diff options
Diffstat (limited to 'kernel/Documentation/DocBook/media/dvb/kdapi.xml')
| -rw-r--r-- | kernel/Documentation/DocBook/media/dvb/kdapi.xml | 2309 |
1 files changed, 0 insertions, 2309 deletions
diff --git a/kernel/Documentation/DocBook/media/dvb/kdapi.xml b/kernel/Documentation/DocBook/media/dvb/kdapi.xml deleted file mode 100644 index 6c11ec52c..000000000 --- a/kernel/Documentation/DocBook/media/dvb/kdapi.xml +++ /dev/null @@ -1,2309 +0,0 @@ -<title>Kernel Demux API</title> -<para>The kernel demux API defines a driver-internal interface for registering low-level, -hardware specific driver to a hardware independent demux layer. It is only of interest for -DVB device driver writers. The header file for this API is named <emphasis role="tt">demux.h</emphasis> and located in -<emphasis role="tt">drivers/media/dvb-core</emphasis>. -</para> -<para>Maintainer note: This section must be reviewed. It is probably out of date. -</para> - -<section id="kernel_demux_data_types"> -<title>Kernel Demux Data Types</title> - - -<section id="dmx_success_t"> -<title>dmx_success_t</title> - <programlisting> - typedef enum { - DMX_OK = 0, /⋆ Received Ok ⋆/ - DMX_LENGTH_ERROR, /⋆ Incorrect length ⋆/ - DMX_OVERRUN_ERROR, /⋆ Receiver ring buffer overrun ⋆/ - DMX_CRC_ERROR, /⋆ Incorrect CRC ⋆/ - DMX_FRAME_ERROR, /⋆ Frame alignment error ⋆/ - DMX_FIFO_ERROR, /⋆ Receiver FIFO overrun ⋆/ - DMX_MISSED_ERROR /⋆ Receiver missed packet ⋆/ - } dmx_success_t; -</programlisting> - -</section> -<section id="ts_filter_types"> -<title>TS filter types</title> - <programlisting> - /⋆--------------------------------------------------------------------------⋆/ - /⋆ TS packet reception ⋆/ - /⋆--------------------------------------------------------------------------⋆/ - - /⋆ TS filter type for set_type() ⋆/ - - #define TS_PACKET 1 /⋆ send TS packets (188 bytes) to callback (default) ⋆/ - #define TS_PAYLOAD_ONLY 2 /⋆ in case TS_PACKET is set, only send the TS - payload (<=184 bytes per packet) to callback ⋆/ - #define TS_DECODER 4 /⋆ send stream to built-in decoder (if present) ⋆/ -</programlisting> - -</section> -<section id="dmx_ts_pes_t"> -<title>dmx_ts_pes_t</title> -<para>The structure -</para> -<programlisting> - typedef enum - { - DMX_TS_PES_AUDIO, /⋆ also send packets to audio decoder (if it exists) ⋆/ - DMX_TS_PES_VIDEO, /⋆ ... ⋆/ - DMX_TS_PES_TELETEXT, - DMX_TS_PES_SUBTITLE, - DMX_TS_PES_PCR, - DMX_TS_PES_OTHER, - } dmx_ts_pes_t; -</programlisting> -<para>describes the PES type for filters which write to a built-in decoder. The correspond (and -should be kept identical) to the types in the demux device. -</para> -<programlisting> - struct dmx_ts_feed_s { - int is_filtering; /⋆ Set to non-zero when filtering in progress ⋆/ - struct dmx_demux_s⋆ parent; /⋆ Back-pointer ⋆/ - void⋆ priv; /⋆ Pointer to private data of the API client ⋆/ - int (⋆set) (struct dmx_ts_feed_s⋆ feed, - __u16 pid, - size_t callback_length, - size_t circular_buffer_size, - int descramble, - struct timespec timeout); - int (⋆start_filtering) (struct dmx_ts_feed_s⋆ feed); - int (⋆stop_filtering) (struct dmx_ts_feed_s⋆ feed); - int (⋆set_type) (struct dmx_ts_feed_s⋆ feed, - int type, - dmx_ts_pes_t pes_type); - }; - - typedef struct dmx_ts_feed_s dmx_ts_feed_t; -</programlisting> - <programlisting> - /⋆--------------------------------------------------------------------------⋆/ - /⋆ PES packet reception (not supported yet) ⋆/ - /⋆--------------------------------------------------------------------------⋆/ - - typedef struct dmx_pes_filter_s { - struct dmx_pes_s⋆ parent; /⋆ Back-pointer ⋆/ - void⋆ priv; /⋆ Pointer to private data of the API client ⋆/ - } dmx_pes_filter_t; -</programlisting> - <programlisting> - typedef struct dmx_pes_feed_s { - int is_filtering; /⋆ Set to non-zero when filtering in progress ⋆/ - struct dmx_demux_s⋆ parent; /⋆ Back-pointer ⋆/ - void⋆ priv; /⋆ Pointer to private data of the API client ⋆/ - int (⋆set) (struct dmx_pes_feed_s⋆ feed, - __u16 pid, - size_t circular_buffer_size, - int descramble, - struct timespec timeout); - int (⋆start_filtering) (struct dmx_pes_feed_s⋆ feed); - int (⋆stop_filtering) (struct dmx_pes_feed_s⋆ feed); - int (⋆allocate_filter) (struct dmx_pes_feed_s⋆ feed, - dmx_pes_filter_t⋆⋆ filter); - int (⋆release_filter) (struct dmx_pes_feed_s⋆ feed, - dmx_pes_filter_t⋆ filter); - } dmx_pes_feed_t; -</programlisting> - <programlisting> - typedef struct { - __u8 filter_value [DMX_MAX_FILTER_SIZE]; - __u8 filter_mask [DMX_MAX_FILTER_SIZE]; - struct dmx_section_feed_s⋆ parent; /⋆ Back-pointer ⋆/ - void⋆ priv; /⋆ Pointer to private data of the API client ⋆/ - } dmx_section_filter_t; -</programlisting> - <programlisting> - struct dmx_section_feed_s { - int is_filtering; /⋆ Set to non-zero when filtering in progress ⋆/ - struct dmx_demux_s⋆ parent; /⋆ Back-pointer ⋆/ - void⋆ priv; /⋆ Pointer to private data of the API client ⋆/ - int (⋆set) (struct dmx_section_feed_s⋆ feed, - __u16 pid, - size_t circular_buffer_size, - int descramble, - int check_crc); - int (⋆allocate_filter) (struct dmx_section_feed_s⋆ feed, - dmx_section_filter_t⋆⋆ filter); - int (⋆release_filter) (struct dmx_section_feed_s⋆ feed, - dmx_section_filter_t⋆ filter); - int (⋆start_filtering) (struct dmx_section_feed_s⋆ feed); - int (⋆stop_filtering) (struct dmx_section_feed_s⋆ feed); - }; - typedef struct dmx_section_feed_s dmx_section_feed_t; - - /⋆--------------------------------------------------------------------------⋆/ - /⋆ Callback functions ⋆/ - /⋆--------------------------------------------------------------------------⋆/ - - typedef int (⋆dmx_ts_cb) ( __u8 ⋆ buffer1, - size_t buffer1_length, - __u8 ⋆ buffer2, - size_t buffer2_length, - dmx_ts_feed_t⋆ source, - dmx_success_t success); - - typedef int (⋆dmx_section_cb) ( __u8 ⋆ buffer1, - size_t buffer1_len, - __u8 ⋆ buffer2, - size_t buffer2_len, - dmx_section_filter_t ⋆ source, - dmx_success_t success); - - typedef int (⋆dmx_pes_cb) ( __u8 ⋆ buffer1, - size_t buffer1_len, - __u8 ⋆ buffer2, - size_t buffer2_len, - dmx_pes_filter_t⋆ source, - dmx_success_t success); - - /⋆--------------------------------------------------------------------------⋆/ - /⋆ DVB Front-End ⋆/ - /⋆--------------------------------------------------------------------------⋆/ - - typedef enum { - DMX_OTHER_FE = 0, - DMX_SATELLITE_FE, - DMX_CABLE_FE, - DMX_TERRESTRIAL_FE, - DMX_LVDS_FE, - DMX_ASI_FE, /⋆ DVB-ASI interface ⋆/ - DMX_MEMORY_FE - } dmx_frontend_source_t; - - typedef struct { - /⋆ The following char⋆ fields point to NULL terminated strings ⋆/ - char⋆ id; /⋆ Unique front-end identifier ⋆/ - char⋆ vendor; /⋆ Name of the front-end vendor ⋆/ - char⋆ model; /⋆ Name of the front-end model ⋆/ - struct list_head