can i add text to rawtobytedata ?

[Madammar]

i have the following code 

Code:

procedure Tform1.rData(Sender: TObject; const Buffer: Pointer;
  BufferSize: Cardinal; var FreeIt: Boolean);
var
Bytes: TIdBytes;
begin


if (Buffer <> nil) and (BufferSize > 0) And (udpreciver.Active) then
begin
udpsender.SendBuffer(ip, port, RawToBytes(Buffer^, Buffersize));
end;

end;

i want to add a text identification to each audio sent and then remove that text when its received 


like following as example 

Code:

if (Buffer <> nil) and (BufferSize > 0) And (udpreciver.Active) then
begin
udpsender.SendBuffer(ip, port, RawToBytes('Audio1'+Buffer^, Buffersize));
end;

how to do this in correct way

[rlebeau]

i want to add a text identification to each audio sent and then remove that text when its received 

like following as example 

Code:

if (Buffer <> nil) and (BufferSize > 0) And (udpreciver.Active) then
begin
udpsender.SendBuffer(ip, port, RawToBytes('Audio1'+Buffer^, Buffersize));
end;

how to do this in correct way

There are many different ways you can handle this.

Code:

// Delphi XE7 or later only ...
var Bytes: TIdBytes;
Bytes := ToBytes('Audio1') + RawToBytes(Buffer^, Buffersize);
// or: Bytes := Concat(ToBytes('Audio1'), RawToBytes(Buffer^, Buffersize));
udpsender.SendBuffer(ip, port, Bytes);

Code:

var Bytes: TidBytes;
Bytes := ToBytes('Audio1');
AppendBytes(Bytes, RawToBytes(Buffer^, Buffersize));
udpsender.SendBuffer(ip, port, Bytes);

Code:

var Bytes: TidBytes;
SetLength(Bytes, 6 + Buffersize);
CopyTIdString('Audio1', Bytes, 0);
CopyTIdBytes(RawToBytes(Buffer^, Buffersize), 0, Bytes, 6, Buffersize);
udpsender.SendBuffer(ip, port, Bytes);

Code:

var Bytes: TIdBytes;
SetLength(Bytes, 6 + Buffersize);
Move(PAnsiChar('Audio1')^, Bytes[0], 6);
Move(Buffer^, Bytes[6], Buffersize);
udpsender.SendBuffer(ip, port, Bytes);

[Madammar]

in receiving part can i delete the Audio1 Text and keep the actual byets ?

[rlebeau]

in receiving part can i delete the Audio1 Text and keep the actual byets ?

You could, by simply using System.Delete() (XE7+ only) or Indy's RemoveBytes(). Or, you could Copy()/CopyTIdBytes() the wanted bytes to another array.

But really, there is usually no need to do any of this. If the 1st 6 bytes are 'Audio1', just ignore those bytes and use/save the remaining bytes as needed. What is so hard about that?

[Madammar]

sorry for my bad english in my replys i wasn't mean to delete the text i was just asking about splitting this buffer

to differentiate between each audio sent sense i am using Audio1 as identification or more likely a header

thats why i wanted to know a way to split this buffer to check if this audio have a text of audio1 or not

which came to my mind i have to split out the Audio1 to a string variable and do the checking

[rlebeau]

which came to my mind i have to split out the Audio1 to a string variable and do the checking

Indy has BytesToString() and BytesToStringRaw() functions, which take an optional index and length as input, eg:

Code:

if BytesToString(bytes, 0, 6) = 'Audio1' then
begin
  // use bytes[6]..bytes[High(bytes)] as needed...
end;

Or, you could simply use the RTL's CompareMem() function, eg:

Code:

if (Length(bytes) >= 6) and CompareMem(PByte(bytes), PAnsiChar('Audio1'), 6) = 0 then
begin
  // use bytes[6]..bytes[High(bytes)] as needed...
end;

[Madammar]

Code:

procedure TForm1.udpreciverUDPRead(AThread: TIdUDPListenerThread;
  const AData: TIdBytes; ABinding: TIdSocketHandle);
var
AudioDataSize: Integer;
deData : TIdBytes;
straudio : string;
begin

straudio := BytesToString(AData, 6, AData[High(AData)]); // here i have tried to get the orginal Bytes without Audio1


dedata := Tobytes(straudio);
end;

i tried to keep the original bytes after cutting it out

but its always get corrupted what i am doing wrong ?

[rlebeau]

i tried to keep the original bytes after cutting it out

but its always get corrupted what i am doing wrong ?

Well, for starters, you are not calling BytesToString() correctly.  The 3rd parameter is the number of bytes to copy, not a reference to a specific byte.  It should be more like this instead:

Code:

straudio := BytesToString(AData, 6, Length(AData)-6);

But why are you copying the binary data to a string at all?  Converting bytes to a string requires a character encoding, which you are not specifying, so Indy's default encoding will be used, which is US-ASCII by default.  So you are still going to get corrupted data for bytes > $7F.

If you are going to use a string, at least use Indy's 8-bit encoding to avoid data loss:

Code:

straudio := BytesToString(AData, 6, Length(AData)-6, IndyTextEncoding_8Bit);
// or: straudio := BytesToStringRaw(AData, 6, Length(AData)-6);
deData := ToBytes(straudio, IndyTextEncoding_8Bit);

But really, just get rid of the string altogether, you don't need it at all:

Code:

procedure TForm1.udpreciverUDPRead(AThread: TIdUDPListenerThread;
  const AData: TIdBytes; ABinding: TIdSocketHandle);
var
  deData : TIdBytes;
begin
  dedata := Copy(AData, 6, Length(AData)-6);
  // use deData as needed...
end;

Or:

Code:

procedure TForm1.udpreciverUDPRead(AThread: TIdUDPListenerThread;
  const AData: TIdBytes; ABinding: TIdSocketHandle);
var
  deData : TIdBytes;
begin
  deData := ToBytes(AData, Length(AData)-6, 6);
  // use deData as needed...
end;

Or:

Code:

procedure TForm1.udpreciverUDPRead(AThread: TIdUDPListenerThread;
  const AData: TIdBytes; ABinding: TIdSocketHandle);
var
  deData : TIdBytes;
begin
  SetLength(deData, Length(AData)-6);
  CopyTIdBytes(AData, 6, deData, 0, Length(deData));
  // use deData as needed...
end;

Or, simply use a pointer to the data, don't even make a copy:

Code:

procedure TForm1.udpreciverUDPRead(AThread: TIdUDPListenerThread;
  const AData: TIdBytes; ABinding: TIdSocketHandle);
var
  AudioDataSize: Integer;
  deData: PByte;
begin
  AudioDataSize := Length(AData)-6;
  deData := @AData[6];
  // use deData up to AudioDataSize bytes as needed...
end;