/*
- * This file is part of the sigrok project.
+ * This file is part of the libsigrok project.
*
- * Copyright (C) 2010 Bert Vermeulen <bert@biot.com>
+ * Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
*
* 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
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
-#include <sigrok.h>
-#include "sigrok-internal.h"
+#include <glib.h>
+#include "libsigrok.h"
+#include "libsigrok-internal.h"
+
+#define LOG_PREFIX "filter"
+
+/**
+ * @file
+ *
+ * Helper functions to filter out unused channels from samples.
+ */
+
+/**
+ * @defgroup grp_filter Channel filter
+ *
+ * Helper functions to filter out unused channels from samples.
+ *
+ * @{
+ */
/**
- * Remove unused probes from samples.
+ * Remove unused channels from samples.
*
- * Convert sample from maximum probes -- the way the hardware driver sent
+ * Convert sample from maximum channels -- the way the hardware driver sent
* it -- to a sample taking up only as much space as required, with
- * unused probes removed.
+ * unused channels removed.
*
- * The "unit size" is the number of bytes used to store probe values.
+ * The "unit size" is the number of bytes used to store channel values.
* For example, a unit size of 1 means one byte is used (which can store
- * 8 probe values, each of them is 1 bit). A unit size of 2 means we can
- * store 16 probe values, 3 means we can store 24 probe values, and so on.
+ * 8 channel values, each of them is 1 bit). A unit size of 2 means we can
+ * store 16 channel values, 3 means we can store 24 channel values, and so on.
*
* If the data coming from the logic analyzer has a unit size of 4 for
- * example (as the device has 32 probes), but only 2 of them are actually
+ * example (as the device has 32 channels), but only 2 of them are actually
* used in an acquisition, this function can convert the samples to only
* use up 1 byte per sample (unit size = 1) instead of 4 bytes per sample.
*
- * The output will contain the probe values in the order specified via the
- * probelist. For example, if in_unitsize = 4, probelist = [5, 16, 30], and
+ * The output will contain the channel values in the order specified via the
+ * channellist. For example, if in_unitsize = 4, channellist = [5, 16, 30], and
* out_unitsize = 1, then the output samples (each of them one byte in size)
- * will have the following format: bit 0 = value of probe 5, bit 1 = value
- * of probe 16, bit 2 = value of probe 30. Unused bit(s) in the output byte(s)
+ * will have the following format: bit 0 = value of channel 5, bit 1 = value
+ * of channel 16, bit 2 = value of channel 30. Unused bit(s) in the output byte(s)
* are zero.
*
* The caller must make sure that length_in is not bigger than the memory
*
* @param in_unitsize The unit size (>= 1) of the input (data_in).
* @param out_unitsize The unit size (>= 1) the output shall have (data_out).
- * @param probelist Pointer to a list of integers (probe numbers). The probe
- * numbers in this list are 1-based, i.e. the first probe
- * is expected to be numbered 1 (not 0!). Must not be NULL.
+ * The requested unit size must be big enough to hold as
+ * much data as is specified by the number of enabled
+ * channels in 'channellist'.
+ * @param channel_array Pointer to a list of channel numbers, numbered starting
+ * from 0. The list is terminated with -1.
* @param data_in Pointer to the input data buffer. Must not be NULL.
* @param length_in The input data length (>= 1), in number of bytes.
* @param data_out Variable which will point to the newly allocated buffer
* or SR_ERR_ARG upon invalid arguments.
* If something other than SR_OK is returned, the values of
* out_unitsize, data_out, and length_out are undefined.
+ *
+ * @since 0.2.0
*/
-int sr_filter_probes(int in_unitsize, int out_unitsize, const int *probelist,
- const unsigned char *data_in, uint64_t length_in,
- char **data_out, uint64_t *length_out)
+SR_API int sr_filter_channels(unsigned int in_unitsize, unsigned int out_unitsize,
+ const GArray *channel_array, const uint8_t *data_in,
+ uint64_t length_in, uint8_t **data_out,
+ uint64_t *length_out)
{
unsigned int in_offset, out_offset;
- int num_enabled_probes, out_bit, i;
- uint64_t sample_in, sample_out;
+ int *channellist, out_bit;
+ unsigned int i;
+ uint8_t *sample_in, *sample_out;
- if (!probelist) {
- sr_err("filter: %s: probelist was NULL", __func__);
+ if (!channel_array) {
+ sr_err("%s: channel_array was NULL", __func__);
return SR_ERR_ARG;
}
+ channellist = (int *)channel_array->data;
if (!data_in) {
- sr_err("filter: %s: data_in was NULL", __func__);
+ sr_err("%s: data_in was NULL", __func__);
return SR_ERR_ARG;
}
if (!data_out) {
- sr_err("filter: %s: data_out was NULL", __func__);
+ sr_err("%s: data_out was NULL", __func__);
return SR_ERR_ARG;
}
if (!length_out) {
- sr_err("filter: %s: length_out was NULL", __func__);
+ sr_err("%s: length_out was NULL", __func__);
+ return SR_ERR_ARG;
+ }
+
+ /* Are there more channels than the target unit size supports? */
+ if (channel_array->len > out_unitsize * 8) {
+ sr_err("%s: too many channels (%d) for the target unit "
+ "size (%d)", __func__, channel_array->len, out_unitsize);
return SR_ERR_ARG;
}
if (!(*data_out = g_try_malloc(length_in))) {
- sr_err("filter: %s: data_out malloc failed", __func__);
+ sr_err("%s: data_out malloc failed", __func__);
return SR_ERR_MALLOC;
}
- num_enabled_probes = 0;
- for (i = 0; probelist[i]; i++)
- num_enabled_probes++;
-
- if (num_enabled_probes == in_unitsize * 8) {
- /* All probes are used -- no need to compress anything. */
+ if (channel_array->len == in_unitsize * 8) {
+ /* All channels are used -- no need to compress anything. */
memcpy(*data_out, data_in, length_in);
*length_out = length_in;
return SR_OK;
}
- /* If we reached this point, not all probes are used, so "compress". */
+ /* If we reached this point, not all channels are used, so "compress". */
in_offset = out_offset = 0;
while (in_offset <= length_in - in_unitsize) {
- memcpy(&sample_in, data_in + in_offset, in_unitsize);
- sample_out = out_bit = 0;
- for (i = 0; probelist[i]; i++) {
- if (sample_in & (1 << (probelist[i] - 1)))
- sample_out |= (1 << out_bit);
+ sample_in = (uint8_t *)data_in + in_offset;
+ sample_out = (*data_out) + out_offset;
+ memset(sample_out, 0, out_unitsize);
+ out_bit = 0;
+ for (i = 0; i < channel_array->len; i++) {
+ if (sample_in[channellist[i]>>3] & (1 << (channellist[i]&7)))
+ sample_out[out_bit>>3] |= (1 << (out_bit&7));
out_bit++;
}
- memcpy((*data_out) + out_offset, &sample_out, out_unitsize);
in_offset += in_unitsize;
out_offset += out_unitsize;
}
return SR_OK;
}
+
+/** @} */
projects / libsigrok.git / blobdiff