connectivity_list; /⋆ List of front-ends that can - be connected to a particular - demux ⋆/ - void⋆ priv; /⋆ Pointer to private data of the API client ⋆/ - dmx_frontend_source_t source; - } dmx_frontend_t; - - /⋆--------------------------------------------------------------------------⋆/ - /⋆ MPEG-2 TS Demux ⋆/ - /⋆--------------------------------------------------------------------------⋆/ - - /⋆ - ⋆ Flags OR'ed in the capabilites field of struct dmx_demux_s. - ⋆/ - - #define DMX_TS_FILTERING 1 - #define DMX_PES_FILTERING 2 - #define DMX_SECTION_FILTERING 4 - #define DMX_MEMORY_BASED_FILTERING 8 /⋆ write() available ⋆/ - #define DMX_CRC_CHECKING 16 - #define DMX_TS_DESCRAMBLING 32 - #define DMX_SECTION_PAYLOAD_DESCRAMBLING 64 - #define DMX_MAC_ADDRESS_DESCRAMBLING 128 -</programlisting> - -</section> -<section id="demux_demux_t"> -<title>demux_demux_t</title> - <programlisting> - /⋆ - ⋆ DMX_FE_ENTRY(): Casts elements in the list of registered - ⋆ front-ends from the generic type struct list_head - ⋆ to the type ⋆ dmx_frontend_t - ⋆. - ⋆/ - - #define DMX_FE_ENTRY(list) list_entry(list, dmx_frontend_t, connectivity_list) - - struct dmx_demux_s { - /⋆ The following char⋆ fields point to NULL terminated strings ⋆/ - char⋆ id; /⋆ Unique demux identifier ⋆/ - char⋆ vendor; /⋆ Name of the demux vendor ⋆/ - char⋆ model; /⋆ Name of the demux model ⋆/ - __u32 capabilities; /⋆ Bitfield of capability flags ⋆/ - dmx_frontend_t⋆ frontend; /⋆ Front-end connected to the demux ⋆/ - struct list_head reg_list; /⋆ List of registered demuxes ⋆/ - void⋆ priv; /⋆ Pointer to private data of the API client ⋆/ - int users; /⋆ Number of users ⋆/ - int (⋆open) (struct dmx_demux_s⋆ demux); - int (⋆close) (struct dmx_demux_s⋆ demux); - int (⋆write) (struct dmx_demux_s⋆ demux, const char⋆ buf, size_t count); - int (⋆allocate_ts_feed) (struct dmx_demux_s⋆ demux, - dmx_ts_feed_t⋆⋆ feed, - dmx_ts_cb callback); - int (⋆release_ts_feed) (struct dmx_demux_s⋆ demux, - dmx_ts_feed_t⋆ feed); - int (⋆allocate_pes_feed) (struct dmx_demux_s⋆ demux, - dmx_pes_feed_t⋆⋆ feed, - dmx_pes_cb callback); - int (⋆release_pes_feed) (struct dmx_demux_s⋆ demux, - dmx_pes_feed_t⋆ feed); - int (⋆allocate_section_feed) (struct dmx_demux_s⋆ demux, - dmx_section_feed_t⋆⋆ feed, - dmx_section_cb callback); - int (⋆release_section_feed) (struct dmx_demux_s⋆ demux, - dmx_section_feed_t⋆ feed); - int (⋆descramble_mac_address) (struct dmx_demux_s⋆ demux, - __u8⋆ buffer1, - size_t buffer1_length, - __u8⋆ buffer2, - size_t buffer2_length, - __u16 pid); - int (⋆descramble_section_payload) (struct dmx_demux_s⋆ demux, - __u8⋆ buffer1, - size_t buffer1_length, - __u8⋆ buffer2, size_t buffer2_length, - __u16 pid); - int (⋆add_frontend) (struct dmx_demux_s⋆ demux, - dmx_frontend_t⋆ frontend); - int (⋆remove_frontend) (struct dmx_demux_s⋆ demux, - dmx_frontend_t⋆ frontend); - struct list_head⋆ (⋆get_frontends) (struct dmx_demux_s⋆ demux); - int (⋆connect_frontend) (struct dmx_demux_s⋆ demux, - dmx_frontend_t⋆ frontend); - int (⋆disconnect_frontend) (struct dmx_demux_s⋆ demux); - - - /⋆ added because js cannot keep track of these himself ⋆/ - int (⋆get_pes_pids) (struct dmx_demux_s⋆ demux, __u16 ⋆pids); - }; - typedef struct dmx_demux_s dmx_demux_t; -</programlisting> - -</section> -<section id="demux_directory"> -<title>Demux directory</title> - <programlisting> - /⋆ - ⋆ DMX_DIR_ENTRY(): Casts elements in the list of registered - ⋆ demuxes from the generic type struct list_head⋆ to the type dmx_demux_t - ⋆. - ⋆/ - - #define DMX_DIR_ENTRY(list) list_entry(list, dmx_demux_t, reg_list) - - int dmx_register_demux (dmx_demux_t⋆ demux); - int dmx_unregister_demux (dmx_demux_t⋆ demux); - struct list_head⋆ dmx_get_demuxes (void); -</programlisting> - </section></section> -<section id="demux_directory_api"> -<title>Demux Directory API</title> -<para>The demux directory is a Linux kernel-wide facility for registering and accessing the -MPEG-2 TS demuxes in the system. Run-time registering and unregistering of demux drivers -is possible using this API. -</para> -<para>All demux drivers in the directory implement the abstract interface dmx_demux_t. -</para> - -<section -role="subsection"><title>dmx_register_demux()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function makes a demux driver interface available to the Linux kernel. It is - usually called by the init_module() function of the kernel module that contains - the demux driver. The caller of this function is responsible for allocating - dynamic or static memory for the demux structure and for initializing its fields - before calling this function. The memory allocated for the demux structure - must not be freed before calling dmx_unregister_demux(),</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int dmx_register_demux ( dmx_demux_t ⋆demux )</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t* - demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux structure.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EEXIST</para> -</entry><entry - align="char"> -<para>A demux with the same value of the id field already stored - in the directory.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOSPC</para> -</entry><entry - align="char"> -<para>No space left in the directory.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>dmx_unregister_demux()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function is called to indicate that the given demux interface is no - longer available. The caller of this function is responsible for freeing the - memory of the demux structure, if it was dynamically allocated before calling - dmx_register_demux(). The cleanup_module() function of the kernel module - that contains the demux driver should call this function. Note that this function - fails if the demux is currently in use, i.e., release_demux() has not been called - for the interface.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int dmx_unregister_demux ( dmx_demux_t ⋆demux )</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t* - demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux structure which is to be - unregistered.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>ENODEV</para> -</entry><entry - align="char"> -<para>The specified demux is not registered in the demux - directory.</para> -</entry> - </row><row><entry - align="char"> -<para>EBUSY</para> -</entry><entry - align="char"> -<para>The specified demux is currently in use.