input: new WAV file module

input/Makefile.am

@@ -2,6 +2,7 @@
 ## This file is part of the sigrok project.
 ##
 ## Copyright (C) 2011 Uwe Hermann <uwe@hermann-uwe.de>
+## 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
@@ -23,8 +24,9 @@ noinst_LTLIBRARIES = libsigrokinput.la
 libsigrokinput_la_SOURCES = \
 	binary.c \
 	chronovu_la8.c \
+	input.c \
 	vcd.c \
-	input.c
+	wav.c
 
 libsigrokinput_la_CFLAGS = \
 	-I$(top_srcdir)

input/input.c

@@ -38,11 +38,13 @@
 extern SR_PRIV struct sr_input_format input_chronovu_la8;
 extern SR_PRIV struct sr_input_format input_binary;
 extern SR_PRIV struct sr_input_format input_vcd;
+extern SR_PRIV struct sr_input_format input_wav;
 /* @endcond */
 
 static struct sr_input_format *input_module_list[] = {
 	&input_vcd,
 	&input_chronovu_la8,
+	&input_wav,
 	/* This one has to be last, because it will take any input. */
 	&input_binary,
 	NULL,

input/wav.c

@@ -0,0 +1,209 @@
+/*
+ * This file is part of the sigrok 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 <string.h>
+#include "libsigrok.h"
+#include "libsigrok-internal.h"
+
+/* Message logging helpers with driver-specific prefix string. */
+#define DRIVER_LOG_DOMAIN "input/wav: "
+#define sr_log(l, s, args...) sr_log(l, DRIVER_LOG_DOMAIN s, ## args)
+#define sr_spew(s, args...) sr_spew(DRIVER_LOG_DOMAIN s, ## args)
+#define sr_dbg(s, args...) sr_dbg(DRIVER_LOG_DOMAIN s, ## args)
+#define sr_info(s, args...) sr_info(DRIVER_LOG_DOMAIN s, ## args)
+#define sr_warn(s, args...) sr_warn(DRIVER_LOG_DOMAIN s, ## args)
+#define sr_err(s, args...) sr_err(DRIVER_LOG_DOMAIN s, ## args)
+
+#define CHUNK_SIZE 4096
+
+struct context {
+	uint64_t samplerate;
+	int samplesize;
+	int num_channels;
+};
+
+static int get_wav_header(const char *filename, char *buf)
+{
+	struct stat st;
+	int fd, l;
+
+	l = strlen(filename);
+	if (l <= 4 || strcasecmp(filename + l - 4, ".wav"))
+		return SR_ERR;
+
+	if (stat(filename, &st) == -1)
+		return SR_ERR;
+	if (st.st_size <= 45)
+		/* Minimum size of header + 1 8-bit mono PCM sample. */
+		return SR_ERR;
+
+	if ((fd = open(filename, O_RDONLY)) == -1)
+		return SR_ERR;
+
+	l = read(fd, buf, 40);
+	close(fd);
+	if (l != 40)
+		return SR_ERR;
+
+	return SR_OK;
+}
+
+static int format_match(const char *filename)
+{
+	char buf[40];
+
+	if (get_wav_header(filename, buf) != SR_OK)
+		return FALSE;
+
+	if (strncmp(buf, "RIFF", 4))
+		return FALSE;
+	if (strncmp(buf + 8, "WAVE", 4))
+		return FALSE;
+	if (strncmp(buf + 12, "fmt ", 4))
+		return FALSE;
+	if (GUINT16_FROM_LE(*(uint16_t *)(buf + 20)) != 1)
+		/* Not PCM. */
+		return FALSE;
+	if (strncmp(buf + 36, "data", 4))
+		return FALSE;
+
+	return TRUE;
+}
+
+static int init(struct sr_input *in, const char *filename)
+{
+	struct sr_probe *probe;
+	struct context *ctx;
+	char buf[40], probename[8];
+	int i;
+
+	if (get_wav_header(filename, buf) != SR_OK)
+		return SR_ERR;
+
+	if (!(ctx = g_try_malloc0(sizeof(struct context))))
