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author | Mauro Carvalho Chehab <mchehab@redhat.com> | 2009-09-06 22:25:36 -0300 |
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committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2009-09-06 22:25:36 -0300 |
commit | 8de1392b607bd886b0a083452b85ce7144ad372c (patch) | |
tree | 48a1584f3c59c1702ffb673cbd3ad9cf59f10350 /dvb-spec/sgml/demux.sgml | |
parent | 9816ad7712708e239c037f0806901d02e0329b51 (diff) | |
download | mediapointer-dvb-s2-8de1392b607bd886b0a083452b85ce7144ad372c.tar.gz mediapointer-dvb-s2-8de1392b607bd886b0a083452b85ce7144ad372c.tar.bz2 |
dvb-spec/sgml: Finish conversion to DocBook XML 4.1.2
From: Mauro Carvalho Chehab <mchehab@redhat.com>
With the conversion of both v4l2 and dvb-spec to the same DocBook
version used in kernel, it is now possible to do some interesting things
like adding the docs upstream and/or merge or share chapters between the
two specs. Also, after promoting this version to official, just one set
of text tools will be needed to generate both DVB and V4L2 specs.
Yet, more work is needed to validate the conversion, improve the
layout of the documents, provide cross references, etc.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'dvb-spec/sgml/demux.sgml')
-rw-r--r-- | dvb-spec/sgml/demux.sgml | 973 |
1 files changed, 973 insertions, 0 deletions
diff --git a/dvb-spec/sgml/demux.sgml b/dvb-spec/sgml/demux.sgml new file mode 100644 index 000000000..ad3448219 --- /dev/null +++ b/dvb-spec/sgml/demux.sgml @@ -0,0 +1,973 @@ +<title>DVB Demux Device</title> + +<para>The DVB demux device controls the filters of the DVB hardware/software. It can be +accessed through <emphasis role="tt">/dev/adapter0/demux0</emphasis>. Data types and and ioctl definitions can be +accessed by including <emphasis role="tt">linux/dvb/dmx.h</emphasis> in your application. +</para> +<section id="dmx_types"> +<title>Demux Data Types</title> + +<section id="dmx_output_t"> +<title>dmx_output_t</title> + <programlisting> + typedef enum + { + DMX_OUT_DECODER, + DMX_OUT_TAP, + DMX_OUT_TS_TAP + } dmx_output_t; +</programlisting> +<para><emphasis role="tt">DMX_OUT_TAP</emphasis> delivers the stream output to the demux device on which the ioctl is +called. +</para> +<para><emphasis role="tt">DMX_OUT_TS_TAP</emphasis> routes output to the logical DVR device <emphasis role="tt">/dev/dvb/adapter0/dvr0</emphasis>, +which delivers a TS multiplexed from all filters for which <emphasis role="tt">DMX_OUT_TS_TAP</emphasis> was +specified. +</para> +</section> + +<section id="dmx_input_t"> +<title>dmx_input_t</title> + <programlisting> + typedef enum + { + DMX_IN_FRONTEND, + DMX_IN_DVR + } dmx_input_t; +</programlisting> +</section> + +<section id="dmx_pes_type_t"> +<title>dmx_pes_type_t</title> + <programlisting> + typedef enum + { + DMX_PES_AUDIO, + DMX_PES_VIDEO, + DMX_PES_TELETEXT, + DMX_PES_SUBTITLE, + DMX_PES_PCR, + DMX_PES_OTHER + } dmx_pes_type_t; +</programlisting> +</section> + +<section id="dmx_event_t"> +<title>dmx_event_t</title> + <programlisting> + typedef enum + { + DMX_SCRAMBLING_EV, + DMX_FRONTEND_EV + } dmx_event_t; +</programlisting> +</section> + +<section id="dmx_scrambling_status_t"> +<title>dmx_scrambling_status_t</title> + <programlisting> + typedef enum + { + DMX_SCRAMBLING_OFF, + DMX_SCRAMBLING_ON + } dmx_scrambling_status_t; +</programlisting> +</section> + +<section id="dmx_filter"> +<title>struct dmx_filter</title> + <programlisting> + typedef struct dmx_filter + { + uint8_t filter[DMX_FILTER_SIZE]; + uint8_t mask[DMX_FILTER_SIZE]; + } dmx_filter_t; +</programlisting> +</section> + +<section id="dmx_sct_filter_params"> +<title>struct dmx_sct_filter_params</title> + <programlisting> + struct dmx_sct_filter_params + { + uint16_t pid; + dmx_filter_t filter; + uint32_t timeout; + uint32_t flags; + #define DMX_CHECK_CRC 1 + #define DMX_ONESHOT 2 + #define DMX_IMMEDIATE_START 4 + }; +</programlisting> +</section> + +<section id="dmx_pes_filter_params"> +<title>struct dmx_pes_filter_params</title> + <programlisting> + struct dmx_pes_filter_params + { + uint16_t pid; + dmx_input_t input; + dmx_output_t output; + dmx_pes_type_t pes_type; + uint32_t flags; + }; +</programlisting> +</section> + +<section id="dmx_event"> +<title>struct dmx_event</title> + <programlisting> + struct dmx_event + { + dmx_event_t event; + time_t timeStamp; + union + { + dmx_scrambling_status_t scrambling; + } u; + }; +</programlisting> +</section> + +<section id="dmx_stc"> +<title>struct dmx_stc</title> + <programlisting> + struct dmx_stc { + unsigned int num; /⋆ input : which