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/>.
20 #include <sys/types.h>
27 #include "libsigrok.h"
28 #include "libsigrok-internal.h"
30 #define LOG_PREFIX "input/wav"
32 /* How many bytes at a time to process and send to the session bus. */
33 #define CHUNK_SIZE 4096
35 /* Minimum size of header + 1 8-bit mono PCM sample. */
36 #define MIN_DATA_CHUNK_OFFSET 45
38 /* Expect to find the "data" chunk within this offset from the start. */
39 #define MAX_DATA_CHUNK_OFFSET 256
41 #define WAVE_FORMAT_PCM 0x0001
42 #define WAVE_FORMAT_IEEE_FLOAT 0x0003
43 #define WAVE_FORMAT_EXTENSIBLE 0xfffe
54 static int parse_wav_header(GString *buf, struct context *inc)
57 unsigned int fmt_code, samplesize, num_channels, unitsize;
59 if (buf->len < MIN_DATA_CHUNK_OFFSET)
62 fmt_code = RL16(buf->str + 20);
63 samplerate = RL32(buf->str + 24);
65 samplesize = RL16(buf->str + 32);
66 if (samplesize != 1 && samplesize != 2 && samplesize != 4) {
67 sr_err("Only 8, 16 or 32 bits per sample supported.");
71 num_channels = RL16(buf->str + 22);
72 if (num_channels == 0)
74 unitsize = samplesize / num_channels;
76 if (fmt_code == WAVE_FORMAT_PCM) {
77 } else if (fmt_code == WAVE_FORMAT_IEEE_FLOAT) {
79 sr_err("only 32-bit floats supported.");
82 } else if (fmt_code == WAVE_FORMAT_EXTENSIBLE) {
84 /* Not enough for extensible header and next chunk. */
85 return SR_OK_CONTINUE;
87 if (RL16(buf->str + 16) != 40) {
88 sr_err("WAV extensible format chunk must be 40 bytes.");
91 if (RL16(buf->str + 36) != 22) {
92 sr_err("WAV extension must be 22 bytes.");
95 if (RL16(buf->str + 34) != RL16(buf->str + 38)) {
96 sr_err("Reduced valid bits per sample not supported.");
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.");
106 sr_err("Only PCM and floating point samples are supported.");
111 inc->fmt_code = fmt_code;
112 inc->samplerate = samplerate;
113 inc->samplesize = samplesize;
114 inc->num_channels = num_channels;
115 inc->unitsize = unitsize;
116 inc->found_data = FALSE;
122 static int format_match(GHashTable *metadata)
126 buf = g_hash_table_lookup(metadata, GINT_TO_POINTER(SR_INPUT_META_HEADER));
127 if (strncmp(buf->str, "RIFF", 4))
129 if (strncmp(buf->str + 8, "WAVE", 4))
131 if (strncmp(buf->str + 12, "fmt ", 4))
134 * Only gets called when we already know this is a WAV file, so
135 * this parser can log error messages.
