[libsigrok.git] / src / input / wav.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2013 Bert Vermeulen <bert@biot.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <ctype.h>
#include <string.h>
#include <stdint.h>
#include "libsigrok.h"
#include "libsigrok-internal.h"

#define LOG_PREFIX "input/wav"

/* How many bytes at a time to process and send to the session bus. */
#define CHUNK_SIZE 4096

/* Minimum size of header + 1 8-bit mono PCM sample. */
#define MIN_DATA_CHUNK_OFFSET    45

/* Expect to find the "data" chunk within this offset from the start. */
#define MAX_DATA_CHUNK_OFFSET    256

#define WAVE_FORMAT_PCM          0x0001
#define WAVE_FORMAT_IEEE_FLOAT   0x0003
#define WAVE_FORMAT_EXTENSIBLE   0xfffe

struct context {
	gboolean started;
	int fmt_code;
	uint64_t samplerate;
	int samplesize;
	int num_channels;
	int unitsize;
	gboolean found_data;
};

static int parse_wav_header(GString *buf, struct context *inc)
{
	uint64_t samplerate;
	unsigned int fmt_code, samplesize, num_channels, unitsize;

	if (buf->len < MIN_DATA_CHUNK_OFFSET)
		return SR_ERR_NA;

	fmt_code = RL16(buf->str + 20);
	samplerate = RL32(buf->str + 24);

	samplesize = RL16(buf->str + 32);
	num_channels = RL16(buf->str + 22);
	if (num_channels == 0)
		return SR_ERR;
	unitsize = samplesize / num_channels;
	if (unitsize != 1 && unitsize != 2 && unitsize != 4) {
		sr_err("Only 8, 16 or 32 bits per sample supported.");
		return SR_ERR_DATA;
	}


	if (fmt_code == WAVE_FORMAT_PCM) {
	} else if (fmt_code == WAVE_FORMAT_IEEE_FLOAT) {
		if (unitsize != 4) {
			sr_err("only 32-bit floats supported.");
			return SR_ERR_DATA;
		}
	} else if (fmt_code == WAVE_FORMAT_EXTENSIBLE) {
		if (buf->len < 70)
			/* Not enough for extensible header and next chunk. */
			return SR_ERR_NA;

		if (RL16(buf->str + 16) != 40) {
			sr_err("WAV extensible format chunk must be 40 bytes.");
			return SR_ERR;
		}
		if (RL16(buf->str + 36) != 22) {
			sr_err("WAV extension must be 22 bytes.");
			return SR_ERR;
		}
		if (RL16(buf->str + 34) != RL16(buf->str + 38)) {
			sr_err("Reduced valid bits per sample not supported.");
			return SR_ERR_DATA;
		}
		/* Real format code is the first two bytes of the GUID. */
		fmt_code = RL16(buf->str + 44);
		if (fmt_code != WAVE_FORMAT_PCM && fmt_code != WAVE_FORMAT_IEEE_FLOAT) {
			sr_err("Only PCM and floating point samples are supported.");
			return SR_ERR_DATA;
		}
		if (fmt_code == WAVE_FORMAT_IEEE_FLOAT && unitsize != 4) {
			sr_err("only 32-bit floats supported.");
			return SR_ERR_DATA;
		}
	} else {
		sr_err("Only PCM and floating point samples are supported.");
		return SR_ERR_DATA;
	}

	if (inc) {
		inc->fmt_code = fmt_code;
		inc->samplerate = samplerate;
		inc->samplesize = samplesize;
		inc->num_channels = num_channels;
		inc->unitsize = unitsize;
		inc->found_data = FALSE;
	}

	return SR_OK;
}

static int format_match(GHashTable *metadata)
{
	GString *buf;
	int ret;

	buf = g_hash_table_lookup(metadata, GINT_TO_POINTER(SR_INPUT_META_HEADER));
	if (strncmp(buf->str, "RIFF", 4))
		return SR_ERR;
	if (strncmp(buf->str + 8, "WAVE", 4))
		return SR_ERR;
	if (strncmp(buf->str + 12, "fmt ", 4))
		return SR_ERR;
	/*
	 * Only gets called when we already know this is a WAV file, so
	 * this parser can log error messages.
	 */
	if ((ret = parse_wav_header(buf, NULL)) != SR_OK)
		return ret;

	return SR_OK;
}

static int init(struct sr_input *in, GHashTable *options)
{
	(void)options;

