/* * 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 /** * 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