2 * This file is part of the libsigrok project.
4 * Copyright (C) 2014 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/>.
22 #include <libsigrok/libsigrok.h>
23 #include "libsigrok-internal.h"
25 #define LOG_PREFIX "output/wav"
27 /* Minimum/maximum number of samples per channel to put in a data chunk */
28 #define MIN_DATA_CHUNK_SAMPLES 10
41 static int realloc_chanbufs(const struct sr_output *o, int size)
43 struct out_context *outc;
47 for (i = 0; i < outc->num_channels; i++) {
48 if (!(outc->chanbuf[i] = g_try_realloc(outc->chanbuf[i], sizeof(float) * size))) {
49 sr_err("Unable to allocate enough output buffer memory.");
52 outc->chanbuf_used[i] = 0;
54 outc->chanbuf_size = size;
59 static int flush_chanbufs(const struct sr_output *o, GString *out)
61 struct out_context *outc;
62 int num_samples, i, j;
67 /* Any one of them will do. */
68 num_samples = outc->chanbuf_used[0];
69 if (!(buf = g_try_malloc(4 * num_samples * outc->num_channels))) {
70 sr_err("Unable to allocate enough interleaved output buffer memory.");
75 for (i = 0; i < num_samples; i++) {
76 for (j = 0; j < outc->num_channels; j++) {
77 memcpy(bufp, outc->chanbuf[j] + i * 4, 4);
81 g_string_append_len(out, buf, 4 * num_samples * outc->num_channels);
84 for (i = 0; i < outc->num_channels; i++)
85 outc->chanbuf_used[i] = 0;
90 static int init(struct sr_output *o, GHashTable *options)
92 struct out_context *outc;
93 struct sr_channel *ch;
96 outc = g_malloc0(sizeof(struct out_context));
98 outc->scale = g_variant_get_double(g_hash_table_lookup(options, "scale"));
100 for (l = o->sdi->channels; l; l = l->next) {
102 if (ch->type != SR_CHANNEL_ANALOG)
106 outc->channels = g_slist_append(outc->channels, ch);
107 outc->num_channels++;
110 outc->chanbuf = g_malloc0(sizeof(float *) * outc->num_channels);
111 outc->chanbuf_used = g_malloc0(sizeof(int) * outc->num_channels);
113 /* Start off the interleaved buffer with 100 samples/channel. */
114 realloc_chanbufs(o, 100);
119 static void add_data_chunk(const struct sr_output *o, GString *gs)
121 struct out_context *outc;
125 g_string_append(gs, "fmt ");
126 /* Remaining chunk size */
128 g_string_append_len(gs, tmp, 4);
129 /* Format code 3 = IEEE float */
131 g_string_append_len(gs, tmp, 2);
132 /* Number of channels */
133 WL16(tmp, outc->num_channels);
134 g_string_append_len(gs, tmp, 2);
136 WL32(tmp, outc->samplerate);
137 g_string_append_len(gs, tmp, 4);
138 /* Byterate, using 32-bit floats. */
139 WL32(tmp, outc->samplerate * outc->num_channels * 4);
140 g_string_append_len(gs, tmp, 4);
142 WL16(tmp, outc->num_channels * 4);
143 g_string_append_len(gs, tmp, 2);
144 /* Bits per sample */
146 g_string_append_len(gs, tmp, 2);
148 g_string_append_len(gs, tmp, 2);
150 g_string_append(gs, "data");
151 /* Data chunk size, max it out. */
152 WL32(tmp, 0xffffffff);
153 g_string_append_len(gs, tmp, 4);
156 static GString *gen_header(const struct sr_output *o)
158 struct out_context *outc;
164 if (outc->samplerate == 0) {
165 if (sr_config_get(o->sdi->driver, o->sdi, NULL, SR_CONF_SAMPLERATE,
167 outc->samplerate = g_variant_get_uint64(gvar);
168 g_variant_unref(gvar);
172 header = g_string_sized_new(512);
173 g_string_append(header, "RIFF");
174 /* Total size. Max out the field. */
175 WL32(tmp, 0xffffffff);
176 g_string_append_len(header, tmp, 4);
177 g_string_append(header, "WAVE");
178 add_data_chunk(o, header);
184 * Stores the float in little-endian BINARY32 IEEE-754 2008 format.
