PSVita has a new version of the VAG file format that was found on the PSP..
Header:
0x0: "VAGp" - Magic Identifier
0xC: Int32(Big Endain) - Waveform Data Size
0x10: Int32(Big Endain) - Sample Rate
0x1E: Int8 - Channels (0x0 = 1 mono, 0x2 = stereo)
0x20: String - Track Name
0x40: ADPCM Audio
Audio Data:
The audio data in VAG files is ADPCM compressed, though not in any standard way
samples are encoded in 0x10 blocks,
the structure of said blocks is as follows:
0x1: Decoding Coefficent
0x2: Loop Data
0x3: ADPCM Encoded Data
if the loop data byte is set to 0x7 then the sample is skipped.
The ADPCM Compression uses the following Coefficent Table:
{
private static int[,] HEVAGCoeffTable = new int[,]
{
{ 0, 0, 0, 0 },
{ 7680, 0, 0, 0 },
{ 14720, -6656, 0, 0 },
{ 12544, -7040, 0, 0 },
{ 15616, -7680, 0, 0 },
{ 14731, -7059, 0, 0 },
{ 14507, -7366, 0, 0 },
{ 13920, -7522, 0, 0 },
{ 13133, -7680, 0, 0 },
{ 12028, -7680, 0, 0 },
{ 10764, -7680, 0, 0 },
{ 9359, -7680, 0, 0 },
{ 7832, -7680, 0, 0 },
{ 6201, -7680, 0, 0 },
{ 4488, -7680, 0, 0 },
{ 2717, -7680, 0, 0 },
{ 910, -7680, 0, 0 },
{ -910, -7680, 0, 0 },
{ -2717, -7680, 0, 0 },
{ -4488, -7680, 0, 0 },
{ -6201, -7680, 0, 0 },
{ -7832, -7680, 0, 0 },
{ -9359, -7680, 0, 0 },
{ -10764, -7680, 0, 0 },
{ -12028, -7680, 0, 0 },
{ -13133, -7680, 0, 0 },
{ -13920, -7522, 0, 0 },
{ -14507, -7366, 0, 0 },
{ -14731, -7059, 0, 0 },
{ 5376, -9216, 3328, -3072 },
{ -6400, -7168, -3328, -2304 },
{ -10496, -7424, -3584, -1024 },
{ -167, -2722, -494, -541 },
{ -7430, -2221, -2298, 424 },
{ -8001, -3166, -2814, 289 },
{ 6018, -4750, 2649, -1298 },
{ 3798, -6946, 3875, -1216 },
{ -8237, -2596, -2071, 227 },
{ 9199, 1982, -1382, -2316 },
{ 13021, -3044, -3792, 1267 },
{ 13112, -4487, -2250, 1665 },
{ -1668, -3744, -6456, 840 },
{ 7819, -4328, 2111, -506 },
{ 9571, -1336, -757, 487 },
{ 10032, -2562, 300, 199 },
{ -4745, -4122, -5486, -1493 },
{ -5896, 2378, -4787, -6947 },
{ -1193, -9117, -1237, -3114 },
{ 2783, -7108, -1575, -1447 },
{ -7334, -2062, -2212, 446 },
{ 6127, -2577, -315, -18 },
{ 9457, -1858, 102, 258 },
{ 7876, -4483, 2126, -538 },
{ -7172, -1795, -2069, 482 },
{ -7358, -2102, -2233, 440 },
{ -9170, -3509, -2674, -391 },
{ -2638, -2647, -1929, -1637 },
{ 1873, 9183, 1860, -5746 },
{ 9214, 1859, -1124, -2427 },
{ 13204, -3012, -4139, 1370 },
{ 12437, -4792, -256, 622 },
{ -2653, -1144, -3182, -6878 },
{ 9331, -1048, -828, 507 },
{ 1642, -620, -946, -4229 },
{ 4246, -7585, -533, -2259 },
{ -8988, -3891, -2807, 44 },
{ -2562, -2735, -1730, -1899 },
{ 3182, -483, -714, -1421 },
{ 7937, -3844, 2821, -1019 },
{ 10069, -2609, 314, 195 },
{ 8400, -3297, 1551, -155 },
{ -8529, -2775, -2432, -336 },
{ 9477, -1882, 108, 256 },
{ 75, -2241, -298, -6937 },
{ -9143, -4160, -2963, 5 },
{ -7270, -1958, -2156, 460 },
{ -2740, 3745, 5936, -1089 },
{ 8993, 1948, -683, -2704 },
{ 13101, -2835, -3854, 1055 },
{ 9543, -1961, 130, 250 },
{ 5272, -4270, 3124, -3157 },
