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Diffstat (limited to 'mediaplugin/src/media/UAudioConverter_SDL.pas')
| -rw-r--r-- | mediaplugin/src/media/UAudioConverter_SDL.pas | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/mediaplugin/src/media/UAudioConverter_SDL.pas b/mediaplugin/src/media/UAudioConverter_SDL.pas new file mode 100644 index 00000000..faed8abb --- /dev/null +++ b/mediaplugin/src/media/UAudioConverter_SDL.pas @@ -0,0 +1,212 @@ +{* 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 UAudioConverter_SDL; + +interface + +{$IFDEF FPC} + {$MODE Delphi} +{$ENDIF} + +{$I switches.inc} + +uses + UMusic, + ULog, + UMediaPlugin, + UMediaCore_SDL, + sdl, + SysUtils, + Math; + +type + TAudioConverter_SDL = class(TInterfacedObject, IAudioConverter) + public + function GetName(): string; + function GetPriority(): integer; + function Init(): boolean; + function Finalize(): boolean; + + function Open(SrcFormatInfo: TAudioFormatInfo; + DstFormatInfo: TAudioFormatInfo): TAudioConvertStream; + end; + + TAudioConvertStream_SDL = class(TAudioConvertStream) + private + cvt: TSDL_AudioCVT; + function Init(): boolean; + protected + constructor Create(SrcFormatInfo: TAudioFormatInfo; + DstFormatInfo: TAudioFormatInfo); + public + destructor Destroy(); override; + + class function Open(SrcFormatInfo: TAudioFormatInfo; + DstFormatInfo: TAudioFormatInfo): TAudioConvertStream_SDL; + + function Convert(InputBuffer: PByteArray; OutputBuffer: PByteArray; var InputSize: integer): integer; override; + function GetOutputBufferSize(InputSize: integer): integer; override; + function GetRatio(): double; override; + end; + +implementation + +{ TAudioConverter_SDL } + +function TAudioConverter_SDL.GetName(): string; +begin + Result := 'AudioConverter_SDL'; +end; + +function TAudioConverter_SDL.GetPriority(): integer; +begin + {* Notes: + * - 44.1kHz to 48kHz conversion or vice versa is not supported + * by SDL 1.2 (will be introduced in 1.3). + * No conversion takes place in this cases. + * This is because SDL just converts differences in powers of 2. + * So the result might not be that accurate. + * This IS audible (voice to high/low) and it needs good synchronization + * with the video or the lyrics timer. + * - float<->int16 conversion is not supported (will be part of 1.3) and + * SDL (<1.3) is not capable of handling floats at all. + * -> Using FFmpeg or libsamplerate for resampling is preferred. + * Use SDL for channel and format conversion only. + *} + Result := 0; +end; + +function TAudioConverter_SDL.Init(): boolean; +begin + Result := true; +end; + +function TAudioConverter_SDL.Finalize(): boolean; +begin + Result := true; +end; + +function TAudioConverter_SDL.Open(SrcFormatInfo: TAudioFormatInfo; + DstFormatInfo: TAudioFormatInfo): TAudioConvertStream; +begin + Result := TAudioConvertStream_SDL.Open(SrcFormatInfo, DstFormatInfo); +end; + +{ TAudioConvertStream_SDL } + +constructor TAudioConvertStream_SDL.Create(SrcFormatInfo: TAudioFormatInfo; + DstFormatInfo: TAudioFormatInfo); +begin + inherited Create(SrcFormatInfo, DstFormatInfo); +end; + +destructor TAudioConvertStream_SDL.Destroy(); +begin + inherited; +end; + +class function TAudioConvertStream_SDL.Open(SrcFormatInfo: TAudioFormatInfo; + DstFormatInfo: TAudioFormatInfo): TAudioConvertStream_SDL; +var + Stream: TAudioConvertStream_SDL; +begin + Result := nil; + Stream := TAudioConvertStream_SDL.Create(SrcFormatInfo, DstFormatInfo); + if (not Stream.Init()) then + begin + Stream.Free; + Exit; + end; + Result := Stream; +end; + +function TAudioConvertStream_SDL.Init(): boolean; +var + srcFormat: UInt16; + dstFormat: UInt16; +begin + Result := false; + + if (not ConvertAudioFormatToSDL(srcFormatInfo.Format, srcFormat) or + not ConvertAudioFormatToSDL(dstFormatInfo.Format, dstFormat)) then + begin + Log.LogError('Audio-format not supported by SDL', 'TSoftMixerPlaybackStream.InitFormatConversion'); + Exit; + end; + + if (SDL_BuildAudioCVT(@cvt, + srcFormat, srcFormatInfo.Channels, Round(srcFormatInfo.SampleRate), + dstFormat, dstFormatInfo.Channels, Round(dstFormatInfo.SampleRate)) = -1) then + begin + Log.LogError(SDL_GetError(), 'TSoftMixerPlaybackStream.InitFormatConversion'); + Exit; + end; + + Result := true; +end; + +(* + * Returns the size of the output buffer. This might be bigger than the actual + * size of resampled audio data. + *) +function TAudioConvertStream_SDL.GetOutputBufferSize(InputSize: integer): integer; +begin + // Note: len_ratio must not be used here. Even if the len_ratio is 1.0, len_mult might be 2. + // Example: 44.1kHz/mono to 22.05kHz/stereo -> len_ratio=1, len_mult=2 + Result := InputSize * cvt.len_mult; +end; + +function TAudioConvertStream_SDL.GetRatio(): double; +begin + Result := cvt.len_ratio; +end; + +function TAudioConvertStream_SDL.Convert(InputBuffer: PByteArray; OutputBuffer: PByteArray; var InputSize: integer): integer; +begin + Result := -1; + + if (InputSize <= 0) then + begin + // avoid div-by-zero problems + if (InputSize = 0) then + Result := 0; + Exit; + end; + + // OutputBuffer is always bigger than or equal to InputBuffer + Move(InputBuffer[0], OutputBuffer[0], InputSize); + cvt.buf := PUint8(OutputBuffer); + cvt.len := InputSize; + if (SDL_ConvertAudio(@cvt) = -1) then + Exit; + + Result := cvt.len_cvt; +end; + +initialization + MediaManager.add(TAudioConverter_SDL.Create); + +end.
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