]> sigrok.org Git - libsigrok.git/blame_incremental - src/input/wav.c
C++: Add SessionDevice class for devices owned by loaded sessions.
[libsigrok.git] / src / input / wav.c
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1/*
2 * This file is part of the libsigrok project.
3 *
4 * Copyright (C) 2013 Bert Vermeulen <bert@biot.com>
5 *
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.
10 *
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.
15 *
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/>.
18 */
19
20#include <sys/types.h>
21#include <sys/stat.h>
22#include <unistd.h>
23#include <fcntl.h>
24#include <ctype.h>
25#include <string.h>
26#include <stdint.h>
27#include "libsigrok.h"
28#include "libsigrok-internal.h"
29
30#define LOG_PREFIX "input/wav"
31
32/* How many bytes at a time to process and send to the session bus. */
33#define CHUNK_SIZE 4096
34
35/* Minimum size of header + 1 8-bit mono PCM sample. */
36#define MIN_DATA_CHUNK_OFFSET 45
37
38/* Expect to find the "data" chunk within this offset from the start. */
39#define MAX_DATA_CHUNK_OFFSET 256
40
41#define WAVE_FORMAT_PCM 0x0001
42#define WAVE_FORMAT_IEEE_FLOAT 0x0003
43#define WAVE_FORMAT_EXTENSIBLE 0xfffe
44
45struct context {
46 int fmt_code;
47 uint64_t samplerate;
48 int samplesize;
49 int num_channels;
50 int unitsize;
51 gboolean found_data;
52};
53
54static int parse_wav_header(GString *buf, struct context *inc)
55{
56 uint64_t samplerate;
57 unsigned int fmt_code, samplesize, num_channels, unitsize;
58
59 if (buf->len < MIN_DATA_CHUNK_OFFSET)
60 return SR_OK_CONTINUE;
61
62 fmt_code = RL16(buf->str + 20);
63 samplerate = RL32(buf->str + 24);
64
65 samplesize = RL16(buf->str + 32);
66 num_channels = RL16(buf->str + 22);
67 if (num_channels == 0)
68 return SR_ERR;
69 unitsize = samplesize / num_channels;
70 if (unitsize != 1 && unitsize != 2 && unitsize != 4) {
71 sr_err("Only 8, 16 or 32 bits per sample supported.");
72 return SR_ERR_DATA;
73 }
74
75
76 if (fmt_code == WAVE_FORMAT_PCM) {
77 } else if (fmt_code == WAVE_FORMAT_IEEE_FLOAT) {
78 if (unitsize != 4) {
79 sr_err("only 32-bit floats supported.");
80 return SR_ERR_DATA;
81 }
82 } else if (fmt_code == WAVE_FORMAT_EXTENSIBLE) {
83 if (buf->len < 70)
84 /* Not enough for extensible header and next chunk. */
85 return SR_OK_CONTINUE;
86
87 if (RL16(buf->str + 16) != 40) {
88 sr_err("WAV extensible format chunk must be 40 bytes.");
89 return SR_ERR;
90 }
91 if (RL16(buf->str + 36) != 22) {
92 sr_err("WAV extension must be 22 bytes.");
93 return SR_ERR;
94 }
95 if (RL16(buf->str + 34) != RL16(buf->str + 38)) {
96 sr_err("Reduced valid bits per sample not supported.");
97 return SR_ERR_DATA;
98 }
99 /* Real format code is the first two bytes of the GUID. */
100 fmt_code = RL16(buf->str + 44);
101 if (fmt_code != WAVE_FORMAT_PCM && fmt_code != WAVE_FORMAT_IEEE_FLOAT) {
102 sr_err("Only PCM and floating point samples are supported.");
103 return SR_ERR_DATA;
104 }
105 if (fmt_code == WAVE_FORMAT_IEEE_FLOAT && unitsize != 4) {
106 sr_err("only 32-bit floats supported.");
107 return SR_ERR_DATA;
108 }
109 } else {
110 sr_err("Only PCM and floating point samples are supported.");
111 return SR_ERR_DATA;
112 }
113
114 if (inc) {
115 inc->fmt_code = fmt_code;
116 inc->samplerate = samplerate;
117 inc->samplesize = samplesize;
118 inc->num_channels = num_channels;
119 inc->unitsize = unitsize;
120 inc->found_data = FALSE;
121 }
122
123 return SR_OK;
124}
125
126static int format_match(GHashTable *metadata)
127{
128 GString *buf;
129 int ret;
130
131 buf = g_hash_table_lookup(metadata, GINT_TO_POINTER(SR_INPUT_META_HEADER));
132 if (strncmp(buf->str, "RIFF", 4))
133 return SR_ERR;
134 if (strncmp(buf->str + 8, "WAVE", 4))
135 return SR_ERR;
136 if (strncmp(buf->str + 12, "fmt ", 4))
137 return SR_ERR;
138 /*
139 * Only gets called when we already know this is a WAV file, so
140 * this parser can log error messages.