186 static void float_to_le(uint8_t *buf, float value)
190 old = (char *)&value;
191 #ifdef WORDS_BIGENDIAN
205 * Returns the number of samples used in the current channel buffers,
206 * or -1 if they're not all the same.
208 static int check_chanbuf_size(const struct sr_output *o)
210 struct out_context *outc;
215 for (i = 0; i < outc->num_channels; i++) {
217 if (outc->chanbuf_used[i] == 0) {
218 /* Nothing in all the buffers yet. */
222 /* New high water mark. */
223 size = outc->chanbuf_used[i];
224 } else if (outc->chanbuf_used[i] != size) {
225 /* All channel buffers are not equally full yet. */
234 static int receive(const struct sr_output *o, const struct sr_datafeed_packet *packet,
237 struct out_context *outc;
238 const struct sr_datafeed_meta *meta;
239 const struct sr_datafeed_analog *analog;
240 const struct sr_config *src;
241 struct sr_channel *ch;
244 int num_channels, size, *chan_idx, idx, i, j;
248 if (!o || !o->sdi || !(outc = o->priv))
251 switch (packet->type) {
253 meta = packet->payload;
254 for (l = meta->config; l; l = l->next) {
256 if (src->key != SR_CONF_SAMPLERATE)
258 outc->samplerate = g_variant_get_uint64(src->data);
262 if (!outc->header_done) {
263 *out = gen_header(o);
264 outc->header_done = TRUE;
266 *out = g_string_sized_new(512);
268 analog = packet->payload;
269 if (analog->num_samples == 0)
272 num_channels = g_slist_length(analog->channels);
273 if (num_channels > outc->num_channels) {
274 sr_err("Packet has %d channels, but only %d were enabled.",
275 num_channels, outc->num_channels);
279 if (analog->num_samples > outc->chanbuf_size) {
280 if (realloc_chanbufs(o, analog->num_samples) != SR_OK)
281 return SR_ERR_MALLOC;
284 /* Index the channels in this packet, so we can interleave quicker. */
285 chan_idx = g_malloc(sizeof(int) * outc->num_channels);
286 for (i = 0; i < num_channels; i++) {
287 ch = g_slist_nth_data(analog->channels, i);
288 chan_idx[i] = g_slist_index(outc->channels, ch);
291 for (i = 0; i < analog->num_samples; i++) {
292 for (j = 0; j < num_channels; j++) {
294 buf = outc->chanbuf[idx] + outc->chanbuf_used[idx]++ * 4;
295 f = analog->data[i * num_channels + j];
296 if (outc->scale != 0.0)
303 size = check_chanbuf_size(o);
304 if (size > MIN_DATA_CHUNK_SAMPLES)
305 if (flush_chanbufs(o, *out) != SR_OK)
309 size = check_chanbuf_size(o);
311 *out = g_string_sized_new(4 * size * outc->num_channels);
312 if (flush_chanbufs(o, *out) != SR_OK)
321 static int cleanup(struct sr_output *o)
323 struct out_context *outc;
327 g_slist_free(outc->channels);
328 for (i = 0; i < outc->num_channels; i++)
329 g_free(outc->chanbuf[i]);
330 g_free(outc->chanbuf_used);
331 g_free(outc->chanbuf);
338 static struct sr_option options[] = {
339 { "scale", "Scale", "Scale values by factor", NULL, NULL },
343 static const struct sr_option *get_options(void)
346 options[0].def = g_variant_ref_sink(g_variant_new_double(0.0));
351 SR_PRIV struct sr_output_module output_wav = {
354 .desc = "Microsoft WAV file format",
355 .exts = (const char*[]){"wav", NULL},
357 .options = get_options,