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>dmx_get_demuxes()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Provides the caller with the list of registered demux interfaces, using the - standard list structure defined in the include file linux/list.h. The include file - demux.h defines the macro DMX_DIR_ENTRY() for converting an element of - the generic type struct list_head* to the type dmx_demux_t*. The caller must - not free the memory of any of the elements obtained via this function call.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>struct list_head ⋆dmx_get_demuxes ()</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>none</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>struct list_head *</para> -</entry><entry - align="char"> -<para>A list of demux interfaces, or NULL in the case of an - empty list.</para> -</entry> - </row></tbody></tgroup></informaltable> - </section></section> -<section id="demux_api"> -<title>Demux API</title> -<para>The demux API should be implemented for each demux in the system. It is used to select -the TS source of a demux and to manage the demux resources. When the demux -client allocates a resource via the demux API, it receives a pointer to the API of that -resource. -</para> -<para>Each demux receives its TS input from a DVB front-end or from memory, as set via the -demux API. In a system with more than one front-end, the API can be used to select one of -the DVB front-ends as a TS source for a demux, unless this is fixed in the HW platform. The -demux API only controls front-ends regarding their connections with demuxes; the APIs -used to set the other front-end parameters, such as tuning, are not defined in this -document. -</para> -<para>The functions that implement the abstract interface demux should be defined static or -module private and registered to the Demux Directory for external access. It is not necessary -to implement every function in the demux_t struct, however (for example, a demux interface -might support Section filtering, but not TS or PES filtering). The API client is expected to -check the value of any function pointer before calling the function: the value of NULL means -“function not available”. -</para> -<para>Whenever the functions of the demux API modify shared data, the possibilities of lost -update and race condition problems should be addressed, e.g. by protecting parts of code with -mutexes. This is especially important on multi-processor hosts. -</para> -<para>Note that functions called from a bottom half context must not sleep, at least in the 2.2.x -kernels. Even a simple memory allocation can result in a kernel thread being put to sleep if -swapping is needed. For example, the Linux kernel calls the functions of a network device -interface from a bottom half context. Thus, if a demux API function is called from network -device code, the function must not sleep. -</para> - - -<section id="kdapi_fopen"> -<title>open()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function reserves the demux for use by the caller and, if necessary, - initializes the demux. When the demux is no longer needed, the function close() - should be called. It should be possible for multiple clients to access the demux - at the same time. Thus, the function implementation should increment the - demux usage count when open() is called and decrement it when close() is - called.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int open ( demux_t⋆ demux );</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>demux_t* demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EUSERS</para> -</entry><entry - align="char"> -<para>Maximum usage count reached.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section> -<section id="kdapi_fclose"> -<title>close()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function reserves the demux for use by the caller and, if necessary, - initializes the demux. When the demux is no longer needed, the function close() - should be called. It should be possible for multiple clients to access the demux - at the same time. Thus, the function implementation should increment the - demux usage count when open() is called and decrement it when close() is - called.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int close(demux_t⋆ demux);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>demux_t* demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENODEV</para> -</entry><entry - align="char"> -<para>The demux was not in use.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section> -<section id="kdapi_fwrite"> -<title>write()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function provides the demux driver with a memory buffer containing TS - packets. Instead of receiving TS packets from the DVB front-end, the demux - driver software will read packets from memory. Any clients of this demux - with active TS, PES or Section filters will receive filtered data via the Demux - callback API (see 0). The function returns when all the data in the buffer has - been consumed by the demux. Demux hardware typically cannot read TS from - memory. If this is the case, memory-based filtering has to be implemented - entirely in software.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int write(demux_t⋆ demux, const char⋆ buf, size_t - count);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>demux_t* demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>const char* buf</para> -</entry><entry - align="char"> -<para>Pointer to the TS data in kernel-space memory.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t length</para> -</entry><entry - align="char"> -<para>Length of the TS data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOSYS</para> -</entry><entry - align="char"> -<para>The command is not implemented.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>allocate_ts_feed()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Allocates a new TS feed, which is used to filter the TS packets carrying a - certain PID. The TS feed normally corresponds to a hardware PID filter on the - demux chip.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int allocate_ts_feed(dmx_demux_t⋆ demux, - dmx_ts_feed_t⋆⋆ feed, dmx_ts_cb callback);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>demux_t* demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_ts_feed_t** - feed</para> -</entry><entry - align="char"> -<para>Pointer to the TS feed API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_ts_cb callback</para> -</entry><entry - align="char"> -<para>Pointer to the callback function for passing received TS - packet</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EBUSY</para> -</entry><entry - align="char"> -<para>No more TS feeds available.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOSYS</para> -</entry><entry - align="char"> -<para>The command is not implemented.