Hi
I have been trying to use coremidi to receive sysex and midi cc commands for a while now, and I have now got to a stage where i think I have progressed, but I am getting BAD EXEC errors, and I cannot run in debugger mode as I get error run error 202. Using Laz 1.4.2 fpc 2.6.4.
The application runs, but as soon as it receives sysex data I then get the errors.
Below is the code I am using for the midiinput call back routine.
I suspect it is something to do with pointers/de-referencing etc, but I cannot find it.
Hoping someone can help.
procedure MyMIDIReadProcInput(const list:MIDIPacketListPtr;
procRef:UnivPtr;
srcRef:UniVPtr); mwpascal;
Var continueSysEx :boolean= false;
nbytes:Integer=0;
sysExLength:integer=0;
lengthToCopy:integer=0;
MPacket:MIDIPacket;
pPacket:MIDIPacketPtr;
iByte:Integer=0;
size:integer=0;
status:byte;
lengthLeftInMessage:Integer=0;
messageType:Byte;
messagechannel:byte;
i,c:integer;
s:string='';
function moveintoarray(start,howmany:integer):boolean;
var c:integer;
begin
for c:=0 to howmany do
begin
sysexmessage[start+c]:=mpacket.data[c];
end;
moveintoarray:=true;
end;
begin
MPacket:= &list.packet[0];
s:=''; // temp to create string
for i := 0 to list.numPackets do
begin
nBytes := Mpacket.length;
// Check if this is the end of a continued SysEx message
if (continueSysEx) then
begin
LengthToCopy := MIN (nBytes, MAX_SYSEX_LENGTH - sysExLength);
// Copy the message into our SysEx message buffer,
// making sure not to overrun the buffer
moveintoarray(sysExLength,lengthToCopy);
sysExLength := sysExLength+lengthToCopy;
// Check if the last byte is SysEx End.
continueSysEx := (mpacket.data[nBytes - 1] = $F7);
if (( not continueSysEx) or (sysExLength = MAX_SYSEX_LENGTH)) then
begin
// process the SysEx message here
// temp dump to memo
s:='';
for c:=0 to sysexlength do s:=s+inttohex(sysexmessage[c],2)+' ';
form1.Memo2.Lines.add(s);
sysExLength := 0;
end;
end
else
begin
iByte := 0;
while (iByte < nBytes) do
begin
size := 0;
// First byte should be status
status := mpacket.data[iByte];
if (status < $C0) then
begin
size := 3;
end
else
if (status < $E0) then
begin
size := 2;
end
else
if (status < $F0) then
begin
size := 3;
end
else
if (status = $F0) then
begin
// MIDI SysEx then we copy the rest of the message into the SysEx message buffer
lengthLeftInMessage := nBytes - iByte;
lengthToCopy := MIN (lengthLeftInMessage,MAX_SYSEX_LENGTH);
moveintoarray(sysExLength,lengthToCopy);
sysExLength:=lengthToCopy;
size := 0;
iByte := nBytes;
// Check whether the message at the end is the end of the SysEx
continueSysEx := (mpacket.data[nBytes - 1] <> $F7);
end
else
if (status < $F3) then
begin
size := 3;
end
else
if (status = $F3) then
begin
size := 2;
end
else
begin
size := 1;
end;
messageType := status and $F0;
messageChannel := status and $F;
case (status and $F0) of
$80:begin
//Note off
end;
$90:begin
// note on
end;
$A0:begin
//after touch
end;
$B0:begin
// cc
end;
$C0:begin
// pc
end;
$D0:begin
// change aftertouch
end;
$E0:begin
// pitchwheel
end;
else begin
// something else;
end;
end;
iByte:= size;
ppacket:=midipacketnext(ppacket);
mpacket:=pPacket^;
nbytes:=mpacket.length;
end;
end;
end;
end;
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