stss.c

MPEG-4编解码的实现(包括MPEG4视音频编解码)

#include "quicktime.h"


int quicktime_stss_init(quicktime_stss_t *stss)
{
	stss->version = 0;
	stss->flags = 0;
	stss->total_entries = 0;
	stss->entries_allocated = 0;
}

int quicktime_stss_init_common(quicktime_t *file, quicktime_stss_t *stss)
{
	if (stss->entries_allocated == 0) {
		stss->entries_allocated = 100;
		stss->table = (quicktime_stss_table_t*)
			malloc(sizeof(quicktime_stss_table_t) * stss->entries_allocated);
	}
}

int quicktime_stss_delete(quicktime_stss_t *stss)
{
	if(stss->total_entries) 
		free(stss->table);
	stss->total_entries = 0;
}

int quicktime_stss_dump(quicktime_stss_t *stss)
{
	int i;
	printf("     sync sample\n");
	printf("      version %d\n", stss->version);
	printf("      flags %d\n", stss->flags);
	printf("      total_entries %d\n", stss->total_entries);
	for(i = 0; i < stss->total_entries; i++)
	{
		printf("       sample %u\n", stss->table[i].sample);
	}
}

int quicktime_read_stss(quicktime_t *file, quicktime_stss_t *stss)
{
	int i;
	stss->version = quicktime_read_char(file);
	stss->flags = quicktime_read_int24(file);
	stss->total_entries = quicktime_read_int32(file);
	
	stss->table = (quicktime_stss_table_t*)malloc(sizeof(quicktime_stss_table_t) * stss->total_entries);
	for(i = 0; i < stss->total_entries; i++)
	{
		stss->table[i].sample = quicktime_read_int32(file);
	}
}


int quicktime_write_stss(quicktime_t *file, quicktime_stss_t *stss)
{
	int i;
	quicktime_atom_t atom;

	if(stss->total_entries)
	{
		quicktime_atom_write_header(file, &atom, "stss");

		quicktime_write_char(file, stss->version);
		quicktime_write_int24(file, stss->flags);
		quicktime_write_int32(file, stss->total_entries);
		for(i = 0; i < stss->total_entries; i++)
		{
			quicktime_write_int32(file, stss->table[i].sample);
		}

		quicktime_atom_write_footer(file, &atom);
	}
}

int quicktime_update_stss(quicktime_stss_t *stss, long sample)
{
	if (stss->total_entries >= stss->entries_allocated) {
		stss->entries_allocated *= 2;
		stss->table = (quicktime_stss_table_t*)realloc(stss->table,
			sizeof(quicktime_stss_table_t) * stss->entries_allocated);
	}
	
	stss->table[stss->total_entries++].sample = sample;
}