Доброго дня, форумчане.
IDE: Delphi 2007 update 3
Требуется написать sample программку, которая загружает MP3/WAV файл в TMemoryStream и
воспроизводит с помощью библиотеки BASS - обязательно используя BASS_StreamCreateFileUser.
BASS_StreamCreateFile не предлагать 
Вот собственно source:
| Код |
unit uPCore;
interface
uses
Windows, Classes,
Bass, uPDecodeStream;
type
TBASSCorePlayer = class(TObject)
public
constructor Create(hwnd:HWND);
procedure Free;
function Play :BOOL;
function Stop :BOOL;
function Pause :BOOL;
function LastError :LongInt;
function GetPlaybackLength :Double;
function GetPlaybackPosition :Double;
function SetPlaybackPosition(seconds:Double) :BOOL;
procedure AssignStream(AStream:TPDecodeStream);
private
BASSCh: HSTREAM;
BASSProcs: BASS_FILEPROCS;
end;
procedure proc_close(user : Pointer); stdcall;
function proc_len(user: Pointer): QWORD; stdcall;
function proc_seek(offset: QWORD; user: Pointer): BOOL; stdcall;
function proc_read(buffer: Pointer; length: DWORD; user: Pointer): DWORD; stdcall;
implementation
constructor TBASSCorePlayer.Create(hwnd:HWND);
begin
inherited Create;
BASS_Init(-1, 44100, 0, hwnd, nil);
end;
procedure TBASSCorePlayer.Free;
begin
BASS_Free;
inherited Free;
end;
function TBASSCorePlayer.GetPlaybackLength :Double;
begin
Result :=
BASS_ChannelBytes2Seconds(BASSCh, BASS_ChannelGetLength(BASSCh, BASS_POS_BYTE));
end;
function TBASSCorePlayer.LastError :LongInt;
begin
Result := BASS_ErrorGetCode;
end;
function TBASSCorePlayer.GetPlaybackPosition :Double;
begin
Result :=
BASS_ChannelBytes2Seconds(BASSCh, BASS_ChannelGetPosition(BASSCh, BASS_POS_BYTE));
end;
function TBASSCorePlayer.SetPlaybackPosition(seconds:Double) :BOOL;
begin
Result :=
BASS_ChannelSetPosition(BASSCh, BASS_ChannelSeconds2Bytes(BASSCh, seconds),BASS_POS_BYTE);
end;
procedure TBASSCorePlayer.AssignStream(AStream: TPDecodeStream);
begin
//BASSCh := BASS_StreamCreateFile(True, AStream.Memory, 0, AStream.Size, 0);
BASSProcs.close := proc_close;
BASSProcs.length := proc_len;
BASSProcs.read := proc_read;
BASSProcs.seek := proc_seek;
BASSCh := BASS_StreamCreateFileUser(STREAMFILE_NOBUFFER, 0, BASSProcs, @AStream)
end;
//CALLBACKS HERE
procedure proc_close(user: Pointer);
var
AStreamInstance: ^TPDecodeStream;
begin
AStreamInstance := user;
//AStreamInstance.Position := 0;
//AStreamInstance^.Free;
end;
function proc_len(user: Pointer): QWORD; stdcall;
var
AStreamInstance: ^TPDecodeStream;
begin
AStreamInstance := user;
Result := AStreamInstance^.Size;
end;
function proc_seek(offset: QWORD; user: Pointer): BOOL; stdcall;
var
AStreamInstance: ^TPDecodeStream;
NewPosition: Int64;
begin
AStreamInstance := user;
NewPosition := AStreamInstance^.Seek(offset, soFromBeginning);
Result := (NewPosition = AStreamInstance^.Position);
end;
function proc_read(buffer: Pointer; length: DWORD; user: Pointer): DWORD; stdcall;
var
AStreamInstance: ^TPDecodeStream;
BytesReaded: DWORD;
begin
AStreamInstance := user;
BytesReaded := 0;
BytesReaded := AStreamInstance^.Read(buffer^, length);
if BytesReaded = length then
Result := BytesReaded
else
Result := 0;
end;
function TBASSCorePlayer.Play :BOOL;
begin
Result := BASS_ChannelPlay(BASSCh, False);
end;
function TBASSCorePlayer.Stop :BOOL;
begin
Result := BASS_ChannelStop(BASSCh);
end;
function TBASSCorePlayer.Pause :BOOL;
begin
Result := BASS_ChannelPause(BASSCh)
end;
end.
|
Работает класс так:
Создаем TMemoryStream, делаем LoadFromFile mp3/wav файла.
Этот MemoryStream отправляем классу через AssignStream, далее Play (Stop/Pause/SetPlaybackPosition etc.)
