From patchwork Sat Oct 10 13:36:09 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mauro Carvalho Chehab X-Patchwork-Id: 7366581 Return-Path: X-Original-To: patchwork-linux-media@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id B61179F32B for ; Sat, 10 Oct 2015 13:37:51 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 8F3292075F for ; Sat, 10 Oct 2015 13:37:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 47437206C3 for ; Sat, 10 Oct 2015 13:37:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752144AbbJJNgz (ORCPT ); Sat, 10 Oct 2015 09:36:55 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:39221 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752019AbbJJNgS (ORCPT ); Sat, 10 Oct 2015 09:36:18 -0400 Received: from [179.183.104.18] (helo=smtp.w2.samsung.com) by bombadil.infradead.org with esmtpsa (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZkuJt-0003Bs-SG; Sat, 10 Oct 2015 13:36:18 +0000 Received: from mchehab by smtp.w2.samsung.com with local (Exim 4.85) (envelope-from ) id 1ZkuJm-0003m0-RW; Sat, 10 Oct 2015 10:36:10 -0300 From: Mauro Carvalho Chehab To: Linux Media Mailing List Cc: Mauro Carvalho Chehab Subject: [PATCH 26/26] [media] DocBook: Remove kdapi.xml Date: Sat, 10 Oct 2015 10:36:09 -0300 Message-Id: X-Mailer: git-send-email 2.4.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Now that the Demux kABI is documented at device-drivers.xml, remove it from the API docbook. Signed-off-by: Mauro Carvalho Chehab delete mode 100644 Documentation/DocBook/media/dvb/kdapi.xml diff --git a/Documentation/DocBook/media/dvb/dvbapi.xml b/Documentation/DocBook/media/dvb/dvbapi.xml index 858fd7d17104..8576481e20ae 100644 --- a/Documentation/DocBook/media/dvb/dvbapi.xml +++ b/Documentation/DocBook/media/dvb/dvbapi.xml @@ -125,9 +125,6 @@ Added ISDB-T test originally written by Patrick Boettcher &sub-audio; - - &sub-kdapi; - &sub-examples; diff --git a/Documentation/DocBook/media/dvb/kdapi.xml b/Documentation/DocBook/media/dvb/kdapi.xml deleted file mode 100644 index ff133a326d50..000000000000 --- a/Documentation/DocBook/media/dvb/kdapi.xml +++ /dev/null @@ -1,1236 +0,0 @@ -Kernel Demux API -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 demux.h and located in -">drivers/media/dvb-core. - -Maintainer note: This section must be reviewed. It is probably out of date. - - -
-Kernel Demux Data Types - - -
-
-TS filter types - - /⋆--------------------------------------------------------------------------⋆/ - /⋆ 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) ⋆/ - - -
-
-dmx_ts_pes_t -The structure - - - 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; - -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. - - - 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; - - - /⋆--------------------------------------------------------------------------⋆/ - /⋆ 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; - - - 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; - - - 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; - - - 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) - - typedef int (⋆dmx_section_cb) ( __u8 ⋆ buffer1, - size_t buffer1_len, - __u8 ⋆ buffer2, - size_t buffer2_len, - dmx_section_filter_t ⋆ source); - - typedef int (⋆dmx_pes_cb) ( __u8 ⋆ buffer1, - size_t buffer1_len, - __u8 ⋆ buffer2, - size_t buffer2_len, - dmx_pes_filter_t⋆ source); - - /⋆--------------------------------------------------------------------------⋆/ - /⋆ DVB Front-End ⋆/ - /⋆--------------------------------------------------------------------------⋆/ - - typedef enum { - DMX_MEMORY_FE, - DMX_FRONTEND_0, - } dmx_frontend_source; - - 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 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 - - -
-
-demux_demux_t - - /⋆ - ⋆ 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 - ⋆. - ⋆/ - - -
-
-Demux directory - - /⋆ - ⋆ 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); - -
-
-Demux Directory API -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. - -All demux drivers in the directory implement the abstract interface dmx_demux_t. - - -
