GARbro-mirror/Experimental/Opus/AudioOPUS.cs

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2016-12-15 17:10:54 +08:00
//! \file AudioOPUS.cs
//! \date Thu Dec 15 11:38:40 2016
//! \brief Handler for Ogg/Opus containers.
//
// Copyright (C) 2016 by morkt
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//
using System;
using System.ComponentModel.Composition;
using System.IO;
using Concentus.Oggfile;
using Concentus.Structs;
namespace GameRes.Formats.Opus
{
[Export(typeof(AudioFormat))]
public class OpusAudio : AudioFormat
{
public override string Tag { get { return "OPUS"; } }
public override string Description { get { return "Ogg/Opus audio format"; } }
public override uint Signature { get { return 0; } }
public override bool CanWrite { get { return false; } }
public override SoundInput TryOpen (IBinaryStream file)
{
if (file.Signature != 0x5367674F) // 'OggS'
return null;
var header = file.ReadHeader (0x1C);
int table_size = header[0x1A];
if (table_size < 1)
return null;
int header_size = header[0x1B];
if (header_size < 0x10)
return null;
int header_pos = 0x1B + table_size;
header = file.ReadHeader (header_pos + header_size);
if (!header.AsciiEqual (header_pos, "OpusHead"))
return null;
int channels = header[header_pos+9];
// int rate = header.ToInt32 (header_pos+0xC);
int rate = 48000;
file.Position = 0;
var decoder = OpusDecoder.Create (rate, channels);
var ogg_in = new OpusOggReadStream (decoder, file.AsStream);
var pcm = new MemoryStream();
try
{
using (var output = new BinaryWriter (pcm, System.Text.Encoding.UTF8, true))
{
while (ogg_in.HasNextPacket)
{
var packet = ogg_in.DecodeNextPacket();
if (packet != null)
{
for (int i = 0; i < packet.Length; ++i)
output.Write (packet[i]);
}
}
}
var format = new WaveFormat
{
FormatTag = 1,
Channels = (ushort)channels,
SamplesPerSecond = (uint)rate,
BitsPerSample = 16,
};
format.BlockAlign = (ushort)(format.Channels*format.BitsPerSample/8);
format.AverageBytesPerSecond = format.SamplesPerSecond*format.BlockAlign;
pcm.Position = 0;
var sound = new RawPcmInput (pcm, format);
file.Dispose();
return sound;
}
catch
{
pcm.Dispose();
throw;
}
}
}
}