Проблема в том, что при попытке воспроизведения mp3 файла - он играет первые полторы секунды, далее валиться
Access Vialation на строку
| Код |
BytesReaded := AStreamInstance^.Read(buffer^, length);
|
Вроде по документации callback функции написаны как надо.
Кстати при попытке воспроизвести WAV проигрывание даже не начинается.
Есть догадки?
SOLVED
Починил
Изменил read и seek.
Но проблема была в указателе на AStreamInstance.
Теперь адрес передается В параметрах AssignStream, а не в теле процедуры как адрес локальной переменной.
Все ^TMemoryStream поменял на PMemoryStream.
Вот рабочий код (кстати, примером с использованием BASS_StreamCreateFileUser в Delphi нет,
может стоит включить куда-нибудь? сам я блога не веду, кому охота поделиться в своем блоге - welcome):
| Код |
unit SamplePlayer;
interface
uses
Windows, Classes,
Bass;
type
PMemoryStream = ^TMemoryStream;
TBASSCorePlayer = class(TObject)
public
constructor Create(hwnd:HWND);
procedure Free;
function Play :BOOL;
function Stop :BOOL;
function Pause :BOOL;
function LastError :LongInt;
function GetPlaybackLength :Double;
function GetPlaybackPosition :Double;
function SetPlaybackPosition(seconds:Double) :BOOL;
procedure AssignStream(AStream:PMemoryStream);
private
BASSCh: HSTREAM;
BASSProcs: BASS_FILEPROCS;
end;
procedure proc_close(user : Pointer); stdcall;
function proc_len(user: Pointer): QWORD; stdcall;
function proc_seek(offset: QWORD; user: Pointer): BOOL; stdcall;
function proc_read(buffer: Pointer; length: DWORD; user: Pointer): DWORD; stdcall;
implementation
constructor TBASSCorePlayer.Create(hwnd:HWND);
begin
inherited Create;
BASS_Init(-1, 44100, 0, hwnd, nil);
end;
procedure TBASSCorePlayer.Free;
begin
BASS_Free;
inherited Free;
end;
function TBASSCorePlayer.GetPlaybackLength :Double;
begin
Result :=
BASS_ChannelBytes2Seconds(BASSCh, BASS_ChannelGetLength(BASSCh, BASS_POS_BYTE));
end;
function TBASSCorePlayer.LastError :LongInt;
begin
Result := BASS_ErrorGetCode;
end;
function TBASSCorePlayer.GetPlaybackPosition :Double;
begin
Result :=
BASS_ChannelBytes2Seconds(BASSCh, BASS_ChannelGetPosition(BASSCh, BASS_POS_BYTE));
end;
function TBASSCorePlayer.SetPlaybackPosition(seconds:Double) :BOOL;
begin
Result :=
BASS_ChannelSetPosition(BASSCh, BASS_ChannelSeconds2Bytes(BASSCh, seconds),BASS_POS_BYTE);
end;
procedure TBASSCorePlayer.AssignStream(AStream: PMemoryStream);
begin
//BASSCh := BASS_StreamCreateFile(True, AStream.Memory, 0, AStream.Size, 0);
BASSProcs.close := proc_close;
BASSProcs.length := proc_len;
BASSProcs.read := proc_read;
BASSProcs.seek := proc_seek;
BASSCh := BASS_StreamCreateFileUser(STREAMFILE_NOBUFFER, 0, BASSProcs, @AStream)
end;
//CALLBACKS HERE
procedure proc_close(user: Pointer);
var
AStreamInstance: PMemoryStream;
begin
AStreamInstance := user;
AStreamInstance.Position := 0;
//AStreamInstance^.Free;
end;
function proc_len(user: Pointer): QWORD; stdcall;
var
AStreamInstance: ^TMemoryStream;
begin
AStreamInstance := user;
Result := AStreamInstance^.Size;
end;
function proc_seek(offset: QWORD; user: Pointer): BOOL; stdcall;
var
AStreamInstance: ^TMemoryStream;
NewPosition: Int64;
begin
AStreamInstance := user;
NewPosition := AStreamInstance^.Seek(offset, soFromBeginning);
Result := (NewPosition < AStreamInstance^.Size);
end;
function proc_read(buffer: Pointer; length: DWORD; user: Pointer): DWORD; stdcall;
var
AStreamInstance: ^TMemoryStream;
BytesReaded: DWORD;
begin
AStreamInstance := user;
Result := AStreamInstance^.Read(buffer^, length);
end;
function TBASSCorePlayer.Play :BOOL;
begin
Result := BASS_ChannelPlay(BASSCh, False);
end;
function TBASSCorePlayer.Stop :BOOL;
begin
Result := BASS_ChannelStop(BASSCh);
end;
function TBASSCorePlayer.Pause :BOOL;
begin
Result := BASS_ChannelPause(BASSCh)
end;
end.
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