BizHawk/BizHawk.Emulation.DiscSystem/CDAudio.cs

304 lines
8.1 KiB
C#

using System;
using System.IO;
using BizHawk.Emulation.Common;
// The state of the cd player is quantized to the frame level.
// This isn't ideal. But life's too short.
// I decided not to let the perfect be the enemy of the good.
// It can always be refactored. It's at least deterministic.
namespace BizHawk.Emulation.DiscSystem
{
public sealed class CDAudio : ISoundProvider
{
public enum CDAudioMode
{
Stopped,
Playing,
Paused
}
public enum PlaybackMode
{
StopOnCompletion,
NextTrackOnCompletion,
LoopOnCompletion,
CallbackOnCompletion
}
public Action CallbackAction = delegate { };
public Disc Disc;
public CDAudioMode Mode = CDAudioMode.Stopped;
public PlaybackMode PlayMode = PlaybackMode.LoopOnCompletion;
public int MaxVolume { get; set; }
public int LogicalVolume = 100;
public int StartLBA, EndLBA;
public int PlayingTrack;
public int CurrentSector, SectorOffset; // Offset is in SAMPLES, not bytes. Sector is 588 samples long.
int CachedSector;
readonly byte[] SectorCache = new byte[2352];
public int FadeOutOverFrames = 0;
public int FadeOutFramesRemaining = 0;
public CDAudio(Disc disc, int maxVolume = short.MaxValue)
{
Disc = disc;
MaxVolume = maxVolume;
}
public void PlayTrack(int track)
{
if (track < 1 || track > Disc.TOC.Sessions[0].Tracks.Count)
return;
StartLBA = Disc.TOC.Sessions[0].Tracks[track - 1].Indexes[1].aba - 150;
EndLBA = StartLBA + Disc.TOC.Sessions[0].Tracks[track - 1].length_aba;
PlayingTrack = track;
CurrentSector = StartLBA;
SectorOffset = 0;
Mode = CDAudioMode.Playing;
FadeOutOverFrames = 0;
FadeOutFramesRemaining = 0;
LogicalVolume = 100;
}
public void PlayStartingAtLba(int lba)
{
var point = Disc.TOC.SeekPoint(lba);
if (point == null || point.Track == null) return;
PlayingTrack = point.TrackNum;
StartLBA = lba;
EndLBA = point.Track.Indexes[1].aba + point.Track.length_aba - 150;
CurrentSector = StartLBA;
SectorOffset = 0;
Mode = CDAudioMode.Playing;
FadeOutOverFrames = 0;
FadeOutFramesRemaining = 0;
LogicalVolume = 100;
}
public void Stop()
{
Mode = CDAudioMode.Stopped;
FadeOutOverFrames = 0;
FadeOutFramesRemaining = 0;
LogicalVolume = 100;
}
public void Pause()
{
if (Mode != CDAudioMode.Playing)
return;
Mode = CDAudioMode.Paused;
FadeOutOverFrames = 0;
FadeOutFramesRemaining = 0;
LogicalVolume = 100;
}
public void Resume()
{
if (Mode != CDAudioMode.Paused)
return;
Mode = CDAudioMode.Playing;
}
public void PauseResume()
{
if (Mode == CDAudioMode.Playing) Mode = CDAudioMode.Paused;
else if (Mode == CDAudioMode.Paused) Mode = CDAudioMode.Playing;
else if (Mode == CDAudioMode.Stopped) return;
}
public void FadeOut(int frames)
{
FadeOutOverFrames = frames;
FadeOutFramesRemaining = frames;
}
void EnsureSector()
{
if (CachedSector != CurrentSector)
{
if (CurrentSector >= Disc.LBACount)
Array.Clear(SectorCache, 0, 2352); // request reading past end of available disc
else
Disc.ReadLBA_2352(CurrentSector, SectorCache, 0);
CachedSector = CurrentSector;
}
}
public void GetSamples(short[] samples)
{
if (Mode != CDAudioMode.Playing)
return;
if (FadeOutFramesRemaining > 0)
{
FadeOutFramesRemaining--;
LogicalVolume = FadeOutFramesRemaining * 100 / FadeOutOverFrames;
}
EnsureSector();
int sampleLen = samples.Length / 2;
int offset = 0;
for (int s = 0; s < sampleLen; s++)
{
int sectorOffset = SectorOffset * 4;
short left = (short)((SectorCache[sectorOffset + 1] << 8) | (SectorCache[sectorOffset + 0]));
short right = (short)((SectorCache[sectorOffset + 3] << 8) | (SectorCache[sectorOffset + 2]));
samples[offset++] += (short)(left * LogicalVolume / 100 * MaxVolume / short.MaxValue);