STC? 0..N ⋆/ + unsigned int base; /⋆ output: divisor for stc to get 90 kHz clock ⋆/ + uint64_t stc; /⋆ output: stc in 'base'⋆90 kHz units ⋆/ + }; +</programlisting> + </section> + +</section> + +<section id="dmx_fcalls"> +<title>Demux Function Calls</title> + +<section id="dmx_fopen"> +<title>open()</title> +<para>DESCRIPTION +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>This system call, used with a device name of /dev/dvb/adapter0/demux0, + allocates a new filter and returns a handle which can be used for subsequent + control of that filter. This call has to be made for each filter to be used, i.e. every + returned file descriptor is a reference to a single filter. /dev/dvb/adapter0/dvr0 + is a logical device to be used for retrieving Transport Streams for digital + video recording. When reading from this device a transport stream containing + the packets from all PES filters set in the corresponding demux device + (/dev/dvb/adapter0/demux0) having the output set to DMX_OUT_TS_TAP. A + recorded Transport Stream is replayed by writing to this device. </para> +<para>The significance of blocking or non-blocking mode is described in the + documentation for functions where there is a difference. It does not affect the + semantics of the open() call itself. A device opened in blocking mode can later + be put into non-blocking mode (and vice versa) using the F_SETFL command + of the fcntl system call.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>SYNOPSIS +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>int open(const char ⋆deviceName, int flags);</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>PARAMETERS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>const char + *deviceName</para> +</entry><entry + align="char"> +<para>Name of demux device.</para> +</entry> + </row><row><entry + align="char"> +<para>int flags</para> +</entry><entry + align="char"> +<para>A bit-wise OR of the following flags:</para> +</entry> + </row><row><entry + align="char"> +</entry><entry + align="char"> +<para>O_RDWR read/write access</para> +</entry> + </row><row><entry + align="char"> +</entry><entry + align="char"> +<para>O_NONBLOCK open in non-blocking mode</para> +</entry> + </row><row><entry + align="char"> +</entry><entry + align="char"> +<para>(blocking mode is the default)</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>ERRORS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>ENODEV</para> +</entry><entry + align="char"> +<para>Device driver not loaded/available.</para> +</entry> + </row><row><entry + align="char"> +<para>EINVAL</para> +</entry><entry + align="char"> +<para>Invalid argument.</para> +</entry> + </row><row><entry + align="char"> +<para>EMFILE</para> +</entry><entry + align="char"> +<para>“Too many open files”, i.e. no more filters available.</para> +</entry> + </row><row><entry + align="char"> +<para>ENOMEM</para> +</entry><entry + align="char"> +<para>The driver failed to allocate enough memory.</para> +</entry> + </row></tbody></tgroup></informaltable> +</section> + +<section id="dmx_fclose"> +<title>close()</title> +<para>DESCRIPTION +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>This system call deactivates and deallocates a filter that was previously + allocated via the open() call.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>SYNOPSIS +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>int close(int fd);</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>PARAMETERS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>int fd</para> +</entry><entry + align="char"> +<para>File descriptor returned by a previous call to open().</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>ERRORS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>EBADF</para> +</entry><entry + align="char"> +<para>fd is not a valid open file descriptor.</para> +</entry> + </row></tbody></tgroup></informaltable> +</section> + +<section id="dmx_fread"> +<title>read()</title> +<para>DESCRIPTION +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>This system call returns filtered data, which might be section or PES data. The + filtered data is transferred from the driver’s internal circular buffer to buf. The + maximum amount of data to be transferred is implied by count.</para> +</entry> + </row><row><entry + align="char"> +<para>When returning section data the driver always tries to return a complete single + section (even though buf would provide buffer space for more data). If the size + of the buffer is smaller than the section as much as possible will be returned, + and the remaining data will be provided in subsequent calls.