| .. -*- coding: utf-8; mode: rst -*- |
| |
| .. _dmx_fcalls: |
| |
| ******************** |
| Demux Function Calls |
| ******************** |
| |
| |
| .. _dmx_fopen: |
| |
| open() |
| ====== |
| |
| DESCRIPTION |
| |
| 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. |
| |
| 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. |
| |
| SYNOPSIS |
| |
| int open(const char *deviceName, int flags); |
| |
| PARAMETERS |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - const char *deviceName |
| |
| - Name of demux device. |
| |
| - .. row 2 |
| |
| - int flags |
| |
| - A bit-wise OR of the following flags: |
| |
| - .. row 3 |
| |
| - |
| - O_RDWR read/write access |
| |
| - .. row 4 |
| |
| - |
| - O_NONBLOCK open in non-blocking mode |
| |
| - .. row 5 |
| |
| - |
| - (blocking mode is the default) |
| |
| |
| RETURN VALUE |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - ENODEV |
| |
| - Device driver not loaded/available. |
| |
| - .. row 2 |
| |
| - EINVAL |
| |
| - Invalid argument. |
| |
| - .. row 3 |
| |
| - EMFILE |
| |
| - “Too many open files”, i.e. no more filters available. |
| |
| - .. row 4 |
| |
| - ENOMEM |
| |
| - The driver failed to allocate enough memory. |
| |
| |
| |
| .. _dmx_fclose: |
| |
| close() |
| ======= |
| |
| DESCRIPTION |
| |
| This system call deactivates and deallocates a filter that was |
| previously allocated via the open() call. |
| |
| SYNOPSIS |
| |
| int close(int fd); |
| |
| PARAMETERS |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - int fd |
| |
| - File descriptor returned by a previous call to open(). |
| |
| |
| RETURN VALUE |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - EBADF |
| |
| - fd is not a valid open file descriptor. |
| |
| |
| |
| .. _dmx_fread: |
| |
| read() |
| ====== |
| |
| DESCRIPTION |
| |
| 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. |
| |
| SYNOPSIS |
| |
| size_t read(int fd, void *buf, size_t count); |
| |
| PARAMETERS |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - int fd |
| |
| - File descriptor returned by a previous call to open(). |
| |
| - .. row 2 |
| |
| - void *buf |
| |
| - Pointer to the buffer to be used for returned filtered data. |
| |
| - .. row 3 |
| |
| - size_t count |
| |
| - Size of buf. |
| |
| |
| RETURN VALUE |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - EWOULDBLOCK |
| |
| - No data to return and O_NONBLOCK was specified. |
| |
| - .. row 2 |
| |
| - EBADF |
| |
| - fd is not a valid open file descriptor. |
| |
| - .. row 3 |
| |
| - ECRC |
| |
| - Last section had a CRC error - no data returned. The buffer is |
| flushed. |
| |
| - .. row 4 |
| |
| - EOVERFLOW |
| |
| - |
| |
| - .. row 5 |
| |
| - |
| - The filtered data was not read from the buffer in due time, |
| resulting in non-read data being lost. The buffer is flushed. |
| |
| - .. row 6 |
| |
| - ETIMEDOUT |
| |
| - The section was not loaded within the stated timeout period. See |
| ioctl DMX_SET_FILTER for how to set a timeout. |
| |
| - .. row 7 |
| |
| - EFAULT |
| |
| - The driver failed to write to the callers buffer due to an invalid |
| *buf pointer. |
| |
| |
| |
| .. _dmx_fwrite: |
| |
| write() |
| ======= |
| |
| DESCRIPTION |
| |
| 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. |
| |
| SYNOPSIS |
| |
| ssize_t write(int fd, const void *buf, size_t count); |
| |
| PARAMETERS |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - int fd |
| |
| - File descriptor returned by a previous call to open(). |
| |
| - .. row 2 |
| |
| - void *buf |
| |
| - Pointer to the buffer containing the Transport Stream. |
| |
| - .. row 3 |
| |
| - size_t count |
| |
| - Size of buf. |
| |
| |
| RETURN VALUE |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - EWOULDBLOCK |
