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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/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 gboolean started;
47 int fmt_code;
48 uint64_t samplerate;
49 int samplesize;
50 int num_channels;
51 int unitsize;
52 gboolean found_data;
53};
54
55static int parse_wav_header(GString *buf, struct context *inc)
56{
57 uint64_t samplerate;
58 unsigned int fmt_code, samplesize, num_channels, unitsize;
59
60 if (buf->len < MIN_DATA_CHUNK_OFFSET)
61 return SR_ERR_NA;
62
63 fmt_code = RL16(buf->str + 20);
64 samplerate = RL32(buf->str + 24);
65
66 samplesize = RL16(buf->str + 32);
67 num_channels = RL16(buf->str + 22);
68 if (num_channels == 0)
69 return SR_ERR;
70 unitsize = samplesize / num_channels;
71 if (unitsize != 1 && unitsize != 2 && unitsize != 4) {
72 sr_err("Only 8, 16 or 32 bits per sample supported.");
73 return SR_ERR_DATA;
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_ERR_NA;
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 = g_malloc0(sizeof(struct sr_dev_inst));
153 in->priv = g_malloc0(sizeof(struct context));
154
155 return SR_OK;
156}
157
158static int find_data_chunk(GString *buf, int initial_offset)
159{
160 unsigned int offset, i;
161
162 offset = initial_offset;
163 while (offset < MIN(MAX_DATA_CHUNK_OFFSET, buf->len)) {
164 if (!memcmp(buf->str + offset, "data", 4))
165 /* Skip into the samples. */
166 return offset + 8;
167 for (i = 0; i < 4; i++) {
168 if (!isalnum(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 void send_chunk(const struct sr_input *in, int offset, int num_samples)
181{
182 struct sr_datafeed_packet packet;
183 struct sr_datafeed_analog analog;
184 struct context *inc;
185 float fdata[CHUNK_SIZE];
186 uint64_t sample;
187 int total_samples, samplenum;
188 char *s, *d;
189
190 inc = in->priv;
191
192 s = in->buf->str + offset;
193 d = (char *)fdata;
194 memset(fdata, 0, CHUNK_SIZE);
195 total_samples = num_samples * inc->num_channels;
196 for (samplenum = 0; samplenum < total_samples; samplenum++) {
197 if (inc->fmt_code == WAVE_FORMAT_PCM_) {
198 sample = 0;
199 memcpy(&sample, s, inc->unitsize);
200 switch (inc->samplesize) {
201 case 1:
202 /* 8-bit PCM samples are unsigned. */
203 fdata[samplenum] = (uint8_t)sample / (float)255;
204 break;
205 case 2:
206 fdata[samplenum] = RL16S(&sample) / (float)INT16_MAX;
207 break;
208 case 4:
209 fdata[samplenum] = RL32S(&sample) / (float)INT32_MAX;
210 break;
211 }
212 } else {
213 /* BINARY32 float */
214#ifdef WORDS_BIGENDIAN
215 int i;
216 for (i = 0; i < inc->unitsize; i++)
217 d[i] = s[inc->unitsize - 1 - i];
218#else
219 memcpy(d, s, inc->unitsize);
220#endif
221 }
222 s += inc->unitsize;
223 d += inc->unitsize;
224 }
225 packet.type = SR_DF_ANALOG;
226 packet.payload = &analog;
227 analog.channels = in->sdi->channels;
228 analog.num_samples = num_samples;
229 analog.mq = 0;
230 analog.mqflags = 0;
231 analog.unit = 0;
232 analog.data = fdata;
233 sr_session_send(in->sdi, &packet);
234}
235
236static int process_buffer(struct sr_input *in)
237{
238 struct context *inc;
239 struct sr_datafeed_packet packet;
240 struct sr_datafeed_meta meta;
241 struct sr_config *src;
242 int offset, chunk_samples, total_samples, processed, max_chunk_samples;
