,1);
SendDlgItemMessage(hwndDlg,IDC_SLIDER1,TBM_SETPOS,1,0);
{
char str[123];
wsprintf(str,"%s%d%%",g_pitch>100?"+":"",g_pitch-100);
SetDlgItemText(hwndDlg,IDC_BOOGA,str);
}
}
if (uMsg == WM_VSCROLL)
{
HWND swnd = (HWND) lParam;
if (swnd == GetDlgItem(hwndDlg,IDC_SLIDER1))
{
g_pitch = -SendDlgItemMessage(hwndDlg,IDC_SLIDER1,TBM_GETPOS,0,0)+100;
{
char str[123];
wsprintf(str,"%s%d%%",g_pitch>100?"+":"",g_pitch-100);
SetDlgItemText(hwndDlg,IDC_BOOGA,str);
}
}
}
return 0;
}