</para> +</entry> + </row><row><entry + align="char"> +<para>The size of the internal buffer is 2 * 4096 bytes (the size of two maximum + sized sections) by default. The size of this buffer may be changed by using the + DMX_SET_BUFFER_SIZE function. If the buffer is not large enough, or if + the read operations are not performed fast enough, this may result in a buffer + overflow error. In this case EOVERFLOW will be returned, and the circular + buffer will be emptied. This call is blocking if there is no data to return, i.e. the + process will be put to sleep waiting for data, unless the O_NONBLOCK flag + is specified.</para> +</entry> + </row><row><entry + align="char"> +<para>Note that in order to be able to read, the filtering process has to be started + by defining either a section or a PES filter by means of the ioctl functions, + and then starting the filtering process via the DMX_START ioctl function + or by setting the DMX_IMMEDIATE_START flag. If the reading is done + from a logical DVR demux device, the data will constitute a Transport Stream + including the packets from all PES filters in the corresponding demux device + /dev/dvb/adapter0/demux0 having the output set to DMX_OUT_TS_TAP.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>SYNOPSIS +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>size_t read(int fd, void ⋆buf, size_t count);</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>PARAMETERS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>int fd</para> +</entry><entry + align="char"> +<para>File descriptor returned by a previous call to open().</para> +</entry> + </row><row><entry + align="char"> +<para>void *buf</para> +</entry><entry + align="char"> +<para>Pointer to the buffer to be used for returned filtered data.</para> +</entry> + </row><row><entry + align="char"> +<para>size_t count</para> +</entry><entry + align="char"> +<para>Size of buf.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>ERRORS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>EWOULDBLOCK</para> +</entry><entry + align="char"> +<para>No data to return and O_NONBLOCK was specified.</para> +</entry> + </row><row><entry + align="char"> +<para>EBADF</para> +</entry><entry + align="char"> +<para>fd is not a valid open file descriptor.</para> +</entry> + </row><row><entry + align="char"> +<para>ECRC</para> +</entry><entry + align="char"> +<para>Last section had a CRC error - no data returned. The + buffer is flushed.</para> +</entry> + </row><row><entry + align="char"> +<para>EOVERFLOW</para> +</entry><entry + align="char"> +</entry> + </row><row><entry + align="char"> +</entry><entry + align="char"> +<para>The filtered data was not read from the buffer in due + time, resulting in non-read data being lost. The buffer is + flushed.</para> +</entry> + </row><row><entry + align="char"> +<para>ETIMEDOUT</para> +</entry><entry + align="char"> +<para>The section was not loaded within the stated timeout + period. See ioctl DMX_SET_FILTER for how to set a + timeout.</para> +</entry> + </row><row><entry + align="char"> +<para>EFAULT</para> +</entry><entry + align="char"> +<para>The driver failed to write to the callers buffer due to an + invalid *buf pointer.</para> +</entry> + </row></tbody></tgroup></informaltable> +</section> + +<section id="dmx_fwrite"> +<title>write()</title> +<para>DESCRIPTION +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>This system call is only provided by the logical device /dev/dvb/adapter0/dvr0, + associated with the physical demux device that provides the actual DVR + functionality. It is used for replay of a digitally recorded Transport Stream. + Matching filters have to be defined in the corresponding physical demux + device, /dev/dvb/adapter0/demux0. The amount of data to be transferred is + implied by count.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>SYNOPSIS +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>ssize_t write(int fd, const void ⋆buf, size_t + count);</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>PARAMETERS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>int fd</para> +</entry><entry + align="char"> +<para>File descriptor returned by a previous call to open().</para> +</entry> + </row><row><entry + align="char"> +<para>void *buf</para> +</entry><entry + align="char"> +<para>Pointer to the buffer containing the Transport Stream.</para> +</entry> + </row><row><entry + align="char"> +<para>size_t count</para> +</entry><entry + align="char"> +<para>Size of buf.