243 int num_samples, i;
244 char channelname[8];
245
246 inc = in->priv;
247 if (!inc->started) {
248 for (i = 0; i < inc->num_channels; i++) {
249 snprintf(channelname, 8, "CH%d", i + 1);
250 sr_channel_new(in->sdi, i, SR_CHANNEL_ANALOG, TRUE, channelname);
251 }
252
253 std_session_send_df_header(in->sdi, LOG_PREFIX);
254
255 packet.type = SR_DF_META;
256 packet.payload = &meta;
257 src = sr_config_new(SR_CONF_SAMPLERATE, g_variant_new_uint64(inc->samplerate));
258 meta.config = g_slist_append(NULL, src);
259 sr_session_send(in->sdi, &packet);
260 sr_config_free(src);
261
262 inc->started = TRUE;
263 }
264
265 if (!inc->found_data) {
266 /* Skip past size of 'fmt ' chunk. */
267 i = 20 + RL32(in->buf->str + 16);
268 offset = find_data_chunk(in->buf, i);
269 if (offset < 0) {
270 if (in->buf->len > MAX_DATA_CHUNK_OFFSET) {
271 sr_err("Couldn't find data chunk.");
272 return SR_ERR;
273 }
274 }
275 inc->found_data = TRUE;
276 } else
277 offset = 0;
278
279 /* Round off up to the last channels * unitsize boundary. */
280 chunk_samples = (in->buf->len - offset) / inc->num_channels / inc->unitsize;
281 max_chunk_samples = CHUNK_SIZE / inc->num_channels / inc->unitsize;
282 processed = 0;
283 total_samples = chunk_samples;
284 while (processed < total_samples) {
285 if (chunk_samples > max_chunk_samples)
286 num_samples = max_chunk_samples;
287 else
288 num_samples = chunk_samples;
289 send_chunk(in, offset, num_samples);
290 offset += num_samples * inc->unitsize;
291 chunk_samples -= num_samples;
292 processed += num_samples;
293 }
294
295 if ((unsigned int)offset < in->buf->len) {
296 /*
297 * The incoming buffer wasn't processed completely. Stash
298 * the leftover data for next time.
299 */
300 g_string_erase(in->buf, 0, offset);
301 } else
302 g_string_truncate(in->buf, 0);
303
304 return SR_OK;
305}
306
307static int receive(struct sr_input *in, GString *buf)
308{
309 struct context *inc;
310 int ret;
311
312 g_string_append_len(in->buf, buf->str, buf->len);
313
314 if (in->buf->len < MIN_DATA_CHUNK_OFFSET) {
315 /*
316 * Don't even try until there's enough room
317 * for the data segment to start.
318 */
319 return SR_OK;
320 }
321
322 inc = in->priv;
323 if (!in->sdi_ready) {
324 if ((ret = parse_wav_header(in->buf, inc)) == SR_ERR_NA)
325 /* Not enough data yet. */
326 return SR_OK;
327 else if (ret != SR_OK)
328 return ret;
329
330 /* sdi is ready, notify frontend. */
331 in->sdi_ready = TRUE;
332 return SR_OK;
333 }
334
335 ret = process_buffer(in);
336
337 return ret;
338}
339
340static int end(struct sr_input *in)
341{
342 struct sr_datafeed_packet packet;
343 struct context *inc;
344 int ret;
345
346 if (in->sdi_ready)
347 ret = process_buffer(in);
348 else
349 ret = SR_OK;
350
351 inc = in->priv;
352 if (inc->started) {
353 packet.type = SR_DF_END;
354 sr_session_send(in->sdi, &packet);
355 }
356
357 return ret;
358}
359
360SR_PRIV struct sr_input_module input_wav = {
361 .id = "wav",
362 .name = "WAV",
363 .desc = "WAV file",
364 .exts = (const char*[]){"wav", NULL},
365 .metadata = { SR_INPUT_META_HEADER | SR_INPUT_META_REQUIRED },
366 .format_match = format_match,
367 .init = init,
368 .receive = receive,
369 .end = end,
370};