virtual_io.cpp

完整的RTP RTSP代码库

/*
 * The contents of this file are subject to the Mozilla Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/MPL/
 * 
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 * 
 * The Original Code is MPEG4IP.
 * 
 * The Initial Developer of the Original Code is Cisco Systems Inc.
 * Portions created by Cisco Systems Inc. are
 * Copyright (C) Cisco Systems Inc. 2001 - 2005.  All Rights Reserved.
 * 
 * Contributor(s): 
 *		Ben Allison			benski at nullsoft.com
 *
 * Virtual I/O support, for file support other than fopen/fread/fwrite
 */

#include "mp4common.h"
#include "virtual_io.h"

/* --------- Virtual IO for FILE * --------- */

u_int64_t FILE_GetFileLength(void *user)
{
	FILE *fp = (FILE *)user;
	struct stat s;
	if (fstat(fileno(fp), &s) < 0) { 
		throw new MP4Error(errno, "stat failed", "MP4Open");
	}
	return s.st_size;
}

int FILE_SetPosition(void *user, u_int64_t position)
{
	FILE *fp = (FILE *)user;
	fpos_t fpos;
	VAR_TO_FPOS(fpos, position);
	return fsetpos(fp, &fpos);
}

int FILE_GetPosition(void *user, u_int64_t *position)
{
	FILE *fp = (FILE *)user;
	fpos_t fpos;
	if (fgetpos(fp, &fpos) < 0) { 
		throw new MP4Error(errno, "MP4GetPosition");
	}
	
	FPOS_TO_VAR(fpos, u_int64_t, *position);
	return 0;
}

size_t FILE_Read(void *user, void *buffer, size_t size)
{
	FILE *fp = (FILE *)user;
	return fread(buffer, 1, size, fp);
}

size_t FILE_Write(void *user, void *buffer, size_t size)
{
	FILE *fp = (FILE *)user;
	return fwrite(buffer, 1, size, fp); 
}

int FILE_EndOfFile(void *user)
{
	FILE *fp = (FILE *)user;
	return feof(fp);
}

int FILE_Close(void *user)
{
	FILE *fp = (FILE *)user;
	return fclose(fp);
}

Virtual_IO FILE_virtual_IO =
{
	FILE_GetFileLength,
		FILE_SetPosition,
		FILE_GetPosition,
		FILE_Read,
		FILE_Write,
		FILE_EndOfFile,
		FILE_Close,
};