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{$M 16384,0,655360}
uses Dos, CRT, objects;
const SBase = $220; {Default port base for Sound Blaster.
Change if necessary}
SIrq = 5; {Default Irq line for Sound Blaster.
Change if necessary}
SDMA = 1; {Default DMA channel for Sound Blaster.}
type
TWAVRec = record
ID: LongInt;
Len: LongInt;
end;
PWAVFmt = ^TWAVFmt;
TWAVFmt = record
case word of
1:( FTag: word;
NChan: word;
SampR: word;
AvgSR: word;
BLKAl: word;
FMTLen: word;
FMTDat: array[0..256] of byte);
2:( Chunk:Pointer);
end;
var
WAVFile: TDosStream; {WAV file object}
BlkID: TWAVRec; {ID for each block in WAV}
BlkFmt: PWAVFmt; {Block format}
TotalSz: LongInt; {Total size of WAV data}
DSPCmd: byte;
NumBits: byte;
SampByte: byte;
BlockSize: word;
EOB: boolean;
DF: String;
procedure NewBlock; interrupt; {Procedure to set up next block or}
var X:Byte; {end playback}
begin
X := port[SBase+$e];
port[$20] := $20;
EOB := true;
end;
procedure PrepareSB;
begin
SetIntVec(SIrq + 8, @NewBlock); {Set up service routine}
asm
in al,$61 {Enable timer 2, but}
and al,$fc {do not turn on sound.}
or al,1
out $61,al
sti
mov dx,SBase+6 {DSP (Digital Sound Processor)
reset port}
mov al,1 {Reset command}
out dx,al
mov bx,4
call @9 {Wait 4 clocks}
mov al,0 {Normal mode}
out dx,al
@3: mov dx,SBase+$e {DSP status port}
@2: in al,dx {Read status}
test al,$80 {If high bit not set, no data}
jz @2 {ready}
mov dx,Sbase+$a {DSP read port}
in al,dx {Read status}
cmp al,$aa {AA indicates ready}
jnz @3
jmp @4
@5:
in al,dx {Wait for response to last byte}
test al,$80 {sent}
jnz @5
mov al,ah
out dx,al {Send next byte}
ret
@9:
push bx
mov al,$b6 {Write count to timer #3}
out $43,al
mov al,0 {Low byte of count}
out $42,al
mov al,$10 {High byte count}
out $42,al
sub bx,$1000
neg bx {1000h-clocks=desired count}
@10:
mov al,$80 {Read count from timer}
out $43,al
in al,$42 {Low byte}
mov ah,al
in al,$42 {High byte}
xchg ah,al
cmp bx,ax {Pause until count reached}
jl @10
pop bx
ret
@4:
mov dx,SBase+$c
mov ah,$40 {Set time constant}
call @5
mov ah,SampByte {Time divisor}
call @5
end;
port[$21] := port[$21] and not (1 shl SIRQ); {Enable SB interrupt}
end;
procedure ErrorEnd;
begin
WAVFile.Done;
Writeln('Error in .WAV');
Halt(1);
end;
procedure PlaySound(SndLen: longint);
var AbsAddr: LongInt;
FirstBlk, SecBlk, CurBlk: Pointer;
begin
EOB := False;
GetMem(BlkFmt, BlockSize*2);
FirstBlk := BlkFmt;
SecBlk := pointer(longint(FirstBlk) + BlockSize);
CurBlk := FirstBlk;
WAVFile.Read(BlkFmt^, BlockSize);
SndLen := SndLen - BlockSize;
repeat
AbsAddr := Seg(CurBlk^);
AbsAddr := AbsAddr * 16 +Ofs(CurBlk^);
SndLen := SndLen - BlockSize;
asm
jmp @4
@5:
in al,dx {Wait for response to last byte}
test al,$80 {sent}
jnz @5
mov al,ah
out dx,al {Send next byte}
ret
@4:
mov bx,1
mov cx,integer(AbsAddr)
mov dx,SBase+$c
mov al,0 {Clear byte high/low flip-flop}
out $c,al
mov al,$49 {Set memory read, single transfer,}
out $b,al {channel 1}
mov al,cl {Enter base address}
out SDMA*2,al
mov al,ch
out SDMA*2,al
mov ax,integer(AbsAddr+2) {High 4 bits goes to DMA page reg}
mov dx,$83
mov cl,SDMA
sub cl,2
mov ch,2 {Calculate DMA page address}
shr ch,cl
xor dl,ch
out dx,al {Send page byte}
mov ax,BlockSize {Set byte count}
{ dec ax }
out SDMA*2+1,al
xchg al,ah
out SDMA*2+1,al
push ax
mov al,SDMA {Re-enable DMA channel 1}
out $a,al
mov dx,SBase+$c {DSP port}
mov ah,DSPCmd {DMA 8-bit transfer}
call @5
pop ax {Get transfer again}
mov bl,al
call @5
mov ah,bl
call @5
end;
DSPCmd := DSPCmd and $fe;
if (CurBlk = FirstBlk) then CurBlk := SecBlk else CurBlk := FirstBlk;
if SndLen > 0 then WAVFile.Read(CurBlk^, BlockSize);
while not EOB do
if Keypressed then ErrorEnd;
EOB := False;
until (SndLen<=0);
end;
begin
DF := ParamStr(1);
WAVFile.Init(DF, stOpenRead); {Open WAV file}
WAVFile.Read(BlkID, SizeOf(TWAVRec)); {Read in first block}
if BlkID.ID = $46464952 then {ID of WAV file}
begin
TotalSz := BlkID.Len; {Get total size}
repeat
WAVFile.Read(BlkID, 4); {Read in type chunk}
TotalSz := TotalSz - 4; {and update TS}
if BlkID.ID <> $45564157 then ErrorEnd; {Must be "WAVE"}
repeat
WAVFile.Read(BlkID, SizeOf(TWAVRec)); {Read in format chunk}
TotalSz := TotalSz - SizeOf(TWavRec);
if BlkID.ID = $20746d66 then {"fmt ", set WAV format}
begin
getmem(BlkFmt, BlkID.Len);
WAVFile.Read(BlkFmt^, BlkID.Len);
TotalSz := TotalSz - BlkID.Len;
with BlkFmt^ do
begin
if FTag = $200 then DSPCmd := $75 else {ADPCM 4-bit compression}
if FTag = 1 then DSPCmd := $14 else {Normal}
ErrorEnd;
if DSPCmd = $75 then NumBits := 4 else NumBits := 8;
if NChan = 2 then DSPCmd := DSPCmd + 8; {Stereo}
SampByte := 256-(1000000 div SampR); {Sampling rate}
BlockSize := BlkAl; {Size of buffer}
end;
freemem(BlkFmt, BlkID.Len);
end else
if BlkID.ID = $61746164 then
begin
PrepareSB; {Perform init stuff}
TotalSz := TotalSz - BlkID.Len;
PlaySound(BlkID.Len);
end else
ErrorEnd;
until TotalSz <= 0;
until TotalSz <= 0;
end else
ErrorEnd;
WAVFile.Done;
port[$21] := port[$21] or (1 shl SIrq);
end.
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