src/input/vcd.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2012 Petteri Aimonen <jpa@sr.mail.kapsi.fi>
   5  * Copyright (C) 2014 Bert Vermeulen <bert@biot.com>
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 /* The VCD input module has the following options:
  22  *
  23  * numchannels: Maximum number of channels to use. The channels are
  24  *              detected in the same order as they are listed
  25  *              in the $var sections of the VCD file.
  26  *
  27  * skip:        Allows skipping until given timestamp in the file.
  28  *              This can speed up analyzing of long captures.
  29  *
  30  *              Value < 0: Skip until first timestamp listed in
  31  *              the file. (default)
  32  *
  33  *              Value = 0: Do not skip, instead generate samples
  34  *              beginning from timestamp 0.
  35  *
  36  *              Value > 0: Start at the given timestamp.
  37  *
  38  * downsample:  Divide the samplerate by the given factor.
  39  *              This can speed up analyzing of long captures.
  40  *
  41  * compress:    Compress idle periods longer than this value.
  42  *              This can speed up analyzing of long captures.
  43  *              Default 0 = don't compress.
  44  *
  45  * Based on Verilog standard IEEE Std 1364-2001 Version C
  46  *
  47  * Supported features:
  48  * - $var with 'wire' and 'reg' types of scalar variables
  49  * - $timescale definition for samplerate
  50  * - multiple character variable identifiers
  51  *
  52  * Most important unsupported features:
  53  * - vector variables (bit vectors etc.)
  54  * - analog, integer and real number variables
  55  * - $dumpvars initial value declaration
  56  * - $scope namespaces
  57  * - more than 64 channels
  58  */
  59
  60 #include <config.h>
  61 #include <stdlib.h>
  62 #include <glib.h>
  63 #include <stdio.h>
  64 #include <string.h>
  65 #include <libsigrok/libsigrok.h>
  66 #include "libsigrok-internal.h"
  67
  68 #define LOG_PREFIX "input/vcd"
  69
  70 #define CHUNK_SIZE (4 * 1024 * 1024)
  71
  72 struct context {
  73         gboolean started;
  74         gboolean got_header;
  75         uint64_t prev_timestamp;
  76         uint64_t samplerate;
  77         unsigned int maxchannels;
  78         unsigned int channelcount;
  79         int downsample;
  80         unsigned compress;
  81         int64_t skip;
  82         gboolean skip_until_end;
  83         GSList *channels;
  84         size_t bytes_per_sample;
  85         size_t samples_in_buffer;
  86         uint8_t *buffer;
  87         uint8_t *current_levels;
  88 };
  89
  90 struct vcd_channel {
  91         gchar *name;
  92         gchar *identifier;
  93 };
  94
  95 /*
  96  * Reads a single VCD section from input file and parses it to name/contents.
  97  * e.g. $timescale 1ps $end => "timescale" "1ps"
  98  */
  99 static gboolean parse_section(GString *buf, gchar **name, gchar **contents)
 100 {
 101         GString *sname, *scontent;
 102         gboolean status;
 103         unsigned int pos;
 104
 105         *name = *contents = NULL;
 106         status = FALSE;
 107         pos = 0;
 108
 109         /* Skip UTF8 BOM */
 110         if (buf->len >= 3 && !strncmp(buf->str, "\xef\xbb\xbf", 3))
 111                 pos = 3;
 112
 113         /* Skip any initial white-space. */
 114         while (pos < buf->len && g_ascii_isspace(buf->str[pos]))
 115                 pos++;
 116
 117         /* Section tag should start with $. */
 118         if (buf->str[pos++] != '$')
 119                 return FALSE;
 120
 121         sname = g_string_sized_new(32);
 122         scontent = g_string_sized_new(128);
 123
 124         /* Read the section tag. */
 125         while (pos < buf->len && !g_ascii_isspace(buf->str[pos]))
 126                 g_string_append_c(sname, buf->str[pos++]);
 127
 128         /* Skip whitespace before content. */
 129         while (pos < buf->len && g_ascii_isspace(buf->str[pos]))
 130                 pos++;
 131
 132         /* Read the content. */
 133         while (pos < buf->len - 4 && strncmp(buf->str + pos, "$end", 4))
 134                 g_string_append_c(scontent, buf->str[pos++]);
 135
 136         if (sname->len && pos < buf->len - 4 && !strncmp(buf->str + pos, "$end", 4)) {
 137                 status = TRUE;
 138                 pos += 4;
 139                 while (pos < buf->len && g_ascii_isspace(buf->str[pos]))
 140                         pos++;
 141                 g_string_erase(buf, 0, pos);
 142         }
 143
 144         *name = g_string_free(sname, !status);
 145         *contents = g_string_free(scontent, !status);
 146         if (*contents)
 147                 g_strchomp(*contents);
 148
 149         return status;
 150 }
 151
 152 static void free_channel(void *data)
 153 {
 154         struct vcd_channel *vcd_ch;
 155
 156         vcd_ch = data;
 157         if (!vcd_ch)
 158                 return;
