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/*
* Definitions for working with H.222 Transport Stream packets
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1
*
* 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 the MPEG TS, PS and ES tools.
*
* The Initial Developer of the Original Code is Amino Communications Ltd.
* Portions created by the Initial Developer are Copyright (C) 2008
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Amino Communications Ltd, Swavesey, Cambridge UK
*
* ***** END LICENSE BLOCK *****
*/
#ifndef _ts_defns
#define _ts_defns
// Transport Stream packets are always the same size
#define TS_PACKET_SIZE 188
// When we are putting data into a TS packet, we need the first four
// bytes for heading information, which means that we will have at most
// 184 bytes for our payload
#define MAX_TS_PAYLOAD_SIZE (TS_PACKET_SIZE-4)
// ------------------------------------------------------------
// The number of TS packets to read ahead
#define TS_READ_AHEAD_COUNT 1024 // aim for multiple of block boundary -- used to be 50
// Thus the number of bytes to read ahead
#define TS_READ_AHEAD_BYTES TS_READ_AHEAD_COUNT*TS_PACKET_SIZE
// A read-ahead buffer for reading TS packets.
//
// Note that `posn` always gives the file position of the *next* TS packet to
// be read from the file (so after reading a TS packet with
// `read_next_TS_packet`, the position of said packet is `posn`-TS_PACKET_SIZE)
struct _ts_reader
{
int file; // the file to read from
offset_t posn; // the position of the next-to-be-read TS packet
void *handle; // handle to pass to read_fn and seek_fn.
// Reader and seek functions. If these are non-NULL we call them
// when we would call read() or seek().
int (*read_fn)(void *, byte *, size_t);
int (*seek_fn)(void *, offset_t);
byte read_ahead[TS_READ_AHEAD_COUNT*TS_PACKET_SIZE];
byte *read_ahead_ptr; // location of next packet in said array
byte *read_ahead_end; // pointer just after the end of `read_ahead`
};
typedef struct _ts_reader *TS_reader_p;
#define SIZEOF_TS_READER sizeof(struct _ts_reader)
#endif // _ts_defns
// Local Variables:
// tab-width: 8
// indent-tabs-mode: nil
// c-basic-offset: 2
// End:
// vim: set tabstop=8 shiftwidth=2 expandtab:
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