关于多媒体播放器VCD左右声道问题的BC代码

kmusttywyc

<>关于多媒体播放器在CB下声道转换的原代码！（DEPHI版的网上有）</P>
<>TSuperPlayerform *SuperPlayerform;
typedef struct
{
    DWORD dwCallback;
. G" _" Z  B! f9 ~0 b    DWORD dwItem;
9 I% a# B' S, L7 c+ q    DWORD dwValue;
4 M1 T( N: S0 A) _! o- F/ X2 d5 [! o    DWORD dwOver;
    LPSTR lpstrAlgorithm;
    LPSTR lpstrQuality;
} MCI_DGV_SETAUDIO_PARMS;
( p. f4 C6 J- [6 c7 h   
9 ?1 o( _) p9 r const MCI_SETAUDIO = 0x873;
const MCI_SETVIDEO = 0x0876;
const MCI_DGV_SETAUDIO_SOURCE_LEFT=1;
const MCI_DGV_SETAUDIO_SOURCE_STEREO=0;
const MCI_DGV_SETAUDIO_SOURCE_RIGHT=2;
9 g% y# T$ @- N; L4 \) X  e  t: u const MCI_DGV_SETAUDIO_SOURCE=0x4004;
const MCI_DGV_SETAUDIO_VOLUME=0x4002;
8 a. Q0 U8 m$ J. c const MAX_VOLUME=65535;
const MIN_VOLUME=0;</P>
3 g! _# \/ o$ U' e<>void __fastcall TSuperPlayerform:RC(char &amp;S)
{
2 n% [" M' C6 L  //char str;
  MCI_DGV_SETAUDIO_PARMS s;
3 D% O1 x1 w5 i; @) @  int err;
  char buf[1001];
4 {3 k  }' n  T9 k( D8 k/ ]  //str=''L'';
$ F0 `0 j8 f0 m  z. a  if (MediaPlayer1-&gt;DeviceID&gt;0)
( N2 L" |  u  c' i8 ^4 D, _  {
    err=mciSendCommand(MediaPlayer1-&gt;DeviceID,MCI_SETAUDIO,MCI_SET_OFF,int(&amp;s));
    if (err!=0)
       mciGetErrorString(err,buf,sizeof(buf) );
& Q# s6 Q" e& F! E2 d" J* w    if (S=='C')
/ V, t6 A5 I& \( p       s.dwValue=MCI_DGV_SETAUDIO_SOURCE_STEREO;
; @( G/ R% N* P+ D' R# h4 S    if (S=='L')
       s.dwValue=MCI_DGV_SETAUDIO_SOURCE_LEFT;
    if (S=='R') s.dwValue=MCI_DGV_SETAUDIO_SOURCE_RIGHT;
       s.dwItem=MCI_DGV_SETAUDIO_SOURCE;
3 F% f( z9 k+ |1 K# h, d    const MCI_DGV_SETAUDIO_VALUE=0x01000000L;
    const MCI_DGV_SETAUDIO_ITEM=0x00800000L;
    //(MCI_DGV_SETAUDIO_VALUE||MCI_DGV_SETAUDIO_ITEM)=0x01800000
    err=mciSendCommand(MediaPlayer1-&gt;DeviceID,MCI_SETAUDIO,0x01800000,int(&amp;s));
0 p. b& j, q( \- t% C$ i7 \    if (err!=0)
       mciGetErrorString(err,buf,sizeof(buf) );
7 |' f1 c6 p* a6 i8 ?  E1 I    err=mciSendCommand(MediaPlayer1-&gt;DeviceID,MCI_SETAUDIO, MCI_SET_ON ,int(&amp;s));
    if (err!=0)
      mciGetErrorString(err,buf,sizeof(buf) );
   }
" C* ]2 J9 G0 a, x6 {5 Q1 P }</P>
) u" b3 L& @+ y/ z1 [, E% l* y<> void __fastcall TSuperPlayerform::popnosoundClick(TObject *Sender)
  u: v+ C* }* _& M {
8 T# S$ t# K! }$ ?4 m" I; i% Z: I     LRC('L');
     Label3-&gt;Caption=“左声道 ";
     tempchannel='L';
0 k" L( F* C  @% M }
6 n  A3 ~: ~- `- M6 C# L  ~. }//---------------------------------------------------------------------------</P>
<> void __fastcall TSuperPlayerform::popsoundClick(TObject *Sender)
{
     LRC('R');
; S8 w1 c. A. b     Label3-&gt;Caption="右声道 ";
3 ^$ D. H( k! X3 [+ b1 t     tempchannel='R';
}
//---------------------------------------------------------------------------</P>
<> void __fastcall TSuperPlayerform::steroClick(TObject *Sender)
6 a3 g2 B* j+ w. ~/ e3 t' n {
  @. t) I/ U3 B9 b! q' k     LRC('C');
     Label3-&gt;Caption="立体声 ";
8 `* r4 y6 Z2 I+ T* T/ V' c     tempchannel='C';
. b9 I( S: Z: t! x3 W }</P>

ilikenba

<>左右声道的设置代码！从网上找到的！</P><>lReturn=mciSendString("set left off",sReturn,32,0)
lReturn=mciSendString("set right off",sReturn,32,0)
lReturn=mciSendString("setaudio left off",sReturn,32,0)
9 m5 M: {6 M4 m4 H5 hlReturn=mciSendString("setaudio right off",sReturn,32,0)
确切地说，以上四句关闭的并不是左右声道，而是左右音箱。由于通常的多媒体音频流多是立体声的，并不是左音箱播放的完全是左声道的音频流，其中掺入轻微的右声道声音，以达到更好的立体效果。
要想关闭左右声道可以这样：
/ a7 ]" ~5 H5 h/ FlReturn=mciSendString("setaudio source to left",sReturn,32,0) '仅开左声道
lReturn=mciSendString("setaudio source to right",sReturn,32,0) '仅开右声道
lReturn=mciSendString("setaudio source to average",sReturn,32,0) '左右平均
lReturn=mciSendString("setaudio source to stereo",sReturn,32,0) '立体声，这是默认设置</P>