input/chronovu_la8: only send data to the session, don't send the header

[libsigrok.git] / src / input / chronovu_la8.c

diff --git a/src/input/chronovu_la8.c b/src/input/chronovu_la8.c
index e83d58229118c5503a16d07bd3afa4d91cb7fd13..11fc36a6d8ac81de2fc56628c366cc74216d3e5b 100644 (file)
--- a/src/input/chronovu_la8.c
+++ b/src/input/chronovu_la8.c
@@ -30,11 +30,27 @@
 #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)
 
 struct context {
        gboolean started;
        uint64_t samplerate;
+       uint64_t samples_remain;
 };
 
 static int format_match(GHashTable *metadata, unsigned int *confidence)
@@ -89,9 +105,12 @@ static int process_buffer(struct sr_input *in)
        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);
 
@@ -105,21 +124,28 @@ static int process_buffer(struct sr_input *in)
                        sr_config_free(src);
                }
 
+               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);