src/transform/invert.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2015 Uwe Hermann <uwe@hermann-uwe.de>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  19  */
  20
  21 #include <config.h>
  22 #include <string.h>
  23 #include <libsigrok/libsigrok.h>
  24 #include "libsigrok-internal.h"
  25
  26 #define LOG_PREFIX "transform/invert"
  27
  28 static int receive(const struct sr_transform *t,
  29                 struct sr_datafeed_packet *packet_in,
  30                 struct sr_datafeed_packet **packet_out)
  31 {
  32         const struct sr_datafeed_logic *logic;
  33         const struct sr_datafeed_analog *analog;
  34         const struct sr_datafeed_analog2 *analog2;
  35         struct sr_channel *ch;
  36         GSList *l;
  37         float *fdata, *f;
  38         int si, num_channels, c;
  39         uint8_t *b;
  40         int64_t p;
  41         uint64_t i, j, q;
  42
  43         if (!t || !t->sdi || !packet_in || !packet_out)
  44                 return SR_ERR_ARG;
  45
  46         switch (packet_in->type) {
  47         case SR_DF_LOGIC:
  48                 logic = packet_in->payload;
  49                 for (i = 0; i <= logic->length - logic->unitsize; i += logic->unitsize) {
  50                         for (j = 0; j < logic->unitsize; j++) {
  51                                 /* For now invert every bit in every byte. */
  52                                 b = (uint8_t *)logic->data + i + logic->unitsize - 1 - j;
  53                                 *b = ~(*b);
  54                         }
  55                 }
  56                 break;
  57         case SR_DF_ANALOG:
  58                 analog = packet_in->payload;
  59                 fdata = (float *)analog->data;
  60                 num_channels = g_slist_length(analog->channels);
  61                 for (si = 0; si < analog->num_samples; si++) {
  62                         /* For now invert all values in all channels. */
  63                         for (l = analog->channels, c = 0; l; l = l->next, c++) {
  64                                 ch = l->data;
  65                                 (void)ch;
  66                                 f = &fdata[si * num_channels + c];
  67                                 *f = 1.0 / *f;
  68                         }
  69                 }
  70                 break;
  71         case SR_DF_ANALOG2:
  72                 analog2 = packet_in->payload;
  73                 p = analog2->encoding->scale.p;
  74                 q = analog2->encoding->scale.q;
  75                 if (q > INT64_MAX)
  76                         return SR_ERR;
  77                 analog2->encoding->scale.p = (p < 0) ? -q : q;
  78                 analog2->encoding->scale.q = (p < 0) ? -p : p;
  79                 break;
  80         default:
  81                 sr_spew("Unsupported packet type %d, ignoring.", packet_in->type);
  82                 break;
  83         }
  84
  85         /* Return the in-place-modified packet. */
  86         *packet_out = packet_in;
  87
  88         return SR_OK;
  89 }
  90
  91 SR_PRIV struct sr_transform_module transform_invert = {
  92         .id = "invert",
  93         .name = "Invert",
  94         .desc = "Invert values",
  95         .options = NULL,
  96         .init = NULL,
  97         .receive = receive,
  98         .cleanup = NULL,
  99 };