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>ERRORS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>EWOULDBLOCK</para> +</entry><entry + align="char"> +<para>No data was written. This + might happen if O_NONBLOCK was specified and there + is no more buffer space available (if O_NONBLOCK is + not specified the function will block until buffer space is + available).</para> +</entry> + </row><row><entry + align="char"> +<para>EBUSY</para> +</entry><entry + align="char"> +<para>This error code indicates that there are conflicting + requests. The corresponding demux device is setup to + receive data from the front- end. Make sure that these + filters are stopped and that the filters with input set to + DMX_IN_DVR are started.</para> +</entry> + </row><row><entry + align="char"> +<para>EBADF</para> +</entry><entry + align="char"> +<para>fd is not a valid open file descriptor.</para> +</entry> + </row></tbody></tgroup></informaltable> +</section> + +<section id="dmx_start"> +<title>DMX_START</title> +<para>DESCRIPTION +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>This ioctl call is used to start the actual filtering operation defined via the ioctl + calls DMX_SET_FILTER or DMX_SET_PES_FILTER.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>SYNOPSIS +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>int ioctl( int fd, int request = DMX_START);</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>PARAMETERS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>int fd</para> +</entry><entry + align="char"> +<para>File descriptor returned by a previous call to open().</para> +</entry> + </row><row><entry + align="char"> +<para>int request</para> +</entry><entry + align="char"> +<para>Equals DMX_START for this command.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>ERRORS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>EBADF</para> +</entry><entry + align="char"> +<para>fd is not a valid file descriptor.</para> +</entry> + </row><row><entry + align="char"> +<para>EINVAL</para> +</entry><entry + align="char"> +<para>Invalid argument, i.e. no filtering parameters provided via + the DMX_SET_FILTER or DMX_SET_PES_FILTER + functions.</para> +</entry> + </row><row><entry + align="char"> +<para>EBUSY</para> +</entry><entry + align="char"> +<para>This error code indicates that there are conflicting + requests. There are active filters filtering data from + another input source. Make sure that these filters are + stopped before starting this filter.</para> +</entry> + </row></tbody></tgroup></informaltable> +</section> + +<section id="dmx_stop"> +<title>DMX_STOP</title> +<para>DESCRIPTION +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>This ioctl call is used to stop the actual filtering operation defined via the + ioctl calls DMX_SET_FILTER or DMX_SET_PES_FILTER and started via + the DMX_START command.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>SYNOPSIS +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>int ioctl( int fd, int request = DMX_STOP);</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>PARAMETERS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>int fd</para> +</entry><entry + align="char"> +<para>File descriptor returned by a previous call to open().</para> +</entry> + </row><row><entry + align="char"> +<para>int request</para> +</entry><entry + align="char"> +<para>Equals DMX_STOP for this command.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>ERRORS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>EBADF</para> +</entry><entry + align="char"> +<para>fd is not a valid file descriptor.</para> +</entry> + </row></tbody></tgroup></informaltable> +</section> + +<section id="dmx_set_filter"> +<title>DMX_SET_FILTER</title> +<para>DESCRIPTION +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>This ioctl call sets up a filter according to the filter and mask parameters + provided. A timeout may be defined stating number of seconds to wait for a + section to be loaded. A value of 0 means that no timeout should be applied. + Finally there is a flag field where it is possible to state whether a section should + be CRC-checked, whether the filter should be a ”one-shot” filter, i.e. if the + filtering operation should be stopped after the first section is received, and + whether the filtering operation should be started immediately (without waiting + for a DMX_START ioctl call). If a filter was previously set-up, this filter will + be canceled, and the receive buffer will be flushed.