Convert .aif files to .pcm samples, and update Makefile to use aif2pcm tool.

4 files changed, 759 insertions, 0 deletions

diff --git a/tools/aif2pcm/LICENSE b/tools/aif2pcm/LICENSE
new file mode 100644
index 000000000..60c9e63c4
--- /dev/null
+++ b/tools/aif2pcm/LICENSE
@@ -0,0 +1,19 @@
+Copyright (c) 2016 huderlem
+
+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.
diff --git a/tools/aif2pcm/Makefile b/tools/aif2pcm/Makefile
new file mode 100644
index 000000000..ec6343b12
--- /dev/null
+++ b/tools/aif2pcm/Makefile
@@ -0,0 +1,15 @@
+CC = gcc
+
+CFLAGS = -Wall -Wextra -Wno-switch -std=c11 -O2
+
+LIBS = -lm
+
+SRCS = main.c extended.c
+
+.PHONY: clean
+
+aif2pcm: $(SRCS)
+	$(CC) $(CFLAGS) $(SRCS) -o $@ $(LIBS)
+
+clean:
+	$(RM) aif2pcm aif2pcm.exe
diff --git a/tools/aif2pcm/extended.c b/tools/aif2pcm/extended.c
new file mode 100644
index 000000000..067019661
--- /dev/null
+++ b/tools/aif2pcm/extended.c
@@ -0,0 +1,171 @@
+/*	$Id: extended.c,v 1.8 2006/12/23 11:17:49 toad32767 Exp $ */
+/*-
+ * Copyright (c) 2005, 2006 by Marco Trillo <marcotrillo@gmail.com>
+ *
+ * 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.
+ */
+
+#include <math.h>
+#include <string.h>
+
+/*
+ * Infinite & NAN values
+ * for non-IEEE systems
+ */
+#ifndef HUGE_VAL
+#ifdef HUGE
+#define INFINITE_VALUE	HUGE
+#define NAN_VALUE	HUGE
+#endif
+#else
+#define INFINITE_VALUE	HUGE_VAL
+#define NAN_VALUE	HUGE_VAL
+#endif
+
+/*
+ * IEEE 754 Extended Precision
+ * 
+ * Implementation here is the 80-bit extended precision
+ * format of Motorola 68881, Motorola 68882 and Motorola
+ * 68040 FPUs, as well as Intel 80x87 FPUs.
+ * 
+ * See:
+ *    http://www.freescale.com/files/32bit/doc/fact_sheet/BR509.pdf
+ */
+/*
+ * Exponent range: [-16383,16383]
+ * Precision for mantissa: 64 bits with no hidden bit
+ * Bias: 16383
+ */
+
+/*
+ * Write IEEE Extended Precision Numbers
+ */
+void
+ieee754_write_extended(double in, unsigned char* out)
+{
+	int sgn, exp, shift;
+	double fraction, t;
+	unsigned int lexp, hexp;
+	unsigned long low, high;
+
+	if (in == 0.0) {
+		memset(out, 0, 10);
+		return;
+	}
+	if (in < 0.0) {
+		in = fabs(in);
+		sgn = 1;
+	} else
+		sgn = 0;
+
+	fraction = frexp(in, &exp);
+
+	if (exp == 0 || exp > 16384) {
+		if (exp > 16384) /* infinite value */
+			low = high = 0;
+		else {
+			low = 0x80000000;
+			high = 0;
+		}
+		exp = 32767;
+		goto done;
+	}
+	fraction = ldexp(fraction, 32);
+	t = floor(fraction);
+	low = (unsigned long) t;
+	fraction -= t;
+	t = floor(ldexp(fraction, 32));
+	high = (unsigned long) t;
+
+	/* Convert exponents < -16382 to -16382 (then they will be
+	 * stored as -16383) */
+	if (exp < -16382) {
+		shift = 0 - exp - 16382;
+		high >>= shift;
+		high |= (low << (32 - shift));
+		low >>= shift;
+		exp = -16382;
+	}
+	exp += 16383 - 1;	/* bias */
+
+done:
+	lexp = ((unsigned int) exp) >> 8;
+	hexp = ((unsigned int) exp) & 0xFF;
+	
+	/* big endian */
+	out[0] = ((unsigned char) sgn) << 7;
+	out[0] |= (unsigned char) lexp;
+	out[1] = (unsigned char) hexp;
+	out[2] = (unsigned char) (low >> 24);
+	out[3] = (unsigned char) ((low >> 16) & 0xFF);
+	out[4] = (unsigned char) ((low >> 8) & 0xFF);
+	out[5] = (unsigned char) (low & 0xFF);
+	out[6] = (unsigned char) (high >> 24);
