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Diffstat (limited to 'Documentation/DocBook/media/dvb/demux.xml')
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diff --git a/Documentation/DocBook/media/dvb/demux.xml b/Documentation/DocBook/media/dvb/demux.xml new file mode 100644 index 000000000000..1b8c4e9835b9 --- /dev/null +++ b/Documentation/DocBook/media/dvb/demux.xml @@ -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> |