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>SYNOPSIS +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>int ioctl( int fd, int request = DMX_SET_FILTER, + struct dmx_sct_filter_params ⋆params);</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>PARAMETERS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>int fd</para> +</entry><entry + align="char"> +<para>File descriptor returned by a previous call to open().</para> +</entry> + </row><row><entry + align="char"> +<para>int request</para> +</entry><entry + align="char"> +<para>Equals DMX_SET_FILTER for this command.</para> +</entry> + </row><row><entry + align="char"> +<para>struct + dmx_sct_filter_params + *params</para> +</entry><entry + align="char"> +<para>Pointer to structure containing filter parameters.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>ERRORS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>EBADF</para> +</entry><entry + align="char"> +<para>fd is not a valid file descriptor.</para> +</entry> + </row><row><entry + align="char"> +<para>EINVAL</para> +</entry><entry + align="char"> +<para>Invalid argument.</para> +</entry> + </row></tbody></tgroup></informaltable> +</section> + +<section id="dmx_set_pes_filter"> +<title>DMX_SET_PES_FILTER</title> +<para>DESCRIPTION +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>This ioctl call sets up a PES filter according to the parameters provided. By a + PES filter is meant a filter that is based just on the packet identifier (PID), i.e. + no PES header or payload filtering capability is supported.</para> +</entry> + </row><row><entry + align="char"> +<para>The transport stream destination for the filtered output may be set. Also the + PES type may be stated in order to be able to e.g. direct a video stream directly + to the video decoder. Finally there is a flag field where it is possible to state + whether the filtering operation should be started immediately (without waiting + for a DMX_START ioctl call). If a filter was previously set-up, this filter will + be cancelled, and the receive buffer will be flushed.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>SYNOPSIS +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>int ioctl( int fd, int request = DMX_SET_PES_FILTER, + struct dmx_pes_filter_params ⋆params);</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>PARAMETERS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>int fd</para> +</entry><entry + align="char"> +<para>File descriptor returned by a previous call to open().</para> +</entry> + </row><row><entry + align="char"> +<para>int request</para> +</entry><entry + align="char"> +<para>Equals DMX_SET_PES_FILTER for this command.</para> +</entry> + </row><row><entry + align="char"> +<para>struct + dmx_pes_filter_params + *params</para> +</entry><entry + align="char"> +<para>Pointer to structure containing filter parameters.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>ERRORS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>EBADF</para> +</entry><entry + align="char"> +<para>fd is not a valid file descriptor.</para> +</entry> + </row><row><entry + align="char"> +<para>EINVAL</para> +</entry><entry + align="char"> +<para>Invalid argument.</para> +</entry> + </row><row><entry + align="char"> +<para>EBUSY</para> +</entry><entry + align="char"> +<para>This error code indicates that there are conflicting + requests. There are active filters filtering data from + another input source. Make sure that these filters are + stopped before starting this filter.</para> +</entry> + </row></tbody></tgroup></informaltable> +</section> + +<section id="dms_set_buffer_size"> +<title>DMX_SET_BUFFER_SIZE</title> +<para>DESCRIPTION +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>This ioctl call is used to set the size of the circular buffer used for filtered data. + The default size is two maximum sized sections, i.e. if this function is not called + a buffer size of 2 * 4096 bytes will be used.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>SYNOPSIS +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>int ioctl( int fd, int request = + DMX_SET_BUFFER_SIZE, unsigned long size);</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>PARAMETERS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>int fd</para> +</entry><entry + align="char"> +<para>File descriptor returned by a previous call to open().</para> +</entry> + </row><row><entry + align="char"> +<para>int request</para> +</entry><entry + align="char"> +<para>Equals DMX_SET_BUFFER_SIZE for this command.</para> +</entry> + </row><row><entry + align="char"> +<para>unsigned long size</para> +</entry><entry + align="char"> +<para>Size of circular buffer.