--- /dev/null
+<title>Examples</title>
+<para>In this section we would like to present some examples for using the DVB API.
+</para>
+<para>Maintainer note: This section is out of date. Please refer to the sample programs packaged
+with the driver distribution from <ulink url="http://linuxtv.org/hg/dvb-apps" />.
+</para>
+
+<section id="tuning">
+<title>Tuning</title>
+<para>We will start with a generic tuning subroutine that uses the frontend and SEC, as well as
+the demux devices. The example is given for QPSK tuners, but can easily be adjusted for
+QAM.
+</para>
+<programlisting>
+ #include <sys/ioctl.h>
+ #include <stdio.h>
+ #include <stdint.h>
+ #include <sys/types.h>
+ #include <sys/stat.h>
+ #include <fcntl.h>
+ #include <time.h>
+ #include <unistd.h>
+
+ #include <linux/dvb/dmx.h>
+ #include <linux/dvb/frontend.h>
+ #include <linux/dvb/sec.h>
+ #include <sys/poll.h>
+
+ #define DMX "/dev/dvb/adapter0/demux1"
+ #define FRONT "/dev/dvb/adapter0/frontend1"
+ #define SEC "/dev/dvb/adapter0/sec1"
+
+ /⋆ routine for checking if we have a signal and other status information⋆/
+ int FEReadStatus(int fd, fe_status_t ⋆stat)
+ {
+ int ans;
+
+ if ( (ans = ioctl(fd,FE_READ_STATUS,stat) < 0)){
+ perror("FE READ STATUS: ");
+ return -1;
+ }
+
+ if (⋆stat & FE_HAS_POWER)
+ printf("FE HAS POWER\n");
+
+ if (⋆stat & FE_HAS_SIGNAL)
+ printf("FE HAS SIGNAL\n");
+
+ if (⋆stat & FE_SPECTRUM_INV)
+ printf("SPEKTRUM INV\n");
+
+ return 0;
+ }
+
+
+ /⋆ tune qpsk ⋆/
+ /⋆ freq: frequency of transponder ⋆/
+ /⋆ vpid, apid, tpid: PIDs of video, audio and teletext TS packets ⋆/
+ /⋆ diseqc: DiSEqC address of the used LNB ⋆/
+ /⋆ pol: Polarisation ⋆/
+ /⋆ srate: Symbol Rate ⋆/
+ /⋆ fec. FEC ⋆/
+ /⋆ lnb_lof1: local frequency of lower LNB band ⋆/
+ /⋆ lnb_lof2: local frequency of upper LNB band ⋆/
+ /⋆ lnb_slof: switch frequency of LNB ⋆/
+
+ int set_qpsk_channel(int freq, int vpid, int apid, int tpid,
+ int diseqc, int pol, int srate, int fec, int lnb_lof1,
+ int lnb_lof2, int lnb_slof)
+ {
+ struct secCommand scmd;
+ struct secCmdSequence scmds;
+ struct dmx_pes_filter_params pesFilterParams;
+ FrontendParameters frp;
+ struct pollfd pfd[1];
+ FrontendEvent event;
+ int demux1, demux2, demux3, front;
+
+ frequency = (uint32_t) freq;
+ symbolrate = (uint32_t) srate;
+
+ if((front = open(FRONT,O_RDWR)) < 0){
+ perror("FRONTEND DEVICE: ");
+ return -1;
+ }
+
+ if((sec = open(SEC,O_RDWR)) < 0){
+ perror("SEC DEVICE: ");
+ return -1;
+ }
+
+ if (demux1 < 0){
+ if ((demux1=open(DMX, O_RDWR|O_NONBLOCK))
+ < 0){
+ perror("DEMUX DEVICE: ");
+ return -1;
+ }
+ }
+
+ if (demux2 < 0){
+ if ((demux2=open(DMX, O_RDWR|O_NONBLOCK))
+ < 0){
+ perror("DEMUX DEVICE: ");
+ return -1;
+ }
+ }
+
+ if (demux3 < 0){
+ if ((demux3=open(DMX, O_RDWR|O_NONBLOCK))
+ < 0){
+ perror("DEMUX DEVICE: ");
+ return -1;
+ }
+ }
+
+ if (freq < lnb_slof) {
+ frp.Frequency = (freq - lnb_lof1);
+ scmds.continuousTone = SEC_TONE_OFF;
