From 5000060b04bed23cbbd88ba43ed546220c4b7c69 Mon Sep 17 00:00:00 2001 From: whiteshark0 Date: Tue, 2 Nov 2010 12:51:22 +0000 Subject: create experimental songmanagement branch - nicer abstraction of songs - split songloading from handling songs - cleanup singscreen git-svn-id: svn://svn.code.sf.net/p/ultrastardx/svn/branches/experimental@2706 b956fd51-792f-4845-bead-9b4dfca2ff2c --- songmanagement/src/media/UAudioPlayback_SDL.pas | 182 ++++++++++++++++++++++++ 1 file changed, 182 insertions(+) create mode 100644 songmanagement/src/media/UAudioPlayback_SDL.pas (limited to 'songmanagement/src/media/UAudioPlayback_SDL.pas') diff --git a/songmanagement/src/media/UAudioPlayback_SDL.pas b/songmanagement/src/media/UAudioPlayback_SDL.pas new file mode 100644 index 00000000..8403ef03 --- /dev/null +++ b/songmanagement/src/media/UAudioPlayback_SDL.pas @@ -0,0 +1,182 @@ +{* 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} + +implementation + +uses + Classes, + sdl, + SysUtils, + UAudioPlayback_SoftMixer, + UMusic, + 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: PByteArray; size: Cardinal; volume: Single); override; + end; + + +{ TAudioPlayback_SDL } + +procedure SDLAudioCallback(userdata: Pointer; stream: PByteArray; 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: PByteArray; 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. -- cgit v1.2.3