From d9d7584d28210e3170a47a0a5ba54dd84684cbd3 Mon Sep 17 00:00:00 2001
From: Vlad P <vladisslav2011@gmail.com>
Date: Sun, 31 Jul 2022 21:15:47 +0300
Subject: [PATCH] Try to resync on sync loss

---
 src/async.c           | 11 +++++++++++
 src/convert/252_s16.c |  1 +
 src/convert/336_s16.c |  1 +
 src/convert/384_s16.c |  1 +
 src/convert/504_s16.c |  1 +
 src/convert/504_s8.c  |  1 +
 src/structs.h         |  1 +
 7 files changed, 17 insertions(+)

diff --git a/src/async.c b/src/async.c
index fbf647c..280768c 100644
--- a/src/async.c
+++ b/src/async.c
@@ -206,6 +206,16 @@ static void LIBUSB_CALL _libusb_callback (struct libusb_transfer *xfer) {
 
         if (bytes > 0) mirisdr_feed_async(p, samples, bytes);
 
+        if (xfer->type == LIBUSB_TRANSFER_TYPE_BULK)
+        {
+            if(p->sync_loss_cnt > (int)p->xfer_buf_num)
+            {
+                p->sync_loss_cnt = -p->xfer_buf_num +1;
+                xfer->length = DEFAULT_BULK_BUFFER - 512;
+                fprintf(stderr,"libmirisdr: Sync lost. Trying to synchronize.\n");
+            }else
+                xfer->length = DEFAULT_BULK_BUFFER;
+        }
         /* pokračujeme dalším přenosem */
         if (libusb_submit_transfer(xfer) < 0) {
             fprintf( stderr, "error re-submitting URB on device %u\n", p->index);
@@ -382,6 +392,7 @@ int mirisdr_read_async (mirisdr_dev_t *p, mirisdr_read_async_cb_t cb, void *ctx,
         fprintf( stderr, "auto");
     }
 #endif
+    p->sync_loss_cnt = 0;
     /* použití správného rozhraní které zasílá data - není kritické */
     switch (p->transfer) {
     case MIRISDR_TRANSFER_BULK:
diff --git a/src/convert/252_s16.c b/src/convert/252_s16.c
index 9184a37..bf3e393 100644
--- a/src/convert/252_s16.c
+++ b/src/convert/252_s16.c
@@ -20,6 +20,7 @@ static int mirisdr_samples_convert_252_s16 (mirisdr_dev_t *p, unsigned char* buf
         /* potenciálně ztracená data */
         if ((i == 0) && (addr != p->addr)) {
             fprintf(stderr, "%u samples lost, %d, %08x:%08x\n", addr - p->addr, cnt, p->addr, addr);
+            p->sync_loss_cnt++;
         }
 
         /* přeskočíme hlavičku 16 bitů, 252 I+Q párů */
diff --git a/src/convert/336_s16.c b/src/convert/336_s16.c
index 565844d..0c62018 100644
--- a/src/convert/336_s16.c
+++ b/src/convert/336_s16.c
@@ -20,6 +20,7 @@ static int mirisdr_samples_convert_336_s16 (mirisdr_dev_t *p, unsigned char* buf
         /* potenciálně ztracená data */
         if ((i == 0) && (addr != p->addr)) {
             fprintf(stderr, "%u samples lost, %d, %08x:%08x\n", addr - p->addr, cnt, p->addr, addr);
+            p->sync_loss_cnt++;
         }
 
         /* přeskočíme hlavičku 16 bitů, 336 I+Q párů */
diff --git a/src/convert/384_s16.c b/src/convert/384_s16.c
index 435f2dd..a14095e 100644
--- a/src/convert/384_s16.c
+++ b/src/convert/384_s16.c
@@ -23,6 +23,7 @@ static int mirisdr_samples_convert_384_s16 (mirisdr_dev_t *p, unsigned char* buf
         /* potenciálně ztracená data */
         if ((i == 0) && (addr != p->addr)) {
             fprintf(stderr, "%u samples lost, %d, %08x:%08x\n", addr - p->addr, cnt, p->addr, addr);
+            p->sync_loss_cnt++;
         }
 
         /* přeskočíme hlavičku 16 bitů, 6 bloků, poslední 4 bajtový posuvný blok zpracujeme */
diff --git a/src/convert/504_s16.c b/src/convert/504_s16.c
index 7e5a350..46ae2a2 100644
--- a/src/convert/504_s16.c
+++ b/src/convert/504_s16.c
@@ -20,6 +20,7 @@ static int mirisdr_samples_convert_504_s16 (mirisdr_dev_t *p, unsigned char* buf
         /* potenciálně ztracená data */
         if ((i == 0) && (addr != p->addr)) {
             fprintf(stderr, "%u samples lost, %d, %08x:%08x\n", addr - p->addr, cnt, p->addr, addr);
+            p->sync_loss_cnt++;
         }
 
         /* přeskočíme hlavičku 16 bitů, 504 I+Q párů */
diff --git a/src/convert/504_s8.c b/src/convert/504_s8.c
index fd25402..1a099ce 100644
--- a/src/convert/504_s8.c
+++ b/src/convert/504_s8.c
@@ -14,6 +14,7 @@ static int mirisdr_samples_convert_504_s8 (mirisdr_dev_t *p, unsigned char* src,
     if (p->addr != addr) {
         fprintf(stderr, "%u samples lost, %d, %08x:%08x\n", addr - p->addr, cnt, p->addr, addr);
         p->addr = addr;
+        p->sync_loss_cnt++;
     }
 
     for (i = 16; i < cnt; i+= 1024, ret+= 1008) {
diff --git a/src/structs.h b/src/structs.h
index 0d73709..1c2b58d 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -100,5 +100,6 @@ struct mirisdr_dev {
     int                 reg8;
     uint8_t             *samples;
     int                 samples_size;
+    int                 sync_loss_cnt;
 };