+ } else {
+ frp.Frequency = (freq - lnb_lof2);
+ scmds.continuousTone = SEC_TONE_ON;
+ }
+ frp.Inversion = INVERSION_AUTO;
+ if (pol) scmds.voltage = SEC_VOLTAGE_18;
+ else scmds.voltage = SEC_VOLTAGE_13;
+
+ scmd.type=0;
+ scmd.u.diseqc.addr=0x10;
+ scmd.u.diseqc.cmd=0x38;
+ scmd.u.diseqc.numParams=1;
+ scmd.u.diseqc.params[0] = 0xF0 | ((diseqc ⋆ 4) & 0x0F) |
+ (scmds.continuousTone == SEC_TONE_ON ? 1 : 0) |
+ (scmds.voltage==SEC_VOLTAGE_18 ? 2 : 0);
+
+ scmds.miniCommand=SEC_MINI_NONE;
+ scmds.numCommands=1;
+ scmds.commands=&scmd;
+ if (ioctl(sec, SEC_SEND_SEQUENCE, &scmds) < 0){
+ perror("SEC SEND: ");
+ return -1;
+ }
+
+ if (ioctl(sec, SEC_SEND_SEQUENCE, &scmds) < 0){
+ perror("SEC SEND: ");
+ return -1;
+ }
+
+ frp.u.qpsk.SymbolRate = srate;
+ frp.u.qpsk.FEC_inner = fec;
+
+ if (ioctl(front, FE_SET_FRONTEND, &frp) < 0){
+ perror("QPSK TUNE: ");
+ return -1;
+ }
+
+ pfd[0].fd = front;
+ pfd[0].events = POLLIN;
+
+ if (poll(pfd,1,3000)){
+ if (pfd[0].revents & POLLIN){
+ printf("Getting QPSK event\n");
+ if ( ioctl(front, FE_GET_EVENT, &event)
+
+ == -EOVERFLOW){
+ perror("qpsk get event");
+ return -1;
+ }
+ printf("Received ");
+ switch(event.type){
+ case FE_UNEXPECTED_EV:
+ printf("unexpected event\n");
+ return -1;
+ case FE_FAILURE_EV:
+ printf("failure event\n");
+ return -1;
+
+ case FE_COMPLETION_EV:
+ printf("completion event\n");
+ }
+ }
+ }
+
+
+ pesFilterParams.pid = vpid;
+ pesFilterParams.input = DMX_IN_FRONTEND;
+ pesFilterParams.output = DMX_OUT_DECODER;
+ pesFilterParams.pes_type = DMX_PES_VIDEO;
+ pesFilterParams.flags = DMX_IMMEDIATE_START;
+ if (ioctl(demux1, DMX_SET_PES_FILTER, &pesFilterParams) < 0){
+ perror("set_vpid");
+ return -1;
+ }
+
+ pesFilterParams.pid = apid;
+ pesFilterParams.input = DMX_IN_FRONTEND;
+ pesFilterParams.output = DMX_OUT_DECODER;
+ pesFilterParams.pes_type = DMX_PES_AUDIO;
+ pesFilterParams.flags = DMX_IMMEDIATE_START;
+ if (ioctl(demux2, DMX_SET_PES_FILTER, &pesFilterParams) < 0){
+ perror("set_apid");
+ return -1;
+ }
+
+ pesFilterParams.pid = tpid;
+ pesFilterParams.input = DMX_IN_FRONTEND;
+ pesFilterParams.output = DMX_OUT_DECODER;
+ pesFilterParams.pes_type = DMX_PES_TELETEXT;
+ pesFilterParams.flags = DMX_IMMEDIATE_START;
+ if (ioctl(demux3, DMX_SET_PES_FILTER, &pesFilterParams) < 0){
+ perror("set_tpid");
+ return -1;
+ }
+
+ return has_signal(fds);
+ }
+
+</programlisting>
+<para>The program assumes that you are using a universal LNB and a standard DiSEqC
+switch with up to 4 addresses. Of course, you could build in some more checking if
+tuning was successful and maybe try to repeat the tuning process. Depending on the
+external hardware, i.e. LNB and DiSEqC switch, and weather conditions this may be
+necessary.
+</para>
+</section>
+
+<section id="the_dvr_device">
+<title>The DVR device</title>
+<para>The following program code shows how to use the DVR device for recording.
