void CollectAudioData()
{
var audio1 = new MemoryStream(); // left channel / mono
var audio2 = new MemoryStream(); // right channel
var adpcmIndex = 0;
var compressed = false;
for (var i = 0; i < Frames; i++)
{
stream.Seek(offsets[i], SeekOrigin.Begin);
var end = (i < Frames - 1) ? offsets[i + 1] : stream.Length;
while (stream.Position < end)
{
var type = stream.ReadASCII(4);
if (type == "SN2J")
{
var jmp = int2.Swap(stream.ReadUInt32());
stream.Seek(jmp, SeekOrigin.Current);
type = stream.ReadASCII(4);
}
var length = int2.Swap(stream.ReadUInt32());
switch (type)
{
case "SND0":
case "SND2":
if (audioChannels == 0)
{
throw new NotSupportedException();
}
else if (audioChannels == 1)
{
var rawAudio = stream.ReadBytes((int)length);
audio1.WriteArray(rawAudio);
}
else
{
var rawAudio = stream.ReadBytes((int)length / 2);
audio1.WriteArray(rawAudio);
rawAudio = stream.ReadBytes((int)length / 2);
audio2.WriteArray(rawAudio);
if (length % 2 != 0)
{
stream.ReadBytes(2);
}
}
compressed = type == "SND2";
break;
default:
if (length + stream.Position > stream.Length)
{
throw new NotSupportedException("Vqa uses unknown Subtype: {0}".F(type));
}
stream.ReadBytes((int)length);
break;
}
// Chunks are aligned on even bytes; advance by a byte if the next one is null
if (stream.Peek() == 0)
{
stream.ReadByte();
}
}
}
if (audioChannels == 1)
{
audioData = compressed ? ImaAdpcmReader.LoadImaAdpcmSound(audio1.ToArray(), ref adpcmIndex) : audio1.ToArray();
}
else
{
byte[] leftData, rightData;
if (!compressed)
{
leftData = audio1.ToArray();
rightData = audio2.ToArray();
}
else
{
adpcmIndex = 0;
leftData = ImaAdpcmReader.LoadImaAdpcmSound(audio1.ToArray(), ref adpcmIndex);
adpcmIndex = 0;
rightData = ImaAdpcmReader.LoadImaAdpcmSound(audio2.ToArray(), ref adpcmIndex);
}
audioData = new byte[rightData.Length + leftData.Length];
var rightIndex = 0;
var leftIndex = 0;
for (var i = 0; i < audioData.Length;)
{
audioData[i++] = leftData[leftIndex++];
audioData[i++] = leftData[leftIndex++];
audioData[i++] = rightData[rightIndex++];
audioData[i++] = rightData[rightIndex++];
}
}
hasAudio = audioData.Length > 0;
}
protected override bool BufferData(Stream baseStream, Queue <byte> data)
{
// Decode each block of IMA ADPCM data
// Each block starts with a initial state per-channel
for (var c = 0; c < channels; c++)
{
predictor[c] = baseStream.ReadInt16();
index[c] = baseStream.ReadUInt8();
baseStream.ReadUInt8(); // Unknown/Reserved
// Output first sample from input
data.Enqueue((byte)predictor[c]);
data.Enqueue((byte)(predictor[c] >> 8));
outOffset += 2;
if (outOffset >= outputSize)
{
return(true);
}
}
// Decode and output remaining data in this block
var blockOffset = 0;
while (blockOffset < blockDataSize)
{
for (var c = 0; c < channels; c++)
{
// Decode 4 bytes (to 16 bytes of output) per channel
var chunk = baseStream.ReadBytes(4);
var decoded = ImaAdpcmReader.LoadImaAdpcmSound(chunk, ref index[c], ref predictor[c]);
// Interleave output, one sample per channel
var interleaveChannelOffset = 2 * c;
for (var i = 0; i < decoded.Length; i += 2)
{
var interleaveSampleOffset = interleaveChannelOffset + i;
interleaveBuffer[interleaveSampleOffset] = decoded[i];
interleaveBuffer[interleaveSampleOffset + 1] = decoded[i + 1];
interleaveChannelOffset += 2 * (channels - 1);
}
blockOffset += 4;
}
var outputRemaining = outputSize - outOffset;
var toCopy = Math.Min(outputRemaining, interleaveBuffer.Length);
for (var i = 0; i < toCopy; i++)
{
data.Enqueue(interleaveBuffer[i]);
}
outOffset += 16 * channels;
if (outOffset >= outputSize)
{
return(true);
}
}
return(++currentBlock >= numBlocks);
}
public byte[] DecodeImaAdpcmData()
{
var s = new MemoryStream(RawOutput);
var numBlocks = DataSize / BlockAlign;
var blockDataSize = BlockAlign - (Channels * 4);
var outputSize = UncompressedSize * Channels * 2;
var outOffset = 0;
var output = new byte[outputSize];
var predictor = new int[Channels];
var index = new int[Channels];
// Decode each block of IMA ADPCM data in RawOutput
for (var block = 0; block < numBlocks; block++)
{
// Each block starts with a initial state per-channel
for (var c = 0; c < Channels; c++)
{
predictor[c] = s.ReadInt16();
index[c] = s.ReadUInt8();
/* unknown/reserved */ s.ReadUInt8();
// Output first sample from input
output[outOffset++] = (byte)predictor[c];
output[outOffset++] = (byte)(predictor[c] >> 8);
if (outOffset >= outputSize)
{
return(output);
}
}
// Decode and output remaining data in this block
var blockOffset = 0;
while (blockOffset < blockDataSize)
{
for (var c = 0; c < Channels; c++)
{
// Decode 4 bytes (to 16 bytes of output) per channel
var chunk = s.ReadBytes(4);
var decoded = ImaAdpcmReader.LoadImaAdpcmSound(chunk, ref index[c], ref predictor[c]);
// Interleave output, one sample per channel
var outOffsetChannel = outOffset + (2 * c);
for (var i = 0; i < decoded.Length; i += 2)
{
var outOffsetSample = outOffsetChannel + i;
if (outOffsetSample >= outputSize)
{
return(output);
}
output[outOffsetSample] = decoded[i];
output[outOffsetSample + 1] = decoded[i + 1];
outOffsetChannel += 2 * (Channels - 1);
}
blockOffset += 4;
}
outOffset += 16 * Channels;
}
}
return(output);
}