[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 {
	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_OK_CONTINUE;

	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_OK_CONTINUE;

		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);

	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 int initial_receive(struct sr_input *in)
{
	struct sr_datafeed_packet packet;
	struct sr_datafeed_meta meta;
	struct sr_channel *ch;
	struct sr_config *src;
	struct context *inc;
	int ret, i;
	char channelname[8];

	if (!in->buf)
		/* Shouldn't happen. */
		return SR_ERR;

	inc = in->priv = g_malloc(sizeof(struct context));
	if ((ret = parse_wav_header(in->buf, inc)) != SR_OK)
		return ret;

	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);

	return SR_OK;
}

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(const struct sr_input *in, GString *buf)
{
	struct context *inc;
	int offset, chunk_samples, total_samples, processed, max_chunk_samples, num_samples, i;

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

	if (!in->priv) {
		if (initial_receive((struct sr_input *)in) != SR_OK)
			return SR_ERR;
		if (in->buf->len < MIN_DATA_CHUNK_OFFSET) {
			/*
			 * Don't even get started until there's enough room
			 * for the data segment to start.
			 */
			return SR_OK;
		}
	}
	inc = in->priv;

	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;

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

		g_free(in->priv);
		in->priv = NULL;
	}

	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 {
17bfaca6	46	int fmt_code;
1d36b4d2 BV	47	uint64_t samplerate;
	48	int samplesize;
	49	int num_channels;
cb41a838	50	int unitsize;
17bfaca6	51	gboolean found_data;
1d36b4d2 BV	52	};
1d36b4d2 BV	53
17bfaca6	54	static int parse_wav_header(GString buf, struct context inc)
1d36b4d2	55	{
17bfaca6	56	uint64_t samplerate;
cbd9e6e9	57	unsigned int fmt_code, samplesize, num_channels, unitsize;
1d36b4d2	58
cbd9e6e9	59	if (buf->len < MIN_DATA_CHUNK_OFFSET)
4f979115	60	return SR_OK_CONTINUE;
1d36b4d2	61
962d4344 BV	62	fmt_code = RL16(buf->str + 20);
962d4344 BV	63	samplerate = RL32(buf->str + 24);
cbd9e6e9	64
962d4344 BV	65	samplesize = RL16(buf->str + 32);
962d4344 BV	66	num_channels = RL16(buf->str + 22);
cbd9e6e9 BV	67	if (num_channels == 0)
cbd9e6e9 BV	68	return SR_ERR;
17bfaca6	69	unitsize = samplesize / num_channels;
e8779db7 BV	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
1d36b4d2	75
17bfaca6	76	if (fmt_code == WAVE_FORMAT_PCM) {
17bfaca6 BV	77	} else if (fmt_code == WAVE_FORMAT_IEEE_FLOAT) {
	78	if (unitsize != 4) {
	79	sr_err("only 32-bit floats supported.");
4f979115	80	return SR_ERR_DATA;
17bfaca6	81	}
cbd9e6e9 BV	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.");
4f979115	97	return SR_ERR_DATA;
cbd9e6e9 BV	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.");
4f979115	103	return SR_ERR_DATA;
cbd9e6e9	104	}
28d9df72 MC	105	if (fmt_code == WAVE_FORMAT_IEEE_FLOAT && unitsize != 4) {
	106	sr_err("only 32-bit floats supported.");
	107	return SR_ERR_DATA;
	108	}
17bfaca6 BV	109	} else {
17bfaca6 BV	110	sr_err("Only PCM and floating point samples are supported.");
4f979115	111	return SR_ERR_DATA;
17bfaca6	112	}
1d36b4d2	113
17bfaca6 BV	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	}
1d36b4d2 BV	122
	123	return SR_OK;
	124	}
	125
17bfaca6	126	static int format_match(GHashTable *metadata)
1d36b4d2	127	{
17bfaca6	128	GString *buf;
4f979115	129	int ret;
1d36b4d2	130
17bfaca6 BV	131	buf = g_hash_table_lookup(metadata, GINT_TO_POINTER(SR_INPUT_META_HEADER));
17bfaca6 BV	132	if (strncmp(buf->str, "RIFF", 4))
4f979115	133	return SR_ERR;
17bfaca6	134	if (strncmp(buf->str + 8, "WAVE", 4))
4f979115	135	return SR_ERR;
17bfaca6	136	if (strncmp(buf->str + 12, "fmt ", 4))
4f979115	137	return SR_ERR;
17bfaca6 BV	138	/*
	139	* Only gets called when we already know this is a WAV file, so
	140	* this parser can log error messages.
	141	*/
4f979115 BV	142	if ((ret = parse_wav_header(buf, NULL)) != SR_OK)
4f979115 BV	143	return ret;
1d36b4d2	144
4f979115	145	return SR_OK;
1d36b4d2 BV	146	}
1d36b4d2 BV	147
17bfaca6	148	static int init(struct sr_input in, GHashTable options)
1d36b4d2	149	{
17bfaca6	150	(void)options;
1d36b4d2	151
