1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
|
unit UAudioDecoder_Bass;
interface
{$IFDEF FPC}
{$MODE Delphi}
{$ENDIF}
{$I switches.inc}
implementation
uses
Classes,
SysUtils,
UMain,
UMusic,
UAudioCore_Bass,
ULog,
bass;
type
TBassDecodeStream = class(TAudioDecodeStream)
private
Handle: HSTREAM;
FormatInfo : TAudioFormatInfo;
Error: boolean;
public
constructor Create(Handle: HSTREAM);
destructor Destroy(); override;
procedure Close(); override;
function GetLength(): real; override;
function GetAudioFormatInfo(): TAudioFormatInfo; override;
function GetPosition: real; override;
procedure SetPosition(Time: real); override;
function GetLoop(): boolean; override;
procedure SetLoop(Enabled: boolean); override;
function IsEOF(): boolean; override;
function IsError(): boolean; override;
function ReadData(Buffer: PChar; BufSize: integer): integer; override;
end;
type
TAudioDecoder_Bass = class( TInterfacedObject, IAudioDecoder )
public
function GetName: string;
function InitializeDecoder(): boolean;
function FinalizeDecoder(): boolean;
function Open(const Filename: string): TAudioDecodeStream;
end;
var
BassCore: TAudioCore_Bass;
{ TBassDecodeStream }
constructor TBassDecodeStream.Create(Handle: HSTREAM);
var
ChannelInfo: BASS_CHANNELINFO;
Format: TAudioSampleFormat;
begin
inherited Create();
Self.Handle := Handle;
// setup format info
if (not BASS_ChannelGetInfo(Handle, ChannelInfo)) then
begin
raise Exception.Create('Failed to open decode-stream');
end;
BassCore.ConvertBASSFlagsToAudioFormat(ChannelInfo.flags, Format);
FormatInfo := TAudioFormatInfo.Create(ChannelInfo.chans, ChannelInfo.freq, format);
Error := false;
end;
destructor TBassDecodeStream.Destroy();
begin
Close();
inherited;
end;
procedure TBassDecodeStream.Close();
begin
if (Handle <> 0) then
begin
BASS_StreamFree(Handle);
Handle := 0;
end;
PerformOnClose();
FreeAndNil(FormatInfo);
Error := false;
end;
function TBassDecodeStream.GetAudioFormatInfo(): TAudioFormatInfo;
begin
Result := FormatInfo;
end;
function TBassDecodeStream.GetLength(): real;
var
bytes: QWORD;
begin
bytes := BASS_ChannelGetLength(Handle, BASS_POS_BYTE);
Result := BASS_ChannelBytes2Seconds(Handle, bytes);
end;
function TBassDecodeStream.GetPosition: real;
var
bytes: QWORD;
begin
bytes := BASS_ChannelGetPosition(Handle, BASS_POS_BYTE);
Result := BASS_ChannelBytes2Seconds(Handle, bytes);
end;
procedure TBassDecodeStream.SetPosition(Time: real);
var
bytes: QWORD;
begin
bytes := BASS_ChannelSeconds2Bytes(Handle, Time);
BASS_ChannelSetPosition(Handle, bytes, BASS_POS_BYTE);
end;
function TBassDecodeStream.GetLoop(): boolean;
var
flags: DWORD;
begin
// retrieve channel flags
flags := BASS_ChannelFlags(Handle, 0, 0);
if (flags = DWORD(-1)) then
begin
Log.LogError('BASS_ChannelFlags: ' + BassCore.ErrorGetString(), 'TBassDecodeStream.GetLoop');
Result := false;
Exit;
end;
Result := (flags and BASS_SAMPLE_LOOP) <> 0;
end;
procedure TBassDecodeStream.SetLoop(Enabled: boolean);
var
flags: DWORD;
begin
// set/unset loop-flag
if (Enabled) then
flags := BASS_SAMPLE_LOOP
else
flags := 0;
// set new flag-bits
if (BASS_ChannelFlags(Handle, flags, BASS_SAMPLE_LOOP) = DWORD(-1)) then
begin
Log.LogError('BASS_ChannelFlags: ' + BassCore.ErrorGetString(), 'TBassDecodeStream.SetLoop');
Exit;
end;
end;
function TBassDecodeStream.IsEOF(): boolean;
begin
Result := (BASS_ChannelIsActive(Handle) = BASS_ACTIVE_STOPPED);
end;
function TBassDecodeStream.IsError(): boolean;
begin
Result := Error;
end;
function TBassDecodeStream.ReadData(Buffer: PChar; BufSize: integer): integer;
begin
Result := BASS_ChannelGetData(Handle, Buffer, BufSize);
// check error state (do not handle EOF as error)
if ((Result = -1) and (BASS_ErrorGetCode() <> BASS_ERROR_ENDED)) then
Error := true
else
Error := false;
end;
{ TAudioDecoder_Bass }
function TAudioDecoder_Bass.GetName: String;
begin
result := 'BASS_Decoder';
end;
function TAudioDecoder_Bass.InitializeDecoder(): boolean;
begin
BassCore := TAudioCore_Bass.GetInstance();
Result := true;
end;
function TAudioDecoder_Bass.FinalizeDecoder(): boolean;
begin
Result := true;
end;
function TAudioDecoder_Bass.Open(const Filename: string): TAudioDecodeStream;
var
Stream: HSTREAM;
ChannelInfo: BASS_CHANNELINFO;
FileExt: string;
begin
Result := nil;
// check if BASS was initialized
// in case the decoder is not used with BASS playback, init the NO_SOUND device
if ((integer(BASS_GetDevice) = -1) and (BASS_ErrorGetCode() = BASS_ERROR_INIT)) then
BASS_Init(0, 44100, 0, 0, nil);
// TODO: use BASS_STREAM_PRESCAN for accurate seeking in VBR-files?
// disadvantage: seeking will slow down.
Stream := BASS_StreamCreateFile(False, PChar(Filename), 0, 0, BASS_STREAM_DECODE);
if (Stream = 0) then
begin
//Log.LogError(BassCore.ErrorGetString(), 'TAudioDecoder_Bass.Open');
Exit;
end;
// check if BASS opened some erroneously recognized file-formats
if BASS_ChannelGetInfo(Stream, channelInfo) then
begin
fileExt := ExtractFileExt(Filename);
// BASS opens FLV-files (maybe others too) although it cannot handle them.
// Setting BASS_CONFIG_VERIFY to the max. value (100000) does not help.
if ((fileExt = '.flv') and (channelInfo.ctype = BASS_CTYPE_STREAM_MP1)) then
begin
BASS_StreamFree(Stream);
Exit;
end;
end;
Result := TBassDecodeStream.Create(Stream);
end;
initialization
MediaManager.Add(TAudioDecoder_Bass.Create);
end.
|
