transform: Add a "scale" transform module.

diff --git a/Makefile.am b/Makefile.am
index e5012f3690bed2513168dfe943be28ab2289f893..c68ceeb3a9e06521df5be6252b7ff3e436200c8b 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -71,7 +71,8 @@ libsigrok_la_SOURCES += \
 # Transform modules
 libsigrok_la_SOURCES += \
        src/transform/transform.c \
-       src/transform/nop.c
+       src/transform/nop.c \
+       src/transform/scale.c
 
 # SCPI support
 libsigrok_la_SOURCES += \

diff --git a/src/transform/scale.c b/src/transform/scale.c
new file mode 100644 (file)
index 0000000..6d3769b
--- /dev/null
+++ b/src/transform/scale.c
@@ -0,0 +1,121 @@
+/*
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#include <string.h>
+#include "libsigrok.h"
+#include "libsigrok-internal.h"
+
+#define LOG_PREFIX "transform/scale"
+
+struct context {
+       double 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));
+
+       ctx->factor = g_variant_get_double(g_hash_table_lookup(options, "factor"));
+
+       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;
+       struct sr_channel *ch;
+       GSList *l;
+       float *fdata;
+       int i, num_channels, c;
+
+       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;
+               fdata = (float *)analog->data;
+               num_channels = g_slist_length(analog->channels);
+               for (i = 0; i < analog->num_samples; i++) {
+                       /* For now scale all values in all channels. */
+                       for (l = analog->channels, c = 0; l; l = l->next, c++) {
+                               ch = l->data;
+                               (void)ch;
+                               fdata[i * num_channels + c] *= ctx->factor;
+                       }
+               }
+               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)
+{
+       /* Default to a scaling factor of 1.0. */
+       if (!options[0].def)
+               options[0].def = g_variant_ref_sink(g_variant_new_double(1.0));
+
+       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,
+};

diff --git a/src/transform/transform.c b/src/transform/transform.c
index 7477dc45e6f1f9407beb8751400ad52cc5fdf64b..f4166dde18c0a35ad97a92c0e6564b0f7d8ca00b 100644 (file)
--- a/src/transform/transform.c
+++ b/src/transform/transform.c
@@ -40,10 +40,12 @@
 
 /** @cond PRIVATE */
 extern SR_PRIV struct sr_transform_module transform_nop;
+extern SR_PRIV struct sr_transform_module transform_scale;
 /* @endcond */
 
 static const struct sr_transform_module *transform_module_list[] = {
        &transform_nop,
+       &transform_scale,
        NULL,
 };