2 * This file is part of the libsigrok project.
4 * Copyright (C) 2013 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/>.
21 #include <sys/types.h>
28 #include <libsigrok/libsigrok.h>
29 #include "libsigrok-internal.h"
31 #define LOG_PREFIX "input/wav"
33 /* How many bytes at a time to process and send to the session bus. */
34 #define CHUNK_SIZE (1 * 1024 * 1024 * sizeof(float))
36 /* Minimum size of header + 1 8-bit mono PCM sample. */
37 #define MIN_DATA_CHUNK_OFFSET 45
39 /* Expect to find the "data" chunk within this offset from the start. */
40 #define MAX_DATA_CHUNK_OFFSET 1024
42 #define WAVE_FORMAT_PCM_ 0x0001
43 #define WAVE_FORMAT_IEEE_FLOAT_ 0x0003
44 #define WAVE_FORMAT_EXTENSIBLE_ 0xfffe
54 gboolean create_channels;
57 static int parse_wav_header(GString *buf, struct context *inc)
60 unsigned int fmt_code, samplesize, num_channels, unitsize;
62 if (buf->len < MIN_DATA_CHUNK_OFFSET)
65 fmt_code = RL16(buf->str + 20);
66 samplerate = RL32(buf->str + 24);
68 samplesize = RL16(buf->str + 32);
69 num_channels = RL16(buf->str + 22);
70 if (num_channels == 0)
72 unitsize = samplesize / num_channels;
73 if (unitsize != 1 && unitsize != 2 && unitsize != 4) {
74 sr_err("Only 8, 16 or 32 bits per sample supported.");
78 if (fmt_code == WAVE_FORMAT_PCM_) {
79 } else if (fmt_code == WAVE_FORMAT_IEEE_FLOAT_) {
81 sr_err("only 32-bit floats supported.");
84 } else if (fmt_code == WAVE_FORMAT_EXTENSIBLE_) {
86 /* Not enough for extensible header and next chunk. */
89 if (RL16(buf->str + 16) != 40) {
90 sr_err("WAV extensible format chunk must be 40 bytes.");
93 if (RL16(buf->str + 36) != 22) {
94 sr_err("WAV extension must be 22 bytes.");
97 if (RL16(buf->str + 34) != RL16(buf->str + 38)) {
98 sr_err("Reduced valid bits per sample not supported.");
101 /* Real format code is the first two bytes of the GUID. */
102 fmt_code = RL16(buf->str + 44);
103 if (fmt_code != WAVE_FORMAT_PCM_ && fmt_code != WAVE_FORMAT_IEEE_FLOAT_) {
104 sr_err("Only PCM and floating point samples are supported.");
107 if (fmt_code == WAVE_FORMAT_IEEE_FLOAT_ && unitsize != 4) {
108 sr_err("only 32-bit floats supported.");
112 sr_err("Only PCM and floating point samples are supported.");
117 inc->fmt_code = fmt_code;
118 inc->samplerate = samplerate;
119 inc->samplesize = samplesize;
120 inc->num_channels = num_channels;
121 inc->unitsize = unitsize;
122 inc->found_data = FALSE;
128 static int format_match(GHashTable *metadata, unsigned int *confidence)
133 buf = g_hash_table_lookup(metadata, GINT_TO_POINTER(SR_INPUT_META_HEADER));
134 if (strncmp(buf->str, "RIFF", 4))
136 if (strncmp(buf->str + 8, "WAVE", 4))
138 if (strncmp(buf->str + 12, "fmt ", 4))
141 * Only gets called when we already know this is a WAV file, so
142 * this parser can log error messages.
