2 * This file is part of the sigrok project.
4 * Copyright (C) 2010 Bert Vermeulen <bert@biot.com>
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 3 of the License, or
9 * (at your option) any later version.
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.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
26 * Convert sample from maximum probes -- the way the hardware driver sent
27 * it -- to a sample taking up only as much space as required, with
28 * unused probes removed.
30 int filter_probes(int in_unitsize, int out_unitsize, int *probelist,
31 char *data_in, uint64_t length_in, char **data_out,
34 unsigned int in_offset, out_offset;
35 int num_enabled_probes, out_bit, i;
36 uint64_t sample_in, sample_out;
38 if (!(*data_out = malloc(length_in)))
41 num_enabled_probes = 0;
42 for (i = 0; probelist[i]; i++)
45 if (num_enabled_probes == in_unitsize * 8) {
46 /* All probes are used -- no need to compress anything. */
47 memcpy(*data_out, data_in, length_in);
48 *length_out = length_in;
52 /* If we reached this point, not all probes are used, so "compress". */
53 in_offset = out_offset = 0;
54 while (in_offset <= length_in - in_unitsize) {
55 memcpy(&sample_in, data_in + in_offset, in_unitsize);
56 sample_out = out_bit = 0;
57 for (i = 0; probelist[i]; i++) {
58 if (sample_in & (1 << (probelist[i] - 1)))
59 sample_out |= (1 << out_bit);
62 memcpy((*data_out) + out_offset, &sample_out, out_unitsize);
63 in_offset += in_unitsize;
64 out_offset += out_unitsize;
66 *length_out = out_offset;