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>release_ts_feed()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Releases the resources allocated with allocate_ts_feed(). Any filtering in - progress on the TS feed should be stopped before calling this function.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int release_ts_feed(dmx_demux_t⋆ demux, - dmx_ts_feed_t⋆ feed);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>demux_t* demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_ts_feed_t* feed</para> -</entry><entry - align="char"> -<para>Pointer to the TS feed API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>allocate_section_feed()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Allocates a new section feed, i.e. a demux resource for filtering and receiving - sections. On platforms with hardware support for section filtering, a section - feed is directly mapped to the demux HW. On other platforms, TS packets are - first PID filtered in hardware and a hardware section filter then emulated in - software. The caller obtains an API pointer of type dmx_section_feed_t as an - out parameter. Using this API the caller can set filtering parameters and start - receiving sections.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int allocate_section_feed(dmx_demux_t⋆ demux, - dmx_section_feed_t ⋆⋆feed, dmx_section_cb callback);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>demux_t *demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_section_feed_t - **feed</para> -</entry><entry - align="char"> -<para>Pointer to the section feed API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_section_cb - callback</para> -</entry><entry - align="char"> -<para>Pointer to the callback function for passing received - sections.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EBUSY</para> -</entry><entry - align="char"> -<para>No more section feeds available.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOSYS</para> -</entry><entry - align="char"> -<para>The command is not implemented.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>release_section_feed()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Releases the resources allocated with allocate_section_feed(), including - allocated filters. Any filtering in progress on the section feed should be stopped - before calling this function.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int release_section_feed(dmx_demux_t⋆ demux, - dmx_section_feed_t ⋆feed);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>demux_t *demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_section_feed_t - *feed</para> -</entry><entry - align="char"> -<para>Pointer to the section feed API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>descramble_mac_address()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function runs a descrambling algorithm on the destination MAC - address field of a DVB Datagram Section, replacing the original address - with its un-encrypted version. Otherwise, the description on the function - descramble_section_payload() applies also to this function.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int descramble_mac_address(dmx_demux_t⋆ demux, __u8 - ⋆buffer1, size_t buffer1_length, __u8 ⋆buffer2, - size_t buffer2_length, __u16 pid);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t - *demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>__u8 *buffer1</para> -</entry><entry - align="char"> -<para>Pointer to the first byte of the section.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t buffer1_length</para> -</entry><entry - align="char"> -<para>Length of the section data, including headers and CRC, - in buffer1.</para> -</entry> - </row><row><entry - align="char"> -<para>__u8* buffer2</para> -</entry><entry - align="char"> -<para>Pointer to the tail of the section data, or NULL. The - pointer has a non-NULL value if the section wraps past - the end of a circular buffer.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t buffer2_length</para> -</entry><entry - align="char"> -<para>Length of the section data, including headers and CRC, - in buffer2.</para> -</entry> - </row><row><entry - align="char"> -<para>__u16 pid</para> -</entry><entry - align="char"> -<para>The PID on which the section was received. Useful - for obtaining the descrambling key, e.g. from a DVB - Common Access facility.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOSYS</para> -</entry><entry - align="char"> -<para>No descrambling facility available.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>descramble_section_payload()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function runs a descrambling algorithm on the payload of a DVB - Datagram Section, replacing the original payload with its un-encrypted - version. The function will be called from the demux API implementation; - the API client need not call this function directly. Section-level scrambling - algorithms are currently standardized only for DVB-RCC (return channel - over 2-directional cable TV network) systems. For all other DVB networks, - encryption schemes are likely to be proprietary to each data broadcaster. Thus, - it is expected that this function pointer will have the value of NULL (i.e., - function not available) in most demux API implementations. Nevertheless, it - should be possible to use the function pointer as a hook for dynamically adding - a “plug-in” descrambling facility to a demux driver.</para> -</entry> - </row><row><entry - align="char"> -<para>While this function is not needed with hardware-based section descrambling, - the descramble_section_payload function pointer can be used to override the - default hardware-based descrambling algorithm: if the function pointer has a - non-NULL value, the corresponding function should be used instead of any - descrambling hardware.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int descramble_section_payload(dmx_demux_t⋆ demux, - __u8 ⋆buffer1, size_t buffer1_length, __u8 ⋆buffer2, - size_t buffer2_length, __u16 pid);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t - *demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>__u8 *buffer1</para> -</entry><entry - align="char"> -<para>Pointer to the first byte of the section.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t buffer1_length</para> -</entry><entry - align="char"> -<para>Length of the section data, including headers and CRC, - in buffer1.</para> -</entry> - </row><row><entry - align="char"> -<para>__u8 *buffer2</para> -</entry><entry - align="char"> -<para>Pointer to the tail of the section data, or NULL. The - pointer has a non-NULL value if the section wraps past - the end of a circular buffer.