+		return SR_ERR_MALLOC;
+
+	/* Create a virtual device. */
+	in->sdi = sr_dev_inst_new(0, SR_ST_ACTIVE, NULL, NULL, NULL);
+	in->sdi->priv = ctx;
+
+   	ctx->samplerate = GUINT32_FROM_LE(*(uint32_t *)(buf + 24));
+	ctx->samplesize = GUINT16_FROM_LE(*(uint16_t *)(buf + 34)) / 8;
+	if (ctx->samplesize != 1 && ctx->samplesize != 2 && ctx->samplesize != 4) {
+		sr_err("only 8, 16 or 32 bits per sample supported.");
+		return SR_ERR;
+	}
+
+	if ((ctx->num_channels = GUINT16_FROM_LE(*(uint16_t *)(buf + 22))) > 20) {
+		sr_err("%d channels seems crazy.", ctx->num_channels);
+		return SR_ERR;
+	}
+
+	for (i = 0; i < ctx->num_channels; i++) {
+		snprintf(probename, 8, "CH%d", i + 1);
+		if (!(probe = sr_probe_new(0, SR_PROBE_ANALOG, TRUE, probename)))
+			return SR_ERR;
+		in->sdi->probes = g_slist_append(in->sdi->probes, probe);
+	}
+
+	return SR_OK;
+}
+
+static int loadfile(struct sr_input *in, const char *filename)
+{
+	struct sr_datafeed_packet packet;
+	struct sr_datafeed_meta meta;
+	struct sr_datafeed_analog analog;
+	struct sr_config *src;
+	struct context *ctx;
+	float fdata[CHUNK_SIZE];
+	uint64_t sample;
+	int num_samples, chunk_samples, s, c, fd, l;
+	char buf[CHUNK_SIZE];
+
+	ctx = in->sdi->priv;
+
+	/* Send header packet to the session bus. */
+	std_session_send_df_header(in->sdi, DRIVER_LOG_DOMAIN);
+
+	packet.type = SR_DF_META;
+	packet.payload = &meta;
+	src = sr_config_make(SR_CONF_SAMPLERATE, (const void *)&ctx->samplerate);
+	meta.config = g_slist_append(NULL, src);
+	sr_session_send(in->sdi, &packet);
+
+	if ((fd = open(filename, O_RDONLY)) == -1)
+		return SR_ERR;
+
+	lseek(fd, 40, SEEK_SET);
+	l = read(fd, buf, 4);
+	num_samples = GUINT32_FROM_LE((uint32_t)*(buf));
+	num_samples /= ctx->samplesize / ctx->num_channels;
+	while (TRUE) {
+		if ((l = read(fd, buf, CHUNK_SIZE)) < 1)
+			break;
+		chunk_samples = l / ctx->samplesize / ctx->num_channels;
+		for (s = 0; s < chunk_samples; s++) {
+			for (c = 0; c < ctx->num_channels; c++) {
+				sample = 0;
+				memcpy(&sample, buf + s * ctx->samplesize + c, ctx->samplesize);
+				switch (ctx->samplesize) {
+				case 1:
+					/* 8-bit PCM samples are unsigned. */
+					fdata[s + c] = (uint8_t)sample / 255.0;
+					break;
+				case 2:
+					fdata[s + c] = GINT16_FROM_LE(sample) / 32767.0;
+					break;
+				case 4:
+					fdata[s + c] = GINT32_FROM_LE(sample) / 65535.0;
+					break;
+				}
+			}
+		}
+		packet.type = SR_DF_ANALOG;
+		packet.payload = &analog;
+		analog.probes = in->sdi->probes;
+		analog.num_samples = chunk_samples;
+		analog.mq = 0;
+		analog.unit = 0;
+		analog.data = fdata;
+		sr_session_send(in->sdi, &packet);
+	}
+
+	close(fd);
+	packet.type = SR_DF_END;
+	sr_session_send(in->sdi, &packet);
+
+	return SR_OK;
+}
+
+
+SR_PRIV struct sr_input_format input_wav = {
+	.id = "wav",
+	.description = "WAV file",
+	.format_match = format_match,
+	.init = init,
+	.loadfile = loadfile,
+};
+