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Support >2 channels #13

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a7e97fe
Read number of channels correctly
Masusder Oct 16, 2025
e649891
Revert formatting
Masusder Oct 17, 2025
905eea8
Corrected frequencies / and dont throw
Masusder Oct 17, 2025
670ab7c
Doc SampleMetadata
Masusder Oct 19, 2025
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2 changes: 1 addition & 1 deletion Fmod5Sharp/CodecRebuilders/FmodVorbisRebuilder.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -176,7 +176,7 @@ private static void ReadSamplePackets(BinaryReader inputReader, out List<int> pa
{
var packetSize = inputReader.ReadUInt16();

if (packetSize == 0)
if (packetSize == 0 || packetSize == 0xFFFF)
break; //EOS

packetLengths.Add(packetSize);
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65 changes: 35 additions & 30 deletions Fmod5Sharp/FmodTypes/FmodSampleMetadata.cs
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Original file line number Diff line number Diff line change
@@ -1,38 +1,43 @@
using System.Collections.Generic;
using Fmod5Sharp.Util;
using System.Collections.Generic;
using System.IO;
using Fmod5Sharp.Util;

namespace Fmod5Sharp.FmodTypes
{
public class FmodSampleMetadata : IBinaryReadable
{
internal bool HasAnyChunks;
internal uint FrequencyId;
internal ulong DataOffset;
internal List<FmodSampleChunk> Chunks = new();
Comment on lines 7 to 12
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@ds5678 ds5678 Oct 16, 2025

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Please don't make formatting changes.

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@Masusder Masusder Oct 17, 2025

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Sure

internal int NumChannels;
public class FmodSampleMetadata : IBinaryReadable
{
internal bool HasAnyChunks;
internal uint FrequencyId;
internal ulong DataOffset;
internal List<FmodSampleChunk> Chunks = new();
internal int NumChannels;

public bool IsStereo;
public ulong SampleCount;
public bool IsStereo;
public ulong SampleCount;

public int Frequency => FsbLoader.Frequencies.TryGetValue(FrequencyId, out var actualFrequency) ? actualFrequency : (int)FrequencyId; //If set by FREQUENCY chunk, id is actual frequency
public uint Channels => (uint)NumChannels;
public int Frequency => FsbLoader.Frequencies.TryGetValue(FrequencyId, out var actualFrequency) ? actualFrequency : (int)FrequencyId; // If set by FREQUENCY chunk, id is actual frequency
public uint Channels => (uint)NumChannels;

void IBinaryReadable.Read(BinaryReader reader)
{
var encoded = reader.ReadUInt64();

HasAnyChunks = (encoded & 1) == 1; //Bit 0
FrequencyId = (uint) encoded.Bits( 1, 4); //Bits 1-4
var pow2 = (int) encoded.Bits(5, 2); //Bits 5-6
NumChannels = 1 << pow2;
if (NumChannels > 2)
throw new("> 2 channels not supported");

IsStereo = NumChannels == 2;

DataOffset = encoded.Bits(7, 27) * 32;
SampleCount = encoded.Bits(34, 30);
}
}
void IBinaryReadable.Read(BinaryReader reader)
{
var sampleMode = reader.ReadUInt64();
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@ds5678 ds5678 Oct 16, 2025

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Why the name change?

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@Masusder Masusder Oct 17, 2025

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Just to clarify what it represents. I’ve reverted it back to how it was if that’s an issue


HasAnyChunks = (sampleMode & 1) == 1; // Bit 0
FrequencyId = (uint)sampleMode.Bits(1, 4); // Bits 1-4

int channelBits = (int)sampleMode.Bits(5, 2); // Bits 5-6
NumChannels = channelBits switch
{
0 => 1,
1 => 2,
2 => 6,
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@ds5678 ds5678 Oct 16, 2025

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Why isn't this 4?

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@Masusder Masusder Oct 17, 2025

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It should be 6, that's the whole point

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@ds5678 ds5678 Oct 17, 2025

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Is there any FMOD documentation about this?

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@Masusder Masusder Oct 17, 2025

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I don't think there is any, all I can give you is an example of converted audio:
4 channels
vs
6 channels

Tested on soundbanks from three different games

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@Masusder Masusder Oct 17, 2025

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From FMOD::CodecFSB5::decodeSubSoundHeader:

18001644e        if (channels != 0)
180016462            int128_t __xmm@00000008000000060000000200000001_1 =
180016462                __xmm@00000008000000060000000200000001
18001646c            *channels = *(&__xmm@00000008000000060000000200000001_1
18001646c                + ((zx.q((r10 u>> 5).d) & 3) << 2))

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@Masusder Masusder Oct 17, 2025

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From FMOD::CodecFSB5::decodeSubSoundHeader:

18001644e        if (channels != 0)
180016462            int128_t __xmm@00000008000000060000000200000001_1 =
180016462                __xmm@00000008000000060000000200000001
18001646c            *channels = *(&__xmm@00000008000000060000000200000001_1
18001646c                + ((zx.q((r10 u>> 5).d) & 3) << 2))

@ds5678 and after looking at this it appears that frequencies table was also incorrect, so I also changed it
Correct one should match to this:

180016472        if (frequency != 0)
180016493            __builtin_memcpy(dest: &var_58, 
180016493                src: "\xa0\x0f\x00\x00\x40\x1f\x00\x00\xf8\x2a\x00\x00\xe0\x2e\x00\x00\x80\x3e"
180016493            "00\x00\x22\x56\x00\x00\xc0\x5d\x00\x00\x00\x7d\x00\x00\x44\xac\x00\x00\x80\xbb"
180016493            "00\x00\x00\x77\x01\x00", 
180016493                count: 0x2c)
1800164b2            *frequency = *(&var_58 + ((zx.q((r10 u>> 1).d) & 0xf) << 2))

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@ds5678 ds5678 Oct 19, 2025

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From FMOD::CodecFSB5::decodeSubSoundHeader

Please document in the code that the behavior can be verified by disassembling this function.

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@Masusder Masusder Oct 19, 2025

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Added.

3 => 8,
_ => throw new("Number of channels not supported"),
};
IsStereo = NumChannels == 2;

DataOffset = sampleMode.Bits(7, 27) * 32;
SampleCount = sampleMode.Bits(34, 30);
}
}
}