libdvbv5: add documentation for the extended descriptor

The extended descriptor is defined on ETSI 300 468, and it
allows to extend the namespace range of the original MPEG-TS
descriptor into an additional 8 bytes codeset.

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

2 files changed, 144 insertions, 3 deletions

diff --git a/doxygen_libdvbv5.cfg b/doxygen_libdvbv5.cfg
index 40499885..201fc216 100644
--- a/doxygen_libdvbv5.cfg
+++ b/doxygen_libdvbv5.cfg
@@ -773,6 +773,7 @@ INPUT                  = $(SRCDIR)/doc/libdvbv5-index.doc \
 			 $(SRCDIR)/lib/include/libdvbv5/desc_cable_delivery.h \
 			 $(SRCDIR)/lib/include/libdvbv5/desc_event_extended.h \
 			 $(SRCDIR)/lib/include/libdvbv5/desc_event_short.h \
+			 $(SRCDIR)/lib/include/libdvbv5/desc_extension.h \
 
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding. Doxygen uses
diff --git a/lib/include/libdvbv5/desc_extension.h b/lib/include/libdvbv5/desc_extension.h
index 5326c1c6..88e931ea 100644
--- a/lib/include/libdvbv5/desc_extension.h
+++ b/lib/include/libdvbv5/desc_extension.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013 - Mauro Carvalho Chehab <m.chehab@samsung.com>
+ * Copyright (c) 2013-2014 - Mauro Carvalho Chehab <m.chehab@samsung.com>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -18,6 +18,25 @@
  *
  */
 
+/**
+ * @file desc_extension.h
+ * @ingroup descriptors
+ * @brief Provides the descriptors for the extension descriptor.
+ * 	  The extension descriptor is used to extend the 8-bit namespace
+ *	  of the descriptor_tag field.
+ * @copyright GNU General Public License version 2 (GPLv2)
+ * @author Mauro Carvalho Chehab
+ *
+ * @par Relevant specs
+ * The descriptor described herein is defined at:
+ *
+ * @see
+ * - ETSI EN 300 468 V1.11.1
+ *
+ * @par Bug Report
+ * Please submit bug reports and patches to linux-media@vger.kernel.org
+ */
+
 #ifndef _EXTENSION_DESC_H
 #define _EXTENSION_DESC_H
 
@@ -25,6 +44,49 @@
 
 struct dvb_v5_fe_parms;
 
+/**
+ * @enum extension_descriptors
+ * @brief List containing all extended descriptors used by Digital TV MPEG-TS
+ *	  as defined at ETSI EN 300 468 V1.11.1
+ * @ingroup descriptors
+ *
+ * @var image_icon_descriptor
+ *	@brief image icon descriptor
+ *
+ * @var cpcm_delivery_signalling_descriptor
+ *	@brief Content Protection/Copy Management (CPCM) delivery signalling
+ *	       descriptor
+ *
+ * @var CP_descriptor
+ *	@brief Content Protection descriptor
+ *
+ * @var CP_identifier_descriptor
+ *	@brief Content Protection identifier descriptor
+ *
+ * @var T2_delivery_system_descriptor
+ *	@brief DVB-T2 delivery system descriptor
+ *
+ * @var SH_delivery_system_descriptor
+ *	@brief DVB-SH delivery system descriptor
+ *
+ * @var supplementary_audio_descriptor
+ *	@brief supplementary audio descriptor
+ *
+ * @var network_change_notify_descriptor
+ *	@brief network change notify descriptor
+ *
+ * @var message_descriptor
+ *	@brief message descriptor
+ *
+ * @var target_region_descriptor
+ *	@brief target region descriptor
+ *
+ * @var target_region_name_descriptor
+ *	@brief target region name descriptor
+ *
+ * @var service_relocated_descriptor
+ *	@brief service relocated descriptor
+ */
 enum extension_descriptors {
 	image_icon_descriptor				= 0x00,
 	cpcm_delivery_signalling_descriptor		= 0x01,
@@ -40,6 +102,17 @@ enum extension_descriptors {
 	service_relocated_descriptor			= 0x0b,
 };
 