dmx_register_demux() -DESCRIPTION - - -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(), - - -SYNOPSIS - - -int dmx_register_demux ( dmx_demux_t ⋆demux ) - - -PARAMETERS - - -dmx_demux_t* - demux - -Pointer to the demux structure. - - -RETURNS - - -0 - -The function was completed without errors. - - --EEXIST - -A demux with the same value of the id field already stored - in the directory. - - --ENOSPC - -No space left in the directory. - - - -
dmx_unregister_demux() -DESCRIPTION - - -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. - - -SYNOPSIS - - -int dmx_unregister_demux ( dmx_demux_t ⋆demux ) - - -PARAMETERS - - -dmx_demux_t* - demux - -Pointer to the demux structure which is to be - unregistered. - - -RETURNS - - -0 - -The function was completed without errors. - - -ENODEV - -The specified demux is not registered in the demux - directory. - - -EBUSY - -The specified demux is currently in use. - - - -
dmx_get_demuxes() -DESCRIPTION - - -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. - - -SYNOPSIS - - -struct list_head ⋆dmx_get_demuxes () - - -PARAMETERS - - -none - - -RETURNS - - -struct list_head * - -A list of demux interfaces, or NULL in the case of an - empty list. - - -
-
-Demux API -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. - -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. - -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”. - -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. - -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. - - -
-
-Demux Callback API -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. - -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. - -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. - - -
dmx_ts_cb() -DESCRIPTION - - -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. - - -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. - - -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. - - -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. - - -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. - - -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. - - -SYNOPSIS - - -int dmx_ts_cb(__u8⋆ buffer1, size_t buffer1_length, - __u8⋆ buffer2, size_t buffer2_length, dmx_ts_feed_t⋆ - source); - - -PARAMETERS - - -__u8* buffer1 - -Pointer to the start of the filtered TS packets. - - -size_t buffer1_length - -Length of the TS data in buffer1. - - -__u8* buffer2 - -Pointer to the tail of the filtered TS packets, or NULL. - - -size_t buffer2_length - -Length of the TS data in buffer2. - - -dmx_ts_feed_t* - source - -Indicates which TS feed is the source of the callback. - - -RETURNS - - -0 - -Continue filtering. - - --1 - -Stop filtering - has the same effect as a call to - stop_filtering() on the TS Feed API. - - - -
dmx_section_cb() -DESCRIPTION - - -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. - - -SYNOPSIS - - -int dmx_section_cb(__u8⋆ buffer1, size_t - buffer1_length, __u8⋆ buffer2, size_t - buffer2_length, dmx_section_filter_t⋆ source); - - -PARAMETERS - - -__u8* buffer1 - -Pointer to the start of the filtered section, e.g. within the - circular buffer of the demux driver. - - -size_t buffer1_length - -Length of the filtered section data in buffer1, including - headers and CRC. - - -__u8* buffer2 - -Pointer to the tail of the filtered section data, or NULL. - Useful to handle the wrapping of a circular buffer. - - -size_t buffer2_length - -Length of the filtered section data in buffer2, including - headers and CRC. - - -dmx_section_filter_t* - filter - -Indicates the filter that triggered the callback. - - -RETURNS - - -0 - -Continue filtering. - - --1 - -Stop filtering - has the same effect as a call to - stop_filtering() on the Section Feed API. - - -
-
-TS Feed API -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. - -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. - - -
