X-Git-Url: http://sigrok.org/gitweb/?a=blobdiff_plain;f=src%2Finput%2Fchronovu_la8.c;h=53fcd682cade27bd107449bad91c74a23a1bab6e;hb=HEAD;hp=6607f3a7e11fba56452223edfebf565bfc7bbce0;hpb=54ee427df0d923c8e17f3dc8ee57552b6c5fd57b;p=libsigrok.git

diff --git a/src/input/chronovu_la8.c b/src/input/chronovu_la8.c
index 6607f3a7..91d05b90 100644
--- a/src/input/chronovu_la8.c
+++ b/src/input/chronovu_la8.c
@@ -30,16 +30,62 @@
 #define DEFAULT_NUM_CHANNELS    8
 #define DEFAULT_SAMPLERATE      SR_MHZ(100)
 #define CHUNK_SIZE              (4 * 1024 * 1024)
-#define CHRONOVU_LA8_FILESIZE   ((8 * 1024 * 1024) + 5)
+
+/*
+ * File layout:
+ * - Fixed size 8MiB data part at offset 0.
+ *   - Either one byte per sample for LA8.
+ *   - Or two bytes per sample for LA16, in little endian format.
+ * - Five byte "header" at offset 8MiB.
+ *   - One "clock divider" byte. The byte value is the divider factor
+ *     minus 1. Value 0xff is invalid. Base clock is 100MHz for LA8, or
+ *     200MHz for LA16.
+ *   - Four bytes for the trigger position. This 32bit value is the
+ *     sample number in little endian format, or 0 when unused.
+ */
+#define CHRONOVU_LA8_DATASIZE   (8 * 1024 * 1024)
+#define CHRONOVU_LA8_HDRSIZE    (sizeof(uint8_t) + sizeof(uint32_t))
+#define CHRONOVU_LA8_FILESIZE   (CHRONOVU_LA8_DATASIZE + CHRONOVU_LA8_HDRSIZE)
+
+/*
+ * Implementation note:
+ *
+ * The .format_match() routine only checks the file size, but none of
+ * the header fields. Only little would be gained (only clock divider
+ * 0xff could get tested), but complexity would increase dramatically.
+ * Also the .format_match() routine is unlikely to receive large enough
+ * a buffer to include the header. Neither is the filename available to
+ * the .format_match() routine.
+ *
+ * There is no way to programmatically tell whether the file was created
+ * by LA8 or LA16 software, i.e. with 8 or 16 logic channels. If the
+ * filename was available, one might guess based on the file extension,
+ * but still would require user specs if neither of the known extensions
+ * were used or the input is fed from a pipe.
+ *
+ * The current input module implementation assumes that users specify
+ * the (channel count and) sample rate. Input data gets processed and
+ * passed along to the session bus, before the file "header" is seen.
+ * A future implementation could move channel creation from init() to
+ * receive() or end() (actually: a common routine called from those two
+ * routines), and could defer sample processing and feeding the session
+ * until the header was seen, including deferred samplerate calculation
+ * after having seen the header. But again this improvement depends on
+ * the availability of either the filename or the device type. Also note
+ * that applications then had to keep sending data to the input module's
+ * receive() routine until sufficient amounts of input data were seen
+ * including the header (see bug #1017).
+ */
 
 struct context {
 	gboolean started;
 	uint64_t samplerate;
+	uint64_t samples_remain;
 };
 
 static int format_match(GHashTable *metadata, unsigned int *confidence)
 {
-	int size;
+	uint64_t size;
 
 	/*
 	 * In the absence of a reliable condition like magic strings,
@@ -47,7 +93,7 @@ static int format_match(GHashTable *metadata, unsigned int *confidence)
 	 * rather weak a condition, signal "little confidence" and
 	 * optionally give precedence to better matches.
 	 */
-	size = GPOINTER_TO_INT(g_hash_table_lookup(metadata,
+	size = GPOINTER_TO_SIZE(g_hash_table_lookup(metadata,
 			GINT_TO_POINTER(SR_INPUT_META_FILESIZE)));
 	if (size != CHRONOVU_LA8_FILESIZE)
 		return SR_ERR;
@@ -84,42 +130,45 @@ static int init(struct sr_input *in, GHashTable *options)
 static int process_buffer(struct sr_input *in)
 {
 	struct sr_datafeed_packet packet;
-	struct sr_datafeed_meta meta;
 	struct sr_datafeed_logic logic;
-	struct sr_config *src;
 	struct context *inc;
 	gsize chunk_size, i;
-	int chunk;
+	gsize chunk;
+	uint16_t unitsize;
 
 	inc = in->priv;
+	unitsize = (g_slist_length(in->sdi->channels) + 7) / 8;
+
 	if (!inc->started) {
 		std_session_send_df_header(in->sdi);
 
 		if (inc->samplerate) {
-			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);
-			g_slist_free(meta.config);
-			sr_config_free(src);
+			(void)sr_session_send_meta(in->sdi, SR_CONF_SAMPLERATE,
+				g_variant_new_uint64(inc->samplerate));
 		}
 
+		inc->samples_remain = CHRONOVU_LA8_DATASIZE;
+		inc->samples_remain /= unitsize;
+
 		inc->started = TRUE;
 	}
 
 	packet.type = SR_DF_LOGIC;
 	packet.payload = &logic;
-	logic.unitsize = (g_slist_length(in->sdi->channels) + 7) / 8;
+	logic.unitsize = unitsize;
 
-	/* Cut off at multiple of unitsize. */
+	/* Cut off at multiple of unitsize. Avoid sending the "header". */
 	chunk_size = in->buf->len / logic.unitsize * logic.unitsize;
+	chunk_size = MIN(chunk_size, inc->samples_remain * unitsize);
 
 	for (i = 0; i < chunk_size; i += chunk) {
 		logic.data = in->buf->str + i;
 		chunk = MIN(CHUNK_SIZE, chunk_size - i);
-		logic.length = chunk;
-		sr_session_send(in->sdi, &packet);
+		if (chunk) {
+			logic.length = chunk;
+			sr_session_send(in->sdi, &packet);
+			inc->samples_remain -= chunk / unitsize;
+		}
 	}
 	g_string_erase(in->buf, 0, chunk_size);
 
@@ -188,9 +237,9 @@ static const struct sr_option *get_options(void)
 
 SR_PRIV struct sr_input_module input_chronovu_la8 = {
 	.id = "chronovu-la8",
-	.name = "ChronoVu LA8",
-	.desc = "ChronoVu LA8 native file format data",
-	.exts = (const char*[]){"kdt", NULL},
+	.name = "ChronoVu LA8/LA16",
+	.desc = "ChronoVu LA8/LA16 native file format data",
+	.exts = (const char*[]){"kdt", "kd1", NULL},
 	.metadata = { SR_INPUT_META_FILESIZE | SR_INPUT_META_REQUIRED },
 	.options = get_options,
 	.format_match = format_match,