+	out[7] = (unsigned char) ((high >> 16) & 0xFF);
+	out[8] = (unsigned char) ((high >> 8) & 0xFF);
+	out[9] = (unsigned char) (high & 0xFF);
+
+	return;
+}
+
+
+/*
+ * Read IEEE Extended Precision Numbers
+ */
+double
+ieee754_read_extended(unsigned char* in)
+{
+	int sgn, exp;
+	unsigned long low, high;
+	double out;
+
+	/* Extract the components from the big endian buffer */
+	sgn = (int) (in[0] >> 7);
+	exp = ((int) (in[0] & 0x7F) << 8) | ((int) in[1]);
+	low = (((unsigned long) in[2]) << 24)
+		| (((unsigned long) in[3]) << 16)
+		| (((unsigned long) in[4]) << 8) | (unsigned long) in[5];
+	high = (((unsigned long) in[6]) << 24)
+		| (((unsigned long) in[7]) << 16)
+		| (((unsigned long) in[8]) << 8) | (unsigned long) in[9];
+
+	if (exp == 0 && low == 0 && high == 0)
+		return (sgn ? -0.0 : 0.0);
+
+	switch (exp) {
+	case 32767:
+		if (low == 0 && high == 0)
+			return (sgn ? -INFINITE_VALUE : INFINITE_VALUE);
+		else
+			return (sgn ? -NAN_VALUE : NAN_VALUE);
+	default:
+		exp -= 16383;	/* unbias exponent */
+
+	}
+
+	out = ldexp((double) low, -31 + exp);
+	out += ldexp((double) high, -63 + exp);
+
+	return (sgn ? -out : out);
+}
diff --git a/tools/aif2pcm/main.c b/tools/aif2pcm/main.c
new file mode 100644
index 000000000..31842ff8e
--- /dev/null
+++ b/tools/aif2pcm/main.c
@@ -0,0 +1,554 @@
+// Copyright(c) 2016 huderlem
+//
+// 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.
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdbool.h>
+
+/* extended.c */
+void ieee754_write_extended (double, unsigned char*);
+double ieee754_read_extended (unsigned char*);
+
+#ifdef _MSC_VER
+
+#define FATAL_ERROR(format, ...)           \
+do                                         \
+{                                          \
+    fprintf(stderr, format, __VA_ARGS__,); \
+    exit(1);                               \
+} while (0)
+
+#else
+
+#define FATAL_ERROR(format, ...)            \
+do                                          \
+{                                           \
+    fprintf(stderr, format, ##__VA_ARGS__); \
+    exit(1);                                \
+} while (0)
+
+#endif // _MSC_VER
+
+typedef struct {
+	unsigned long num_samples;
+	char *samples;
+	unsigned char midi_note;
+	unsigned long loop_offset;
+	double sample_rate;
+} AifData;
+
+
+char * get_file_extension(char *filename)
+{
+	char *dot = strrchr(filename, '.');
+	if (!dot || dot == filename)
+	{
+		FATAL_ERROR("Input file has no file extension.\n");
+	}
+
+	return dot + 1;
+}
+
+void change_file_extension(char *filename, const char *new_extension)
+{
+	char *dot = strrchr(filename, '.');
+	if (!dot || dot == filename)
+	{
+		FATAL_ERROR("Input file has no file extension.\n");
+	}
+
+	memcpy(dot + 1, new_extension, 3);
+}
+
+AifData *read_aif(char * aif_file_data, unsigned long aif_file_data_size)
+{
+	AifData *aif_data = (AifData *)malloc(sizeof(AifData));
+
+	unsigned long pos = 0;
+	char chunk_name[5]; chunk_name[4] = '\0';
+	char chunk_type[5]; chunk_type[4] = '\0';
+
+	// Check for FORM Chunk
+	memcpy(chunk_name, aif_file_data + pos, 4);
+	pos += 4;
+	if (strcmp(chunk_name, "FORM") != 0)
+	{
+		FATAL_ERROR("Input .aif file has invalid header Chunk '%s'!\n", chunk_name);
+	}
+
+	// Read size of whole file.