 159         g_free(vcd_ch->name);
 160         g_free(vcd_ch->identifier);
 161         g_free(vcd_ch);
 162 }
 163
 164 /* Remove empty parts from an array returned by g_strsplit. */
 165 static void remove_empty_parts(gchar **parts)
 166 {
 167         gchar **src = parts;
 168         gchar **dest = parts;
 169         while (*src != NULL) {
 170                 if (**src != '\0')
 171                         *dest++ = *src;
 172                 src++;
 173         }
 174
 175         *dest = NULL;
 176 }
 177
 178 /*
 179  * Parse VCD header to get values for context structure.
 180  * The context structure should be zeroed before calling this.
 181  */
 182 static gboolean parse_header(const struct sr_input *in, GString *buf)
 183 {
 184         struct vcd_channel *vcd_ch;
 185         uint64_t p, q;
 186         struct context *inc;
 187         gboolean status;
 188         gchar *name, *contents, **parts;
 189
 190         inc = in->priv;
 191         name = contents = NULL;
 192         status = FALSE;
 193         while (parse_section(buf, &name, &contents)) {
 194                 sr_dbg("Section '%s', contents '%s'.", name, contents);
 195
 196                 if (g_strcmp0(name, "enddefinitions") == 0) {
 197                         status = TRUE;
 198                         break;
 199                 } else if (g_strcmp0(name, "timescale") == 0) {
 200                         /*
 201                          * The standard allows for values 1, 10 or 100
 202                          * and units s, ms, us, ns, ps and fs.
 203                          */
 204                         if (sr_parse_period(contents, &p, &q) == SR_OK) {
 205                                 inc->samplerate = q / p;
 206                                 if (q % p != 0) {
 207                                         /* Does not happen unless time value is non-standard */
 208                                         sr_warn("Inexact rounding of samplerate, %" PRIu64 " / %" PRIu64 " to %" PRIu64 " Hz.",
 209                                                 q, p, inc->samplerate);
 210                                 }
 211
 212                                 sr_dbg("Samplerate: %" PRIu64, inc->samplerate);
 213                         } else {
 214                                 sr_err("Parsing timescale failed.");
 215                         }
 216                 } else if (g_strcmp0(name, "var") == 0) {
 217                         /* Format: $var type size identifier reference [opt. index] $end */
 218                         unsigned int length;
 219
 220                         parts = g_strsplit_set(contents, " \r\n\t", 0);
 221                         remove_empty_parts(parts);
 222                         length = g_strv_length(parts);
 223
 224                         if (length != 4 && length != 5)
 225                                 sr_warn("$var section should have 4 or 5 items");
 226                         else if (g_strcmp0(parts[0], "reg") != 0 && g_strcmp0(parts[0], "wire") != 0)
 227                                 sr_info("Unsupported signal type: '%s'", parts[0]);
 228                         else if (strtol(parts[1], NULL, 10) != 1)
 229                                 sr_info("Unsupported signal size: '%s'", parts[1]);
 230                         else if (inc->maxchannels && inc->channelcount >= inc->maxchannels)
 231                                 sr_warn("Skipping '%s%s' because only %d channels requested.",
 232                                         parts[3], parts[4] ? : "", inc->maxchannels);
 233                         else {
 234                                 vcd_ch = g_malloc(sizeof(struct vcd_channel));
 235                                 vcd_ch->identifier = g_strdup(parts[2]);
 236                                 if (length == 4)
 237                                         vcd_ch->name = g_strdup(parts[3]);
 238                                 else
 239                                         vcd_ch->name = g_strconcat(parts[3], parts[4], NULL);
 240
 241                                 sr_info("Channel %d is '%s' identified by '%s'.",
 242                                                 inc->channelcount, vcd_ch->name, vcd_ch->identifier);
 243
 244                                 sr_channel_new(in->sdi, inc->channelcount++, SR_CHANNEL_LOGIC, TRUE, vcd_ch->name);
 245                                 inc->channels = g_slist_append(inc->channels, vcd_ch);
 246                         }
 247
 248                         g_strfreev(parts);
 249                 }
 250
 251                 g_free(name);
 252                 name = NULL;
 253                 g_free(contents);
 254                 contents = NULL;
 255         }
 256         g_free(name);
 257         g_free(contents);
 258
 259         /*
 260          * Compute how many bytes each sample will have and initialize the
 261          * current levels. The current levels will be updated whenever VCD
 262          * has changes.
