cuetools.net/CUETools.Codecs.FLAKE/Flake.cs

/**
 * CUETools.Flake: pure managed FLAC audio encoder
 * Copyright (c) 2009 Gregory S. Chudov
 * Based on Flake encoder, http://flake-enc.sourceforge.net/
 * Copyright (c) 2006-2009 Justin Ruggles
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

using System;
using System.Collections.Generic;
using System.Text;
using CUETools.Codecs;

namespace CUETools.Codecs.FLAKE
{
	public class Flake
	{
		public const int MAX_BLOCKSIZE = 65535;
		public const int MAX_RICE_PARAM = 14;
		public const int MAX_PARTITION_ORDER = 8;
		public const int MAX_PARTITIONS = 1 << MAX_PARTITION_ORDER;

		public const int FLAC__STREAM_METADATA_SEEKPOINT_SAMPLE_NUMBER_LEN = 64; /* bits */
		public const int FLAC__STREAM_METADATA_SEEKPOINT_STREAM_OFFSET_LEN = 64; /* bits */
		public const int FLAC__STREAM_METADATA_SEEKPOINT_FRAME_SAMPLES_LEN = 16; /* bits */

		public static readonly int[] flac_samplerates = new int[16] {
				0, 0, 0, 0,
				8000, 16000, 22050, 24000, 32000, 44100, 48000, 96000,
				0, 0, 0, 0
			};
		public static readonly int[] flac_blocksizes = new int[15] { 0, 192, 576, 1152, 2304, 4608, 0, 0, 256, 512, 1024, 2048, 4096, 8192, 16384 };
		public static readonly int[] flac_bitdepths = new int[8] { 0, 8, 12, 0, 16, 20, 24, 0 };

		public static PredictionType LookupPredictionType(string name)
		{
			return (PredictionType)(Enum.Parse(typeof(PredictionType), name, true));
		}

		public static StereoMethod LookupStereoMethod(string name)
		{
			return (StereoMethod)(Enum.Parse(typeof(StereoMethod), name, true));
		}

		public static WindowMethod LookupWindowMethod(string name)
		{
			return (WindowMethod)(Enum.Parse(typeof(WindowMethod), name, true));
		}

		public static OrderMethod LookupOrderMethod(string name)
		{
			return (OrderMethod)(Enum.Parse(typeof(OrderMethod), name, true));
		}

		public static WindowFunction LookupWindowFunction(string name)
		{
			return (WindowFunction)(Enum.Parse(typeof(WindowFunction), name, true));
		}
	}

	unsafe public class RiceContext
	{
		public RiceContext()
		{
			rparams = new int[Flake.MAX_PARTITIONS];
			esc_bps = new int[Flake.MAX_PARTITIONS];
		}
		/// <summary>
		/// partition order
		/// </summary>
		public int porder;

		/// <summary>
		/// coding method: rice parameters use 4 bits for coding_method 0 and 5 bits for coding_method 1
		/// </summary>
		public int coding_method;

		/// <summary>
		/// Rice parameters
		/// </summary>
		public int[] rparams;

		/// <summary>
		/// bps if using escape code
		/// </summary>
		public int[] esc_bps;
	};

	unsafe public class FlacSubframe
	{
		public FlacSubframe()
		{
			rc = new RiceContext();
			coefs = new int[lpc.MAX_LPC_ORDER];
		}
		public SubframeType type;
		public int order;
		public int* residual;
		public RiceContext rc;
		public uint size;

		public int cbits;
		public int shift;
		public int[] coefs;
		public int window;
	};

	unsafe public class FlacSubframeInfo
	{
		public FlacSubframeInfo()
		{
			best = new FlacSubframe();
			lpc_ctx = new LpcContext[lpc.MAX_LPC_WINDOWS];
			for (int i = 0; i < lpc.MAX_LPC_WINDOWS; i++)
				lpc_ctx[i] = new LpcContext();
		}

		public void Init(int* s, int* r, int bps, int w)
		{
			if (w > bps)
				throw new Exception("internal error");
			samples = s;
			obits = bps - w;
			wbits = w;
			best.residual = r;
			best.type = SubframeType.Verbatim;
			best.size = AudioSamples.UINT32_MAX;
			for (int iWindow = 0; iWindow < lpc.MAX_LPC_WINDOWS; iWindow++)
				lpc_ctx[iWindow].Reset();
			done_fixed = 0;
		}

		public FlacSubframe best;
		public int obits;
		public int wbits;
		public int* samples;
		public uint done_fixed;
		public LpcContext[] lpc_ctx;
	};

	unsafe public class FlacFrame
	{
		public FlacFrame(int subframes_count)
		{
			subframes = new FlacSubframeInfo[subframes_count];
			for (int ch = 0; ch < subframes_count; ch++)
				subframes[ch] = new FlacSubframeInfo();
			current = new FlacSubframe();
		}