+	unsigned long whole_chunk_size = aif_file_data[pos++] << 24;
+	whole_chunk_size |= (aif_file_data[pos++] << 16);
+	whole_chunk_size |= (aif_file_data[pos++] <<  8);
+	whole_chunk_size |= (unsigned char)aif_file_data[pos++];
+
+	unsigned long expected_whole_chunk_size = aif_file_data_size - 8;
+	if (whole_chunk_size != expected_whole_chunk_size)
+	{
+		FATAL_ERROR("FORM Chunk ckSize '%lu' doesn't match actual size '%lu'!\n", whole_chunk_size, expected_whole_chunk_size);
+	}
+
+	// Check for AIFF Form Type
+	memcpy(chunk_type, aif_file_data + pos, 4);
+	pos += 4;
+	if (strcmp(chunk_type, "AIFF") != 0)
+	{
+		FATAL_ERROR("FORM Type is '%s', but it must be AIFF!", chunk_type);
+	}
+
+	unsigned long num_sample_frames = 0;
+
+	// Read all the Chunks to populate the AifData struct.
+	while (pos < aif_file_data_size)
+	{
+		// Read Chunk id
+		memcpy(chunk_name, aif_file_data + pos, 4);
+		pos += 4;
+
+		unsigned long chunk_size = (aif_file_data[pos++] << 24);
+		chunk_size |= (aif_file_data[pos++] << 16);
+		chunk_size |= (aif_file_data[pos++] <<  8);
+		chunk_size |=  aif_file_data[pos++];
+
+		if (strcmp(chunk_name, "COMM") == 0)
+		{
+			short num_channels = (aif_file_data[pos++] << 8);
+			num_channels |= (unsigned char)aif_file_data[pos++];
+			if (num_channels != 1)
+			{
+				FATAL_ERROR("numChannels (%d) in the COMM Chunk must be 1!\n", num_channels);
+			}
+
+			num_sample_frames =  (aif_file_data[pos++] << 24);
+			num_sample_frames |= (aif_file_data[pos++] << 16);
+			num_sample_frames |= (aif_file_data[pos++] <<  8);
+			num_sample_frames |=  (unsigned char)aif_file_data[pos++];
+
+			short sample_size = (aif_file_data[pos++] << 8);
+			sample_size |= (unsigned char)aif_file_data[pos++];
+			if (sample_size != 8)
+			{
+				FATAL_ERROR("sampleSize (%d) in the COMM Chunk must be 8!\n", sample_size);
+			}
+
+			double sample_rate = ieee754_read_extended((unsigned char*)(aif_file_data + pos));
+			pos += 10;
+
+			aif_data->num_samples = num_sample_frames;
+			aif_data->sample_rate = sample_rate;
+		}
+		else if (strcmp(chunk_name, "MARK") == 0)
+		{
+			unsigned short num_markers = (aif_file_data[pos++] << 8);
+			num_markers |= (unsigned char)aif_file_data[pos++];
+
+			unsigned long loop_start = 0;
+
+			// Read each marker and look for the "START" marker.
+			for (int i = 0; i < num_markers; i++)
+			{
+				unsigned short marker_id = (aif_file_data[pos++] << 8);
+				marker_id |= (unsigned char)aif_file_data[pos++];
+
+				unsigned long marker_position = (aif_file_data[pos++] << 24);
+				marker_position |= (aif_file_data[pos++] << 16);
+				marker_position |= (aif_file_data[pos++] << 8);
+				marker_position |=  (unsigned char)aif_file_data[pos++];
+
+				// Marker id is a pascal-style string.
+				unsigned char marker_name_size = aif_file_data[pos++];
+				char *marker_name = (char *)malloc((marker_name_size + 1) * sizeof(char));
+				memcpy(marker_name, aif_file_data + pos, marker_name_size);
+				marker_name[marker_name_size] = '\0';
+				pos += marker_name_size;
+
+				if (strcmp(marker_name, "START") == 0)
+				{
+					loop_start = marker_position;
+				}
+
+				free(marker_name);
+			}
+
+			aif_data->loop_offset = loop_start;
+		}
+		else if (strcmp(chunk_name, "INST") == 0)
+		{
+			unsigned char midi_note = (unsigned char)aif_file_data[pos++];
+
+			aif_data->midi_note = midi_note;
+
+			// Skip over data we don't need.
