Copy of aRts for Trinity modifications

git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/dependencies/arts@1070145 283d02a7-25f6-0310-bc7c-ecb5cbfe19da

1 files changed, 167 insertions, 0 deletions

diff --git a/flow/resample.h b/flow/resample.h
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+    /*
+
+    Copyright (C) 2000 Stefan Westerfeld
+                       stefan@space.twc.de
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Library General Public
+    License as published by the Free Software Foundation; either
+    version 2 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
+    Library General Public License for more details.
+   
+    You should have received a copy of the GNU Library General Public License
+    along with this library; see the file COPYING.LIB.  If not, write to
+    the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+    Boston, MA 02111-1307, USA.
+
+    */
+
+
+#ifndef ARTS_FLOW_RESAMPLE_H
+#define ARTS_FLOW_RESAMPLE_H
+
+#include "arts_export.h"
+
+/*
+ * BC - Status (2002-03-08): Resampler / Refiller.
+ *
+ * These classes will be kept binary compatible. Resampler has a private
+ * data pointer for this purpose.
+ */
+
+namespace Arts {
+
+/**
+ * Refiller interface
+ *
+ * this is used by the resampler class
+ */
+class ARTS_EXPORT Refiller {
+public:
+	/**
+	 * callback method to supply data to the Resampler
+	 *
+	 * here you supply data in the encoding specified in the Resampler class
+	 * (bits, channels, endianness) to the Resampler
+	 *
+	 * @param buffer a pointer to a buffer where the data can be filled to
+	 * @param len the size of the buffer in bytes
+	 *
+	 * @returns the number of bytes really available
+	 */
+	virtual unsigned long read(unsigned char *buffer, unsigned long len) = 0;
+	virtual ~Refiller();
+};
+
+class ResamplerPrivate;
+
+/**
+ * The Resampler class resamples data from an input stream, which is read
+ * through the Refiller interface, and renders it into the float format which
+ * aRts usually uses, converting the sampling rate and format as needed.
+ */
+class ARTS_EXPORT Resampler {
+protected:
+	static const unsigned int bufferSize = 256;		//  64 samples in buffer
+	static const unsigned int bufferWrap = 64;		// + "wrap around"
+	/*
+	 * BC: bufferWrap just needs channels * (filtersize - 1) * bytes per sample
+	 * bytes wrap around - this used to be 4: 2 channels, linear interpolation,
+	 * 16bit. However, for supporting float resampling and/or better filters,
+	 * we'll make this 64 to be safe.
+	 */
+
+	int bufferSamples;
+	int sampleSize;
+	int dropBytes;
+
+	Refiller *refiller;
+	double pos, step;
+	int channels,bits;
+
+	unsigned char buffer[bufferSize+bufferWrap];
+	float fbuffer[bufferSize+bufferWrap];
+	long block, haveBlock;
+
+	class ResamplerPrivate *d;
+
+	void updateSampleSize();
+	void ensureRefill();
+public:
+	/**
+	 * constructor
+	 *
+	 */
+	Resampler(Refiller *refiller);
+	~Resampler();
+
+	/**
+	 * sets the resampling step in the input stream
+	 *
+	 * for instance, settings step to 2.0, the file would be played twice as
+	 * fast - you can calculate the resampling step from the sampling rate
+	 * the stream you resample was recorded at, and the sampling rate you want
+	 * it to be resampled to, using
+	 *
+	 *   step = originalSamplingRate / desiredSamplingRate
+	 *
+	 * for instance, if a stream recorded at 22050 Hz is to be played at 48000
+	 * Hz, step would be
+	 *
+	 *   step = 22050 / 48000 = 0.46
+	 */
+	void setStep(double step);
+
+	/**
+	 * sets the number of channels in the input stream
+	 *
+	 * the channels are expected to be interleaved, thus if you have two
+	 * channels, you will have one sample for the left stream, one for the
+	 * right, one for the left, ... and so on
+	 *
+	 * currently only either mono (channels = 1) or stereo (channels = 2)
+	 * streams are supported
+	 */
+	void setChannels(int channels);
+
+	/**
+	 * sets the number of bits in the input stream
+	 *
+	 * currently, only 16 bit and 8 bit streams are supported
+	 */
+	void setBits(int bits);
+
+	enum Endianness { bigEndian, littleEndian };
+
+	/**
+	 * sets the endianess of the input stream
+	 *
+	 * supported are bigEndian and littleEndian
+	 */
+	void setEndianness(Endianness endianness);
+
+	/**
+	 * renders a buffer of float samples from the input stream
+	 *
+	 * the data is obtained by querying the refiller for data from the
+	 * input stream and filling them into the float array pointed to by
+	 * left and right - if reading data fails, the underrun flag is set
+	 */
+	void run(float *left, float *right, unsigned long samples);
+
+	/**
+	 * query the underrun flag
+	 *
+	 * underruns occur if run is called, but no data is available from the
+	 * Refiller object
+	 */
+	bool underrun();
+};
+
+}
+
+#endif /* ARTS_FLOW_RESAMPLE_H */