	in->sdi = sr_dev_inst_new(SR_ST_ACTIVE, NULL, NULL, NULL);
	in->priv = g_malloc0(sizeof(struct context));

	return SR_OK;
}

static int find_data_chunk(GString *buf, int initial_offset)
{
	unsigned int offset, i;

	offset = initial_offset;
	while(offset < MIN(MAX_DATA_CHUNK_OFFSET, buf->len)) {
		if (!memcmp(buf->str + offset, "data", 4))
			/* Skip into the samples. */
			return offset + 8;
		for (i = 0; i < 4; i++) {
			if (!isalpha(buf->str[offset + i])
					&& !isascii(buf->str[offset + i])
					&& !isblank(buf->str[offset + i]))
				/* Doesn't look like a chunk ID. */
				return -1;
		}
		/* Skip past this chunk. */
		offset += 8 + RL32(buf->str + offset + 4);
	}

	return offset;
}

static void send_chunk(const struct sr_input *in, int offset, int num_samples)
{
	struct sr_datafeed_packet packet;
	struct sr_datafeed_analog analog;
	struct context *inc;
	float fdata[CHUNK_SIZE];
	uint64_t sample;
	int total_samples, samplenum;
	char *s, *d;

	inc = in->priv;

	s = in->buf->str + offset;
	d = (char *)fdata;
	memset(fdata, 0, CHUNK_SIZE);
	total_samples = num_samples * inc->num_channels;
	for (samplenum = 0; samplenum < total_samples; samplenum++) {
		if (inc->fmt_code == WAVE_FORMAT_PCM) {
			sample = 0;
			memcpy(&sample, s, inc->unitsize);
			switch (inc->samplesize) {
			case 1:
				/* 8-bit PCM samples are unsigned. */
				fdata[samplenum] = (uint8_t)sample / (float)255;
				break;
			case 2:
				fdata[samplenum] = RL16S(&sample) / (float)INT16_MAX;
				break;
			case 4:
				fdata[samplenum] = RL32S(&sample) / (float)INT32_MAX;
				break;
			}
		} else {
			/* BINARY32 float */
#ifdef WORDS_BIGENDIAN
			int i;
			for (i = 0; i < inc->unitsize; i++)
				d[i] = s[inc->unitsize - 1 - i];
#else
			memcpy(d, s, inc->unitsize);
#endif
		}
		s += inc->unitsize;
		d += inc->unitsize;
	}
	packet.type = SR_DF_ANALOG;
	packet.payload = &analog;
	analog.channels = in->sdi->channels;
	analog.num_samples = num_samples;
	analog.mq = 0;
	analog.mqflags = 0;
	analog.unit = 0;
	analog.data = fdata;
	sr_session_send(in->sdi, &packet);
}

static int receive(struct sr_input *in, GString *buf)
{
	struct sr_datafeed_packet packet;
	struct sr_datafeed_meta meta;
	struct sr_channel *ch;
	struct sr_config *src;
	struct context *inc;
	int offset, chunk_samples, total_samples, processed, max_chunk_samples;
	int num_samples, ret, i;
	char channelname[8];

	g_string_append_len(in->buf, buf->str, buf->len);

	if (in->buf->len < MIN_DATA_CHUNK_OFFSET) {
		/*
		 * Don't even try until there's enough room
		 * for the data segment to start.
		 */
		return SR_OK;
	}

	inc = in->priv;
	if (!in->sdi_ready) {
		if ((ret = parse_wav_header(in->buf, inc)) == SR_ERR_NA)
			/* Not enough data yet. */
			return SR_OK;
		else if (ret != SR_OK)
			return ret;

		/* sdi is ready, notify frontend. */
		in->sdi_ready = TRUE;
		return SR_OK;
	}

	if (!inc->started) {
		for (i = 0; i < inc->num_channels; i++) {
			snprintf(channelname, 8, "CH%d", i + 1);
			ch = sr_channel_new(i, SR_CHANNEL_ANALOG, TRUE, channelname);
			in->sdi->channels = g_slist_append(in->sdi->channels, ch);
		}

		std_session_send_df_header(in->sdi, LOG_PREFIX);

		packet.type = SR_DF_META;
		packet.payload = &meta;
		src = sr_config_new(SR_CONF_SAMPLERATE, g_variant_new_uint64(inc->samplerate));
		meta.config = g_slist_append(NULL, src);
		sr_session_send(in->sdi, &packet);
		sr_config_free(src);

		inc->started = TRUE;
	}

	if (!inc->found_data) {
		/* Skip past size of 'fmt ' chunk. */
		i = 20 + RL32(in->buf->str + 16);
		offset = find_data_chunk(in->buf, i);
		if (offset < 0) {
			if (in->buf->len > MAX_DATA_CHUNK_OFFSET) {
				sr_err("Couldn't find data chunk.");
				return SR_ERR;
			}
		}
		inc->found_data = TRUE;
	} else
		offset = 0;

