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