| |
| - 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). |
| |
| - .. row 2 |
| |
| - EBUSY |
| |
| - 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. |
| |
| - .. row 3 |
| |
| - EBADF |
| |
| - fd is not a valid open file descriptor. |
| |
| |
| |
| .. _DMX_START: |
| |
| DMX_START |
| ========= |
| |
| DESCRIPTION |
| |
| This ioctl call is used to start the actual filtering operation defined |
| via the ioctl calls DMX_SET_FILTER or DMX_SET_PES_FILTER. |
| |
| SYNOPSIS |
| |
| int ioctl( int fd, int request = DMX_START); |
| |
| PARAMETERS |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - int fd |
| |
| - File descriptor returned by a previous call to open(). |
| |
| - .. row 2 |
| |
| - int request |
| |
| - Equals DMX_START for this command. |
| |
| |
| RETURN VALUE |
| |
| On success 0 is returned, on error -1 and the ``errno`` variable is set |
| appropriately. The generic error codes are described at the |
| :ref:`Generic Error Codes <gen-errors>` chapter. |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - EINVAL |
| |
| - Invalid argument, i.e. no filtering parameters provided via the |
| DMX_SET_FILTER or DMX_SET_PES_FILTER functions. |
| |
| - .. row 2 |
| |
| - EBUSY |
| |
| - 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. |
| |
| |
| |
| .. _DMX_STOP: |
| |
| DMX_STOP |
| ======== |
| |
| DESCRIPTION |
| |
| 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. |
| |
| SYNOPSIS |
| |
| int ioctl( int fd, int request = DMX_STOP); |
| |
| PARAMETERS |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - int fd |
| |
| - File descriptor returned by a previous call to open(). |
| |
| - .. row 2 |
| |
| - int request |
| |
| - Equals DMX_STOP for this command. |
| |
| |
| RETURN VALUE |
| |
| On success 0 is returned, on error -1 and the ``errno`` variable is set |
| appropriately. The generic error codes are described at the |
| :ref:`Generic Error Codes <gen-errors>` chapter. |
| |
| |
| .. _DMX_SET_FILTER: |
| |
| DMX_SET_FILTER |
| ============== |
| |
| DESCRIPTION |
| |
| 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. |
| |
| SYNOPSIS |
| |
| int ioctl( int fd, int request = DMX_SET_FILTER, struct |
| dmx_sct_filter_params *params); |
| |
| PARAMETERS |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - int fd |
| |
| - File descriptor returned by a previous call to open(). |
| |
| - .. row 2 |
| |
| - int request |
| |
| - Equals DMX_SET_FILTER for this command. |
| |
| - .. row 3 |
| |
| - struct dmx_sct_filter_params *params |
| |
| - Pointer to structure containing filter parameters. |
| |
| |
| RETURN VALUE |
| |
| On success 0 is returned, on error -1 and the ``errno`` variable is set |
| appropriately. The generic error codes are described at the |
| :ref:`Generic Error Codes <gen-errors>` chapter. |
| |
| |
| .. _DMX_SET_PES_FILTER: |
| |
| DMX_SET_PES_FILTER |
| ================== |
| |
| DESCRIPTION |
| |
| 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. |
| |
| SYNOPSIS |
| |
| int ioctl( int fd, int request = DMX_SET_PES_FILTER, struct |
| dmx_pes_filter_params *params); |
| |
| PARAMETERS |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - int fd |
| |
| - File descriptor returned by a previous call to open(). |
| |
| - .. row 2 |
| |
| - int request |
| |
| - Equals DMX_SET_PES_FILTER for this command. |
| |
| - .. row 3 |
| |
| - struct dmx_pes_filter_params *params |
| |
| - Pointer to structure containing filter parameters. |
| |
| |
| RETURN VALUE |
| |
| On success 0 is returned, on error -1 and the ``errno`` variable is set |
| appropriately. The generic error codes are described at the |
