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Diffstat (limited to 'lib/libucsi/section_buf.h')
-rw-r--r-- | lib/libucsi/section_buf.h | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/lib/libucsi/section_buf.h b/lib/libucsi/section_buf.h new file mode 100644 index 0000000..52d2f84 --- /dev/null +++ b/lib/libucsi/section_buf.h @@ -0,0 +1,124 @@ +/* + * section and descriptor parser + * + * Copyright (C) 2005 Andrew de Quincey (adq_dvb@lidskialf.net) + * + * 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 + */ + +#ifndef _UCSI_SECTION_BUF_H +#define _UCSI_SECTION_BUF_H 1 + +#ifdef __cplusplus +extern "C" +{ +#endif + +#include <stdint.h> + +#define DVB_MAX_SECTION_BYTES 4096 + +/** + * Buffer used to keep track of section fragments. You should allocate an + * area of memory of size (sizeof(section_buf) + <maxsectionsize>), and pass that area + * to section_buf_init() to set it up. + */ +struct section_buf { + uint32_t max; /* maximum size of section - setup by section_buf_init() */ + uint32_t count; /* number of bytes currently accumulated */ + uint32_t len; /* total number of bytes expected in the complete section */ + uint8_t header:1; /* flag indicating the section header has been commpletely received */ + uint8_t wait_pdu:1;/* flag indicating to wait till the next PDU start */ + /* uint8_t data[] */ +}; + +/** + * Initialise a section_buf structure. + * + * @param section The section_buf to initialise. + * @param max Maximum number of bytes in section (must be > 3) + * @return 0 on success, nonzero on error. + */ +extern int section_buf_init(struct section_buf *section, int max); + +/** + * Reset a section_buf structure (e.g. if a discontinuity occurred). The + * section_buf will wait for the first PDU start indicator. + * + * @param section The section_buf to reset. + */ +static inline void section_buf_reset(struct section_buf *section) +{ + int tmp = section->wait_pdu; + section_buf_init(section, section->max); + section->wait_pdu = tmp; +} + +/** + * Add a data fragment to a section_buf. + * + * @param section section_buf to add to. + * @param frag Pointer to data fragment. + * @param len Number of bytes of data. + * @param section_status 0: nothing special. 1: section complete. -ERANGE indicates that the + * section is larger than section->max. + * @return Number of bytes which were consumed. + */ +extern int section_buf_add(struct section_buf *section, uint8_t* frag, int len, int *section_status); + +/** + * Add a transport packet PSI payload to a section_buf. This takes into account + * the extra byte present in PDU_START flagged packets. + * + * @param section section_buf to add to. + * @param payload Pointer to packet payload data. + * @param len Number of bytes of data. + * @param pdu_start True if the payload_unit_start_indicator flag was set in the + * TS packet. + * @param section_status 0: nothing special. 1: section complete. -ERANGE indicates that the + * section is larger than section->max. -EINVAL indicates the pointer_field was completely + * invalid (too large). + */ +extern int section_buf_add_transport_payload(struct section_buf *section, + uint8_t* payload, int len, + int pdu_start, int *section_status); + +/** + * Get the number of bytes left to be received in a section_buf. + * + * @param section The section_buf concerned. + * @return The number of bytes. + */ +static inline int section_buf_remaining(struct section_buf *section) +{ + return section->len - section->count; +} + +/** + * Return a pointer to the start of the data in the section_buf. + * + * @param section The section_buf concerned. + * @return The data. + */ +static inline uint8_t* section_buf_data(struct section_buf *section) +{ + return (uint8_t*) section + sizeof(struct section_buf); +} + +#ifdef __cplusplus +} +#endif + +#endif |