+			pos += 19;
+		}
+		else if (strcmp(chunk_name, "SSND") == 0)
+		{
+			// SKip offset and blockSize
+			pos += 8;
+
+			char *sample_data = (char *)malloc(num_sample_frames * sizeof(char));
+			memcpy(sample_data, aif_file_data + pos, num_sample_frames);
+
+			aif_data->samples = sample_data;
+			pos += num_sample_frames;
+		}
+		else
+		{
+			// Skip over stuff we unsupported chunks.
+			pos += chunk_size;
+		}
+	}
+
+	return aif_data;
+}
+
+// Reads an .aif file and produces a .pcm file containing an array of 8-bit samples.
+void aif2pcm(const char *aif_filename)
+{
+	// Get .pcm filename.
+	char pcm_filename[strlen(aif_filename)];
+	strcpy(pcm_filename, aif_filename);
+	change_file_extension(pcm_filename, "pcm");
+
+	// Open the given .aif file so we can read its contents.
+	FILE *aif_file;
+	aif_file = fopen(aif_filename, "rb");
+	if (!aif_file)
+	{
+		FATAL_ERROR("Failed to open '%s' for reading!\n", aif_filename);
+	}
+
+	// Get file length.
+	fseek(aif_file, 0, SEEK_END);
+	unsigned long aif_file_length = ftell(aif_file);
+	fseek(aif_file, 0, SEEK_SET);
+
+	// Create buffer for samples.
+	char *aif_file_data = (char *)malloc(aif_file_length * sizeof(char));
+	if (!aif_file_data)
+	{
+		FATAL_ERROR("Failed to allocate buffer for aif file data!\n");
+	}
+	
+	// Populate buffer from file.
+	unsigned long read = fread(aif_file_data, aif_file_length, 1, aif_file);
+	fclose(aif_file);
+	if (read <= 0)
+	{
+		FATAL_ERROR("Failed to read data from '%s'!\n", aif_filename);
+	}
+
+	AifData *aif_data = read_aif(aif_file_data, aif_file_length);
+
+	// Write the output .pcm file
+	FILE *pcm_file;
+	pcm_file = fopen(pcm_filename, "wb");
+	fwrite(aif_data->samples, aif_data->num_samples, 1, pcm_file);
+	fclose(pcm_file);
+
+	free(aif_data->samples);
+	free(aif_data);
+	free(aif_file_data);
+}
+
+// Reads a .pcm file containing an array of 8-bit samples and produces an .aif file.
+// See http://www-mmsp.ece.mcgill.ca/documents/audioformats/aiff/Docs/AIFF-1.3.pdf for .aif file specification.
+void pcm2aif(const char *pcm_filename, char base_note, long pitch_adjust, long loop_start)
+{
+	// Get .aif filename.
+	char aif_filename[strlen(pcm_filename)];
+	strcpy(aif_filename, pcm_filename);
+	change_file_extension(aif_filename, "aif");
+
+	// Open the given .pcm file so we can read its 8-bit samples.
+	FILE *pcm_file;
+	pcm_file = fopen(pcm_filename, "rb");
+	if (!pcm_file)
+	{
+		FATAL_ERROR("Failed to open '%s' for reading!\n", pcm_filename);
+	}
+
+	// Get file length.
+	fseek(pcm_file, 0, SEEK_END);
+	unsigned long num_samples = ftell(pcm_file);
+	fseek(pcm_file, 0, SEEK_SET);
+
+	unsigned long num_samples_extended = num_samples * 1;
+
+	// Create buffer for samples.
+	signed char *pcm_samples = (signed char *)malloc(num_samples_extended * sizeof(signed char));
+	if (!pcm_samples)
+	{
+		FATAL_ERROR("Failed to allocate buffer for pcm samples!\n");
+	}
+
+	// Populate buffer from file.
