/*C

(c) 2005 bl0rg.net

**/

#include "conf.h"

#include <assert.h>

#include <stdlib.h>

#include "buf.h"

#include "ogg.h"

#include "crc32.h"

#include "pack.h"

crc32_t ogg_crc32;

void ogg_init(void) {

crc32_init(&ogg_crc32, OGG_CRC32_POLY, 0, 0);

}

void ogg_page_init(ogg_page_t *page) {

assert(page != NULL);

page->raw.size = 0;

page->raw.data = NULL;

page->page_segments = 0;

page->page_no = 0;

page->stream = 0;

page->page_cksum = 0;

buf_alloc(&page->raw, 4000);

assert(page->raw.data != NULL);

page->size = 0;

}

void ogg_page_destroy(ogg_page_t *page) {

assert(page != NULL);

buf_free(&page->raw);

}

/* XXX make pointer array? */

unsigned char *ogg_segment(ogg_page_t *page, int num) {

assert(page != NULL);

if (num > page->page_segments)

return NULL;

unsigned char *res = page->raw.data +

OGG_HDR_MIN_SIZE + page->page_segments;

int i;

for (i = 0; i < num; i++)

res += page->lacing_values[i];

return res;

}

/*M

\emph{Converts a sample position in an OGG page to a number in

msecs.}

**/

unsigned long ogg_position_to_msecs(ogg_page_t *page,

unsigned long sample_rate) {

assert(page != NULL);

unsigned char *ptr = page->position;

unsigned long position[2];

position[0] = LE_UINT32_UNPACK(ptr);

position[1] = LE_UINT32_UNPACK(ptr);

double dmsecs = (position[0] + position[1] * 2147483648.0) /

(sample_rate / 1000.0);

return (unsigned long)dmsecs;

}

/*C

**/