	/* Round off up to the last channels * unitsize boundary. */
	chunk_samples = (in->buf->len - offset) / inc->num_channels / inc->unitsize;
	max_chunk_samples = CHUNK_SIZE / inc->num_channels / inc->unitsize;
	processed = 0;
	total_samples = chunk_samples;
	while (processed < total_samples) {
		if (chunk_samples > max_chunk_samples)
			num_samples = max_chunk_samples;
		else
			num_samples = chunk_samples;
		send_chunk(in, offset, num_samples);
		offset += num_samples * inc->unitsize;
		chunk_samples -= num_samples;
		processed += num_samples;
	}

	if ((unsigned int)offset < in->buf->len) {
		/*
		 * The incoming buffer wasn't processed completely. Stash
		 * the leftover data for next time.
		 */
		g_string_erase(in->buf, 0, offset);
	} else
		g_string_truncate(in->buf, 0);

	return SR_OK;
}

static int cleanup(struct sr_input *in)
{
	struct sr_datafeed_packet packet;
	struct context *inc;

	inc = in->priv;
	if (inc->started) {
		/* End of stream. */
		packet.type = SR_DF_END;
		sr_session_send(in->sdi, &packet);
	}

	return SR_OK;
}

SR_PRIV struct sr_input_module input_wav = {
	.id = "wav",
	.name = "WAV",
	.desc = "WAV file",
	.metadata = { SR_INPUT_META_HEADER | SR_INPUT_META_REQUIRED },
	.format_match = format_match,
	.init = init,
	.receive = receive,
	.cleanup = cleanup,
};
Commit	Line	Data
1d36b4d2	1	/*
50985c20	2	* This file is part of the libsigrok project.
1d36b4d2 BV	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>
cb41a838	24	#include <ctype.h>
1d36b4d2	25	#include <string.h>
962d4344	26	#include <stdint.h>
1d36b4d2 BV	27	#include "libsigrok.h"
	28	#include "libsigrok-internal.h"
	29
3544f848	30	#define LOG_PREFIX "input/wav"
1d36b4d2	31
cb41a838	32	/* How many bytes at a time to process and send to the session bus. */
1d36b4d2	33	#define CHUNK_SIZE 4096
17bfaca6 BV	34
	35	/* Minimum size of header + 1 8-bit mono PCM sample. */
	36	#define MIN_DATA_CHUNK_OFFSET 45
	37
cb41a838 BV	38	/* Expect to find the "data" chunk within this offset from the start. */
	39	#define MAX_DATA_CHUNK_OFFSET 256
	40
cbd9e6e9 BV	41	#define WAVE_FORMAT_PCM 0x0001
	42	#define WAVE_FORMAT_IEEE_FLOAT 0x0003
	43	#define WAVE_FORMAT_EXTENSIBLE 0xfffe
1d36b4d2 BV	44
1d36b4d2 BV	45	struct context {
d0181813	46	gboolean started;
17bfaca6	47	int fmt_code;
1d36b4d2 BV	48	uint64_t samplerate;
	49	int samplesize;
	50	int num_channels;
cb41a838	51	int unitsize;
17bfaca6	52	gboolean found_data;
1d36b4d2 BV	53	};
1d36b4d2 BV	54
17bfaca6	55	static int parse_wav_header(GString buf, struct context inc)
1d36b4d2	56	{
17bfaca6	57	uint64_t samplerate;
cbd9e6e9	58	unsigned int fmt_code, samplesize, num_channels, unitsize;
1d36b4d2	59
cbd9e6e9	60	if (buf->len < MIN_DATA_CHUNK_OFFSET)
d0181813	61	return SR_ERR_NA;
1d36b4d2	62
962d4344 BV	63	fmt_code = RL16(buf->str + 20);
962d4344 BV	64	samplerate = RL32(buf->str + 24);
cbd9e6e9	65
962d4344 BV	66	samplesize = RL16(buf->str + 32);
962d4344 BV	67	num_channels = RL16(buf->str + 22);
cbd9e6e9 BV	68	if (num_channels == 0)
cbd9e6e9 BV	69	return SR_ERR;
17bfaca6	70	unitsize = samplesize / num_channels;
