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- Committer: Bazaar Package Importer
- Author(s): Hamish Moffatt
- Date: 2001-12-27 12:07:46 UTC
- Revision ID: james.westby@ubuntu.com-20011227120746-iz2p5k757bcla8ov
Tags: upstream-981011
Import upstream version 981011
- files added:
- bitmaps
added
removed
sblaster.c
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/*
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ACfax - Fax reception with X11-interface for amateur radio
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Copyright (C) 1995-1998 Andreas Czechanowski, DL4SDC
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software Foundation,
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Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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andreas.czechanowski@ins.uni-stuttgart.de
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*/
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/*
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* sblaster.c - this file should contain all hardware-dependent functions
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* on top of mod_demod.c for the SoundBlaster under linux.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <fcntl.h>
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#include <sys/ioctl.h>
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#include <sys/soundcard.h>
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#include "mod_demod.h"
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#include "sblaster.h"
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#include <unistd.h>
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static int afd, mfd;
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static int blsize;
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static int decsize;
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static int amode;
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static int aspeed;
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static int afilter;
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static int adevi;
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static int amaxval;
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int rx_level;
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int dspfd;
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char *smplptr;
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char *decptr;
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/* this constants should go to a configuration file in future.... */
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unsigned fm_smplf = (unsigned)(FM_SMPLF * 65536);
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unsigned am_smplf = (unsigned)(AM_SMPLF * 65536);
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static void set_speed(int);
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/* initialize the interface: open it, set it to mono, 8bits per sample,
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* and allocate space for the input- and output-buffers of the modem-
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* routines. return a pointer to the decoded data and the number of
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* values per call to do_receive.
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*/
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void interface_init(char **dta_return, int *cnt_return)
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{
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int speed = 8000;
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int bits = 8;
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int stereo = 0;
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int linevol = 80;
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int mastervol = 55;
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#ifdef SBL_16
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int recsrc = SOUND_MASK_LINE;
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#endif
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static int inited = 0;
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/* already initialized ? return values although... */
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if (inited) {
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*dta_return = decptr;
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*cnt_return = decsize;
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return;
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}
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fprintf(stderr, "opening and initializing sound-interface\n");
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if ((afd = open(DSPDEV, O_RDWR, 0666)) < 0) {
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perror("open_dsp");
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exit(1);
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}
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dspfd = afd;
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#ifdef SBL_16
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if ((mfd = open(MIXDEV, O_RDWR, 0666)) < 0) {
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perror("open_mixer");
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exit(1);
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}
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linevol &= 0xff;
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linevol += linevol << 8;
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mastervol &= 0xff;
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mastervol += mastervol << 8;
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if ((ioctl(mfd, SOUND_MIXER_WRITE_LINE, &linevol) < 0) ||
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(ioctl(mfd, SOUND_MIXER_WRITE_VOLUME, &mastervol) < 0) ||
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(ioctl(mfd, SOUND_MIXER_WRITE_RECSRC, &recsrc) < 0)) {
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perror("mixer_ioctl");
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exit(1);
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}
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close (mfd);
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#endif
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if ((ioctl(afd, SNDCTL_DSP_SPEED, &speed) < 0) ||
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(ioctl(afd, SNDCTL_DSP_SAMPLESIZE, &bits) < 0) ||
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(ioctl(afd, SNDCTL_DSP_STEREO, &stereo) < 0) ||
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(ioctl(afd, SNDCTL_DSP_GETBLKSIZE, &blsize) < 0)) {
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perror("dsp_ioctl");
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exit(1);
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}
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decsize = blsize / 2;
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/* set up defaults for the modem */
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amode = MOD_FM;
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afilter = FIL_MIDL;
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adevi = 400;
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set_modem_param (afilter, amaxval, adevi);
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if (!(decptr = malloc((decsize))) ||
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!(smplptr = malloc(blsize))) {
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perror("setup_buffers");
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exit(1);
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}
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printf("block size is %d bytes\n", blsize);
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*dta_return = decptr;
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*cnt_return = decsize;
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inited = -1;
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}
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/* stop the interface, don't let it overrun by no more reading/writing */
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void interface_stop(void)
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{
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if (ioctl(afd, SNDCTL_DSP_RESET, NULL) < 0) {
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perror("interface_stop: cannot reset pcm");
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}
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}
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/* set up the desired mode, the decoded value range and the deviation for
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* FM. Return the number of demodulated sample-points per second (for APT)
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*/
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void setup_mode(int mode, int maxval, int devi, unsigned *smplf)
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{
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char *dummy1;
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int dummy2;
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int id;
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/* be sure interface is initialized */
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interface_init(&dummy1, &dummy2);
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if ((id = (mode & MOD_BITS))) {
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switch (id) {
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case MOD_FM:
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set_speed(8000);
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break;
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case MOD_AM:
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set_speed(9600);
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break;
