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<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968" /><title>Chapter 15. Kernel Demux API</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /><link rel="home" href="index.html" title="LINUX MEDIA INFRASTRUCTURE API" /><link rel="up" href="pt02.html" title="Part II. LINUX DVB API" /><link rel="prev" href="ch14.html" title="Chapter 14. DVB Network API" /><link rel="next" href="ch15s02.html" title="Demux Directory API" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 15. Kernel Demux API</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ch14.html">Prev</a> </td><th width="60%" align="center">Part II. LINUX DVB API</th><td width="20%" align="right"> <a accesskey="n" href="ch15s02.html">Next</a></td></tr></table><hr /></div><div class="chapter" title="Chapter 15. Kernel Demux API"><div class="titlepage"><div><div><h2 class="title"><a id="dvb_kdapi"></a>Chapter 15. Kernel Demux API</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="ch15.html#kernel_demux_data_types">Kernel Demux Data Types</a></span></dt><dd><dl><dt><span class="section"><a href="ch15.html#dmx_success_t">dmx_success_t</a></span></dt><dt><span class="section"><a href="ch15.html#ts_filter_types">TS filter types</a></span></dt><dt><span class="section"><a href="ch15.html#dmx_ts_pes_t">dmx_ts_pes_t</a></span></dt><dt><span class="section"><a href="ch15.html#demux_demux_t">demux_demux_t</a></span></dt><dt><span class="section"><a href="ch15.html#demux_directory">Demux directory</a></span></dt></dl></dd><dt><span class="section"><a href="ch15s02.html">Demux Directory API</a></span></dt><dd><dl><dt><span class="section"><a href="ch15s02.html#id2873402">dmx_register_demux()</a></span></dt><dt><span class="section"><a href="ch15s02.html#id2873550">dmx_unregister_demux()</a></span></dt><dt><span class="section"><a href="ch15s02.html#id2873700">dmx_get_demuxes()</a></span></dt></dl></dd><dt><span class="section"><a href="ch15s03.html">Demux API</a></span></dt><dd><dl><dt><span class="section"><a href="ch15s03.html#kdapi_fopen">open()</a></span></dt><dt><span class="section"><a href="ch15s03.html#kdapi_fclose">close()</a></span></dt><dt><span class="section"><a href="ch15s03.html#kdapi_fwrite">write()</a></span></dt><dt><span class="section"><a href="ch15s03.html#id2874357">allocate_ts_feed()</a></span></dt><dt><span class="section"><a href="ch15s03.html#id2874557">release_ts_feed()</a></span></dt><dt><span class="section"><a href="ch15s03.html#id2874700">allocate_section_feed()</a></span></dt><dt><span class="section"><a href="ch15s03.html#id2874907">release_section_feed()</a></span></dt><dt><span class="section"><a href="ch15s03.html#id2875051">descramble_mac_address()</a></span></dt><dt><span class="section"><a href="ch15s03.html#id2875295">descramble_section_payload()</a></span></dt><dt><span class="section"><a href="ch15s03.html#id2875576">add_frontend()</a></span></dt><dt><span class="section"><a href="ch15s03.html#id2875781">remove_frontend()</a></span></dt><dt><span class="section"><a href="ch15s03.html#id2875951">get_frontends()</a></span></dt><dt><span class="section"><a href="ch15s03.html#id2876073">connect_frontend()</a></span></dt><dt><span class="section"><a href="ch15s03.html#id2876249">disconnect_frontend()</a></span></dt></dl></dd><dt><span class="section"><a href="ch15s04.html">Demux Callback API</a></span></dt><dd><dl><dt><span class="section"><a href="ch15s04.html#id2876413">dmx_ts_cb()</a></span></dt><dt><span class="section"><a href="ch15s04.html#id2876755">dmx_section_cb()</a></span></dt></dl></dd><dt><span class="section"><a href="ch15s05.html">TS Feed API</a></span></dt><dd><dl><dt><span class="section"><a href="ch15s05.html#id2877022">set()</a></span></dt><dt><span class="section"><a href="ch15s05.html#id2877284">start_filtering()</a></span></dt><dt><span class="section"><a href="ch15s05.html#id2877410">stop_filtering()</a></span></dt></dl></dd><dt><span class="section"><a href="ch15s06.html">Section Feed API</a></span></dt><dt><span class="section"><a href="ch15s07.html">set()</a></span></dt><dt><span class="section"><a href="ch15s08.html">allocate_filter()</a></span></dt><dt><span class="section"><a href="ch15s09.html">release_filter()</a></span></dt><dt><span class="section"><a href="ch15s10.html">start_filtering()</a></span></dt><dt><span class="section"><a href="ch15s11.html">stop_filtering()</a></span></dt></dl></div><p>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 <span class="tt">demux.h</span> and located in
<span class="tt">drivers/media/dvb/dvb-core</span>.
</p><p>Maintainer note: This section must be reviewed. It is probably out of date.
</p><div class="section" title="Kernel Demux Data Types"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="kernel_demux_data_types"></a>Kernel Demux Data Types</h2></div></div></div><div class="toc"><dl><dt><span class="section"><a href="ch15.html#dmx_success_t">dmx_success_t</a></span></dt><dt><span class="section"><a href="ch15.html#ts_filter_types">TS filter types</a></span></dt><dt><span class="section"><a href="ch15.html#dmx_ts_pes_t">dmx_ts_pes_t</a></span></dt><dt><span class="section"><a href="ch15.html#demux_demux_t">demux_demux_t</a></span></dt><dt><span class="section"><a href="ch15.html#demux_directory">Demux directory</a></span></dt></dl></div><div class="section" title="dmx_success_t"><div class="titlepage"><div><div><h3 class="title"><a id="dmx_success_t"></a>dmx_success_t</h3></div></div></div><pre class="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;
</pre></div><div class="section" title="TS filter types"><div class="titlepage"><div><div><h3 class="title"><a id="ts_filter_types"></a>TS filter types</h3></div></div></div><pre class="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) ⋆/
</pre></div><div class="section" title="dmx_ts_pes_t"><div class="titlepage"><div><div><h3 class="title"><a id="dmx_ts_pes_t"></a>dmx_ts_pes_t</h3></div></div></div><p>The structure
</p><pre class="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;
</pre><p>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.
</p><pre class="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;
</pre><pre class="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;
</pre><pre class="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;
</pre><pre class="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;
</pre><pre class="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
</pre></div><div class="section" title="demux_demux_t"><div class="titlepage"><div><div><h3 class="title"><a id="demux_demux_t"></a>demux_demux_t</h3></div></div></div><pre class="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;
</pre></div><div class="section" title="Demux directory"><div class="titlepage"><div><div><h3 class="title"><a id="demux_directory"></a>Demux directory</h3></div></div></div><pre class="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);
</pre></div></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ch14.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="pt02.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ch15s02.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 14. DVB Network API </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Demux Directory API</td></tr></table></div></body></html>