 263          */
 264         inc->bytes_per_sample = (inc->channelcount + 7) / 8;
 265         inc->current_levels = g_malloc0(inc->bytes_per_sample);
 266
 267         inc->got_header = status;
 268
 269         return status;
 270 }
 271
 272 static int format_match(GHashTable *metadata, unsigned int *confidence)
 273 {
 274         GString *buf, *tmpbuf;
 275         gboolean status;
 276         gchar *name, *contents;
 277
 278         buf = g_hash_table_lookup(metadata, GINT_TO_POINTER(SR_INPUT_META_HEADER));
 279         tmpbuf = g_string_new_len(buf->str, buf->len);
 280
 281         /*
 282          * If we can parse the first section correctly,
 283          * then it is assumed to be a VCD file.
 284          */
 285         status = parse_section(tmpbuf, &name, &contents);
 286         g_string_free(tmpbuf, TRUE);
 287         g_free(name);
 288         g_free(contents);
 289
 290         if (!status)
 291                 return SR_ERR;
 292         *confidence = 1;
 293
 294         return SR_OK;
 295 }
 296
 297 /* Send all accumulated bytes from inc->buffer. */
 298 static void send_buffer(const struct sr_input *in)
 299 {
 300         struct context *inc;
 301         struct sr_datafeed_packet packet;
 302         struct sr_datafeed_logic logic;
 303
 304         inc = in->priv;
 305
 306         if (inc->samples_in_buffer == 0)
 307                 return;
 308
 309         packet.type = SR_DF_LOGIC;
 310         packet.payload = &logic;
 311         logic.unitsize = inc->bytes_per_sample;
 312         logic.data = inc->buffer;
 313         logic.length = inc->bytes_per_sample * inc->samples_in_buffer;
 314         sr_session_send(in->sdi, &packet);
 315         inc->samples_in_buffer = 0;
 316 }
 317
 318 /*
 319  * Add N copies of the current sample to buffer.
 320  * When the buffer fills up, automatically send it.
 321  */
 322 static void add_samples(const struct sr_input *in, size_t count)
 323 {
 324         struct context *inc;
 325         size_t samples_per_chunk;
 326         size_t space_left, i;
 327         uint8_t *p;
 328
 329         inc = in->priv;
 330         samples_per_chunk = CHUNK_SIZE / inc->bytes_per_sample;
 331
 332         while (count) {
 333                 space_left = samples_per_chunk - inc->samples_in_buffer;
 334
 335                 if (space_left > count)
 336                         space_left = count;
 337
 338                 p = inc->buffer + inc->samples_in_buffer * inc->bytes_per_sample;
 339                 for (i = 0; i < space_left; i++) {
 340                         memcpy(p, inc->current_levels, inc->bytes_per_sample);
 341                         p += inc->bytes_per_sample;
 342                         inc->samples_in_buffer++;
 343                         count--;
 344                 }
 345
 346                 if (inc->samples_in_buffer == samples_per_chunk)
 347                         send_buffer(in);
 348         }
 349 }
 350
 351 /* Set the channel level depending on the identifier and parsed value. */
 352 static void process_bit(struct context *inc, char *identifier, unsigned int bit)
 353 {
 354         GSList *l;
 355         struct vcd_channel *vcd_ch;
 356         unsigned int j;
 357
 358         for (j = 0, l = inc->channels; j < inc->channelcount && l; j++, l = l->next) {
 359                 vcd_ch = l->data;
 360                 if (g_strcmp0(identifier, vcd_ch->identifier) == 0) {
 361                         /* Found our channel. */
 362                         size_t byte_idx = (j / 8);
 363                         size_t bit_idx = j - 8 * byte_idx;
 364                         if (bit)
 365                                 inc->current_levels[byte_idx] |= (uint8_t)1 << bit_idx;
 366                         else
 367                                 inc->current_levels[byte_idx] &= ~((uint8_t)1 << bit_idx);
 368                         break;
 369                 }
 370         }
 371         if (j == inc->channelcount)
 372                 sr_dbg("Did not find channel for identifier '%s'.", identifier);
 373 }
 374
 375 /* Parse a set of lines from the data section. */
 376 static void parse_contents(const struct sr_input *in, char *data)
 377 {
 378         struct context *inc;
 379         uint64_t timestamp;
 380         unsigned int bit, i;
 381         char **tokens;
 382
 383         inc = in->priv;
 384
 385         /* Read one space-delimited token at a time. */
