Initial community commit

Src/replicant/nsid3v2/util.cpp

@@ -0,0 +1,161 @@
+#include "util.h"
+
+uint32_t ID3v2::Util::Int28To32(uint32_t val)
+{
+	// TODO: big endian safe?
+	uint32_t ret;
+
+	ret = (val & 0x7FU);
+	val >>= 1;
+	ret |= (val & 0x3F80U);
+	val >>= 1;
+	ret |= (val & 0x1FC000U);
+	val >>= 1;
+	ret |= (val & 0xFE00000U);
+	
+	return ret;
+	/*
+	uint8_t *bytes = (uint8_t *)&ret;
+	const uint8_t *value = (const uint8_t *)&val;
+
+	ret = (value[0] << 21) + (value[1] << 14) + (value[2] << 7) + (value[3]);
+	
+	//	for (size_t i=0;i<sizeof(uint32_t);i++ )
+	//		value[sizeof(uint32_t)-1-i]=(uint8_t)(val>>(i*8)) & 0xFF;
+
+	return ret;
+	*/
+}
+
+uint32_t ID3v2::Util::Int32To28(uint32_t val)
+{
+	// TODO: big endian safe?
+	uint32_t ret;
+	ret = (val & 0x7FU);
+	ret |= (val & 0x3F80U) << 1;
+	ret |= (val & 0x1FC000U) << 2;
+	ret |= (val & 0xFE00000U) << 3;
+	
+	return ret;
+}
+
+size_t ID3v2::Util::UnsynchroniseTo(void *_output, const void *_input, size_t bytes)
+{
+	uint8_t *output = (uint8_t *)_output;
+	const uint8_t *input = (const uint8_t *)_input;
+	size_t bytes_read = 0;
+	while (bytes)
+	{
+		if (input[0] == 0xFF && input[1] == 0)
+		{
+			*output++ = 0xFF;
+			input+=2;
+			bytes_read+=2;
+			bytes--;
+		}
+		else
+		{
+			*output++=*input++;
+			bytes_read++;
+			bytes--;
+		}
+	}
+	return bytes_read;
+}
+
+size_t ID3v2::Util::UnsynchronisedInputSize(const void *data, size_t output_bytes)
+{
+	const uint8_t *input = (const uint8_t *)data;
+	size_t bytes_read = 0;
+	while (output_bytes)
+	{
+		if (input[0] == 0xFF && input[1] == 0)
+		{
+			input+=2;
+			bytes_read+=2;
+			output_bytes--;
+		}
+		else
+		{
+			input++;
+			bytes_read++;
+			output_bytes--;
+		}
+	}
+	return bytes_read;
+}
+
+size_t ID3v2::Util::UnsynchronisedOutputSize(const void *data, size_t input_bytes)
+{
+		const uint8_t *input = (const uint8_t *)data;
+	size_t bytes_written = 0;
+	while (input_bytes)
+	{
+		if (input[0] == 0xFF && input_bytes > 1 && input[1] == 0)
+		{
+			input+=2;
+			bytes_written++;
+			input_bytes-=2;
+		}
+		else
+		{
+			input++;
+			bytes_written++;
+			input_bytes--;
+		}
+	}
+	return bytes_written;
+}
+
+// returns output bytes used
+size_t ID3v2::Util::SynchroniseTo(void *_output, const void *data, size_t bytes)
+{
+	uint8_t *output = (uint8_t *)_output;
+	const uint8_t *input = (const uint8_t *)data;
+	size_t bytes_needed = 0;
+	while (bytes)
+	{
+		*output++=*input;
+		bytes_needed++;
+		if (*input++ == 0xFF)
+		{
+			if (bytes == 1)
+			{
+				// if this is the last byte, we need to make room for an extra 0
+				*output = 0;
+				return bytes_needed + 1;
+			}
+			else if ((*input & 0xE0) == 0xE0 || *input == 0)
+			{
+				*output++ = 0;
+				bytes_needed++;
+			}
+		}
+		bytes--;
+	}
+	return bytes_needed;
+}
+
+size_t ID3v2::Util::SynchronisedSize(const void *data, size_t bytes)
+{
+	const uint8_t *input = (const uint8_t *)data;
+	size_t bytes_needed = 0;
+	while (bytes)
+	{
+		bytes_needed++;
+		if (*input++ == 0xFF)
+		{
+			if (bytes == 1)
+			{
+				// if this is the last byte, we need to make room for an extra 0
+				return bytes_needed + 1;
+			}
+			else if ((*input & 0xE0) == 0xE0 || *input == 0)
+			{
+				bytes_needed++;
+			}
+		}
+		bytes--;
+	}
+	return bytes_needed;
+}