		public void InitSize(int bs, bool vbs)
		{
			blocksize = bs;
			int i = 15;
			if (!vbs)
			{
				for (i = 0; i < 15; i++)
				{
					if (bs == Flake.flac_blocksizes[i])
					{
						bs_code0 = i;
						bs_code1 = -1;
						break;
					}
				}
			}
			if (i == 15)
			{
				if (blocksize <= 256)
				{
					bs_code0 = 6;
					bs_code1 = blocksize - 1;
				}
				else
				{
					bs_code0 = 7;
					bs_code1 = blocksize - 1;
				}
			}
		}

		public void ChooseBestSubframe(int ch)
		{
			if (current.size >= subframes[ch].best.size)
				return;
			FlacSubframe tmp = subframes[ch].best;
			subframes[ch].best = current;
			current = tmp;
		}

		public void SwapSubframes(int ch1, int ch2)
		{
			FlacSubframeInfo tmp = subframes[ch1];
			subframes[ch1] = subframes[ch2];
			subframes[ch2] = tmp;
		}

		/// <summary>
		/// Swap subframes according to channel mode.
		/// It is assumed that we have 4 subframes,
		/// 0 is right, 1 is left, 2 is middle, 3 is difference
		/// </summary>
		public void ChooseSubframes()
		{
			switch (ch_mode)
			{
				case ChannelMode.MidSide:
					SwapSubframes(0, 2);
					SwapSubframes(1, 3);
					break;
				case ChannelMode.RightSide:
					SwapSubframes(0, 3);
					break;
				case ChannelMode.LeftSide:
					SwapSubframes(1, 3);
					break;
			}
		}

		public int blocksize;
		public int bs_code0, bs_code1;
		public ChannelMode ch_mode;
		//public int ch_order0, ch_order1;
		public byte crc8;
		public FlacSubframeInfo[] subframes;
		public int frame_number;
		public FlacSubframe current;
		public float* window_buffer;

		public BitWriter writer = null;
		public int writer_offset = 0;
	}

	public enum OrderMethod
	{
		/// <summary>
		/// Select orders based on Akaike's criteria
		/// </summary>
		Akaike = 0
	}

	/// <summary>
	/// Type of linear prediction
	/// </summary>
	public enum PredictionType
	{
		/// <summary>
		/// Verbatim
		/// </summary>
		None = 0,
		/// <summary>
		/// Fixed prediction only
		/// </summary>
		Fixed = 1,
		/// <summary>
		/// Levinson-Durbin recursion
		/// </summary>
		Levinson = 2,
		/// <summary>
		/// Exhaustive search
		/// </summary>
		Search = 3
	}

	public enum StereoMethod
	{
		Independent = 0,
		Estimate = 1,
		Evaluate = 2,
		Search = 3
	}

	public enum WindowMethod
	{
		Estimate = 0,
		Evaluate = 1,
		Search = 2
	}

	public enum SubframeType
	{
		Constant = 0,
		Verbatim = 1,
		Fixed = 8,
		LPC = 32
	};

	public enum ChannelMode
	{
		NotStereo = 0,
		LeftRight = 1,
		LeftSide = 8,
		RightSide = 9,
		MidSide = 10
	}

	public enum WindowFunction
	{
		Welch = 1,
		Tukey = 2,
		Hann = 4,
		Flattop = 8,
		Bartlett = 16,
		TukeyFlattop = 10
	}

	public struct SeekPoint
	{
		public long number;
		public long offset;
		public int framesize;
	}

	public enum MetadataType
	{
		/// <summary>
		/// <A HREF="../format.html#metadata_block_streaminfo">STREAMINFO</A> block
		/// </summary>
		StreamInfo = 0,

		/// <summary>
		/// <A HREF="../format.html#metadata_block_padding">PADDING</A> block
		/// </summary>
		Padding = 1,

		/// <summary>
		/// <A HREF="../format.html#metadata_block_application">APPLICATION</A> block 
		/// </summary>
		Application = 2,

		/// <summary>
		/// <A HREF="../format.html#metadata_block_seektable">SEEKTABLE</A> block
		/// </summary>
		Seektable = 3,

		/// <summary>
		/// <A HREF="../format.html#metadata_block_vorbis_comment">VORBISCOMMENT</A> block (a.k.a. FLAC tags)
		/// </summary>
		VorbisComment = 4,

		/// <summary>
		/// <A HREF="../format.html#metadata_block_cuesheet">CUESHEET</A> block
		/// </summary>
		CUESheet = 5,

		/// <summary>
		/// <A HREF="../format.html#metadata_block_picture">PICTURE</A> block
		/// </summary>
		Picture = 6,

		/// <summary>
		/// marker to denote beginning of undefined type range; this number will increase as new metadata types are added
		/// </summary>
		Undefined = 7
	};
}