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Merge pull request #1475 from 1div0/BMFF

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Base Media File Format
This commit is contained in:
Robin Mills
2021-03-10 10:34:21 +00:00
committed by GitHub
parent 301f3c51ba 19aab434a5
commit 9e2ac47cf9
45 changed files with 2271 additions and 165 deletions
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src/futils.cpp
+64 -104
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@@ -139,123 +139,83 @@ namespace Exiv2 {
delete [] decodeStr;
}
// https://stackoverflow.com/questions/342409/how-do-i-base64-encode-decode-in-c
static char base64_encode[]={'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z', '0', '1', '2', '3',
'4', '5', '6', '7', '8', '9', '+', '/'};
int base64encode(const void* data_buf, size_t dataLength, char* result, size_t resultSize) {
const char base64chars[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
const uint8_t* data = (const uint8_t*)data_buf;
size_t resultIndex = 0;
size_t x;
uint32_t n = 0;
size_t padCount = dataLength % 3;
uint8_t n0, n1, n2, n3;
char* encoding_table = (char*)base64_encode;
size_t mod_table[] = {0, 2, 1};
/* increment over the length of the string, three characters at a time */
for (x = 0; x < dataLength; x += 3)
{
/* these three 8-bit (ASCII) characters become one 24-bit number */
n = data[x] << 16;
size_t output_length = 4 * ((dataLength + 2) / 3);
int rc = result && data_buf && output_length < resultSize ? 1 : 0;
if ( rc ) {
const unsigned char* data = (const unsigned char*) data_buf ;
for (size_t i = 0, j = 0 ; i < dataLength;) {
if((x+1) < dataLength)
n += data[x+1] << 8;
uint32_t octet_a = i < dataLength ? data[i++] : 0 ;
uint32_t octet_b = i < dataLength ? data[i++] : 0 ;
uint32_t octet_c = i < dataLength ? data[i++] : 0 ;
if((x+2) < dataLength)
n += data[x+2];
uint32_t triple = (octet_a << 0x10) + (octet_b << 0x08) + octet_c;
/* this 24-bit number gets separated into four 6-bit numbers */
n0 = (uint8_t)(n >> 18) & 63;
n1 = (uint8_t)(n >> 12) & 63;
n2 = (uint8_t)(n >> 6) & 63;
n3 = (uint8_t)n & 63;
/*
* if we have one byte available, then its encoding is spread
* out over two characters
*/
if(resultIndex >= resultSize) return 0; /* indicate failure: buffer too small */
result[resultIndex++] = base64chars[n0];
if(resultIndex >= resultSize) return 0; /* indicate failure: buffer too small */
result[resultIndex++] = base64chars[n1];
/*
* if we have only two bytes available, then their encoding is
* spread out over three chars
*/
if((x+1) < dataLength)
{
if(resultIndex >= resultSize) return 0; /* indicate failure: buffer too small */
result[resultIndex++] = base64chars[n2];
result[j++] = encoding_table[(triple >> 3 * 6) & 0x3F];
result[j++] = encoding_table[(triple >> 2 * 6) & 0x3F];
result[j++] = encoding_table[(triple >> 1 * 6) & 0x3F];
result[j++] = encoding_table[(triple >> 0 * 6) & 0x3F];
}
/*
* if we have all three bytes available, then their encoding is spread
* out over four characters
*/
if((x+2) < dataLength)
{
if(resultIndex >= resultSize) return 0; /* indicate failure: buffer too small */
result[resultIndex++] = base64chars[n3];
}
for (size_t i = 0; i < mod_table[dataLength % 3]; i++)
result[output_length - 1 - i] = '=';
result[output_length]=0;
}
/*
* create and add padding that is required if we did not have a multiple of 3
* number of characters available
*/
if (padCount > 0)
{
for (; padCount < 3; padCount++)
{
if(resultIndex >= resultSize) return 0; /* indicate failure: buffer too small */
result[resultIndex++] = '=';
}
}
if(resultIndex >= resultSize) return 0; /* indicate failure: buffer too small */
result[resultIndex] = 0;
return 1; /* indicate success */
return rc;
} // base64encode
long base64decode(const char *in, char *out, size_t out_size) {
static const char decode[] = "|$$$}rstuvwxyz{$$$$$$$>?@ABCDEFGHIJKLMNOPQRSTUVW"
"$$$$$$XYZ[\\]^_`abcdefghijklmnopq";
long len;
long i;
long done = 0;
unsigned char v;
unsigned char quad[4];
long base64decode(const char* in,char* out,size_t out_size) {
long result = 0;
size_t input_length = in ? ::strlen(in) : 0;
if (!in || input_length % 4 != 0) return result;
while (*in) {
len = 0;
for (i = 0; i < 4 && *in; i++) {
v = 0;
while (*in && !v) {
v = *in++;
v = (v < 43 || v > 122) ? 0 : decode[v - 43];
if (v)
v = (v == '$') ? 0 : v - 61;
if (*in) {
len++;
if (v)
quad[i] = v - 1;
} else
quad[i] = 0;
}
unsigned char* encoding_table = (unsigned char*)base64_encode;
unsigned char decoding_table[256];
for (unsigned char i = 0; i < 64; i++)
decoding_table[encoding_table[i]] = i;
size_t output_length = input_length / 4 * 3;
const unsigned char* buff = (const unsigned char*) in;
if (buff[input_length - 1] == '=') (output_length)--;
if (buff[input_length - 2] == '=') (output_length)--;
if ( output_length+1 < out_size ) {
for (size_t i = 0, j = 0; i < input_length;) {
uint32_t sextet_a = buff[i] == '=' ? 0 & i++ : decoding_table[buff[i++]];
uint32_t sextet_b = buff[i] == '=' ? 0 & i++ : decoding_table[buff[i++]];
uint32_t sextet_c = buff[i] == '=' ? 0 & i++ : decoding_table[buff[i++]];
uint32_t sextet_d = buff[i] == '=' ? 0 & i++ : decoding_table[buff[i++]];
uint32_t triple = (sextet_a << 3 * 6)
+ (sextet_b << 2 * 6)
+ (sextet_c << 1 * 6)
+ (sextet_d << 0 * 6);
if (j < output_length) out[j++] = (triple >> 2 * 8) & 0xFF;
if (j < output_length) out[j++] = (triple >> 1 * 8) & 0xFF;
if (j < output_length) out[j++] = (triple >> 0 * 8) & 0xFF;
}
if (!len)
continue;
if (out_size < (size_t) (done + len - 1))
/* out buffer is too small */
return -1;
if (len >= 2)
*out++ = quad[0] << 2 | quad[1] >> 4;
if (len >= 3)
*out++ = quad[1] << 4 | quad[2] >> 2;
if (len >= 4)
*out++ = ((quad[2] << 6) & 0xc0) | quad[3];
done += len - 1;
out[output_length]=0;
result = (long) output_length;
}
if ((size_t)(done + 1) >= out_size)
return -1;
*out++ = '\0';
return done;
return result;
} // base64decode
Protocol fileProtocol(const std::string& path) {