 386         tokens = g_strsplit_set(data, " \t\r\n", 0);
 387         remove_empty_parts(tokens);
 388         for (i = 0; tokens[i]; i++) {
 389                 if (inc->skip_until_end) {
 390                         if (!strcmp(tokens[i], "$end")) {
 391                                 /* Done with unhandled/unknown section. */
 392                                 inc->skip_until_end = FALSE;
 393                                 break;
 394                         }
 395                 }
 396                 if (tokens[i][0] == '#' && g_ascii_isdigit(tokens[i][1])) {
 397                         /* Numeric value beginning with # is a new timestamp value */
 398                         timestamp = strtoull(tokens[i] + 1, NULL, 10);
 399
 400                         if (inc->downsample > 1)
 401                                 timestamp /= inc->downsample;
 402
 403                         /*
 404                          * Skip < 0 => skip until first timestamp.
 405                          * Skip = 0 => don't skip
 406                          * Skip > 0 => skip until timestamp >= skip.
 407                          */
 408                         if (inc->skip < 0) {
 409                                 inc->skip = timestamp;
 410                                 inc->prev_timestamp = timestamp;
 411                         } else if (inc->skip > 0 && timestamp < (uint64_t)inc->skip) {
 412                                 inc->prev_timestamp = inc->skip;
 413                         } else if (timestamp == inc->prev_timestamp) {
 414                                 /* Ignore repeated timestamps (e.g. sigrok outputs these) */
 415                         } else if (timestamp < inc->prev_timestamp) {
 416                                 sr_err("Invalid timestamp: %" PRIu64 " (smaller than previous timestamp).", timestamp);
 417                                 inc->skip_until_end = TRUE;
 418                                 break;
 419                         } else {
 420                                 if (inc->compress != 0 && timestamp - inc->prev_timestamp > inc->compress) {
 421                                         /* Compress long idle periods */
 422                                         inc->prev_timestamp = timestamp - inc->compress;
 423                                 }
 424
 425                                 sr_dbg("New timestamp: %" PRIu64, timestamp);
 426
 427                                 /* Generate samples from prev_timestamp up to timestamp - 1. */
 428                                 add_samples(in, timestamp - inc->prev_timestamp);
 429                                 inc->prev_timestamp = timestamp;
 430                         }
 431                 } else if (tokens[i][0] == '$' && tokens[i][1] != '\0') {
 432                         /*
 433                          * This is probably a $dumpvars, $comment or similar.
 434                          * $dump* contain useful data.
 435                          */
 436                         if (g_strcmp0(tokens[i], "$dumpvars") == 0
 437                                         || g_strcmp0(tokens[i], "$dumpon") == 0
 438                                         || g_strcmp0(tokens[i], "$dumpoff") == 0
 439                                         || g_strcmp0(tokens[i], "$end") == 0) {
 440                                 /* Ignore, parse contents as normally. */
 441                         } else {
 442                                 /* Ignore this and future lines until $end. */
 443                                 inc->skip_until_end = TRUE;
 444                                 break;
 445                         }
 446                 } else if (strchr("rR", tokens[i][0]) != NULL) {
 447                         sr_dbg("Real type vector values not supported yet!");
 448                         if (!tokens[++i])
 449                                 /* No tokens left, bail out */
 450                                 break;
 451                         else
 452                                 /* Process next token */
 453                                 continue;
 454                 } else if (strchr("bB", tokens[i][0]) != NULL) {
 455                         bit = (tokens[i][1] == '1');
 456
 457                         /*
 458                          * Bail out if a) char after 'b' is NUL, or b) there is
 459                          * a second character after 'b', or c) there is no
 460                          * identifier.
