stco.c

这个库实现了录象功能

/*******************************************************************************
 stco.c

 libquicktime - A library for reading and writing quicktime/avi/mp4 files.
 http://libquicktime.sourceforge.net

 Copyright (C) 2002 Heroine Virtual Ltd.
 Copyright (C) 2002-2007 Members of the libquicktime project.

 This library is free software; you can redistribute it and/or modify it under
 the terms of the GNU Lesser General Public License as published by the Free
 Software Foundation; either version 2.1 of the License, or (at your option)
 any later version.

 This library is distributed in the hope that it will be useful, but WITHOUT
 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 details.

 You should have received a copy of the GNU Lesser General Public License along
 with this library; if not, write to the Free Software Foundation, Inc., 51
 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*******************************************************************************/ 

#include "lqt_private.h"
#include <stdlib.h>

#define LOG_DOMAIN "stco"

void quicktime_stco_init(quicktime_stco_t *stco)
{
	stco->version = 0;
	stco->flags = 0;
	stco->total_entries = 0;
	stco->entries_allocated = 0;
}

void quicktime_stco_delete(quicktime_stco_t *stco)
{
	if(stco->total_entries) free(stco->table);
	stco->total_entries = 0;
	stco->entries_allocated = 0;
}

void quicktime_stco_init_common(quicktime_t *file, quicktime_stco_t *stco)
{
	if(!stco->entries_allocated)
	{
		stco->entries_allocated = 2048;
		stco->total_entries = 0;
		stco->table = (quicktime_stco_table_t*)malloc(sizeof(quicktime_stco_table_t) * stco->entries_allocated);
	}
}

void quicktime_stco_dump(quicktime_stco_t *stco)
{
	int i;
        if(stco->co64)
          lqt_dump("     chunk offset (co64)\n");
        else
          lqt_dump("     chunk offset (stco)\n");
        lqt_dump("      version %d\n", stco->version);
	lqt_dump("      flags %ld\n", stco->flags);
	lqt_dump("      total_entries %ld\n", stco->total_entries);
	for(i = 0; i < stco->total_entries; i++)
	{
		lqt_dump("       offset %d %"PRId64" (%"PRIx64")\n",
                         i, stco->table[i].offset,
                         stco->table[i].offset);
	}
}

void quicktime_read_stco(quicktime_t *file, quicktime_stco_t *stco)
{
	int i;
	stco->version = quicktime_read_char(file);
	stco->flags = quicktime_read_int24(file);
	stco->total_entries = quicktime_read_int32(file);
	stco->entries_allocated = stco->total_entries;
	stco->table = (quicktime_stco_table_t*)calloc(1, sizeof(quicktime_stco_table_t) * stco->entries_allocated);
	for(i = 0; i < stco->total_entries; i++)
	{
		stco->table[i].offset = quicktime_read_uint32(file);
	}
}

void quicktime_read_stco64(quicktime_t *file, quicktime_stco_t *stco)
{
	int i;
	stco->version = quicktime_read_char(file);
	stco->flags = quicktime_read_int24(file);
	stco->total_entries = quicktime_read_int32(file);
	stco->entries_allocated = stco->total_entries;
	stco->table = (quicktime_stco_table_t*)calloc(1, sizeof(quicktime_stco_table_t) * stco->entries_allocated);
	for(i = 0; i < stco->total_entries; i++)
	{
		stco->table[i].offset = quicktime_read_int64(file);
	}
        stco->co64 = 1;
}

void quicktime_write_stco(quicktime_t *file, quicktime_stco_t *stco)
{
	int i;
	quicktime_atom_t atom;

        if(stco->co64)
          quicktime_atom_write_header(file, &atom, "co64");
        else
          quicktime_atom_write_header(file, &atom, "stco");
        
	quicktime_write_char(file, stco->version);
	quicktime_write_int24(file, stco->flags);
	quicktime_write_int32(file, stco->total_entries);

        if(stco->co64)
          {
          for(i = 0; i < stco->total_entries; i++)
            quicktime_write_int64(file, stco->table[i].offset);
          }
        else
          {
          for(i = 0; i < stco->total_entries; i++)
            quicktime_write_int32(file, stco->table[i].offset);
          }
	quicktime_atom_write_footer(file, &atom);
}

// Chunk starts at 1
void quicktime_update_stco(quicktime_stco_t *stco, long chunk, int64_t offset)
{
        if(chunk <= 0)
          lqt_log(NULL, LQT_LOG_ERROR, LOG_DOMAIN,
                  "quicktime_update_stco chunk must start at 1. chunk=%ld\n",
                  chunk);
        
	if(chunk > stco->entries_allocated)
	{
		stco->entries_allocated = chunk * 2;
		stco->table = (quicktime_stco_table_t*)realloc(stco->table, sizeof(quicktime_stco_table_t) * stco->entries_allocated);
	}
	
	stco->table[chunk - 1].offset = offset;
	if(chunk > stco->total_entries) stco->total_entries = chunk;
        if(offset >= 0x100000000LL)
          stco->co64 = 1;
}