137 if (parse_wav_header(buf, NULL) != SR_OK)
143 static int init(struct sr_input *in, GHashTable *options)
147 in->sdi = sr_dev_inst_new(0, SR_ST_ACTIVE, NULL, NULL, NULL);
152 static int find_data_chunk(GString *buf, int initial_offset)
154 unsigned int offset, i;
156 offset = initial_offset;
157 while(offset < MIN(MAX_DATA_CHUNK_OFFSET, buf->len)) {
158 if (!memcmp(buf->str + offset, "data", 4))
159 /* Skip into the samples. */
161 for (i = 0; i < 4; i++) {
162 if (!isalpha(buf->str[offset + i])
163 && !isascii(buf->str[offset + i])
164 && !isblank(buf->str[offset + i]))
165 /* Doesn't look like a chunk ID. */
168 /* Skip past this chunk. */
169 offset += 8 + RL32(buf->str + offset + 4);
175 static int initial_receive(struct sr_input *in)
177 struct sr_datafeed_packet packet;
178 struct sr_datafeed_meta meta;
179 struct sr_channel *ch;
180 struct sr_config *src;
186 /* Shouldn't happen. */
189 inc = in->priv = g_malloc(sizeof(struct context));
190 if (parse_wav_header(in->buf, inc) != SR_OK)
193 for (i = 0; i < inc->num_channels; i++) {
194 snprintf(channelname, 8, "CH%d", i + 1);
195 ch = sr_channel_new(i, SR_CHANNEL_ANALOG, TRUE, channelname);
196 in->sdi->channels = g_slist_append(in->sdi->channels, ch);
199 std_session_send_df_header(in->sdi, LOG_PREFIX);
201 packet.type = SR_DF_META;
202 packet.payload = &meta;
203 src = sr_config_new(SR_CONF_SAMPLERATE, g_variant_new_uint64(inc->samplerate));
204 meta.config = g_slist_append(NULL, src);
205 sr_session_send(in->sdi, &packet);
211 static void send_chunk(const struct sr_input *in, int offset, int num_samples)
213 struct sr_datafeed_packet packet;
214 struct sr_datafeed_analog analog;
216 float fdata[CHUNK_SIZE];
218 int total_samples, samplenum;
223 s = in->buf->str + offset;
225 memset(fdata, 0, CHUNK_SIZE);
226 total_samples = num_samples * inc->num_channels;
227 for (samplenum = 0; samplenum < total_samples; samplenum++) {
228 if (inc->fmt_code == WAVE_FORMAT_PCM) {
230 memcpy(&sample, s, inc->unitsize);
231 switch (inc->samplesize) {
233 /* 8-bit PCM samples are unsigned. */
234 fdata[samplenum] = (uint8_t)sample / (float)255;
237 fdata[samplenum] = RL16S(&sample) / (float)INT16_MAX;
240 fdata[samplenum] = RL32S(&sample) / (float)INT32_MAX;
245 #ifdef WORDS_BIGENDIAN
246 for (i = 0; i < inc->unitsize; i++)
247 d[i] = s[inc->unitsize - i];
249 memcpy(d, s, inc->unitsize);
255 packet.type = SR_DF_ANALOG;
256 packet.payload = &analog;
257 analog.channels = in->sdi->channels;
258 analog.num_samples = num_samples;
263 sr_session_send(in->sdi, &packet);
266 static int receive(const struct sr_input *in, GString *buf)
269 int offset, chunk_samples, total_samples, processed, max_chunk_samples, num_samples, i;
271 g_string_append_len(in->buf, buf->str, buf->len);
274 if (initial_receive((struct sr_input *)in) != SR_OK)
276 if (in->buf->len < MIN_DATA_CHUNK_OFFSET) {
278 * Don't even get started until there's enough room
279 * for the data segment to start.
286 if (!inc->found_data) {
287 /* Skip past size of 'fmt ' chunk. */
288 i = 20 + RL32(in->buf->str + 16);
289 offset = find_data_chunk(in->buf, i);
291 if (in->buf->len > MAX_DATA_CHUNK_OFFSET) {
292 sr_err("Couldn't find data chunk.");
296 inc->found_data = TRUE;
300 /* Round off up to the last channels * unitsize boundary. */
301 chunk_samples = (in->buf->len - offset) / inc->num_channels / inc->unitsize;
302 max_chunk_samples = CHUNK_SIZE / inc->num_channels / inc->unitsize;
304 total_samples = chunk_samples;
305 while (processed < total_samples) {
306 if (chunk_samples > max_chunk_samples)
307 num_samples = max_chunk_samples;
309 num_samples = chunk_samples;
310 send_chunk(in, offset, num_samples);
311 offset += num_samples * inc->unitsize;
312 chunk_samples -= num_samples;
313 processed += num_samples;
316 if ((unsigned int)offset < in->buf->len) {
318 * The incoming buffer wasn't processed completely. Stash
319 * the leftover data for next time.
321 g_string_erase(in->buf, 0, offset);
323 g_string_truncate(in->buf, 0);
328 static int cleanup(struct sr_input *in)
330 struct sr_datafeed_packet packet;
334 packet.type = SR_DF_END;
335 sr_session_send(in->sdi, &packet);
344 SR_PRIV struct sr_input_module input_wav = {
348 .metadata = { SR_INPUT_META_HEADER | SR_INPUT_META_REQUIRED },
349 .format_match = format_match,