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t buffer2_length</para> -</entry><entry - align="char"> -<para>Length of the section data, including headers and CRC, - in buffer2.</para> -</entry> - </row><row><entry - align="char"> -<para>__u16 pid</para> -</entry><entry - align="char"> -<para>The PID on which the section was received. Useful - for obtaining the descrambling key, e.g. from a DVB - Common Access facility.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOSYS</para> -</entry><entry - align="char"> -<para>No descrambling facility available.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>add_frontend()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Registers a connectivity between a demux and a front-end, i.e., indicates that - the demux can be connected via a call to connect_frontend() to use the given - front-end as a TS source. The client of this function has to allocate dynamic or - static memory for the frontend structure and initialize its fields before calling - this function. This function is normally called during the driver initialization. - The caller must not free the memory of the frontend struct before successfully - calling remove_frontend().</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int add_frontend(dmx_demux_t ⋆demux, dmx_frontend_t - ⋆frontend);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t* - demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_frontend_t* - frontend</para> -</entry><entry - align="char"> -<para>Pointer to the front-end instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EEXIST</para> -</entry><entry - align="char"> -<para>A front-end with the same value of the id field already - registered.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINUSE</para> -</entry><entry - align="char"> -<para>The demux is in use.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOMEM</para> -</entry><entry - align="char"> -<para>No more front-ends can be added.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>remove_frontend()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Indicates that the given front-end, registered by a call to add_frontend(), can - no longer be connected as a TS source by this demux. The function should be - called when a front-end driver or a demux driver is removed from the system. - If the front-end is in use, the function fails with the return value of -EBUSY. - After successfully calling this function, the caller can free the memory of - the frontend struct if it was dynamically allocated before the add_frontend() - operation.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int remove_frontend(dmx_demux_t⋆ demux, - dmx_frontend_t⋆ frontend);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t* - demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_frontend_t* - frontend</para> -</entry><entry - align="char"> -<para>Pointer to the front-end instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row><row><entry - align="char"> -<para>-EBUSY</para> -</entry><entry - align="char"> -<para>The front-end is in use, i.e. a call to connect_frontend() - has not been followed by a call to disconnect_frontend().</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>get_frontends()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Provides the APIs of the front-ends that have been registered for this demux. - Any of the front-ends obtained with this call can be used as a parameter for - connect_frontend().</para> -</entry> - </row><row><entry - align="char"> -<para>The include file demux.h contains the macro DMX_FE_ENTRY() for - converting an element of the generic type struct list_head* to the type - dmx_frontend_t*. The caller must not free the memory of any of the elements - obtained via this function call.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>struct list_head⋆ get_frontends(dmx_demux_t⋆ demux);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t* - demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t*</para> -</entry><entry - align="char"> -<para>A list of front-end interfaces, or NULL in the case of an - empty list.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>connect_frontend()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Connects the TS output of the front-end to the input of the demux. A demux - can only be connected to a front-end registered to the demux with the function - add_frontend().</para> -</entry> - </row><row><entry - align="char"> -<para>It may or may not be possible to connect multiple demuxes to the same - front-end, depending on the capabilities of the HW platform. When not used, - the front-end should be released by calling disconnect_frontend().</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int connect_frontend(dmx_demux_t⋆ demux, - dmx_frontend_t⋆ frontend);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t* - demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_frontend_t* - frontend</para> -</entry><entry - align="char"> -<para>Pointer to the front-end instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row><row><entry - align="char"> -<para>-EBUSY</para> -</entry><entry - align="char"> -<para>The front-end is in use.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>disconnect_frontend()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Disconnects the demux and a front-end previously connected by a - connect_frontend() call.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int disconnect_frontend(dmx_demux_t⋆ demux);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t* - demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - </section></section> -<section id="demux_callback_api"> -<title>Demux Callback API</title> -<para>This kernel-space API comprises the callback functions that deliver filtered data to the -demux client. Unlike the other APIs, these API functions are provided by the client and called -from the demux code. -</para> -<para>The function pointers of this abstract interface are not packed into a structure as in the -other demux APIs, because the callback functions are registered and used independent -of each other. As an example, it is possible for the API client to provide several -callback functions for receiving TS packets and no callbacks for PES packets or -sections. -</para> -<para>The functions that implement the callback API need not be re-entrant: when a demux -driver calls one of these functions, the driver is not allowed to call the function again before -the original call returns. If a callback is triggered by a hardware interrupt, it is recommended -to use the Linux “bottom half” mechanism or start a tasklet instead of making the callback -function call directly from a hardware interrupt. -</para> - -<section -role="subsection"><title>dmx_ts_cb()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function, provided by the client of the demux API, is called from the - demux code. The function is only called when filtering on this TS feed has - been enabled using the start_filtering() function.