set() -DESCRIPTION - - -This function sets the parameters of a TS feed. Any filtering in progress on the - TS feed must be stopped before calling this function. - - -SYNOPSIS - - -int set ( dmx_ts_feed_t⋆ feed, __u16 pid, size_t - callback_length, size_t circular_buffer_size, int - descramble, struct timespec timeout); - - -PARAMETERS - - -dmx_ts_feed_t* feed - -Pointer to the TS feed API and instance data. - - -__u16 pid - -PID value to filter. Only the TS packets carrying the - specified PID will be passed to the API client. - - -size_t - callback_length - -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. - - -size_t - circular_buffer_size - -Size of the circular buffer for the filtered TS packets. - - -int descramble - -If non-zero, descramble the filtered TS packets. - - -struct timespec - timeout - -Maximum time to wait before delivering received TS - packets to the client. - - -RETURNS - - -0 - -The function was completed without errors. - - --ENOMEM - -Not enough memory for the requested buffer size. - - --ENOSYS - -No descrambling facility available for TS. - - --EINVAL - -Bad parameter. - - - -
start_filtering() -DESCRIPTION - - -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(). - - -SYNOPSIS - - -int start_filtering(dmx_ts_feed_t⋆ feed); - - -PARAMETERS - - -dmx_ts_feed_t* feed - -Pointer to the TS feed API and instance data. - - -RETURNS - - -0 - -The function was completed without errors. - - --EINVAL - -Bad parameter. - - - -
stop_filtering() -DESCRIPTION - - -Stops filtering TS packets on this TS feed. - - -SYNOPSIS - - -int stop_filtering(dmx_ts_feed_t⋆ feed); - - -PARAMETERS - - -dmx_ts_feed_t* feed - -Pointer to the TS feed API and instance data. - - -RETURNS - - -0 - -The function was completed without errors. - - --EINVAL - -Bad parameter. - - -
-
-Section Feed API -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. - -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. - - -
-
-set() -DESCRIPTION - - -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. - - -SYNOPSIS - - -int set(dmx_section_feed_t⋆ feed, __u16 pid, size_t - circular_buffer_size, int descramble, int - check_crc); - - -PARAMETERS - - -dmx_section_feed_t* - feed - -Pointer to the section feed API and instance data. - - -__u16 pid - -PID value to filter; only the TS packets carrying the - specified PID will be accepted. - - -size_t - circular_buffer_size - -Size of the circular buffer for filtered sections. - - -int descramble - -If non-zero, descramble any sections that are scrambled. - - -int check_crc - -If non-zero, check the CRC values of filtered sections. - - -RETURNS - - -0 - -The function was completed without errors. - - --ENOMEM - -Not enough memory for the requested buffer size. - - --ENOSYS - -No descrambling facility available for sections. - - --EINVAL - -Bad parameters. - - - -
allocate_filter() -DESCRIPTION - - -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. - - -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. - - -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. - - -SYNOPSIS - - -int allocate_filter(dmx_section_feed_t⋆ feed, - dmx_section_filter_t⋆⋆ filter); - - -PARAMETERS - - -dmx_section_feed_t* - feed - -Pointer to the section feed API and instance data. - - -dmx_section_filter_t** - filter - -Pointer to the allocated filter. - - -RETURNS - - -0 - -The function was completed without errors. - - --ENOSPC - -No filters of given type and length available. - - --EINVAL - -Bad parameters. - - - -
release_filter() -DESCRIPTION - - -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. - - -SYNOPSIS - - -int release_filter ( dmx_section_feed_t⋆ feed, - dmx_section_filter_t⋆ filter); - - -PARAMETERS - - -dmx_section_feed_t* - feed - -Pointer to the section feed API and instance data. - - -dmx_section_filter_t* - filter - -I/O Pointer to the instance data of a section filter. - - -RETURNS - - -0 - -The function was completed without errors. - - --ENODEV - -No such filter allocated. - - --EINVAL - -Bad parameter. - - - -
start_filtering() -DESCRIPTION - - -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(). - - -SYNOPSIS - - -int start_filtering ( dmx_section_feed_t⋆ feed ); - - -PARAMETERS - - -dmx_section_feed_t* - feed - -Pointer to the section feed API and instance data. - - -RETURNS - - -0 - -The function was completed without errors. - - --EINVAL - -Bad parameter. - - - -
stop_filtering() -DESCRIPTION - - -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. - - -SYNOPSIS - - -int stop_filtering ( dmx_section_feed_t⋆ feed ); - - -PARAMETERS - - -dmx_section_feed_t* - feed - -Pointer to the section feed API and instance data. - - -RETURNS - - -0 - -The function was completed without errors. - - --EINVAL - -Bad parameter. - - - -