141 */
142 if ((ret = parse_wav_header(buf, NULL)) != SR_OK)
143 return ret;
144
145 return SR_OK;
146}
147
148static int init(struct sr_input *in, GHashTable *options)
149{
150 (void)options;
151
152 in->sdi = sr_dev_inst_new(0, SR_ST_ACTIVE, NULL, NULL, NULL);
153
154 return SR_OK;
155}
156
157static int find_data_chunk(GString *buf, int initial_offset)
158{
159 unsigned int offset, i;
160
161 offset = initial_offset;
162 while(offset < MIN(MAX_DATA_CHUNK_OFFSET, buf->len)) {
163 if (!memcmp(buf->str + offset, "data", 4))
164 /* Skip into the samples. */
165 return offset + 8;
166 for (i = 0; i < 4; i++) {
167 if (!isalpha(buf->str[offset + i])
168 && !isascii(buf->str[offset + i])
169 && !isblank(buf->str[offset + i]))
170 /* Doesn't look like a chunk ID. */
171 return -1;
172 }
173 /* Skip past this chunk. */
174 offset += 8 + RL32(buf->str + offset + 4);
175 }
176
177 return offset;
178}
179
180static int initial_receive(struct sr_input *in)
181{
182 struct sr_datafeed_packet packet;
183 struct sr_datafeed_meta meta;
184 struct sr_channel *ch;
185 struct sr_config *src;
186 struct context *inc;
187 int ret, i;
188 char channelname[8];
189
190 if (!in->buf)
191 /* Shouldn't happen. */
192 return SR_ERR;
193
194 inc = in->priv = g_malloc(sizeof(struct context));
195 if ((ret = parse_wav_header(in->buf, inc)) != SR_OK)
196 return ret;
197
198 for (i = 0; i < inc->num_channels; i++) {
199 snprintf(channelname, 8, "CH%d", i + 1);
200 ch = sr_channel_new(i, SR_CHANNEL_ANALOG, TRUE, channelname);
201 in->sdi->channels = g_slist_append(in->sdi->channels, ch);
202 }
203
204 std_session_send_df_header(in->sdi, LOG_PREFIX);
205
206 packet.type = SR_DF_META;
207 packet.payload = &meta;
208 src = sr_config_new(SR_CONF_SAMPLERATE, g_variant_new_uint64(inc->samplerate));
209 meta.config = g_slist_append(NULL, src);
210 sr_session_send(in->sdi, &packet);
211 sr_config_free(src);
212
213 return SR_OK;
214}
215
216static void send_chunk(const struct sr_input *in, int offset, int num_samples)
217{
218 struct sr_datafeed_packet packet;
219 struct sr_datafeed_analog analog;
220 struct context *inc;
221 float fdata[CHUNK_SIZE];
222 uint64_t sample;
223 int total_samples, samplenum;
224 char *s, *d;
225
226 inc = in->priv;
227
228 s = in->buf->str + offset;
229 d = (char *)fdata;
230 memset(fdata, 0, CHUNK_SIZE);
231 total_samples = num_samples * inc->num_channels;
232 for (samplenum = 0; samplenum < total_samples; samplenum++) {
233 if (inc->fmt_code == WAVE_FORMAT_PCM) {
234 sample = 0;
235 memcpy(&sample, s, inc->unitsize);
236 switch (inc->samplesize) {
237 case 1:
238 /* 8-bit PCM samples are unsigned. */
239 fdata[samplenum] = (uint8_t)sample / (float)255;
240 break;
241 case 2:
242 fdata[samplenum] = RL16S(&sample) / (float)INT16_MAX;
243 break;
244 case 4:
245 fdata[samplenum] = RL32S(&sample) / (float)INT32_MAX;
246 break;
247 }
248 } else {