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}
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amode = id;
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fprintf(stderr, "setting demodulator mode to 0x%04x\n", amode);
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}
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/* range checking for afilter, adevi and amaxval is done in mod_demod.c */
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if ((id = mode & FIL_MASK)) {
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afilter = id;
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fprintf(stderr, "setting filter selection to 0x%04x\n", afilter);
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}
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if (devi) {
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adevi = devi;
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fprintf(stderr, "setting deviation to %d\n", adevi);
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}
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if (maxval) {
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amaxval = maxval;
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fprintf(stderr, "setting max.demod.value to %d\n", amaxval);
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}
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if ((mode & FIL_MASK) | (devi) | (maxval)) {
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set_modem_param (afilter, amaxval, adevi);
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}
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/* return the number of samples per second (16 bits int, 16 bits frac) */
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if (smplf) {
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switch(amode) {
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case MOD_AM:
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*smplf = am_smplf;
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break;
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case MOD_FM:
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*smplf = fm_smplf;
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break;
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}
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}
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}
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/* receive the signal, demodulate it, ant put the demodulated values
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* into an array starting at decptr with decsize bytes. (1 byte / value)
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*/
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void do_receive(void)
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{
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int cnt;
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int hi, lo;
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int i, sample;
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cnt = read(afd, smplptr, blsize);
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if (cnt <= 0) {
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perror("do_receive");
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exit(1);
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}
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fputc('<', stderr);
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switch(amode) {
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case MOD_AM:
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am_demod(smplptr, cnt, decptr);
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break;
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case MOD_FM:
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fm_demod(smplptr, cnt, decptr);
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break;
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default:
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return;
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}
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/* determine the signal level and put it into rx_level (0..255) */
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lo = 255;
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hi = 0;
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for (i = 0; i < blsize / 4; i++)
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{
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sample = smplptr[i] & 0xff;
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if (sample > hi) hi = sample;
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if (sample < lo) lo = sample;
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}
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rx_level = hi - lo;
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}
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/* modulate the sample-values from decptr into smplptr, and transmit them
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* over the interface. The number of input-values is always decsize.
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*/
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void do_transmit(void)
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{
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int cnt;
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switch(amode) {
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case MOD_FM:
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fm_modulate(decptr, decsize, smplptr);
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case MOD_AM:
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am_modulate(decptr, decsize, smplptr);
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default:
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return;
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}
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cnt = write(afd, smplptr, blsize);
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if (cnt <= 0) {
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perror("do_transmit");
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exit(1);
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}
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fputc('>', stderr);
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}
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/* check for signal level, return a value between 0 and 256 */
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int signal_level(void)
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{
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char buf[512];
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int i, p, lo, hi;
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if (read(afd, buf, 512) != 512) {
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perror("signal_level: cannot get samples");
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}
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if (ioctl(afd, SNDCTL_DSP_SYNC, NULL) < 0) {
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perror("signal_level: cannot reset pcm");
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}
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lo = 255;
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hi = 0;
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for (i=0; i<512; i++) {
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p = buf[i]&0xff;
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if (p > hi) hi = p;
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if (p < lo) lo = p;
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}
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return (hi-lo);
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}
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/* just assign new value to either the AM or FM sample-frequency,
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and hold values permanently until next change
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*/
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void tune_frequency(unsigned freq)
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{
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switch(amode) {
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case MOD_FM:
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fm_smplf = freq;
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case MOD_AM:
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am_smplf = freq;
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default:
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return;
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}
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}
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/* set a new sample-rate for the DSP-device. We need to restart input
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in order to do so, because Linux does not update the SB-registers
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when sending the command, but only on start of input/output
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*/
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static void set_speed(int speed)
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{
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if (ioctl(afd, SNDCTL_DSP_SPEED, &speed) < 0) {
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perror("set_speed: cannot set new sample-rate");
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}
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fprintf(stderr,"speed set to %d\n", speed);
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if (ioctl(afd, SNDCTL_DSP_SYNC, NULL) < 0) {
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perror("set_speed: cannot reset pcm");
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}
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aspeed = speed;
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}
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