144 if ((ret = parse_wav_header(buf, NULL)) != SR_OK)
152 static int init(struct sr_input *in, GHashTable *options)
158 in->sdi = g_malloc0(sizeof(struct sr_dev_inst));
159 in->priv = g_malloc0(sizeof(struct context));
162 inc->create_channels = TRUE;
167 static int find_data_chunk(GString *buf, int initial_offset)
169 unsigned int offset, i;
171 offset = initial_offset;
172 while (offset < MIN(MAX_DATA_CHUNK_OFFSET, buf->len)) {
173 if (!memcmp(buf->str + offset, "data", 4))
174 /* Skip into the samples. */
176 for (i = 0; i < 4; i++) {
177 if (!isalnum(buf->str[offset + i])
178 && !isblank(buf->str[offset + i]))
179 /* Doesn't look like a chunk ID. */
182 /* Skip past this chunk. */
183 offset += 8 + RL32(buf->str + offset + 4);
186 if (offset > MAX_DATA_CHUNK_OFFSET)
192 static void send_chunk(const struct sr_input *in, int offset, int num_samples)
194 struct sr_datafeed_packet packet;
195 struct sr_datafeed_analog analog;
196 struct sr_analog_encoding encoding;
197 struct sr_analog_meaning meaning;
198 struct sr_analog_spec spec;
201 int total_samples, samplenum;
206 total_samples = num_samples * inc->num_channels;
207 fdata = g_malloc0(total_samples * sizeof(float));
208 s = in->buf->str + offset;
211 for (samplenum = 0; samplenum < total_samples; samplenum++) {
212 if (inc->fmt_code == WAVE_FORMAT_PCM_) {
213 switch (inc->unitsize) {
215 /* 8-bit PCM samples are unsigned. */
216 fdata[samplenum] = *(uint8_t*)(s) / (float)255;
219 fdata[samplenum] = RL16S(s) / (float)INT16_MAX;
222 fdata[samplenum] = RL32S(s) / (float)INT32_MAX;
227 #ifdef WORDS_BIGENDIAN
229 for (i = 0; i < inc->unitsize; i++)
230 d[i] = s[inc->unitsize - 1 - i];
232 memcpy(d, s, inc->unitsize);
239 /* TODO: Use proper 'digits' value for this device (and its modes). */
240 sr_analog_init(&analog, &encoding, &meaning, &spec, 2);
241 packet.type = SR_DF_ANALOG;
242 packet.payload = &analog;
243 analog.num_samples = num_samples;
245 analog.meaning->channels = in->sdi->channels;
246 analog.meaning->mq = 0;
247 analog.meaning->mqflags = 0;
248 analog.meaning->unit = 0;
249 sr_session_send(in->sdi, &packet);
253 static int process_buffer(struct sr_input *in)
256 struct sr_datafeed_packet packet;
257 struct sr_datafeed_meta meta;
258 struct sr_config *src;
259 int offset, chunk_samples, total_samples, processed, max_chunk_samples;
264 std_session_send_df_header(in->sdi);
266 packet.type = SR_DF_META;
267 packet.payload = &meta;
268 src = sr_config_new(SR_CONF_SAMPLERATE, g_variant_new_uint64(inc->samplerate));
269 meta.config = g_slist_append(NULL, src);
270 sr_session_send(in->sdi, &packet);
271 g_slist_free(meta.config);
277 if (!inc->found_data) {
278 /* Skip past size of 'fmt ' chunk. */
279 i = 20 + RL32(in->buf->str + 16);
280 offset = find_data_chunk(in->buf, i);
282 if (in->buf->len > MAX_DATA_CHUNK_OFFSET) {
283 sr_err("Couldn't find data chunk.");
287 inc->found_data = TRUE;
291 /* Round off up to the last channels * unitsize boundary. */
292 chunk_samples = (in->buf->len - offset) / inc->samplesize;
293 max_chunk_samples = CHUNK_SIZE / inc->samplesize;
295 total_samples = chunk_samples;
296 while (processed < total_samples) {
297 if (chunk_samples > max_chunk_samples)
298 num_samples = max_chunk_samples;
300 num_samples = chunk_samples;
301 send_chunk(in, offset, num_samples);
302 offset += num_samples * inc->samplesize;
303 chunk_samples -= num_samples;
304 processed += num_samples;
307 if ((unsigned int)offset < in->buf->len) {
309 * The incoming buffer wasn't processed completely. Stash
310 * the leftover data for next time.
312 g_string_erase(in->buf, 0, offset);
314 g_string_truncate(in->buf, 0);
319 static int receive(struct sr_input *in, GString *buf)
323 char channelname[16];
325 g_string_append_len(in->buf, buf->str, buf->len);
327 if (in->buf->len < MIN_DATA_CHUNK_OFFSET) {
329 * Don't even try until there's enough room
330 * for the data segment to start.
336 if (!in->sdi_ready) {
337 if ((ret = parse_wav_header(in->buf, inc)) == SR_ERR_NA)
338 /* Not enough data yet. */
340 else if (ret != SR_OK)
343 if (inc->create_channels) {
344 for (int i = 0; i < inc->num_channels; i++) {
345 snprintf(channelname, sizeof(channelname), "CH%d", i + 1);
346 sr_channel_new(in->sdi, i, SR_CHANNEL_ANALOG, TRUE, channelname);
350 inc->create_channels = FALSE;
352 /* sdi is ready, notify frontend. */
353 in->sdi_ready = TRUE;
357 ret = process_buffer(in);
362 static int end(struct sr_input *in)
368 ret = process_buffer(in);
374 std_session_send_df_end(in->sdi);
379 static int reset(struct sr_input *in)
381 memset(in->priv, 0, sizeof(struct context));
384 * We only want to create the sigrok channels once, so
385 * inc->create_channels won't be set to TRUE this time around.
388 g_string_truncate(in->buf, 0);
393 SR_PRIV struct sr_input_module input_wav = {
396 .desc = "Microsoft WAV file format data",
397 .exts = (const char*[]){"wav", NULL},
398 .metadata = { SR_INPUT_META_HEADER | SR_INPUT_META_REQUIRED },
399 .format_match = format_match,