 461                          */
 462                         if (!tokens[i][1] || tokens[i][2] || !tokens[++i]) {
 463                                 sr_dbg("Unexpected vector format!");
 464                                 break;
 465                         }
 466
 467                         process_bit(inc, tokens[i], bit);
 468                 } else if (strchr("01xXzZ", tokens[i][0]) != NULL) {
 469                         char *identifier;
 470
 471                         /* A new 1-bit sample value */
 472                         bit = (tokens[i][0] == '1');
 473
 474                         /*
 475                          * The identifier is either the next character, or, if
 476                          * there was whitespace after the bit, the next token.
 477                          */
 478                         if (tokens[i][1] == '\0') {
 479                                 if (!tokens[++i]) {
 480                                         sr_dbg("Identifier missing!");
 481                                         break;
 482                                 }
 483                                 identifier = tokens[i];
 484                         } else {
 485                                 identifier = tokens[i] + 1;
 486                         }
 487                         process_bit(inc, identifier, bit);
 488                 } else {
 489                         sr_warn("Skipping unknown token '%s'.", tokens[i]);
 490                 }
 491         }
 492         g_strfreev(tokens);
 493 }
 494
 495 static int init(struct sr_input *in, GHashTable *options)
 496 {
 497         struct context *inc;
 498
 499         inc = in->priv = g_malloc0(sizeof(struct context));
 500
 501         inc->maxchannels = g_variant_get_int32(g_hash_table_lookup(options, "numchannels"));
 502         inc->downsample = g_variant_get_int32(g_hash_table_lookup(options, "downsample"));
 503         if (inc->downsample < 1)
 504                 inc->downsample = 1;
 505
 506         inc->compress = g_variant_get_int32(g_hash_table_lookup(options, "compress"));
 507         inc->skip = g_variant_get_int32(g_hash_table_lookup(options, "skip"));
 508         inc->skip /= inc->downsample;
 509
 510         in->sdi = g_malloc0(sizeof(struct sr_dev_inst));
 511         in->priv = inc;
 512
 513         inc->buffer = g_malloc(CHUNK_SIZE);
 514
 515         return SR_OK;
 516 }
 517
 518 static gboolean have_header(GString *buf)
 519 {
 520         unsigned int pos;
 521         char *p;
 522
 523         if (!(p = g_strstr_len(buf->str, buf->len, "$enddefinitions")))
 524                 return FALSE;
 525         pos = p - buf->str + 15;
 526         while (pos < buf->len - 4 && g_ascii_isspace(buf->str[pos]))
 527                 pos++;
 528         if (!strncmp(buf->str + pos, "$end", 4))
 529                 return TRUE;
 530
 531         return FALSE;
 532 }
 533
 534 static int process_buffer(struct sr_input *in)
 535 {
 536         struct sr_datafeed_packet packet;
 537         struct sr_datafeed_meta meta;
 538         struct sr_config *src;
 539         struct context *inc;
 540         uint64_t samplerate;
 541         char *p;
 542
 543         inc = in->priv;
 544         if (!inc->started) {
 545                 std_session_send_df_header(in->sdi);
 546
 547                 packet.type = SR_DF_META;
 548                 packet.payload = &meta;
 549                 samplerate = inc->samplerate / inc->downsample;
 550                 src = sr_config_new(SR_CONF_SAMPLERATE, g_variant_new_uint64(samplerate));
 551                 meta.config = g_slist_append(NULL, src);
 552                 sr_session_send(in->sdi, &packet);
 553                 g_slist_free(meta.config);
 554                 sr_config_free(src);
 555
 556                 inc->started = TRUE;
 557         }
 558
 559         while ((p = g_strrstr_len(in->buf->str, in->buf->len, "\n"))) {
 560                 *p = '\0';
 561                 g_strstrip(in->buf->str);
 562                 if (in->buf->str[0] != '\0')