samples[offset++] += (short)(right * LogicalVolume / 100 * MaxVolume / short.MaxValue);
SectorOffset++;
if (SectorOffset == 588)
{
CurrentSector++;
SectorOffset = 0;
if (CurrentSector == EndLBA)
{
switch (PlayMode)
{
case PlaybackMode.NextTrackOnCompletion:
PlayTrack(PlayingTrack + 1);
break;
case PlaybackMode.StopOnCompletion:
Stop();
return;
case PlaybackMode.LoopOnCompletion:
CurrentSector = StartLBA;
break;
case PlaybackMode.CallbackOnCompletion:
CallbackAction();
if (Mode != CDAudioMode.Playing)
return;
break;
}
}
EnsureSector();
}
}
}
public short VolumeLeft
{
get
{
if (Mode != CDAudioMode.Playing)
return 0;
int offset = SectorOffset * 4;
short sample = (short)((SectorCache[offset + 1] << 8) | (SectorCache[offset + 0]));
return (short)(sample * LogicalVolume / 100);
}
}
public short VolumeRight
{
get
{
if (Mode != CDAudioMode.Playing)
return 0;
int offset = SectorOffset * 4;
short sample = (short)((SectorCache[offset + 3] << 8) | (SectorCache[offset + 2]));
return (short)(sample * LogicalVolume / 100);
}
}
public void DiscardSamples() { }
public void SaveStateText(TextWriter writer)
{
writer.WriteLine("[CDAudio]");
writer.WriteLine("Mode " + Enum.GetName(typeof(CDAudioMode), Mode));
writer.WriteLine("PlayMode " + Enum.GetName(typeof(PlaybackMode), PlayMode));
writer.WriteLine("LogicalVolume {0}", LogicalVolume);
writer.WriteLine("StartLBA {0}", StartLBA);
writer.WriteLine("EndLBA {0}", EndLBA);
writer.WriteLine("PlayingTrack {0}", PlayingTrack);
writer.WriteLine("CurrentSector {0}", CurrentSector);
writer.WriteLine("SectorOffset {0}", SectorOffset);
writer.WriteLine("FadeOutOverFrames {0}", FadeOutOverFrames);
writer.WriteLine("FadeOutFramesRemaining {0}", FadeOutFramesRemaining);
writer.WriteLine("[/CDAudio]");
writer.WriteLine();
}
public void LoadStateText(TextReader reader)
{
while (true)
{
string[] args = reader.ReadLine().Split(' ');
if (args[0].Trim() == "") continue;
if (args[0] == "[/CDAudio]") break;
if (args[0] == "Mode")
Mode = (CDAudioMode)Enum.Parse(typeof(CDAudioMode), args[1]);
else if (args[0] == "PlayMode")
PlayMode = (PlaybackMode)Enum.Parse(typeof(PlaybackMode), args[1]);
else if (args[0] == "LogicalVolume")
LogicalVolume = int.Parse(args[1]);
else if (args[0] == "StartLBA")
StartLBA = int.Parse(args[1]);
else if (args[0] == "EndLBA")
EndLBA = int.Parse(args[1]);
else if (args[0] == "PlayingTrack")
PlayingTrack = int.Parse(args[1]);
else if (args[0] == "CurrentSector")
CurrentSector = int.Parse(args[1]);
else if (args[0] == "SectorOffset")
SectorOffset = int.Parse(args[1]);
else if (args[0] == "FadeOutOverFrames")
FadeOutOverFrames = int.Parse(args[1]);
else if (args[0] == "FadeOutFramesRemaining")
FadeOutFramesRemaining = int.Parse(args[1]);
else
Console.WriteLine("Skipping unrecognized identifier " + args[0]);
}
EnsureSector();
}
public void SaveStateBinary(BinaryWriter writer)
{
writer.Write((byte)Mode);
writer.Write((byte)PlayMode);
writer.Write(LogicalVolume);
writer.Write(CurrentSector);
writer.Write(SectorOffset);
writer.Write(StartLBA);
writer.Write(EndLBA);
writer.Write(PlayingTrack);
writer.Write((short)FadeOutOverFrames);
writer.Write((short)FadeOutFramesRemaining);
}
public void LoadStateBinary(BinaryReader reader)
{
Mode = (CDAudioMode)reader.ReadByte();
PlayMode = (PlaybackMode)reader.ReadByte();
LogicalVolume = reader.ReadInt32();
CurrentSector = reader.ReadInt32();
SectorOffset = reader.ReadInt32();
StartLBA = reader.ReadInt32();
EndLBA = reader.ReadInt32();
PlayingTrack = reader.ReadInt32();
FadeOutOverFrames = reader.ReadInt16();
FadeOutFramesRemaining = reader.ReadInt16();
}
}
}