/*
* section and descriptor parser
*
* Copyright (C) 2005 Kenneth Aafloy (kenneth@linuxtv.org)
* 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_MPEG_ODSMT_SECTION_H
#define _UCSI_MPEG_ODSMT_SECTION_H 1
#ifdef __cplusplus
extern "C"
{
#endif
#include <libucsi/section.h>
/**
* mpeg_odsmt_section structure.
*/
struct mpeg_odsmt_section {
struct section_ext head;
uint8_t stream_count;
/* stream_count==0 => struct mpeg_odsmt_stream_single streams
stream_count>0 => struct mpeg_odsmt_stream_multi streams[] */
/* uint8_t object_descriptors[] */
} __ucsi_packed;
struct mpeg_odsmt_stream_single
{
uint16_t esid;
uint8_t es_info_length;
/* struct descriptor descriptors[] */
} __ucsi_packed;
struct mpeg_odsmt_stream_multi
{
uint16_t esid;
uint8_t fmc;
uint8_t es_info_length;
/* struct descriptor descriptors[] */
} __ucsi_packed;
/**
* Structure describing the stream information held in an mpeg_odsmt_section.
*/
struct mpeg_odsmt_stream {
union {
struct mpeg_odsmt_stream_single single;
struct mpeg_odsmt_stream_multi multi;
} u;
} __ucsi_packed;
/**
* Process an mpeg_odsmt_section.
*
* @param section Pointer to the generic section_ext structure.
* @return Pointer to a mpeg_odsmt_section structure, or NULL on error.
*/
extern struct mpeg_odsmt_section *mpeg_odsmt_section_codec(struct section_ext *section);
/**
* Accessor for the PID field of an ODSMT.
*
* @param odsmt odsmt pointer.
* @return The pid.
*/
static inline uint16_t mpeg_odsmt_section_pid(struct mpeg_odsmt_section *odsmt)
{
return odsmt->head.table_id_ext & 0x1fff;
}
/**
* Convenience iterator for the streams field of an mpeg_odsmt_section.
*
* @param osdmt Pointer to the mpeg_odsmt_section structure.
* @param pos Variable holding pointer to the current mpeg_odsmt_stream structure.
* @param index Variable holding the stream index.
*/
#define mpeg_odsmt_section_streams_for_each(osdmt, pos, index) \
for (index=0, (pos) = mpeg_odsmt_section_streams_first(odsmt); \
(pos); \
(pos) = mpeg_odsmt_section_streams_next(odsmt, pos, ++index))
/**
* Convenience iterator for the descriptors field of an mpeg_odsmt_stream.
*
* @param osdmt Pointer to the mpeg_odsmt_section structure.
* @param stream Pointer to the mpeg_odsmt_stream structure.
* @param pos Variable holding pointer to the current descriptor structure.
*/
#define mpeg_odsmt_stream_descriptors_for_each(osdmt, stream, pos) \
for ((pos) = mpeg_odsmt_stream_descriptors_first(odsmt, stream); \
(pos); \
(pos) = mpeg_odsmt_stream_descriptors_next(odsmt, stream, pos))
/**
* Retrieve a pointer to the object_descriptors field of an mpeg_odsmt_section.
*
* @param osdmt Pointer to the mpeg_odsmt_section structure.
* @param len On return, will contain the number of bytes in the object descriptors field.
* @return Pointer to the object_descriptors field, or NULL on error.
*/
static inline uint8_t*
mpeg_odsmt_section_object_descriptors(struct mpeg_odsmt_section * odsmt,
size_t* len);
/******************************** PRIVATE CODE ********************************/
static inline struct mpeg_odsmt_stream *
mpeg_odsmt_section_streams_first(struct mpeg_odsmt_section *odsmt)
{
size_t pos = sizeof(struct mpeg_odsmt_section);
if (pos >= section_ext_length(&odsmt->head))
return NULL;
return (struct mpeg_odsmt_stream *) ((uint8_t *) odsmt + pos);
}
static inline struct mpeg_odsmt_stream *
mpeg_odsmt_section_streams_next(struct mpeg_odsmt_section *odsmt,
struct mpeg_odsmt_stream *pos,
int _index)
{
uint8_t *end = (uint8_t*) odsmt + section_ext_length(&odsmt->head);
uint8_t *next;
if (_index > odsmt->stream_count)
return NULL;
next = (uint8_t *) pos + sizeof(struct mpeg_odsmt_stream_multi) +
pos->u.multi.es_info_length;
if (next >= end)
return NULL;
return (struct mpeg_odsmt_stream *) next;
}
static inline struct descriptor *
mpeg_odsmt_stream_descriptors_first(struct mpeg_odsmt_section *odsmt,
struct mpeg_odsmt_stream *stream)
{
if (odsmt->stream_count == 0) {
if (stream->u.single.es_info_length == 0)
return NULL;
return (struct descriptor *)
((uint8_t*) stream + sizeof(struct mpeg_odsmt_stream_single));
} else {
if (stream->u.multi.es_info_length == 0)
return NULL;
return (struct descriptor *)
((uint8_t*) stream + sizeof(struct mpeg_odsmt_stream_multi));
}
}
static inline struct descriptor *
mpeg_odsmt_stream_descriptors_next(struct mpeg_odsmt_section *odsmt,
struct mpeg_odsmt_stream *stream,
struct descriptor* pos)
{
if (odsmt->stream_count == 0) {
return next_descriptor((uint8_t *) stream + sizeof(struct mpeg_odsmt_stream_single),
stream->u.single.es_info_length,
pos);
} else {
return next_descriptor((uint8_t *) stream + sizeof(struct mpeg_odsmt_stream_multi),
stream->u.multi.es_info_length,
pos);
}
}
static inline uint8_t*
mpeg_odsmt_section_object_descriptors(struct mpeg_odsmt_section * odsmt,
size_t* len)
{
struct mpeg_odsmt_stream* pos;
size_t size = sizeof(struct mpeg_odsmt_section);
int _index;
mpeg_odsmt_section_streams_for_each(odsmt, pos, _index) {
if (odsmt->stream_count == 0)
size += sizeof(struct mpeg_odsmt_stream_single) +
pos->u.single.es_info_length;
else
size += sizeof(struct mpeg_odsmt_stream_multi) +
pos->u.multi.es_info_length;
}
*len = section_ext_length(&odsmt->head) - size;
return (uint8_t*) odsmt + size;
}
#ifdef __cplusplus
}
#endif
#endif
