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Diffstat (limited to 'src/dls.c')
-rw-r--r-- | src/dls.c | 447 |
1 files changed, 447 insertions, 0 deletions
diff --git a/src/dls.c b/src/dls.c new file mode 100644 index 0000000..1a9cc7c --- /dev/null +++ b/src/dls.c @@ -0,0 +1,447 @@ +/* + Copyright (C) 2014 CSP Innovazione nelle ICT s.c.a r.l. (http://rd.csp.it/) + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. + + dls.c + Generete PAD data for DLS + + Authors: + Matthias P. Braendli + http://opendigitalradio.org + + Sergio Sagliocco <sergio.sagliocco@csp.it> +*/ + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <getopt.h> + +#include "lib_crc.h" + +#define MIN(a,b) (((a)<(b))?(a):(b)) +#define MAX(a,b) (((a)>(b))?(a):(b)) + +#define MAXSEGLEN 8179 +#define MAXDLS 129 + +typedef unsigned char UCHAR; +typedef unsigned short int USHORT; + +void create_dls_datagroup (char* text, int padlen, unsigned char*** p_dlsdg, int* p_numdg); +void writeDLS(int output_fd, const char* dls_file, int padlen); + +int get_xpadlengthmask(int padlen); +#define ALLOWED_PADLEN "23, 26, 34, 42, 58" + +void usage(char* name) +{ + fprintf(stderr, "DAB DLS encoder %s\n\n" + "By CSP Innovazione nelle ICT s.c.a r.l. (http://rd.csp.it/)\n" + "and Opendigitalradio.org\n\n" + "Reads DLS from /tmp/dls.file\n\n" + "WARNING: This program has memory leaks! Do not attempt\n" + "to leave it running for long periods of time!\n\n" + " http://opendigitalradio.org\n\n", +#if defined(GITVERSION) + GITVERSION +#else + PACKAGE_VERSION +#endif + ); + fprintf(stderr, "Usage: %s [OPTIONS...]\n", name); + fprintf(stderr, + " -o, --output=FILENAME Fifo to write PAD data into.\n" + " Default: /tmp/pad.fifo\n" + " -t, --dls=FILENAME Fifo or file to read DLS text from.\n" + " Default: /tmp/dls.txt\n" + " -p, --pad=LENGTH Set the pad length.\n" + " Possible values: " ALLOWED_PADLEN "\n" + " Default: 58\n" + ); +} + +#define no_argument 0 +#define required_argument 1 +#define optional_argument 2 +int main(int argc, char *argv[]) +{ + int len, ret; + int padlen=58; + + char* output = "/tmp/pad.fifo"; + char* dls_file = "/tmp/dls.txt"; + + const struct option longopts[] = { + {"output", required_argument, 0, 'o'}, + {"dls", required_argument, 0, 't'}, + {"pad", required_argument, 0, 'p'}, + {"help", no_argument, 0, 'h'}, + {0,0,0,0}, + }; + + if (argc < 2) { + fprintf(stderr, "Error: too few arguments!\n"); + usage(argv[0]); + return 2; + } + + int ch=0; + int index; + while(ch != -1) { + ch = getopt_long(argc, argv, "ho:t:p:", longopts, &index); + switch (ch) { + case 'o': + output = optarg; + break; + case 't': + dls_file = optarg; + break; + case 'p': + padlen = atoi(optarg); + break; + case '?': + case 'h': + usage(argv[0]); + return 0; + } + } + + if (get_xpadlengthmask(padlen) == -1) { + fprintf(stderr, "Error: pad length %d invalid: Possible values: " + ALLOWED_PADLEN "\n", + padlen); + return 2; + } + + int output_fd = open(output, O_WRONLY); + if (output_fd == -1) { + perror("Failed to open output"); + return 3; + } + + writeDLS(output_fd, dls_file, padlen); + + return 0; +} + + +void writeDLS(int output_fd, const char* dls_file, int padlen) { + char dlstext[MAXDLS]; + static char dlstextprev[MAXDLS]; + int dlslen; + int i; + static unsigned char** dlsdg; + static int numdg = 0; + + static int dlsfd = 0; + + if (dlsfd!