+	unsigned long read = fread(pcm_samples, num_samples, 1, pcm_file);
+	fclose(pcm_file);
+	if (read <= 0)
+	{
+		FATAL_ERROR("Failed to read data from '%s'!\n", pcm_filename);
+	}
+
+	// Allocate buffer for output .aif file.
+	unsigned long aif_file_size = 54 + 60 + num_samples_extended;
+	char *aif_buffer = (char *)malloc(aif_file_size * sizeof(char));
+	if (!aif_buffer)
+	{
+		FATAL_ERROR("Failed to allocate buffer for aif file!\n");
+	}
+
+	long pos = 0;
+
+	// First, write the FORM header chunk.
+	// FORM Chunk ckID
+	aif_buffer[pos++] = 'F';
+	aif_buffer[pos++] = 'O';
+	aif_buffer[pos++] = 'R';
+	aif_buffer[pos++] = 'M';
+
+	// FORM Chunk ckSize
+	unsigned long data_size = aif_file_size - 8;
+	aif_buffer[pos++] = ((data_size >> 24) & 0xFF);
+	aif_buffer[pos++] = ((data_size >> 16) & 0xFF);
+	aif_buffer[pos++] = ((data_size >>  8) & 0xFF);
+	aif_buffer[pos++] = (data_size & 0xFF);
+
+	// FORM Chunk formType
+	aif_buffer[pos++]  = 'A';
+	aif_buffer[pos++]  = 'I';
+	aif_buffer[pos++] = 'F';
+	aif_buffer[pos++] = 'F';
+
+	// Next, write the Common Chunk
+	// Common Chunk ckID
+	aif_buffer[pos++] = 'C';
+	aif_buffer[pos++] = 'O';
+	aif_buffer[pos++] = 'M';
+	aif_buffer[pos++] = 'M';
+
+	// Common Chunk ckSize
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 18;
+
+	// Common Chunk numChannels
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 1;  // 1 channel
+
+	// Common Chunk numSampleFrames
+	aif_buffer[pos++] = ((num_samples_extended >> 24) & 0xFF);
+	aif_buffer[pos++] = ((num_samples_extended >> 16) & 0xFF);
+	aif_buffer[pos++] = ((num_samples_extended >> 8)  & 0xFF);
+	aif_buffer[pos++] = (num_samples_extended & 0xFF);
+
+	// Common Chunk sampleSize
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 8;  // 8 bits per sample
+
+	// Common Chunk sampleRate
+	double sample_rate = pitch_adjust / 1024.0;
+	unsigned char sample_rate_buffer[10];
+	ieee754_write_extended(sample_rate, sample_rate_buffer);
+	for (int i = 0; i < 10; i++)
+	{
+		aif_buffer[pos++] = sample_rate_buffer[i];
+	}
+
+	// Marker Chunk ckID
+	aif_buffer[pos++] = 'M';
+	aif_buffer[pos++] = 'A';
+	aif_buffer[pos++] = 'R';
+	aif_buffer[pos++] = 'K';
+
+	// Marker Chunk ckSize
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 24;
+
+	// Marker Chunk numMarkers
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 2;
+
+	// Marker loop start
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 1;  // id = 1
+
+	aif_buffer[pos++] = ((loop_start >> 24) & 0xFF);
+	aif_buffer[pos++] = ((loop_start >> 16) & 0xFF);
+	aif_buffer[pos++] = ((loop_start >> 8)  & 0xFF);
+	aif_buffer[pos++] = (loop_start & 0xFF);  // position
+
+	aif_buffer[pos++] = 5;  // pascal-style string length
+	aif_buffer[pos++] = 'S';
+	aif_buffer[pos++] = 'T';
+	aif_buffer[pos++] = 'A';
+	aif_buffer[pos++] = 'R';
+	aif_buffer[pos++] = 'T';  // markerName
+
+	// Marker loop end
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 2;  // id = 2
+
+	long loop_end = num_samples;
+	aif_buffer[pos++] = ((loop_end >> 24) & 0xFF);
+	aif_buffer[pos++] = ((loop_end >> 16) & 0xFF);
+	aif_buffer[pos++] = ((loop_end >> 8)  & 0xFF);
+	aif_buffer[pos++] = (loop_end & 0xFF);  // position
+
+	aif_buffer[pos++] = 3;  // pascal-style string length
+	aif_buffer[pos++] = 'E';
+	aif_buffer[pos++] = 'N';
