forked from OpenRA/OpenRA
/
AudLoader.cs
159 lines (133 loc) · 4.1 KB
/
AudLoader.cs
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#region Copyright & License Information
/*
* Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
* This file is part of OpenRA, which is free software. It is made
* available to you under the terms of the GNU General Public License
* as published by the Free Software Foundation. For more information,
* see COPYING.
*/
#endregion
using System;
using System.IO;
namespace OpenRA.FileFormats
{
[Flags]
enum SoundFlags
{
Stereo = 0x1,
_16Bit = 0x2,
}
enum SoundFormat
{
WestwoodCompressed = 1,
ImaAdpcm = 99,
}
struct Chunk
{
public int CompressedSize;
public int OutputSize;
public static Chunk Read(BinaryReader r)
{
Chunk c;
c.CompressedSize = r.ReadUInt16();
c.OutputSize = r.ReadUInt16();
if (0xdeaf != r.ReadUInt32())
throw new InvalidDataException("Chunk header is bogus");
return c;
}
}
public static class AudLoader
{
static int[] IndexAdjust = { -1, -1, -1, -1, 2, 4, 6, 8 };
static int[] StepTable = {
7, 8, 9, 10, 11, 12, 13, 14, 16,
17, 19, 21, 23, 25, 28, 31, 34, 37,
41, 45, 50, 55, 60, 66, 73, 80, 88,
97, 107, 118, 130, 143, 157, 173, 190, 209,
230, 253, 279, 307, 337, 371, 408, 449, 494,
544, 598, 658, 724, 796, 876, 963, 1060, 1166,
1282, 1411, 1552, 1707, 1878, 2066, 2272, 2499, 2749,
3024, 3327, 3660, 4026, 4428, 4871, 5358, 5894, 6484,
7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899, 15289,
16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767 };
static short DecodeSample(byte b, ref int index, ref int current)
{
var sb = (b & 8) != 0;
b &= 7;
var delta = (StepTable[index] * b) / 4 + StepTable[index] / 8;
if (sb) delta = -delta;
current += delta;
if (current > short.MaxValue) current = short.MaxValue;
if (current < short.MinValue) current = short.MinValue;
index += IndexAdjust[b];
if (index < 0) index = 0;
if (index > 88) index = 88;
return (short)current;
}
public static byte[] LoadSound(byte[] raw, ref int index)
{
var br = new BinaryReader(new MemoryStream(raw));
var dataSize = raw.Length;
var outputSize = raw.Length * 4;
var output = new byte[outputSize];
var offset = 0;
var currentSample = 0;
while (dataSize-- > 0)
{
var b = br.ReadByte();
var t = DecodeSample(b, ref index, ref currentSample);
output[offset++] = (byte)t;
output[offset++] = (byte)(t >> 8);
t = DecodeSample((byte)(b >> 4), ref index, ref currentSample);
output[offset++] = (byte)t;
output[offset++] = (byte)(t >> 8);
}
return output;
}
public static float SoundLength(Stream s)
{
var br = new BinaryReader(s);
var sampleRate = br.ReadUInt16();
/*var dataSize = */ br.ReadInt32();
var outputSize = br.ReadInt32();
var flags = (SoundFlags) br.ReadByte();
var samples = outputSize;
if (0 != (flags & SoundFlags.Stereo)) samples /= 2;
if (0 != (flags & SoundFlags._16Bit)) samples /= 2;
return samples / sampleRate;
}
public static byte[] LoadSound(Stream s)
{
var br = new BinaryReader(s);
/*var sampleRate =*/ br.ReadUInt16();
var dataSize = br.ReadInt32();
var outputSize = br.ReadInt32();
/*var flags = (SoundFlags)*/ br.ReadByte();
/*var format = (SoundFormat)*/ br.ReadByte();
var output = new byte[outputSize];
var offset = 0;
var index = 0;
var currentSample = 0;
while (dataSize > 0)
{
var chunk = Chunk.Read(br);
for (int n = 0; n < chunk.CompressedSize; n++)
{
var b = br.ReadByte();
var t = DecodeSample(b, ref index, ref currentSample);
output[offset++] = (byte)t;
output[offset++] = (byte)(t >> 8);
if (offset < outputSize)
{
/* possible that only half of the final byte is used! */
t = DecodeSample((byte)(b >> 4), ref index, ref currentSample);
output[offset++] = (byte)t;
output[offset++] = (byte)(t >> 8);
}
}
dataSize -= 8 + chunk.CompressedSize;
}
return output;
}
}
}