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diff --git a/dvb-spec/sgml/examples.sgml b/dvb-spec/sgml/examples.sgml index e69de29bb..fcdea820a 100644 --- a/dvb-spec/sgml/examples.sgml +++ b/dvb-spec/sgml/examples.sgml @@ -0,0 +1,365 @@ +<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Maintainer note: This section is out of date.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 <emphasis role="tt">http://linuxtv.org/</emphasis>. +</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>
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