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
|
{* UltraStar Deluxe - Karaoke Game
*
* UltraStar Deluxe is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
* $URL$
* $Id$
*}
unit UAudioPlayback_SDL;
interface
{$IFDEF FPC}
{$MODE Delphi}
{$ENDIF}
{$I switches.inc}
uses
Classes,
SysUtils,
UMusic;
implementation
uses
sdl,
UAudioPlayback_SoftMixer,
ULog,
UIni,
UMain;
type
TAudioPlayback_SDL = class(TAudioPlayback_SoftMixer)
private
Latency: double;
function EnumDevices(): boolean;
protected
function InitializeAudioPlaybackEngine(): boolean; override;
function StartAudioPlaybackEngine(): boolean; override;
procedure StopAudioPlaybackEngine(); override;
function FinalizeAudioPlaybackEngine(): boolean; override;
function GetLatency(): double; override;
public
function GetName: String; override;
procedure MixBuffers(dst, src: PChar; size: Cardinal; volume: Single); override;
end;
{ TAudioPlayback_SDL }
procedure SDLAudioCallback(userdata: Pointer; stream: PChar; len: integer); cdecl;
var
Engine: TAudioPlayback_SDL;
begin
Engine := TAudioPlayback_SDL(userdata);
Engine.AudioCallback(stream, len);
end;
function TAudioPlayback_SDL.GetName: String;
begin
Result := 'SDL_Playback';
end;
function TAudioPlayback_SDL.EnumDevices(): boolean;
begin
// Note: SDL does not provide Device-Selection capabilities (will be introduced in 1.3)
ClearOutputDeviceList();
SetLength(OutputDeviceList, 1);
OutputDeviceList[0] := TAudioOutputDevice.Create();
OutputDeviceList[0].Name := '[SDL Default-Device]';
Result := true;
end;
function TAudioPlayback_SDL.InitializeAudioPlaybackEngine(): boolean;
var
DesiredAudioSpec, ObtainedAudioSpec: TSDL_AudioSpec;
SampleBufferSize: integer;
begin
Result := false;
EnumDevices();
if (SDL_InitSubSystem(SDL_INIT_AUDIO) = -1) then
begin
Log.LogError('SDL_InitSubSystem failed!', 'TAudioPlayback_SDL.InitializeAudioPlaybackEngine');
Exit;
end;
SampleBufferSize := IAudioOutputBufferSizeVals[Ini.AudioOutputBufferSizeIndex];
if (SampleBufferSize <= 0) then
begin
// Automatic setting default
// FIXME: too much glitches with 1024 samples
SampleBufferSize := 2048; //1024;
end;
FillChar(DesiredAudioSpec, SizeOf(DesiredAudioSpec), 0);
with DesiredAudioSpec do
begin
freq := 44100;
format := AUDIO_S16SYS;
channels := 2;
samples := SampleBufferSize;
callback := @SDLAudioCallback;
userdata := Self;
end;
// Note: always use the "obtained" parameter, otherwise SDL might try to convert
// the samples itself if the desired format is not available. This might lead
// to problems if for example ALSA does not support 44100Hz and proposes 48000Hz.
// Without the obtained parameter, SDL would try to convert 44.1kHz to 48kHz with
// its crappy (non working) converter resulting in a wrong (too high) pitch.
if(SDL_OpenAudio(@DesiredAudioSpec, @ObtainedAudioSpec) = -1) then
begin
Log.LogStatus('SDL_OpenAudio: ' + SDL_GetError(), 'TAudioPlayback_SDL.InitializeAudioPlaybackEngine');
Exit;
end;
FormatInfo := TAudioFormatInfo.Create(
ObtainedAudioSpec.channels,
ObtainedAudioSpec.freq,
asfS16
);
// Note: SDL does not provide info of the internal buffer state.
// So we use the average buffer-size.
Latency := (ObtainedAudioSpec.samples/2) / FormatInfo.SampleRate;
Log.LogStatus('Opened audio device', 'TAudioPlayback_SDL.InitializeAudioPlaybackEngine');
Result := true;
end;
function TAudioPlayback_SDL.StartAudioPlaybackEngine(): boolean;
begin
SDL_PauseAudio(0);
Result := true;
end;
procedure TAudioPlayback_SDL.StopAudioPlaybackEngine();
begin
SDL_PauseAudio(1);
end;
function TAudioPlayback_SDL.FinalizeAudioPlaybackEngine(): boolean;
begin
SDL_CloseAudio();
SDL_QuitSubSystem(SDL_INIT_AUDIO);
Result := true;
end;
function TAudioPlayback_SDL.GetLatency(): double;
begin
Result := Latency;
end;
procedure TAudioPlayback_SDL.MixBuffers(dst, src: PChar; size: Cardinal; volume: Single);
begin
SDL_MixAudio(PUInt8(dst), PUInt8(src), size, Round(volume * SDL_MIX_MAXVOLUME));
end;
initialization
MediaManager.add(TAudioPlayback_SDL.Create);
end.
|