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>ERRORS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>EBADF</para> +</entry><entry + align="char"> +<para>fd is not a valid file descriptor.</para> +</entry> + </row><row><entry + align="char"> +<para>ENOMEM</para> +</entry><entry + align="char"> +<para>The driver was not able to allocate a buffer of the + requested size.</para> +</entry> + </row></tbody></tgroup></informaltable> +</section> + +<section id="dmx_get_event"> +<title>DMX_GET_EVENT</title> +<para>DESCRIPTION +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>This ioctl call returns an event if available. If an event is not available, + the behavior depends on whether the device is in blocking or non-blocking + mode. In the latter case, the call fails immediately with errno set to + EWOULDBLOCK. In the former case, the call blocks until an event becomes + available.</para> +</entry> + </row><row><entry + align="char"> +<para>The standard Linux poll() and/or select() system calls can be used with the + device file descriptor to watch for new events. For select(), the file descriptor + should be included in the exceptfds argument, and for poll(), POLLPRI should + be specified as the wake-up condition. Only the latest event for each filter is + saved.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>SYNOPSIS +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>int ioctl( int fd, int request = DMX_GET_EVENT, + struct dmx_event ⋆ev);</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>PARAMETERS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>int fd</para> +</entry><entry + align="char"> +<para>File descriptor returned by a previous call to open().</para> +</entry> + </row><row><entry + align="char"> +<para>int request</para> +</entry><entry + align="char"> +<para>Equals DMX_GET_EVENT for this command.</para> +</entry> + </row><row><entry + align="char"> +<para>struct dmx_event *ev</para> +</entry><entry + align="char"> +<para>Pointer to the location where the event is to be stored.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>ERRORS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>EBADF</para> +</entry><entry + align="char"> +<para>fd is not a valid file descriptor.</para> +</entry> + </row><row><entry + align="char"> +<para>EFAULT</para> +</entry><entry + align="char"> +<para>ev points to an invalid address.</para> +</entry> + </row><row><entry + align="char"> +<para>EWOULDBLOCK</para> +</entry><entry + align="char"> +<para>There is no event pending, and the device is in + non-blocking mode.</para> +</entry> + </row></tbody></tgroup></informaltable> +</section> + +<section id="dmx_get_stc"> +<title>DMX_GET_STC</title> +<para>DESCRIPTION +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>This ioctl call returns the current value of the system time counter (which is driven + by a PES filter of type DMX_PES_PCR). Some hardware supports more than one + STC, so you must specify which one by setting the num field of stc before the ioctl + (range 0...n). The result is returned in form of a ratio with a 64 bit numerator + and a 32 bit denominator, so the real 90kHz STC value is stc->stc / + stc->base + .</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>SYNOPSIS +</para> +<informaltable><tgroup cols="1"><tbody><row><entry + align="char"> +<para>int ioctl( int fd, int request = DMX_GET_STC, struct + dmx_stc ⋆stc);</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>PARAMETERS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>int fd</para> +</entry><entry + align="char"> +<para>File descriptor returned by a previous call to open().</para> +</entry> + </row><row><entry + align="char"> +<para>int request</para> +</entry><entry + align="char"> +<para>Equals DMX_GET_STC for this command.</para> +</entry> + </row><row><entry + align="char"> +<para>struct dmx_stc *stc</para> +</entry><entry + align="char"> +<para>Pointer to the location where the stc is to be stored.</para> +</entry> + </row></tbody></tgroup></informaltable> +<para>ERRORS +</para> +<informaltable><tgroup cols="2"><tbody><row><entry + align="char"> +<para>EBADF</para> +</entry><entry + align="char"> +<para>fd is not a valid file descriptor.</para> +</entry> + </row><row><entry + align="char"> +<para>EFAULT</para> +</entry><entry + align="char"> +<para>stc points to an invalid address.</para> +</entry> + </row><row><entry + align="char"> +<para>EINVAL</para> +</entry><entry + align="char"> +<para>Invalid stc number.</para> +</entry> + </row></tbody></tgroup></informaltable> + </section></section>
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