| :ref:`Generic Error Codes <gen-errors>` chapter. |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - EBUSY |
| |
| - 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. |
| |
| |
| |
| .. _DMX_SET_BUFFER_SIZE: |
| |
| DMX_SET_BUFFER_SIZE |
| =================== |
| |
| DESCRIPTION |
| |
| 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. |
| |
| SYNOPSIS |
| |
| int ioctl( int fd, int request = DMX_SET_BUFFER_SIZE, unsigned long |
| size); |
| |
| PARAMETERS |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - int fd |
| |
| - File descriptor returned by a previous call to open(). |
| |
| - .. row 2 |
| |
| - int request |
| |
| - Equals DMX_SET_BUFFER_SIZE for this command. |
| |
| - .. row 3 |
| |
| - unsigned long size |
| |
| - Size of circular buffer. |
| |
| |
| RETURN VALUE |
| |
| On success 0 is returned, on error -1 and the ``errno`` variable is set |
| appropriately. The generic error codes are described at the |
| :ref:`Generic Error Codes <gen-errors>` chapter. |
| |
| |
| .. _DMX_GET_EVENT: |
| |
| DMX_GET_EVENT |
| ============= |
| |
| DESCRIPTION |
| |
| 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. |
| |
| SYNOPSIS |
| |
| int ioctl( int fd, int request = DMX_GET_EVENT, struct dmx_event |
| *ev); |
| |
| PARAMETERS |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - int fd |
| |
| - File descriptor returned by a previous call to open(). |
| |
| - .. row 2 |
| |
| - int request |
| |
| - Equals DMX_GET_EVENT for this command. |
| |
| - .. row 3 |
| |
| - struct dmx_event *ev |
| |
| - Pointer to the location where the event is to be stored. |
| |
| |
| RETURN VALUE |
| |
| On success 0 is returned, on error -1 and the ``errno`` variable is set |
| appropriately. The generic error codes are described at the |
| :ref:`Generic Error Codes <gen-errors>` chapter. |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - EWOULDBLOCK |
| |
| - There is no event pending, and the device is in non-blocking mode. |
| |
| |
| |
| .. _DMX_GET_STC: |
| |
| DMX_GET_STC |
| =========== |
| |
| DESCRIPTION |
| |
| 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 . |
| |
| SYNOPSIS |
| |
| int ioctl( int fd, int request = DMX_GET_STC, struct dmx_stc *stc); |
| |
| PARAMETERS |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - int fd |
| |
| - File descriptor returned by a previous call to open(). |
| |
| - .. row 2 |
| |
| - int request |
| |
| - Equals DMX_GET_STC for this command. |
| |
| - .. row 3 |
| |
| - struct dmx_stc *stc |
| |
| - Pointer to the location where the stc is to be stored. |
| |
| |
| RETURN VALUE |
| |
| On success 0 is returned, on error -1 and the ``errno`` variable is set |
| appropriately. The generic error codes are described at the |
| :ref:`Generic Error Codes <gen-errors>` chapter. |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - EINVAL |
| |
| - Invalid stc number. |
| |
| |
| |
| .. _DMX_GET_PES_PIDS: |
| |
| DMX_GET_PES_PIDS |
| ================ |
| |
| DESCRIPTION |
| |
| This ioctl is undocumented. Documentation is welcome. |
| |
| SYNOPSIS |
| |
| int ioctl(fd, int request = DMX_GET_PES_PIDS, __u16[5]); |
| |
| PARAMETERS |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - int fd |
| |
| - File descriptor returned by a previous call to open(). |
| |
| - .. row 2 |
| |
| - int request |
| |
| - Equals DMX_GET_PES_PIDS for this command. |
| |
| - .. row 3 |
| |
| - __u16[5] |
| |
| - Undocumented. |
| |
| |
| RETURN VALUE |
| |
| On success 0 is returned, on error -1 and the ``errno`` variable is set |
| appropriately. The generic error codes are described at the |
| :ref:`Generic Error Codes <gen-errors>` chapter. |
| |
| |
| .. _DMX_GET_CAPS: |
| |
| DMX_GET_CAPS |
| ============ |
| |
| DESCRIPTION |
| |