e8779db7 BV	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
1d36b4d2	76
17bfaca6	77	if (fmt_code == WAVE_FORMAT_PCM) {
17bfaca6 BV	78	} else if (fmt_code == WAVE_FORMAT_IEEE_FLOAT) {
	79	if (unitsize != 4) {
	80	sr_err("only 32-bit floats supported.");
4f979115	81	return SR_ERR_DATA;
17bfaca6	82	}
cbd9e6e9 BV	83	} else if (fmt_code == WAVE_FORMAT_EXTENSIBLE) {
	84	if (buf->len < 70)
	85	/* Not enough for extensible header and next chunk. */
d0181813	86	return SR_ERR_NA;
cbd9e6e9 BV	87
	88	if (RL16(buf->str + 16) != 40) {
	89	sr_err("WAV extensible format chunk must be 40 bytes.");
	90	return SR_ERR;
	91	}
	92	if (RL16(buf->str + 36) != 22) {
	93	sr_err("WAV extension must be 22 bytes.");
	94	return SR_ERR;
	95	}
	96	if (RL16(buf->str + 34) != RL16(buf->str + 38)) {
	97	sr_err("Reduced valid bits per sample not supported.");
4f979115	98	return SR_ERR_DATA;
cbd9e6e9 BV	99	}
	100	/* Real format code is the first two bytes of the GUID. */
	101	fmt_code = RL16(buf->str + 44);
	102	if (fmt_code != WAVE_FORMAT_PCM && fmt_code != WAVE_FORMAT_IEEE_FLOAT) {
	103	sr_err("Only PCM and floating point samples are supported.");
4f979115	104	return SR_ERR_DATA;
cbd9e6e9	105	}
28d9df72 MC	106	if (fmt_code == WAVE_FORMAT_IEEE_FLOAT && unitsize != 4) {
	107	sr_err("only 32-bit floats supported.");
	108	return SR_ERR_DATA;
	109	}
17bfaca6 BV	110	} else {
17bfaca6 BV	111	sr_err("Only PCM and floating point samples are supported.");
4f979115	112	return SR_ERR_DATA;
17bfaca6	113	}
1d36b4d2	114
17bfaca6 BV	115	if (inc) {
	116	inc->fmt_code = fmt_code;
	117	inc->samplerate = samplerate;
	118	inc->samplesize = samplesize;
	119	inc->num_channels = num_channels;
	120	inc->unitsize = unitsize;
	121	inc->found_data = FALSE;
	122	}
1d36b4d2 BV	123
	124	return SR_OK;
	125	}
	126
17bfaca6	127	static int format_match(GHashTable *metadata)
1d36b4d2	128	{
17bfaca6	129	GString *buf;
4f979115	130	int ret;
1d36b4d2	131
17bfaca6 BV	132	buf = g_hash_table_lookup(metadata, GINT_TO_POINTER(SR_INPUT_META_HEADER));
17bfaca6 BV	133	if (strncmp(buf->str, "RIFF", 4))
4f979115	134	return SR_ERR;
17bfaca6	135	if (strncmp(buf->str + 8, "WAVE", 4))
4f979115	136	return SR_ERR;
17bfaca6	137	if (strncmp(buf->str + 12, "fmt ", 4))
4f979115	138	return SR_ERR;
17bfaca6 BV	139	/*
	140	* Only gets called when we already know this is a WAV file, so
	141	* this parser can log error messages.
	142	*/
4f979115 BV	143	if ((ret = parse_wav_header(buf, NULL)) != SR_OK)
4f979115 BV	144	return ret;
1d36b4d2	145
4f979115	146	return SR_OK;
1d36b4d2 BV	147	}
1d36b4d2 BV	148
17bfaca6	149	static int init(struct sr_input in, GHashTable options)
1d36b4d2	150	{
17bfaca6	151	(void)options;
1d36b4d2	152
f2209364	153	in->sdi = sr_dev_inst_new(SR_ST_ACTIVE, NULL, NULL, NULL);
d0181813	154	in->priv = g_malloc0(sizeof(struct context));
1d36b4d2 BV	155
	156	return SR_OK;
	157	}
	158
17bfaca6	159	static int find_data_chunk(GString *buf, int initial_offset)
cb41a838	160	{
17bfaca6	161	unsigned int offset, i;
cb41a838 BV	162
cb41a838 BV	163	offset = initial_offset;
