winamp/Src/replicant/nsid3v2/util.cpp
2024-09-24 14:54:57 +02:00

162 lines
3.0 KiB
C++

#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;
}