=0) { + close(dlsfd); + } + + dlsfd = open(dls_file, O_RDONLY); + if (dlsfd == -1) { + fprintf(stderr,"Error - Cannot open dls file\n"); + return; + } + + dlslen = read(dlsfd, dlstext, MAXDLS); + dlstext[dlslen] = 0x00; + //if (strcmp(dlstext,dlstextprev)!=0) { + create_dls_datagroup(dlstext, padlen, &dlsdg, &numdg); + strcpy(dlstextprev, dlstext); + //} + for (i = 0; i < numdg; i++) { + write(output_fd, dlsdg[i], padlen); + } + +} + +void create_dls_datagroup (char* text, int padlen, UCHAR*** p_dlsdg, int* p_numdg) { + + UCHAR dlsseg[8][16]; // max 8 segments, each max 16 chars + UCHAR** dlsdg; // Array of datagroups composing dls text; + + + int numseg; // Number of DSL segments + int lastseglen; // Length of the last segment + int numdg; // Number of data group + int xpadlengthmask; + int i, j, k, z, idx_start_crc, idx_stop_crc; + USHORT dlscrc; + static UCHAR toggle = 0; + + if (toggle == 0) + toggle = 1; + else + toggle = 0; + + numseg = strlen(text) / 16; + lastseglen = strlen(text) % 16; + if (padlen-9 >= 16) { + if (lastseglen > 0) { + numseg++; // The last incomplete segment + } + + // The PAD can contain the full segmnet and overhead (9 bytes) + numdg = numseg; + + } + else { + // Each 16 char segment span over 2 dg + numdg = numseg * 2; + + if (lastseglen > 0) { + numseg++; // The last incomplete segment + + if (lastseglen <= padlen-9) { + numdg += 1; + } + else { + numdg += 2; + } + } + } + + *p_numdg = numdg; + fprintf(stderr, "PAD Length: %d\n", padlen); + fprintf(stderr, "DLS text: %s\n", text); + fprintf(stderr, "Number of DLS segments: %d\n", numseg); + fprintf(stderr, "Number of DLS data groups: %d\n", numdg); + + xpadlengthmask = get_xpadlengthmask(padlen); + + *p_dlsdg = (UCHAR**) malloc(numdg * sizeof(UCHAR*)); + dlsdg = *p_dlsdg; + + i = 0; + for (z=0; z < numseg; z++) { + char* curseg; + int curseglen; + UCHAR firstseg, lastseg; + + curseg = &text[z * 16]; + fprintf(stderr, "Segment number %d\n", z+1); + + if (z == 0) { // First segment + firstseg = 1; + } + else { + firstseg = 0; + } + + if (z == numseg-1) { //Last segment + if (lastseglen != 0) { + curseglen = lastseglen; + } + else { + curseglen = 16; + } + lastseg = 1; + } + else { + curseglen = 16; + lastseg = 0; + } + + if (curseglen <= padlen-9) { // Segment is composed of 1 data group + dlsdg[i] = (UCHAR*) malloc(padlen * sizeof(UCHAR)); + + // FF-PAD Byte L (CI=1) + dlsdg[i][padlen-1]=0x02; + + // FF-PAD Byte L-1 (Variable size X_PAD) + dlsdg[i][padlen-2]=0x20; + + // CI => data length = 12 (011) - Application Type=2 + // (DLS - start of X-PAD data group) + dlsdg[i][padlen-3]=(xpadlengthmask<<5) | 0x02; + + // End of CI list + dlsdg[i][padlen-4]=0x00; + + // DLS Prefix (T=1,Only one segment,segment length-1) + dlsdg[i][padlen-5]=((toggle*8+firstseg*4+lastseg*2+0)<<4) | (curseglen-1); + + if (firstseg==1) { + // DLS Prefix (Charset standard) + dlsdg[i][padlen-6]=0x00; + } + else { + // DLS SegNum + dlsdg[i][padlen-6]=z<<4; + } + + // CRC start from prefix + idx_start_crc = padlen-5; + + // DLS text + for (j = 0; j < curseglen; j++) { + dlsdg[i][padlen-7-j] = curseg[j]; + } + + idx_stop_crc = padlen - 7 - curseglen+1; + + dlscrc = 0xffff; + for (j = idx_start_crc; j >= idx_stop_crc; j--) { + dlscrc = update_crc_ccitt(dlscrc, dlsdg[i][j]); + } + + dlscrc = ~dlscrc; + fprintf(stderr, "crc=%x ~crc=%x\n", ~dlscrc, dlscrc); + + dlsdg[i][padlen-7-curseglen] = (dlscrc & 0xFF00) >> 8; // HI CRC + dlsdg[i][padlen-7-curseglen-1] = dlscrc & 0x00FF; // LO CRC + + // NULL PADDING + for (j = padlen-7-curseglen-2; j >= 0; j--) { + dlsdg[i][j]=0x00; + } + + fprintf(stderr, "Data group: "); + for (j = 0; j < padlen; j++) + fprintf(stderr, "%x ", dlsdg[i][j]); + fprintf(stderr, "\n"); + i++; + + } + else { // Segment is composed of 2 data groups + + // FIRST DG (NO CRC) + dlscrc = 0xffff; + + dlsdg[i] = (UCHAR*) malloc(padlen * sizeof(UCHAR)); + + // FF-PAD Byte L (CI=1) + dlsdg[i][padlen-1]=0x02; + + // FF-PAD Byte L-1 (Variable size X_PAD) + dlsdg[i][padlen-2]=0x20; + + // CI => data length = 12 (011) - Application Type=2 + // (DLS - start of X-PAD data group) + dlsdg[i][padlen-3]=(xpadlengthmask<<5) | 0x02; + + // End of CI list + dlsdg[i][padlen-4]=0x00; + + // DLS Prefix (T=1,Only one segment,segment length-1) + dlsdg[i][padlen-5]=((toggle*8+firstseg*4+lastseg*2+0)<<4) | (curseglen-1); + + + if (firstseg == 1) { + // DLS Prefix (Charset standard) + dlsdg[i][padlen-6] = 0x00; + } + else { + // DLS SegNum + dlsdg[i][padlen-6]=(i-1)<<4; + } + + dlscrc = update_crc_ccitt(dlscrc, dlsdg[i][padlen-5]); + dlscrc = update_crc_ccitt(dlscrc, dlsdg[i][padlen-6]); + + // DLS text + for (j=0; j < MIN(curseglen, padlen-7); j++) { + dlsdg[i][padlen-7-j] = curseg[j]; + dlscrc = update_crc_ccitt(dlscrc, dlsdg[i][padlen-7-j]); + } + k = j; + + // end of segment + if (curseglen == padlen-8) { + dlscrc = ~dlscrc; + dlsdg[i][1] = (dlscrc & 0xFF00) >> 8; // HI CRC + fprintf(stderr, "crc=%x ~crc=%x\n", ~dlscrc, dlscrc); + } + else if (curseglen == padlen-7) { + dlscrc = ~dlscrc; + fprintf(stderr, "crc=%x ~crc=%x\n", ~dlscrc, dlscrc); + } + dlsdg[i][0]=0x00; + + fprintf(stderr, "First Data group: "); + for (j = 0; j < padlen; j++) + fprintf(stderr, "%x ", dlsdg[i][j]); + fprintf(stderr,"\n"); + + // SECOND DG (NO CI, NO PREFIX) + i++; + + dlsdg[i] = (UCHAR*) malloc(padlen*sizeof(UCHAR)); + + // FF-PAD Byte L (CI=0) + dlsdg[i][padlen-1] = 0x00; + + // FF-PAD Byte L-1 (Variable size X_PAD) + dlsdg[i][padlen-2] = 0x20; + + if (curseglen == padlen-8) { + dlsdg[i][padlen-3] = dlscrc & 0x00FF; // LO CRC + } + else if (curseglen==padlen-7) { + dlsdg[i][padlen-3] = (dlscrc & 0xFF00) >> 8; // HI CRC + dlsdg[i][padlen-4] = dlscrc & 0x00FF; // LO CRC + } + else { + // DLS text + for (j = 0; j < curseglen-k; j++) { + dlsdg[i][padlen-3-j] = curseg[k+j]; + dlscrc = update_crc_ccitt(dlscrc, dlsdg[i][padlen-3-j]); + } + dlscrc = ~dlscrc; + dlsdg[i][padlen-3-curseglen+k] = (dlscrc & 0xFF00) >> 8; // HI CRC + dlsdg[i][padlen-3-curseglen+k-1] = dlscrc & 0x00FF; // LO CRC + } + + fprintf(stderr, "Second Data group: "); + for (j = 0; j < padlen; j++) + fprintf(stderr, "%x ", dlsdg[i][j]); + + fprintf(stderr, "\n"); + fprintf(stderr, "**** crc=%x ~crc=%x\n", ~dlscrc, dlscrc); + i++; + } + } +} + +int get_xpadlengthmask(int padlen) +{ + int xpadlengthmask; + + /* Don't forget to change ALLOWED_PADLEN + * if you change this check + */ + if (padlen == 23) + xpadlengthmask = 3; + else if (padlen == 26) + xpadlengthmask = 4; + else if (padlen == 34) + xpadlengthmask = 5; + else if (padlen == 42) + xpadlengthmask = 6; + else if (padlen == 58) + xpadlengthmask = 7; + else + xpadlengthmask = -1; // Error + + return xpadlengthmask; +} + |