libreal.h

realmedia解压源码

/*****************************************************************************
 * libreal  -  A library for writing and extracting data streams to and from *
 *             RealMedia files.                                              *
 * Copyright (C) 2001 Leo Howell                                             *
 *                                                                           *
 * This program is free software; you can redistribute it and/or modify      *
 * it under the terms of the GNU General Public License as published by      *
 * the Free Software Foundation; either version 2 of the License, or         *
 * (at your option) and later version.                                       *
 *                                                                           *
 * This program 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 General Public License for more details.                              *
 *                                                                           *
 * You should have received a copy of the GNU General Public License         *
 * along with this program; if not, write to the Free Software               *
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston MA  02111-1307  USA  *
 *                                                                           *
 * You can contact me by email, [e-mail]             *
 *****************************************************************************/

#ifndef _LIBRM_H
#define _LIBRM_H

#include <stdint.h> /* for uint32_t etc */

#define MAKE_FOURCC(a, b, c, d) \
         (((uint32_t)(a)) << 24 \
        | ((uint32_t)(b)) << 16 \
        | ((uint32_t)(c)) << 8  \
        | ((uint32_t)(d)))

#define FILE_HEADER_ID      MAKE_FOURCC('.','R','M','F')
#define PROPERTIES_ID       MAKE_FOURCC('P','R','O','P')
#define MEDIA_PROPERTIES_ID MAKE_FOURCC('M','D','P','R')
#define CONTENT_HEADER_ID   MAKE_FOURCC('C','O','N','T')
#define DATA_HEADER_ID      MAKE_FOURCC('D','A','T','A')
#define INDEX_HEADER_ID     MAKE_FOURCC('I','N','D','X')

#define PN_SAVE_ENABLED         0x0001
#define PN_PERFECT_PLAY_ENABLED 0x0002
#define PN_LIVE_BROADCAST       0x0004

#define PN_RELIABLE_FLAG 0x0001
#define PN_KEYFRAME_FLAG 0x0002

typedef struct {
	uint32_t object_id;
	uint32_t size;
	uint16_t object_version;
} RM_Tagged_Chunk_Header;

typedef struct {
	uint32_t file_version;
	uint32_t num_headers;
} RM_File_Header;

typedef struct {
	uint32_t max_bit_rate;
	uint32_t avg_bit_rate;
	uint32_t max_packet_size;
	uint32_t avg_packet_size;
	uint32_t num_packets;
	uint32_t duration;
	uint32_t preroll;
	uint32_t index_offset;
	uint32_t data_offset;
	uint16_t num_streams;
	uint16_t flags;
} RM_Properties;

typedef struct {
	uint16_t stream_number;
	uint32_t max_bit_rate;
	uint32_t avg_bit_rate;
	uint32_t max_packet_size;
	uint32_t avg_packet_size;
	uint32_t start_time;
	uint32_t preroll;
	uint32_t duration;
	uint8_t  stream_name_size;
	uint8_t *stream_name;
	uint8_t  mime_type_size;
	uint8_t *mime_type;
	uint32_t type_specific_len;
	uint8_t *type_specific_data;
} RM_Media_Properties;

typedef struct {
	uint16_t title_len;
	uint8_t *title;
	uint16_t author_len;
	uint8_t *author;
	uint16_t copyright_len;
	uint8_t *copyright;
	uint16_t comment_len;
	uint8_t *comment;
} RM_Content_Description;

typedef struct {
	uint32_t num_packets;
	uint32_t next_data_header;
} RM_Data_Chunk_Header;

/* NOTE:
 *  This is the complete Media Packet Header,
 * ie, it does *not* include object_id or size.
 *
 * Also note, the "length" in this structure will be
 * adjusted on read to be the length of the data *ONLY*.
 */
typedef struct {
	uint16_t object_version;
	uint16_t length;
	uint16_t stream_number;
	uint32_t timestamp;
	uint8_t  reserved;
	uint8_t  flags;
	uint8_t *data;
} RM_Media_Packet_Header;

typedef struct {
	uint32_t num_indices;
	uint16_t stream_number;
	uint32_t next_index_header;
} RM_Index_Chunk_Header;

/* NOTE:
 *  Again, this is a complete sub-chunk.
 */
typedef struct {
	uint16_t object_version;
	uint32_t timestamp;
	uint32_t offset;
	uint32_t packet_count_for_this_packet;
} RM_Index_Record;

typedef struct {
	RM_Tagged_Chunk_Header header;
	union {
		RM_File_Header file_header;
		RM_Properties properties;
		RM_Media_Properties media_properties;
		RM_Content_Description content_description;
		RM_Data_Chunk_Header data_chunk_header;
		RM_Index_Chunk_Header index_chunk_header;
	} data;
} RM_Chunk;

/* Function declarations */
int rm_read_chunk(int fd, RM_Chunk *);

int rm_read_tagged_chunk_header(int fd, RM_Tagged_Chunk_Header *);
int rm_read_file_header(int fd, RM_File_Header *);
int rm_read_properties(int fd, RM_Properties *);
int rm_read_media_properties(int fd, RM_Media_Properties *);
int rm_read_content_description(int fd, RM_Content_Description *);
int rm_read_data_chunk_header(int fd, RM_Data_Chunk_Header *);
int rm_read_media_packet_header(int fd, RM_Media_Packet_Header *);
int rm_read_index_chunk_header(int fd, RM_Index_Chunk_Header *);
int rm_read_index_record(int fd, RM_Index_Record *);

int rm_write_chunk(int fd, const RM_Chunk *);

int rm_write_tagged_chunk_header(int fd, const RM_Tagged_Chunk_Header *);
int rm_write_file_header(int fd, const RM_File_Header *);
int rm_write_properties(int fd, const RM_Properties *);
int rm_write_media_properties(int fd, const RM_Media_Properties *);
int rm_write_content_description(int fd, const RM_Content_Description *);
int rm_write_data_chunk_header(int fd, const RM_Data_Chunk_Header *);
int rm_write_media_packet_header(int fd, const RM_Media_Packet_Header *);
int rm_write_index_chunk_header(int fd, const RM_Index_Chunk_Header *);
int rm_write_index_record(int fd, const RM_Index_Record *);

#endif