+</para>
+<programlisting>
+ #include <sys/ioctl.h>
+ #include <stdio.h>
+ #include <stdint.h>
+ #include <sys/types.h>
+ #include <sys/stat.h>
+ #include <fcntl.h>
+ #include <time.h>
+ #include <unistd.h>
+
+ #include <linux/dvb/dmx.h>
+ #include <linux/dvb/video.h>
+ #include <sys/poll.h>
+ #define DVR "/dev/dvb/adapter0/dvr1"
+ #define AUDIO "/dev/dvb/adapter0/audio1"
+ #define VIDEO "/dev/dvb/adapter0/video1"
+
+ #define BUFFY (188⋆20)
+ #define MAX_LENGTH (1024⋆1024⋆5) /⋆ record 5MB ⋆/
+
+
+ /⋆ switch the demuxes to recording, assuming the transponder is tuned ⋆/
+
+ /⋆ demux1, demux2: file descriptor of video and audio filters ⋆/
+ /⋆ vpid, apid: PIDs of video and audio channels ⋆/
+
+ int switch_to_record(int demux1, int demux2, uint16_t vpid, uint16_t apid)
+ {
+ struct dmx_pes_filter_params pesFilterParams;
+
+ if (demux1 < 0){
+ if ((demux1=open(DMX, O_RDWR|O_NONBLOCK))
+ < 0){
+ perror("DEMUX DEVICE: ");
+ return -1;
+ }
+ }
+
+ if (demux2 < 0){
+ if ((demux2=open(DMX, O_RDWR|O_NONBLOCK))
+ < 0){
+ perror("DEMUX DEVICE: ");
+ return -1;
+ }
+ }
+
+ pesFilterParams.pid = vpid;
+ pesFilterParams.input = DMX_IN_FRONTEND;
+ pesFilterParams.output = DMX_OUT_TS_TAP;
+ pesFilterParams.pes_type = DMX_PES_VIDEO;
+ pesFilterParams.flags = DMX_IMMEDIATE_START;
+ if (ioctl(demux1, DMX_SET_PES_FILTER, &pesFilterParams) < 0){
+ perror("DEMUX DEVICE");
+ return -1;
+ }
+ pesFilterParams.pid = apid;
+ pesFilterParams.input = DMX_IN_FRONTEND;
+ pesFilterParams.output = DMX_OUT_TS_TAP;
+ pesFilterParams.pes_type = DMX_PES_AUDIO;
+ pesFilterParams.flags = DMX_IMMEDIATE_START;
+ if (ioctl(demux2, DMX_SET_PES_FILTER, &pesFilterParams) < 0){
+ perror("DEMUX DEVICE");
+ return -1;
+ }
+ return 0;
+ }
+
+ /⋆ start recording MAX_LENGTH , assuming the transponder is tuned ⋆/
+
+ /⋆ demux1, demux2: file descriptor of video and audio filters ⋆/
+ /⋆ vpid, apid: PIDs of video and audio channels ⋆/
+ int record_dvr(int demux1, int demux2, uint16_t vpid, uint16_t apid)
+ {
+ int i;
+ int len;
+ int written;
+ uint8_t buf[BUFFY];
+ uint64_t length;
+ struct pollfd pfd[1];
+ int dvr, dvr_out;
+
+ /⋆ open dvr device ⋆/
+ if ((dvr = open(DVR, O_RDONLY|O_NONBLOCK)) < 0){
+ perror("DVR DEVICE");
+ return -1;
+ }
+
+ /⋆ switch video and audio demuxes to dvr ⋆/
+ printf ("Switching dvr on\n");
+ i = switch_to_record(demux1, demux2, vpid, apid);
+ printf("finished: ");
+
+ printf("Recording %2.0f MB of test file in TS format\n",
+ MAX_LENGTH/(1024.0⋆1024.0));
+ length = 0;
+
+ /⋆ open output file ⋆/
+ if ((dvr_out = open(DVR_FILE,O_WRONLY|O_CREAT
+ |O_TRUNC, S_IRUSR|S_IWUSR
+ |S_IRGRP|S_IWGRP|S_IROTH|
+ S_IWOTH)) < 0){
+ perror("Can't open file for dvr test");
+ return -1;
+ }
+
+ pfd[0].fd = dvr;
+ pfd[0].events = POLLIN;
+
+ /⋆ poll for dvr data and write to file ⋆/
+ while (length < MAX_LENGTH ) {
+ if (poll(pfd,1,1)){
+ if (pfd[0].revents & POLLIN){
+ len = read(dvr, buf, BUFFY);
+ if (len < 0){
+ perror("recording");
+ return -1;
+ }
+ if (len > 0){
+ written = 0;
+ while (written < len)
+ written +=
+ write (dvr_out,
+ buf, len);
+ length += len;
+ printf("written %2.0f MB\r",
+ length/1024./1024.);
+ }
+ }
+ }
+ }
+ return 0;
+ }
+
+</programlisting>
+
+</section>
Code Review / kvmfornfv.git / blobdiff