f2209364	152	in->sdi = sr_dev_inst_new(SR_ST_ACTIVE, NULL, NULL, NULL);
1d36b4d2 BV	153
	154	return SR_OK;
	155	}
	156
17bfaca6	157	static int find_data_chunk(GString *buf, int initial_offset)
cb41a838	158	{
17bfaca6	159	unsigned int offset, i;
cb41a838 BV	160
cb41a838 BV	161	offset = initial_offset;
17bfaca6 BV	162	while(offset < MIN(MAX_DATA_CHUNK_OFFSET, buf->len)) {
17bfaca6 BV	163	if (!memcmp(buf->str + offset, "data", 4))
cb41a838 BV	164	/* Skip into the samples. */
	165	return offset + 8;
	166	for (i = 0; i < 4; i++) {
17bfaca6 BV	167	if (!isalpha(buf->str[offset + i])
	168	&& !isascii(buf->str[offset + i])
	169	&& !isblank(buf->str[offset + i]))
cb41a838 BV	170	/* Doesn't look like a chunk ID. */
	171	return -1;
	172	}
	173	/* Skip past this chunk. */
962d4344	174	offset += 8 + RL32(buf->str + offset + 4);
cb41a838 BV	175	}
	176
	177	return offset;
	178	}
	179
7db06394	180	static int initial_receive(struct sr_input *in)
1d36b4d2 BV	181	{
	182	struct sr_datafeed_packet packet;
	183	struct sr_datafeed_meta meta;
17bfaca6	184	struct sr_channel *ch;
1d36b4d2	185	struct sr_config *src;
17bfaca6	186	struct context *inc;
4f979115	187	int ret, i;
17bfaca6 BV	188	char channelname[8];
	189
	190	if (!in->buf)
	191	/* Shouldn't happen. */
	192	return SR_ERR;
1d36b4d2	193
7db06394	194	inc = in->priv = g_malloc(sizeof(struct context));
4f979115 BV	195	if ((ret = parse_wav_header(in->buf, inc)) != SR_OK)
4f979115 BV	196	return ret;
17bfaca6 BV	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	}
1d36b4d2	203
29a27196	204	std_session_send_df_header(in->sdi, LOG_PREFIX);
1d36b4d2 BV	205
	206	packet.type = SR_DF_META;
	207	packet.payload = &meta;
17bfaca6	208	src = sr_config_new(SR_CONF_SAMPLERATE, g_variant_new_uint64(inc->samplerate));
1d36b4d2 BV	209	meta.config = g_slist_append(NULL, src);
1d36b4d2 BV	210	sr_session_send(in->sdi, &packet);
ec4063b8	211	sr_config_free(src);
1d36b4d2	212
17bfaca6 BV	213	return SR_OK;
	214	}
	215
	216	static 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;
1d36b4d2	225
7db06394	226	inc = in->priv;
17bfaca6 BV	227
	228	s = in->buf->str + offset;
	229	d = (char *)fdata;
cb41a838	230	memset(fdata, 0, CHUNK_SIZE);
17bfaca6 BV	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. */
962d4344	239	fdata[samplenum] = (uint8_t)sample / (float)255;
17bfaca6 BV	240	break;
17bfaca6 BV	241	case 2:
962d4344	242	fdata[samplenum] = RL16S(&sample) / (float)INT16_MAX;
17bfaca6 BV	243	break;
17bfaca6 BV	244	case 4:
962d4344	245	fdata[samplenum] = RL32S(&sample) / (float)INT32_MAX;
17bfaca6 BV	246	break;
	247	}
	248	} else {
	249	/* BINARY32 float */
cb41a838	250	#ifdef WORDS_BIGENDIAN
28d9df72	251	int i;
17bfaca6	252	for (i = 0; i < inc->unitsize; i++)
28d9df72	253	d[i] = s[inc->unitsize - 1 - i];
cb41a838	254	#else
17bfaca6	255	memcpy(d, s, inc->unitsize);
cb41a838	256	#endif
1d36b4d2	257	}
17bfaca6 BV	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
	272	static int receive(const struct sr_input in, GString buf)
	273	{
17bfaca6 BV	274	struct context *inc;
	275	int offset, chunk_samples, total_samples, processed, max_chunk_samples, num_samples, i;
	276
17bfaca6 BV	277	g_string_append_len(in->buf, buf->str, buf->len);
17bfaca6 BV	278
7db06394 BV	279	if (!in->priv) {
7db06394 BV	280	if (initial_receive((struct sr_input *)in) != SR_OK)
17bfaca6 BV	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	}
7db06394	290	inc = in->priv;
17bfaca6 BV	291
	292	if (!inc->found_data) {
	293	/* Skip past size of 'fmt ' chunk. */
962d4344	294	i = 20 + RL32(in->buf->str + 16);
17bfaca6 BV	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);
1d36b4d2 BV	330
	331	return SR_OK;
	332	}
	333
7db06394 BV	334	static int cleanup(struct sr_input *in)
7db06394 BV	335	{
0a4d68f7 BV	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	}
7db06394 BV	346
	347	return SR_OK;
	348	}
	349
d4c93774	350	SR_PRIV struct sr_input_module input_wav = {
1d36b4d2	351	.id = "wav",
17bfaca6 BV	352	.name = "WAV",
	353	.desc = "WAV file",
	354	.metadata = { SR_INPUT_META_HEADER \| SR_INPUT_META_REQUIRED },
1d36b4d2 BV	355	.format_match = format_match,
1d36b4d2 BV	356	.init = init,
17bfaca6	357	.receive = receive,
7db06394	358	.cleanup = cleanup,
1d36b4d2 BV	359	};
1d36b4d2 BV	360