</para> -</entry> - </row><row><entry - align="char"> -<para>Any TS packets that match the filter settings are copied to a circular buffer. The - filtered TS packets are delivered to the client using this callback function. The - size of the circular buffer is controlled by the circular_buffer_size parameter - of the set() function in the TS Feed API. It is expected that the buffer1 and - buffer2 callback parameters point to addresses within the circular buffer, but - other implementations are also possible. Note that the called party should not - try to free the memory the buffer1 and buffer2 parameters point to.</para> -</entry> - </row><row><entry - align="char"> -<para>When this function is called, the buffer1 parameter typically points to the - start of the first undelivered TS packet within a circular buffer. The buffer2 - buffer parameter is normally NULL, except when the received TS packets have - crossed the last address of the circular buffer and ”wrapped” to the beginning - of the buffer. In the latter case the buffer1 parameter would contain an address - within the circular buffer, while the buffer2 parameter would contain the first - address of the circular buffer.</para> -</entry> - </row><row><entry - align="char"> -<para>The number of bytes delivered with this function (i.e. buffer1_length + - buffer2_length) is usually equal to the value of callback_length parameter - given in the set() function, with one exception: if a timeout occurs before - receiving callback_length bytes of TS data, any undelivered packets are - immediately delivered to the client by calling this function. The timeout - duration is controlled by the set() function in the TS Feed API.</para> -</entry> - </row><row><entry - align="char"> -<para>If a TS packet is received with errors that could not be fixed by the TS-level - forward error correction (FEC), the Transport_error_indicator flag of the TS - packet header should be set. The TS packet should not be discarded, as - the error can possibly be corrected by a higher layer protocol. If the called - party is slow in processing the callback, it is possible that the circular buffer - eventually fills up. If this happens, the demux driver should discard any TS - packets received while the buffer is full. The error should be indicated to the - client on the next callback by setting the success parameter to the value of - DMX_OVERRUN_ERROR.</para> -</entry> - </row><row><entry - align="char"> -<para>The type of data returned to the callback can be selected by the new - function int (*set_type) (struct dmx_ts_feed_s* feed, int type, dmx_ts_pes_t - pes_type) which is part of the dmx_ts_feed_s struct (also cf. to the - include file ost/demux.h) The type parameter decides if the raw TS packet - (TS_PACKET) or just the payload (TS_PACKET—TS_PAYLOAD_ONLY) - should be returned. If additionally the TS_DECODER bit is set the stream - will also be sent to the hardware MPEG decoder. In this case, the second - flag decides as what kind of data the stream should be interpreted. The - possible choices are one of DMX_TS_PES_AUDIO, DMX_TS_PES_VIDEO, - DMX_TS_PES_TELETEXT, DMX_TS_PES_SUBTITLE, - DMX_TS_PES_PCR, or DMX_TS_PES_OTHER.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int dmx_ts_cb(__u8⋆ buffer1, size_t buffer1_length, - __u8⋆ buffer2, size_t buffer2_length, dmx_ts_feed_t⋆ - source, dmx_success_t success);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>__u8* buffer1</para> -</entry><entry - align="char"> -<para>Pointer to the start of the filtered TS packets.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t buffer1_length</para> -</entry><entry - align="char"> -<para>Length of the TS data in buffer1.</para> -</entry> - </row><row><entry - align="char"> -<para>__u8* buffer2</para> -</entry><entry - align="char"> -<para>Pointer to the tail of the filtered TS packets, or NULL.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t buffer2_length</para> -</entry><entry - align="char"> -<para>Length of the TS data in buffer2.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_ts_feed_t* - source</para> -</entry><entry - align="char"> -<para>Indicates which TS feed is the source of the callback.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_success_t - success</para> -</entry><entry - align="char"> -<para>Indicates if there was an error in TS reception.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>Continue filtering.</para> -</entry> - </row><row><entry - align="char"> -<para>-1</para> -</entry><entry - align="char"> -<para>Stop filtering - has the same effect as a call to - stop_filtering() on the TS Feed API.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>dmx_section_cb()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function, provided by the client of the demux API, is called from the - demux code. The function is only called when filtering of sections has been - enabled using the function start_filtering() of the section feed API. When the - demux driver has received a complete section that matches at least one section - filter, the client is notified via this callback function. Normally this function is - called for each received section; however, it is also possible to deliver multiple - sections with one callback, for example when the system load is high. If an - error occurs while receiving a section, this function should be called with - the corresponding error type set in the success field, whether or not there is - data to deliver. The Section Feed implementation should maintain a circular - buffer for received sections. However, this is not necessary if the Section Feed - API is implemented as a client of the TS Feed API, because the TS Feed - implementation then buffers the received data. The size of the circular buffer - can be configured using the set() function in the Section Feed API. If there - is no room in the circular buffer when a new section is received, the section - must be discarded. If this happens, the value of the success parameter should - be DMX_OVERRUN_ERROR on the next callback.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int dmx_section_cb(__u8⋆ buffer1, size_t - buffer1_length, __u8⋆ buffer2, size_t - buffer2_length, dmx_section_filter_t⋆ source, - dmx_success_t success);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>__u8* buffer1</para> -</entry><entry - align="char"> -<para>Pointer to the start of the filtered section, e.g. within the - circular buffer of the demux driver.