+	aif_buffer[pos++] = 'D';
+
+
+	// Instrument Chunk ckID
+	aif_buffer[pos++] = 'I';
+	aif_buffer[pos++] = 'N';
+	aif_buffer[pos++] = 'S';
+	aif_buffer[pos++] = 'T';
+
+	// Instrument Chunk ckSize
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 20;
+
+	aif_buffer[pos++] = base_note;  // baseNote
+	aif_buffer[pos++] = 0;          // detune
+	aif_buffer[pos++] = 0;          // lowNote
+	aif_buffer[pos++] = 127;        // highNote
+	aif_buffer[pos++] = 1;          // lowVelocity
+	aif_buffer[pos++] = 127;        // highVelocity
+	aif_buffer[pos++] = 0;          // gain (hi)
+	aif_buffer[pos++] = 0;          // gain (lo)
+
+	// Instrument Chunk sustainLoop
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 1; // playMode = ForwardLooping
+
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 1;  // beginLoop marker id
+
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 2;  // endLoop marker id
+
+		// Instrument Chunk releaseLoop
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 1; // playMode = ForwardLooping
+
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 1;  // beginLoop marker id
+
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 2;  // endLoop marker id
+
+	// Finally, write the Sound Data Chunk
+	// Sound Data Chunk ckID
+	aif_buffer[pos++] = 'S';
+	aif_buffer[pos++] = 'S';
+	aif_buffer[pos++] = 'N';
+	aif_buffer[pos++] = 'D';
+
+	// Sound Data Chunk ckSize
+	unsigned long sound_data_size = num_samples_extended + 8;
+	aif_buffer[pos++] = ((sound_data_size >> 24) & 0xFF);
+	aif_buffer[pos++] = ((sound_data_size >> 16) & 0xFF);
+	aif_buffer[pos++] = ((sound_data_size >> 8)  & 0xFF);
+	aif_buffer[pos++] = (sound_data_size & 0xFF);
+
+	// Sound Data Chunk offset
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 0;
+
+	// Sound Data Chunk blockSize
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 0;
+	aif_buffer[pos++] = 0;
+
+	// Sound Data Chunk soundData
+	for (unsigned int i = 0; i < loop_start; i++)
+	{
+		aif_buffer[pos++] = pcm_samples[i];
+	}
+
+	int j = 0;
+	for (unsigned int i = loop_start; i < num_samples_extended; i++)
+	{
+		int pcm_index = loop_start + (j++ % (num_samples - loop_start - 1));
+		aif_buffer[pos++] = pcm_samples[pcm_index];
+	}
+
+	// Write the .aif file contents.
+	FILE *aif_file;
+	aif_file = fopen(aif_filename, "wb");
+	if (!aif_file)
+	{
+		FATAL_ERROR("Failed to open '%s' for writing!\n", aif_filename);
+	}
+
+	fwrite(aif_buffer, 1, aif_file_size, aif_file);
+	fclose(aif_file);
+
+	free(aif_buffer);
+	free(pcm_samples);
+
+	printf("Wrote %s\n", aif_filename);
+}
+
+int main(int argc, char **argv)
+{
+	if (argc < 2)
+	{
+    	FATAL_ERROR("Usage: aif2pcm <aif_file>\n");
+	}
+
+	char *input_filename = argv[1];
+	char *extension = get_file_extension(input_filename);
+	
+	if (strcmp(extension, "aif") == 0)
+	{
+		aif2pcm(input_filename);
+	}
+	else if (strcmp(extension, "pcm") == 0)
+	{
+		if (argc < 5)
+		{
+			FATAL_ERROR("Usage: aif2pcm <pcm_file> <midi_note> <pitch_adjust> <loop_start>\n");
+		}
+
+		char base_note = atoi(argv[2]);
+		long pitch_adjust = atol(argv[3]);
+		long loop_start = atol(argv[4]);
+		pcm2aif(input_filename, base_note, pitch_adjust, loop_start);
+	}
+	else
+	{
+		FATAL_ERROR("Input file must be .aif or .pcm: '%s'\n", input_filename);
+	}
+
+   	return 0;
+}