{ -7696, -3383, -2907, -456 },
{ 7309, 2523, 434, -2461 },
{ 10275, -2867, 391, 172 },
{ 10940, -3721, 665, 97 },
{ 24, -310, -1262, 320 },
{ -8122, -2411, -2311, -271 },
{ -8511, -3067, -2337, 163 },
{ 326, -3846, 419, -933 },
{ 8895, 2194, -541, -2880 },
{ 12073, -1876, -2017, -601 },
{ 8729, -3423, 1674, -169 },
{ 12950, -3847, -3007, 1946 },
{ 10038, -2570, 302, 198 },
{ 9385, -2757, 1008, 41 },
{ -4720, -5006, -2852, -1161 },
{ 7869, -4326, 2135, -501 },
{ 2450, -8597, 1299, -2780 },
{ 10192, -2763, 360, 181 },
{ 11313, -4213, 833, 53 },
{ 10154, -2716, 345, 185 },
{ 9638, -1417, -737, 482 },
{ 3854, -4554, 2843, -3397 },
{ 6699, -5659, 2249, -1074 },
{ 11082, -3908, 728, 80 },
{ -1026, -9810, -805, -3462 },
{ 10396, -3746, 1367, -96 },
{ 10287, 988, -1915, -1437 },
{ 7953, 3878, -764, -3263 },
{ 12689, -3375, -3354, 2079 },
{ 6641, 3166, 231, -2089 },
{ -2348, -7354, -1944, -4122 },
{ 9290, -4039, 1885, -246 },
{ 4633, -6403, 1748, -1619 },
{ 11247, -4125, 802, 61 },
{ 9807, -2284, 219, 222 },
{ 9736, -1536, -706, 473 },
{ 8440, -3436, 1562, -176 },
{ 9307, -1021, -835, 509 },
{ 1698, -9025, 688, -3037 },
{ 10214, -2791, 368, 179 },
{ 8390, 3248, -758, -2989 },
{ 7201, 3316, 46, -2614 },
{ -88, -7809, -538, -4571 },
{ 6193, -5189, 2760, -1245 },
{ 12325, -1290, -3284, 253 },
{ 13064, -4075, -2824, 1877 },
{ 5333, 2999, 775, -1132 },
};
the ADPCM samples can then be decoded into PCM using the following code (C#)
public static byte[] DecodePCM()
{
int Hist = 0;
int Hist2 = 0;
int Hist3 = 0;
int Hist4 = 0;
int FileSize = GetWaveformDataSize() - 0x40;
BinaryReader VagReader = new BinaryReader(VagStream);
MemoryStream PCMStream = new MemoryStream();
BinaryWriter PCMWriter = new BinaryWriter(PCMStream);
VagStream.Seek(0x40, SeekOrigin.Begin);
while (VagStream.Position < FileSize)
{
byte DecodingCoefficent = VagReader.ReadByte();
int ShiftBy = DecodingCoefficent & 0xf;
int PredictNr = DecodingCoefficent >> 0x4;
byte LoopData = VagReader.ReadByte();
PredictNr |= LoopData & 0xF0;
int LoopFlag = LoopData & 0xf;
if (LoopFlag == 0x7)
{
VagStream.Seek(14, SeekOrigin.Current);
Hist = 0;
Hist2 = 0;
Hist3 = 0;
Hist4 = 0;
}
else
{
for (int i = 0; i < 14; i++)
{
byte ADPCMData = VagReader.ReadByte();
int SampleFlags = ADPCMData & 0xF;
int Coefficent;
short Sample;
for(int ii = 0; ii <= 1; ii++)
{
if (SampleFlags > 7)
{
SampleFlags -= 16;
}
if (PredictNr < 128)
{
Coefficent = Hist * HEVAGCoeffTable[PredictNr, 0] + Hist2 * HEVAGCoeffTable[PredictNr, 1] + Hist3 * HEVAGCoeffTable[PredictNr, 2] + Hist4 * HEVAGCoeffTable[PredictNr, 3];
}
else
{
Coefficent = 0;
}
Sample = (short)(Coefficent / 32 + (SampleFlags << 20 - ShiftBy) + 128 >> 8 ) ;
PCMWriter.Write(Sample);
Hist4 = Hist3;
Hist3 = Hist2;
Hist2 = Hist;
Hist = Sample;
SampleFlags = ADPCMData >> 4;
}
}
}
}
}
full "vag.cs" for reference:
https://bitbucket.org/SilicaAndPina/cxml-decompiler/src/master/AppInfoCli/VAG.cs
Show Posts