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t buffer1_length</para> -</entry><entry - align="char"> -<para>Length of the filtered section data in buffer1, including - headers and CRC.</para> -</entry> - </row><row><entry - align="char"> -<para>__u8* buffer2</para> -</entry><entry - align="char"> -<para>Pointer to the tail of the filtered section data, or NULL. - Useful to handle the wrapping of a circular buffer.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t buffer2_length</para> -</entry><entry - align="char"> -<para>Length of the filtered section data in buffer2, including - headers and CRC.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_section_filter_t* - filter</para> -</entry><entry - align="char"> -<para>Indicates the filter that triggered the callback.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_success_t - success</para> -</entry><entry - align="char"> -<para>Indicates if there was an error in section reception.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>Continue filtering.</para> -</entry> - </row><row><entry - align="char"> -<para>-1</para> -</entry><entry - align="char"> -<para>Stop filtering - has the same effect as a call to - stop_filtering() on the Section Feed API.</para> -</entry> - </row></tbody></tgroup></informaltable> - </section></section> -<section id="ts_feed_api"> -<title>TS Feed API</title> -<para>A TS feed is typically mapped to a hardware PID filter on the demux chip. -Using this API, the client can set the filtering properties to start/stop filtering TS -packets on a particular TS feed. The API is defined as an abstract interface of the type -dmx_ts_feed_t. -</para> -<para>The functions that implement the interface should be defined static or module private. The -client can get the handle of a TS feed API by calling the function allocate_ts_feed() in the -demux API. -</para> - -<section -role="subsection"><title>set()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function sets the parameters of a TS feed. Any filtering in progress on the - TS feed must be stopped before calling this function.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int set ( dmx_ts_feed_t⋆ feed, __u16 pid, size_t - callback_length, size_t circular_buffer_size, int - descramble, struct timespec timeout);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_ts_feed_t* feed</para> -</entry><entry - align="char"> -<para>Pointer to the TS feed API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>__u16 pid</para> -</entry><entry - align="char"> -<para>PID value to filter. Only the TS packets carrying the - specified PID will be passed to the API client.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t - callback_length</para> -</entry><entry - align="char"> -<para>Number of bytes to deliver with each call to the - dmx_ts_cb() callback function. The value of this - parameter should be a multiple of 188.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t - circular_buffer_size</para> -</entry><entry - align="char"> -<para>Size of the circular buffer for the filtered TS packets.</para> -</entry> - </row><row><entry - align="char"> -<para>int descramble</para> -</entry><entry - align="char"> -<para>If non-zero, descramble the filtered TS packets.</para> -</entry> - </row><row><entry - align="char"> -<para>struct timespec - timeout</para> -</entry><entry - align="char"> -<para>Maximum time to wait before delivering received TS - packets to the client.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOMEM</para> -</entry><entry - align="char"> -<para>Not enough memory for the requested buffer size.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOSYS</para> -</entry><entry - align="char"> -<para>No descrambling facility available for TS.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>start_filtering()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Starts filtering TS packets on this TS feed, according to its settings. The PID - value to filter can be set by the API client. All matching TS packets are - delivered asynchronously to the client, using the callback function registered - with allocate_ts_feed().</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int start_filtering(dmx_ts_feed_t⋆ feed);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_ts_feed_t* feed</para> -</entry><entry - align="char"> -<para>Pointer to the TS feed API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>stop_filtering()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Stops filtering TS packets on this TS feed.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int stop_filtering(dmx_ts_feed_t⋆ feed);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_ts_feed_t* feed</para> -</entry><entry - align="char"> -<para>Pointer to the TS feed API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - </section></section> -<section id="section_feed_api"> -<title>Section Feed API</title> -<para>A section feed is a resource consisting of a PID filter and a set of section filters. Using this -API, the client can set the properties of a section feed and to start/stop filtering. The API is -defined as an abstract interface of the type dmx_section_feed_t. The functions that implement -the interface should be defined static or module private. The client can get the handle of -a section feed API by calling the function allocate_section_feed() in the demux -API. -</para> -<para>On demux platforms that provide section filtering in hardware, the Section Feed API -implementation provides a software wrapper for the demux hardware. Other platforms may -support only PID filtering in hardware, requiring that TS packets are converted to sections in -software. In the latter case the Section Feed API implementation can be a client of the TS -Feed API. -</para> - -</section> -<section id="kdapi_set"> -<title>set()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function sets the parameters of a section feed. Any filtering in progress on - the section feed must be stopped before calling this function. If descrambling - is enabled, the payload_scrambling_control and address_scrambling_control - fields of received DVB datagram sections should be observed. If either one is - non-zero, the section should be descrambled either in hardware or using the - functions descramble_mac_address() and descramble_section_payload() of the - demux API. Note that according to the MPEG-2 Systems specification, only - the payloads of private sections can be scrambled while the rest of the section - data must be sent in the clear.