17bfaca6 BV	164	while(offset < MIN(MAX_DATA_CHUNK_OFFSET, buf->len)) {
17bfaca6 BV	165	if (!memcmp(buf->str + offset, "data", 4))
cb41a838 BV	166	/* Skip into the samples. */
	167	return offset + 8;
	168	for (i = 0; i < 4; i++) {
17bfaca6 BV	169	if (!isalpha(buf->str[offset + i])
	170	&& !isascii(buf->str[offset + i])
	171	&& !isblank(buf->str[offset + i]))
cb41a838 BV	172	/* Doesn't look like a chunk ID. */
	173	return -1;
	174	}
	175	/* Skip past this chunk. */
962d4344	176	offset += 8 + RL32(buf->str + offset + 4);
cb41a838 BV	177	}
	178
	179	return offset;
	180	}
	181
17bfaca6 BV	182	static void send_chunk(const struct sr_input *in, int offset, int num_samples)
	183	{
	184	struct sr_datafeed_packet packet;
	185	struct sr_datafeed_analog analog;
	186	struct context *inc;
	187	float fdata[CHUNK_SIZE];
	188	uint64_t sample;
	189	int total_samples, samplenum;
	190	char s, d;
1d36b4d2	191
7db06394	192	inc = in->priv;
17bfaca6 BV	193
	194	s = in->buf->str + offset;
	195	d = (char *)fdata;
cb41a838	196	memset(fdata, 0, CHUNK_SIZE);
17bfaca6 BV	197	total_samples = num_samples * inc->num_channels;
	198	for (samplenum = 0; samplenum < total_samples; samplenum++) {
	199	if (inc->fmt_code == WAVE_FORMAT_PCM) {
	200	sample = 0;
	201	memcpy(&sample, s, inc->unitsize);
	202	switch (inc->samplesize) {
	203	case 1:
	204	/* 8-bit PCM samples are unsigned. */
962d4344	205	fdata[samplenum] = (uint8_t)sample / (float)255;
17bfaca6 BV	206	break;
17bfaca6 BV	207	case 2:
962d4344	208	fdata[samplenum] = RL16S(&sample) / (float)INT16_MAX;
17bfaca6 BV	209	break;
17bfaca6 BV	210	case 4:
962d4344	211	fdata[samplenum] = RL32S(&sample) / (float)INT32_MAX;
17bfaca6 BV	212	break;
	213	}
	214	} else {
	215	/* BINARY32 float */
cb41a838	216	#ifdef WORDS_BIGENDIAN
28d9df72	217	int i;
17bfaca6	218	for (i = 0; i < inc->unitsize; i++)
28d9df72	219	d[i] = s[inc->unitsize - 1 - i];
cb41a838	220	#else
17bfaca6	221	memcpy(d, s, inc->unitsize);
cb41a838	222	#endif
1d36b4d2	223	}
17bfaca6 BV	224	s += inc->unitsize;
	225	d += inc->unitsize;
	226	}
	227	packet.type = SR_DF_ANALOG;
	228	packet.payload = &analog;
	229	analog.channels = in->sdi->channels;
	230	analog.num_samples = num_samples;
	231	analog.mq = 0;
	232	analog.mqflags = 0;
	233	analog.unit = 0;
	234	analog.data = fdata;
	235	sr_session_send(in->sdi, &packet);
	236	}
	237
d0181813	238	static int receive(struct sr_input in, GString buf)
17bfaca6	239	{
d0181813 BV	240	struct sr_datafeed_packet packet;
	241	struct sr_datafeed_meta meta;
	242	struct sr_channel *ch;
	243	struct sr_config *src;
17bfaca6	244	struct context *inc;
d0181813 BV	245	int offset, chunk_samples, total_samples, processed, max_chunk_samples;
	246	int num_samples, ret, i;
	247	char channelname[8];
17bfaca6	248
17bfaca6 BV	249	g_string_append_len(in->buf, buf->str, buf->len);
17bfaca6 BV	250
d0181813 BV	251	if (in->buf->len < MIN_DATA_CHUNK_OFFSET) {
	252	/*
	253	* Don't even try until there's enough room
	254	* for the data segment to start.
	255	*/
	256	return SR_OK;
	257	}
	258
	259	inc = in->priv;