249 /* BINARY32 float */
250#ifdef WORDS_BIGENDIAN
251 int i;
252 for (i = 0; i < inc->unitsize; i++)
253 d[i] = s[inc->unitsize - 1 - i];
254#else
255 memcpy(d, s, inc->unitsize);
256#endif
257 }
258 s += inc->unitsize;
259 d += inc->unitsize;
260 }
261 packet.type = SR_DF_ANALOG;
262 packet.payload = &analog;
263 analog.channels = in->sdi->channels;
264 analog.num_samples = num_samples;
265 analog.mq = 0;
266 analog.mqflags = 0;
267 analog.unit = 0;
268 analog.data = fdata;
269 sr_session_send(in->sdi, &packet);
270}
271
272static int receive(const struct sr_input *in, GString *buf)
273{
274 struct context *inc;
275 int offset, chunk_samples, total_samples, processed, max_chunk_samples, num_samples, i;
276
277 g_string_append_len(in->buf, buf->str, buf->len);
278
279 if (!in->priv) {
280 if (initial_receive((struct sr_input *)in) != SR_OK)
281 return SR_ERR;
282 if (in->buf->len < MIN_DATA_CHUNK_OFFSET) {
283 /*
284 * Don't even get started until there's enough room
285 * for the data segment to start.
286 */
287 return SR_OK;
288 }
289 }
290 inc = in->priv;
291
292 if (!inc->found_data) {
293 /* Skip past size of 'fmt ' chunk. */
294 i = 20 + RL32(in->buf->str + 16);
295 offset = find_data_chunk(in->buf, i);
296 if (offset < 0) {
297 if (in->buf->len > MAX_DATA_CHUNK_OFFSET) {
298 sr_err("Couldn't find data chunk.");
299 return SR_ERR;
300 }
301 }
302 inc->found_data = TRUE;
303 } else
304 offset = 0;
305
306 /* Round off up to the last channels * unitsize boundary. */
307 chunk_samples = (in->buf->len - offset) / inc->num_channels / inc->unitsize;
308 max_chunk_samples = CHUNK_SIZE / inc->num_channels / inc->unitsize;
309 processed = 0;
310 total_samples = chunk_samples;
311 while (processed < total_samples) {
312 if (chunk_samples > max_chunk_samples)
313 num_samples = max_chunk_samples;
314 else
315 num_samples = chunk_samples;
316 send_chunk(in, offset, num_samples);
317 offset += num_samples * inc->unitsize;
318 chunk_samples -= num_samples;
319 processed += num_samples;
320 }
321
322 if ((unsigned int)offset < in->buf->len) {
323 /*
324 * The incoming buffer wasn't processed completely. Stash
325 * the leftover data for next time.
326 */
327 g_string_erase(in->buf, 0, offset);
328 } else
329 g_string_truncate(in->buf, 0);
330
331 return SR_OK;
332}
333
334static int cleanup(struct sr_input *in)
335{
336 struct sr_datafeed_packet packet;
337
338 if (in->priv) {
339 /* End of stream. */
340 packet.type = SR_DF_END;
341 sr_session_send(in->sdi, &packet);
342
343 g_free(in->priv);
344 in->priv = NULL;
345 }
346
347 return SR_OK;
348}
349
350SR_PRIV struct sr_input_module input_wav = {
351 .id = "wav",
352 .name = "WAV",
353 .desc = "WAV file",
354 .metadata = { SR_INPUT_META_HEADER | SR_INPUT_META_REQUIRED },
355 .format_match = format_match,
356 .init = init,
357 .receive = receive,
358 .cleanup = cleanup,
359};
360