diff options
Diffstat (limited to 'dvb-spec/dvbapi/demux.tex')
| -rw-r--r-- | dvb-spec/dvbapi/demux.tex | 101 |
1 files changed, 51 insertions, 50 deletions
diff --git a/dvb-spec/dvbapi/demux.tex b/dvb-spec/dvbapi/demux.tex index c74b133ec..dd032f58d 100644 --- a/dvb-spec/dvbapi/demux.tex +++ b/dvb-spec/dvbapi/demux.tex @@ -1,16 +1,14 @@ \devsec{DVB Demux Device} The DVB demux device controls the filters of the DVB hardware/software. -It can be accessed through \texttt{/dev/ost/demux}. +It can be accessed through \texttt{/dev/adapter0/demux0}. +Data types and and ioctl definitions can be accessed by including +\texttt{linux/dvb/dmx.h} in your application. \devsubsec{Demux Data Types} -\begin{verbatim} -typedef uint16_t uint16_t; -\end{verbatim} - -\devsubsubsec{dmxOutput\_t} +\devsubsubsec{dmx\_output\_t} \label{dmxoutput} \begin{verbatim} @@ -19,26 +17,30 @@ typedef enum DMX_OUT_DECODER, DMX_OUT_TAP, DMX_OUT_TS_TAP -} dmx\_output_t; +} dmx_output_t; \end{verbatim} -/* Output multiplexed into a new TS */ -/* (to be retrieved by reading from the */ -/* logical DVR device). */ + +\noindent\texttt{DMX\_OUT\_TAP} delivers the stream output to the demux device +on which the ioctl is called. + +\noindent\texttt{DMX\_OUT\_TS\_TAP} routes output to the logical DVR device +\texttt{/dev/dvb/adapter0/dvr0}, which delivers a TS multiplexed from +all filters for which \texttt{DMX\_OUT\_TS\_TAP} was specified. -\devsubsubsec{dmxInput\_t} +\devsubsubsec{dmx\_input\_t} \label{dmxinput} \begin{verbatim} typedef enum { - DMX_IN_FRONTEND, /* Input from a front-end device. */ - DMX_IN_DVR /* Input from the logical DVR device. */ -} dmx\_input_t; + DMX_IN_FRONTEND, + DMX_IN_DVR +} dmx_input_t; \end{verbatim} -\devsubsubsec{dmxPesType\_t} +\devsubsubsec{dmx\_pes\_type\_t} \label{dmxpestype} \begin{verbatim} @@ -50,7 +52,7 @@ typedef enum DMX_PES_SUBTITLE, DMX_PES_PCR, DMX_PES_OTHER -} dmx\_pes\_type_t; +} dmx_pes_type_t; \end{verbatim} @@ -62,11 +64,11 @@ typedef enum { DMX_SCRAMBLING_EV, DMX_FRONTEND_EV -} dmx\_event_t; +} dmx_event_t; \end{verbatim} -\devsubsubsec{dmxScramblingStatus\_t} +\devsubsubsec{dmx\_scrambling\_status\_t} \label{dmxscramblingstatus} \begin{verbatim} @@ -74,32 +76,32 @@ typedef enum { DMX_SCRAMBLING_OFF, DMX_SCRAMBLING_ON -} dmx\_scrambling_status_t; +} dmx_scrambling_status_t; \end{verbatim} -\devsubsubsec{dmx\_filter\_t} +\devsubsubsec{struct dmx\_filter} \label{dmxfilter} \begin{verbatim} -typedef struct dmx\_filter +typedef struct dmx_filter { uint8_t filter[DMX_FILTER_SIZE]; uint8_t mask[DMX_FILTER_SIZE]; -} dmx\_filter\_t; +} dmx_filter_t; \end{verbatim} -\devsubsubsec{dmx\_sct\_filter\_params} +\devsubsubsec{struct dmx\_sct\_filter\_params} \label{dmxsctfilterparams} \begin{verbatim} -struct dmx\_sct\_filter\_params +struct dmx_sct_filter_params { - uint16_t pid; - dmx\_filter\_t filter; - uint32_t timeout; - uint32_t flags; + 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 @@ -107,32 +109,32 @@ struct dmx\_sct\_filter\_params \end{verbatim} -\devsubsubsec{dmx\_pes\_filter\_params} +\devsubsubsec{struct dmx\_pes\_filter\_params} \label{dmxpesfilterparams} \begin{verbatim} -struct dmx\_pes\_filter\_params +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; + uint16_t pid; + dmx_input_t input; + dmx_output_t output; + dmx_pes_type_t pes_type; + uint32_t flags; }; \end{verbatim} -\devsubsubsec{dmx\_event} +\devsubsubsec{struct dmx\_event} \label{dmxevent} \begin{verbatim} -struct dmx\_event +struct dmx_event { - dmx\_event_t event; - time_t timeStamp; + dmx_event_t event; + time_t timeStamp; union { - dmx\_scrambling_status_t scrambling; + dmx_scrambling_status_t scrambling; } u; }; \end{verbatim} @@ -142,16 +144,15 @@ struct dmx\_event \devsubsec{Demux Function Calls} \function{open()}{ int open(const char *deviceName, int flags);}{ - This system call, used with a device name of /dev/ost/demuxn, where n - denotes the specific demux device to be opened, allocates a new filter + 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/ost/dvrn is a logical device to be used for retrieving Transport - Streams for digital video recording. n identifies the physical demux - device that provides the actual DVR functionality. When reading from + /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/ost/demuxn) + 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. % This device can only be opened in read-write mode. @@ -211,7 +212,7 @@ struct dmx\_event 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/ost/demuxn having the output set + in the corresponding demux device /dev/dvb/adapter0/demux0 having the output set to DMX\_OUT\_TS\_TAP. }{ int fd & File descriptor returned by a previous call to open().\\ @@ -236,11 +237,11 @@ struct dmx\_event \function{write()}{ ssize\_t write(int fd, const void *buf, size\_t count); }{ - This system call is only provided by the logical device /dev/ost/dvrn, - where n identifies the physical demux device that provides the actual + 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/ost/demuxn. + corresponding physical demux device, /dev/dvb/adapter0/demux0. The amount of data to be transferred is implied by count. }{ int fd & File descriptor returned by a previous call to open().\\ |