+/**
+ * @struct dvb_extension_descriptor
+ * @ingroup descriptors
+ * @brief Structure containing the extended descriptors
+ *
+ * @param type			Descriptor type
+ * @param length		Length of the descriptor
+ * @param next			pointer to the dvb_desc descriptor
+ * @param extension_code	extension code
+ * @param descriptor		pointer to struct dvb_desc
+ */
 struct dvb_extension_descriptor {
 	uint8_t type;
 	uint8_t length;
@@ -51,15 +124,51 @@ struct dvb_extension_descriptor {
 } __attribute__((packed));
 
 
+/**
+ * @brief Function prototype for the extended descriptors parsing init code
+ * @ingroup dvb_table
+ *
+ * @param parms		Struct dvb_v5_fe_parms pointer
+ * @param buf		buffer with the content of the descriptor
+ * @param ext		struct dvb_extension_descriptor pointer
+ * @param desc		struct dvb_desc pointer
+ */
 typedef int  (*dvb_desc_ext_init_func) (struct dvb_v5_fe_parms *parms,
 					const uint8_t *buf,
 					struct dvb_extension_descriptor *ext,
 					void *desc);
+/**
+ * @brief Function prototype for the extended descriptors parsing print code
+ * @ingroup dvb_table
+ *
+ * @param parms		Struct dvb_v5_fe_parms pointer
+ * @param buf		buffer with the content of the descriptor
+ * @param ext		struct dvb_extension_descriptor pointer
+ * @param desc		struct dvb_desc pointer
+ */
 typedef void (*dvb_desc_ext_print_func)(struct dvb_v5_fe_parms *parms,
 					const struct dvb_extension_descriptor *ext,
 					const void *desc);
+/**
+ * @brief Function prototype for the extended descriptors parsing free code
+ * @ingroup dvb_table
+ *
+ * @param desc		struct dvb_desc pointer
+ */
 typedef void (*dvb_desc_ext_free_func) (const void *desc);
 
+/**
+ * @struct dvb_ext_descriptor
+ * @ingroup descriptors
+ * @brief Structure that describes the parser functions for the extended
+ *	  descriptors. Works on a similar way as struct dvb_descriptor.
+ *
+ * @param name	name of the descriptor
+ * @param init	init dvb_desc_ext_init_func pointer
+ * @param print	print dvb_desc_ext_print_func pointer
+ * @param free	free dvb_desc_ext_free_func pointer
+ * @param size	size of the descriptor
+ */
 struct dvb_ext_descriptor {
 	const char *name;
 	dvb_desc_ext_init_func init;
@@ -73,11 +182,42 @@ struct dvb_ext_descriptor {
 extern "C" {
 #endif
 
-int dvb_extension_descriptor_init(struct dvb_v5_fe_parms *parms, const uint8_t *buf, struct dvb_desc *desc);
-void dvb_extension_descriptor_free(struct dvb_desc *descriptor);
+/**
+ * @brief Initializes and parses the extended descriptor
+ * @ingroup descriptors
+ *
+ * @param parms	struct dvb_v5_fe_parms pointer to the opened device
+ * @param buf	buffer containing the descriptor's raw data
+ * @param desc	pointer to struct dvb_desc to be allocated and filled
+ *
+ * This function allocates a the descriptor and fills the fields inside
+ * the struct. It also makes sure that all fields will follow the CPU
+ * endianness. Due to that, the content of the buffer may change.
+ *
+ * @return On success, it returns the size of the allocated struct.
+ *	   A negative value indicates an error.
+ */
+int dvb_extension_descriptor_init(struct dvb_v5_fe_parms *parms,
+				  const uint8_t *buf, struct dvb_desc *desc);
+
+/**
+ * @brief Prints the content of the extended descriptor
+ * @ingroup descriptors
+ *
+ * @param parms	struct dvb_v5_fe_parms pointer to the opened device
+ * @param desc	pointer to struct dvb_desc
+ */
 void dvb_extension_descriptor_print(struct dvb_v5_fe_parms *parms,
 				    const struct dvb_desc *desc);
 
+/**
+ * @brief Frees all data allocated by the extended descriptor
+ * @ingroup descriptors
+ *
+ * @param desc pointer to struct dvb_desc to be freed
+ */
+void dvb_extension_descriptor_free(struct dvb_desc *desc);
+
 #ifdef __cplusplus
 }
 #endif