 563                         parse_contents(in, in->buf->str);
 564                 g_string_erase(in->buf, 0, p - in->buf->str + 1);
 565         }
 566
 567         return SR_OK;
 568 }
 569
 570 static int receive(struct sr_input *in, GString *buf)
 571 {
 572         struct context *inc;
 573         int ret;
 574
 575         g_string_append_len(in->buf, buf->str, buf->len);
 576
 577         inc = in->priv;
 578         if (!inc->got_header) {
 579                 if (!have_header(in->buf))
 580                         return SR_OK;
 581                 if (!parse_header(in, in->buf))
 582                         /* There was a header in there, but it was malformed. */
 583                         return SR_ERR;
 584
 585                 in->sdi_ready = TRUE;
 586                 /* sdi is ready, notify frontend. */
 587                 return SR_OK;
 588         }
 589
 590         ret = process_buffer(in);
 591
 592         return ret;
 593 }
 594
 595 static int end(struct sr_input *in)
 596 {
 597         struct context *inc;
 598         int ret;
 599
 600         inc = in->priv;
 601
 602         if (in->sdi_ready)
 603                 ret = process_buffer(in);
 604         else
 605                 ret = SR_OK;
 606
 607         /* Send any samples that haven't been sent yet. */
 608         send_buffer(in);
 609
 610         if (inc->started)
 611                 std_session_send_df_end(in->sdi);
 612
 613         return ret;
 614 }
 615
 616 static void cleanup(struct sr_input *in)
 617 {
 618         struct context *inc;
 619
 620         inc = in->priv;
 621         g_slist_free_full(inc->channels, free_channel);
 622         inc->channels = NULL;
 623         g_free(inc->buffer);
 624         inc->buffer = NULL;
 625         g_free(inc->current_levels);
 626         inc->current_levels = NULL;
 627 }
 628
 629 static int reset(struct sr_input *in)
 630 {
 631         struct context *inc = in->priv;
 632
 633         cleanup(in);
 634         g_string_truncate(in->buf, 0);
 635
 636         inc->started = FALSE;
 637         inc->got_header = FALSE;
 638         inc->prev_timestamp = 0;
 639         inc->skip_until_end = FALSE;
 640         inc->channelcount = 0;
 641         /* The inc->channels list was released in cleanup() above. */
 642         inc->buffer = g_malloc(CHUNK_SIZE);
 643
 644         return SR_OK;
 645 }
 646
 647 static struct sr_option options[] = {
 648         { "numchannels", "Number of logic channels", "The number of (logic) channels in the data", NULL, NULL },
 649         { "skip", "Skip samples until timestamp", "Skip samples until the specified timestamp; "
 650                 "< 0: Skip until first timestamp listed; 0: Don't skip", NULL, NULL },
 651         { "downsample", "Downsampling factor", "Downsample, i.e. divide the samplerate by the specified factor", NULL, NULL },
 652         { "compress", "Compress idle periods", "Compress idle periods longer than the specified value", NULL, NULL },
 653         ALL_ZERO
 654 };
 655
 656 static const struct sr_option *get_options(void)
 657 {
 658         if (!options[0].def) {
 659                 options[0].def = g_variant_ref_sink(g_variant_new_int32(0));
 660                 options[1].def = g_variant_ref_sink(g_variant_new_int32(-1));
 661                 options[2].def = g_variant_ref_sink(g_variant_new_int32(1));
 662                 options[3].def = g_variant_ref_sink(g_variant_new_int32(0));
 663         }
 664
 665         return options;
 666 }
 667
 668 SR_PRIV struct sr_input_module input_vcd = {
 669         .id = "vcd",
 670         .name = "VCD",
 671         .desc = "Value Change Dump data",
 672         .exts = (const char*[]){"vcd", NULL},
 673         .metadata = { SR_INPUT_META_HEADER | SR_INPUT_META_REQUIRED },
 674         .options = get_options,
 675         .format_match = format_match,
 676         .init = init,
 677         .receive = receive,
 678         .end = end,
 679         .cleanup = cleanup,
 680         .reset = reset,
 681 };