	260	if (!in->sdi_ready) {
	261	if ((ret = parse_wav_header(in->buf, inc)) == SR_ERR_NA)
	262	/* Not enough data yet. */
17bfaca6	263	return SR_OK;
d0181813 BV	264	else if (ret != SR_OK)
	265	return ret;
	266
	267	/* sdi is ready, notify frontend. */
	268	in->sdi_ready = TRUE;
	269	return SR_OK;
	270	}
	271
	272	if (!inc->started) {
	273	for (i = 0; i < inc->num_channels; i++) {
	274	snprintf(channelname, 8, "CH%d", i + 1);
	275	ch = sr_channel_new(i, SR_CHANNEL_ANALOG, TRUE, channelname);
	276	in->sdi->channels = g_slist_append(in->sdi->channels, ch);
17bfaca6	277	}
d0181813 BV	278
	279	std_session_send_df_header(in->sdi, LOG_PREFIX);
	280
	281	packet.type = SR_DF_META;
	282	packet.payload = &meta;
	283	src = sr_config_new(SR_CONF_SAMPLERATE, g_variant_new_uint64(inc->samplerate));
	284	meta.config = g_slist_append(NULL, src);
	285	sr_session_send(in->sdi, &packet);
	286	sr_config_free(src);
	287
	288	inc->started = TRUE;
17bfaca6	289	}
17bfaca6 BV	290
	291	if (!inc->found_data) {
	292	/* Skip past size of 'fmt ' chunk. */
962d4344	293	i = 20 + RL32(in->buf->str + 16);
17bfaca6 BV	294	offset = find_data_chunk(in->buf, i);
	295	if (offset < 0) {
	296	if (in->buf->len > MAX_DATA_CHUNK_OFFSET) {
	297	sr_err("Couldn't find data chunk.");
	298	return SR_ERR;
	299	}
	300	}
	301	inc->found_data = TRUE;
	302	} else
	303	offset = 0;
	304
	305	/* Round off up to the last channels * unitsize boundary. */
	306	chunk_samples = (in->buf->len - offset) / inc->num_channels / inc->unitsize;
	307	max_chunk_samples = CHUNK_SIZE / inc->num_channels / inc->unitsize;
	308	processed = 0;
	309	total_samples = chunk_samples;
	310	while (processed < total_samples) {
	311	if (chunk_samples > max_chunk_samples)
	312	num_samples = max_chunk_samples;
	313	else
	314	num_samples = chunk_samples;
	315	send_chunk(in, offset, num_samples);
	316	offset += num_samples * inc->unitsize;
	317	chunk_samples -= num_samples;
	318	processed += num_samples;
	319	}
	320
	321	if ((unsigned int)offset < in->buf->len) {
	322	/*
	323	* The incoming buffer wasn't processed completely. Stash
	324	* the leftover data for next time.
	325	*/
	326	g_string_erase(in->buf, 0, offset);
	327	} else
	328	g_string_truncate(in->buf, 0);
1d36b4d2 BV	329
	330	return SR_OK;
	331	}
	332
7db06394 BV	333	static int cleanup(struct sr_input *in)
7db06394 BV	334	{
0a4d68f7	335	struct sr_datafeed_packet packet;
d0181813	336	struct context *inc;
0a4d68f7	337
d0181813 BV	338	inc = in->priv;
d0181813 BV	339	if (inc->started) {
0a4d68f7 BV	340	/* End of stream. */
	341	packet.type = SR_DF_END;
	342	sr_session_send(in->sdi, &packet);
0a4d68f7	343	}
7db06394 BV	344
	345	return SR_OK;
	346	}
	347
d4c93774	348	SR_PRIV struct sr_input_module input_wav = {
1d36b4d2	349	.id = "wav",
17bfaca6 BV	350	.name = "WAV",
	351	.desc = "WAV file",
	352	.metadata = { SR_INPUT_META_HEADER \| SR_INPUT_META_REQUIRED },
1d36b4d2 BV	353	.format_match = format_match,
1d36b4d2 BV	354	.init = init,
17bfaca6	355	.receive = receive,
7db06394	356	.cleanup = cleanup,
1d36b4d2 BV	357	};
1d36b4d2 BV	358