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int set(dmx_section_feed_t⋆ feed, __u16 pid, size_t - circular_buffer_size, int descramble, int - check_crc);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_section_feed_t* - feed</para> -</entry><entry - align="char"> -<para>Pointer to the section feed API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>__u16 pid</para> -</entry><entry - align="char"> -<para>PID value to filter; only the TS packets carrying the - specified PID will be accepted.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t - circular_buffer_size</para> -</entry><entry - align="char"> -<para>Size of the circular buffer for filtered sections.</para> -</entry> - </row><row><entry - align="char"> -<para>int descramble</para> -</entry><entry - align="char"> -<para>If non-zero, descramble any sections that are scrambled.</para> -</entry> - </row><row><entry - align="char"> -<para>int check_crc</para> -</entry><entry - align="char"> -<para>If non-zero, check the CRC values of filtered sections.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOMEM</para> -</entry><entry - align="char"> -<para>Not enough memory for the requested buffer size.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOSYS</para> -</entry><entry - align="char"> -<para>No descrambling facility available for sections.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameters.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>allocate_filter()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function is used to allocate a section filter on the demux. It should only be - called when no filtering is in progress on this section feed. If a filter cannot be - allocated, the function fails with -ENOSPC. See in section ?? for the format of - the section filter.</para> -</entry> - </row><row><entry - align="char"> -<para>The bitfields filter_mask and filter_value should only be modified when no - filtering is in progress on this section feed. filter_mask controls which bits of - filter_value are compared with the section headers/payload. On a binary value - of 1 in filter_mask, the corresponding bits are compared. The filter only accepts - sections that are equal to filter_value in all the tested bit positions. Any changes - to the values of filter_mask and filter_value are guaranteed to take effect only - when the start_filtering() function is called next time. The parent pointer in - the struct is initialized by the API implementation to the value of the feed - parameter. The priv pointer is not used by the API implementation, and can - thus be freely utilized by the caller of this function. Any data pointed to by the - priv pointer is available to the recipient of the dmx_section_cb() function call.</para> -</entry> - </row><row><entry - align="char"> -<para>While the maximum section filter length (DMX_MAX_FILTER_SIZE) is - currently set at 16 bytes, hardware filters of that size are not available on all - platforms. Therefore, section filtering will often take place first in hardware, - followed by filtering in software for the header bytes that were not covered - by a hardware filter. The filter_mask field can be checked to determine how - many bytes of the section filter are actually used, and if the hardware filter will - suffice. Additionally, software-only section filters can optionally be allocated - to clients when all hardware section filters are in use. Note that on most demux - hardware it is not possible to filter on the section_length field of the section - header – thus this field is ignored, even though it is included in filter_value and - filter_mask fields.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int allocate_filter(dmx_section_feed_t⋆ feed, - dmx_section_filter_t⋆⋆ filter);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_section_feed_t* - feed</para> -</entry><entry - align="char"> -<para>Pointer to the section feed API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_section_filter_t** - filter</para> -</entry><entry - align="char"> -<para>Pointer to the allocated filter.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOSPC</para> -</entry><entry - align="char"> -<para>No filters of given type and length available.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameters.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>release_filter()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function releases all the resources of a previously allocated section filter. - The function should not be called while filtering is in progress on this section - feed. After calling this function, the caller should not try to dereference the - filter pointer.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int release_filter ( dmx_section_feed_t⋆ feed, - dmx_section_filter_t⋆ filter);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_section_feed_t* - feed</para> -</entry><entry - align="char"> -<para>Pointer to the section feed API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_section_filter_t* - filter</para> -</entry><entry - align="char"> -<para>I/O Pointer to the instance data of a section filter.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENODEV</para> -</entry><entry - align="char"> -<para>No such filter allocated.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>start_filtering()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Starts filtering sections on this section feed, according to its settings. Sections - are first filtered based on their PID and then matched with the section - filters allocated for this feed. If the section matches the PID filter and - at least one section filter, it is delivered to the API client. The section - is delivered asynchronously using the callback function registered with - allocate_section_feed().</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int start_filtering ( dmx_section_feed_t⋆ feed );</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_section_feed_t* - feed</para> -</entry><entry - align="char"> -<para>Pointer to the section feed API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>stop_filtering()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Stops filtering sections on this section feed. Note that any changes to the - filtering parameters (filter_value, filter_mask, etc.) should only be made when - filtering is stopped.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int stop_filtering ( dmx_section_feed_t⋆ feed );</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_section_feed_t* - feed</para> -</entry><entry - align="char"> -<para>Pointer to the section feed API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section> |