libsigrok/src/transform/scale.c

114 lines
2.6 KiB
C

/*
* This file is part of the libsigrok project.
*
* Copyright (C) 2015 Uwe Hermann <uwe@hermann-uwe.de>
*
* 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 2 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/>.
*/
#include <config.h>
#include <string.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"
#define LOG_PREFIX "transform/scale"
struct context {
struct sr_rational factor;
};
static int init(struct sr_transform *t, GHashTable *options)
{
struct context *ctx;
if (!t || !t->sdi || !options)
return SR_ERR_ARG;
t->priv = ctx = g_malloc0(sizeof(struct context));
g_variant_get(g_hash_table_lookup(options, "factor"), "(xt)",
&ctx->factor.p, &ctx->factor.q);
return SR_OK;
}
static int receive(const struct sr_transform *t,
struct sr_datafeed_packet *packet_in,
struct sr_datafeed_packet **packet_out)
{
struct context *ctx;
const struct sr_datafeed_analog *analog;
if (!t || !t->sdi || !packet_in || !packet_out)
return SR_ERR_ARG;
ctx = t->priv;
switch (packet_in->type) {
case SR_DF_ANALOG:
analog = packet_in->payload;
analog->encoding->scale.p *= ctx->factor.p;
analog->encoding->scale.q *= ctx->factor.q;
break;
default:
sr_spew("Unsupported packet type %d, ignoring.", packet_in->type);
break;
}
/* Return the in-place-modified packet. */
*packet_out = packet_in;
return SR_OK;
}
static int cleanup(struct sr_transform *t)
{
struct context *ctx;
if (!t || !t->sdi)
return SR_ERR_ARG;
ctx = t->priv;
g_free(ctx);
t->priv = NULL;
return SR_OK;
}
static struct sr_option options[] = {
{ "factor", "Factor", "Factor by which to scale the analog values", NULL, NULL },
ALL_ZERO
};
static const struct sr_option *get_options(void)
{
int64_t p = 1;
uint64_t q = 1;
/* Default to a scaling factor of 1.0. */
if (!options[0].def)
options[0].def = g_variant_ref_sink(g_variant_new("(xt)", &p, &q));
return options;
}
SR_PRIV struct sr_transform_module transform_scale = {
.id = "scale",
.name = "Scale",
.desc = "Scale analog values by a specified factor",
.options = get_options,
.init = init,
.receive = receive,
.cleanup = cleanup,
};