| This ioctl is undocumented. Documentation is welcome. |
| |
| SYNOPSIS |
| |
| int ioctl(fd, int request = DMX_GET_CAPS, dmx_caps_t *); |
| |
| PARAMETERS |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - int fd |
| |
| - File descriptor returned by a previous call to open(). |
| |
| - .. row 2 |
| |
| - int request |
| |
| - Equals DMX_GET_CAPS for this command. |
| |
| - .. row 3 |
| |
| - dmx_caps_t * |
| |
| - Undocumented. |
| |
| |
| RETURN VALUE |
| |
| On success 0 is returned, on error -1 and the ``errno`` variable is set |
| appropriately. The generic error codes are described at the |
| :ref:`Generic Error Codes <gen-errors>` chapter. |
| |
| |
| .. _DMX_SET_SOURCE: |
| |
| DMX_SET_SOURCE |
| ============== |
| |
| DESCRIPTION |
| |
| This ioctl is undocumented. Documentation is welcome. |
| |
| SYNOPSIS |
| |
| int ioctl(fd, int request = DMX_SET_SOURCE, dmx_source_t *); |
| |
| PARAMETERS |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - int fd |
| |
| - File descriptor returned by a previous call to open(). |
| |
| - .. row 2 |
| |
| - int request |
| |
| - Equals DMX_SET_SOURCE for this command. |
| |
| - .. row 3 |
| |
| - dmx_source_t * |
| |
| - Undocumented. |
| |
| |
| RETURN VALUE |
| |
| On success 0 is returned, on error -1 and the ``errno`` variable is set |
| appropriately. The generic error codes are described at the |
| :ref:`Generic Error Codes <gen-errors>` chapter. |
| |
| |
| .. _DMX_ADD_PID: |
| |
| DMX_ADD_PID |
| =========== |
| |
| DESCRIPTION |
| |
| This ioctl call allows to add multiple PIDs to a transport stream filter |
| previously set up with DMX_SET_PES_FILTER and output equal to |
| DMX_OUT_TSDEMUX_TAP. |
| |
| SYNOPSIS |
| |
| int ioctl(fd, int request = DMX_ADD_PID, __u16 *); |
| |
| PARAMETERS |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - int fd |
| |
| - File descriptor returned by a previous call to open(). |
| |
| - .. row 2 |
| |
| - int request |
| |
| - Equals DMX_ADD_PID for this command. |
| |
| - .. row 3 |
| |
| - __u16 * |
| |
| - PID number to be filtered. |
| |
| |
| RETURN VALUE |
| |
| On success 0 is returned, on error -1 and the ``errno`` variable is set |
| appropriately. The generic error codes are described at the |
| :ref:`Generic Error Codes <gen-errors>` chapter. |
| |
| |
| .. _DMX_REMOVE_PID: |
| |
| DMX_REMOVE_PID |
| ============== |
| |
| DESCRIPTION |
| |
| This ioctl call allows to remove a PID when multiple PIDs are set on a |
| transport stream filter, e. g. a filter previously set up with output |
| equal to DMX_OUT_TSDEMUX_TAP, created via either |
| DMX_SET_PES_FILTER or DMX_ADD_PID. |
| |
| SYNOPSIS |
| |
| int ioctl(fd, int request = DMX_REMOVE_PID, __u16 *); |
| |
| PARAMETERS |
| |
| |
| |
| .. flat-table:: |
| :header-rows: 0 |
| :stub-columns: 0 |
| |
| |
| - .. row 1 |
| |
| - int fd |
| |
| - File descriptor returned by a previous call to open(). |
| |
| - .. row 2 |
| |
| - int request |
| |
| - Equals DMX_REMOVE_PID for this command. |
| |
| - .. row 3 |
| |
| - __u16 * |
| |
| - PID of the PES filter to be removed. |
| |
| |
| RETURN VALUE |
| |
| On success 0 is returned, on error -1 and the ``errno`` variable is set |
| appropriately. The generic error codes are described at the |
| :ref:`Generic Error Codes <gen-errors>` chapter. |
| |
| |
| .. ------------------------------------------------------------------------------ |
| .. This file was automatically converted from DocBook-XML with the dbxml |
| .. library (https://github.com/return42/sphkerneldoc). The origin XML comes |
| .. from the linux kernel, refer to: |
| .. |
| .. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook |
| .. ------------------------------------------------------------------------------ |