Handle frame headers split between 2 packets

3 files changed, 46 insertions, 8 deletions

diff --git a/base.c b/base.c
index 1355486..1adc185 100644
--- a/base.c
+++ b/base.c
@@ -351,6 +351,10 @@ int ipecamera_start(pcilib_context_t *vctx, pcilib_event_t event_mask, pcilib_ev
     ctx->parse_data = (flags&PCILIB_EVENT_FLAG_RAW_DATA_ONLY)?0:1;
     ctx->cur_size = 0;
 
+#ifdef IPECAMERA_BUG_MULTIFRAME_HEADERS
+    ctx->saved_header_size = 0;
+#endif /* IPECAMERA_BUG_MULTIFRAME_HEADERS */
+
     switch (ctx->firmware) {
      case IPECAMERA_FIRMWARE_UFO5:
 	ctx->dim.width = CMOSIS_WIDTH;
diff --git a/private.h b/private.h
index a0034c8..18138e7 100644
--- a/private.h
+++ b/private.h
@@ -20,6 +20,7 @@
 
 #define IPECAMERA_BUG_MISSING_PAYLOAD		//**< CMOSIS fails to provide a first payload for each frame, therefore the frame is 32 bit shorter */
 #define IPECAMERA_BUG_MULTIFRAME_PACKETS	//**< This is by design, start of packet comes directly after the end of last one in streaming mode */
+#define IPECAMERA_BUG_MULTIFRAME_HEADERS	//**< UFO Camera operates with 32-byte entities, but some times there is 16-byte padding before the data which may result in spliting the header between 2 DMA packets. We still need to define a minimal number of bytes which are always in the same DMA packet (CMOSIS_ENTITY_SIZE) */
 #define IPECAMERA_BUG_REPEATING_DATA		//**< 16 bytes repeated at frame offset 4096, the problem start/stop happenning on board restart */
 //#define IPECAMERA_BUG_INCOMPLETE_PACKETS	//**< Support incomplete packets, i.e. check for frame magic even if full frame size is not reached yet (slow) */
 //#define IPECAMERA_ANNOUNCE_READY		//**< Announce new event only after the reconstruction is done */
@@ -46,8 +47,13 @@
 #define IPECAMERA_END_OF_SEQUENCE 0x1F001001
 
 
-#define CMOSIS_FRAME_HEADER_SIZE	8 * sizeof(ipecamera_payload_t)
-#define CMOSIS_FRAME_TAIL_SIZE		8 * sizeof(ipecamera_payload_t)
+#define CMOSIS_FRAME_HEADER_SIZE	(8 * sizeof(ipecamera_payload_t))
+#define CMOSIS_FRAME_TAIL_SIZE		(8 * sizeof(ipecamera_payload_t))
+#ifdef IPECAMERA_BUG_MULTIFRAME_HEADERS
+# define CMOSIS_ENTITY_SIZE		(4 * sizeof(ipecamera_payload_t))		//**< This normaly should be equal to 32 bytes like header and tail, but in fact is only 16 bytes */
+#else /* IPECAMERA_BUG_MULTIFRAME_HEADERS */
+# define CMOSIS_ENTITY_SIZE		(8 * sizeof(ipecamera_payload_t))		//**< This normaly should be equal to 32 bytes like header and tail, but in fact is only 16 bytes */
+#endif /* IPECAMERA_BUG_MULTIFRAME_HEADERS */
 
 #define CMOSIS_MAX_CHANNELS 16
 #define CMOSIS_PIXELS_PER_CHANNEL 128
@@ -228,7 +234,11 @@ struct ipecamera_s {
     void *buffer;
     ipecamera_change_mask_t *cmask;
     ipecamera_frame_t *frame;
-    
+
+#ifdef IPECAMERA_BUG_MULTIFRAME_HEADERS
+    size_t saved_header_size;				/**< If it happened that the frame header is split between 2 DMA packets, this variable holds the size of the part containing in the first packet */
+    char saved_header[CMOSIS_FRAME_HEADER_SIZE];	/**< If it happened that the frame header is split between 2 DMA packets, this variable holds the part containing in the first packet */
+#endif /* IPECAMERA_BUG_MULTIFRAME_HEADERS */
 
     ipecamera_image_dimensions_t dim;
 
diff --git a/reader.c b/reader.c
index e293005..b603e47 100644
--- a/reader.c
+++ b/reader.c
@@ -163,13 +163,30 @@ static int ipecamera_data_callback(void *user, pcilib_dma_flags_t flags, size_t
     ipecamera_debug_buffer(RAW_PACKETS, bufsize, buf, PCILIB_DEBUG_BUFFER_MKDIR, "frame%4lu/frame%9lu", ctx->event_id, packet_id);
 
     if (!ctx->cur_size) {
+#ifdef IPECAMERA_BUG_MULTIFRAME_HEADERS
+	if (ctx->saved_header_size) {
+	    void *buf2 = alloca(ctx->saved_header_size + bufsize);
+	    if (!buf2) {
+		pcilib_error("Error allocating %zu bytes of memory in stack", ctx->saved_header_size + bufsize);
+		return -PCILIB_ERROR_MEMORY;
+	    }
+	    memcpy(buf2, ctx->saved_header, ctx->saved_header_size);
+	    memcpy(buf2 + ctx->saved_header_size, buf, bufsize);
+
+	    buf = buf2;
+	    bufsize += ctx->saved_header_size;
+
+	    ctx->saved_header_size = 0;
+	}
+#endif /* IPECAMERA_BUG_MULTIFRAME_HEADERS */
+
 #if defined(IPECAMERA_BUG_INCOMPLETE_PACKETS)||defined(IPECAMERA_BUG_MULTIFRAME_PACKETS)
 	size_t startpos;
-	for (startpos = 0; (startpos + CMOSIS_FRAME_HEADER_SIZE) <= bufsize; startpos += sizeof(ipecamera_payload_t)) {
+	for (startpos = 0; (startpos + CMOSIS_ENTITY_SIZE) <= bufsize; startpos += sizeof(ipecamera_payload_t)) {
 	    if (!CHECK_FRAME_MAGIC(buf + startpos)) break;
 	}
 	
-	if ((startpos + CMOSIS_FRAME_HEADER_SIZE) > bufsize) {
+	if ((startpos +  CMOSIS_ENTITY_SIZE) > bufsize) {
 	    ipecamera_debug_buffer(RAW_PACKETS, bufsize, NULL, 0, "frame%4lu/frame%9lu.invalid", ctx->event_id, packet_id);
 	    
 	    if (invalid_frame_id != ctx->event_id) {
@@ -200,8 +217,15 @@ static int ipecamera_data_callback(void *user, pcilib_dma_flags_t flags, size_t
 		// We should handle the case when multi-header is split between multiple DMA packets
 	    if (!ipecamera_parse_header(ctx, buf, bufsize))
 		return PCILIB_STREAMING_CONTINUE;
+
+#ifdef IPECAMERA_BUG_MULTIFRAME_HEADERS
+	} else if ((bufsize >= CMOSIS_ENTITY_SIZE)&&(!CHECK_FRAME_MAGIC(buf))) {
+	    memcpy(ctx->saved_header, buf, bufsize);
+	    ctx->saved_header_size = bufsize;
+	    return PCILIB_STREAMING_REQ_FRAGMENT;
+#endif /* IPECAMERA_BUG_MULTIFRAME_HEADERS */
 	} else {
-	    ipecamera_debug(HARDWARE, "Frame magic is not found, ignoring broken data...");
+	    ipecamera_debug(HARDWARE, "Frame magic is not found in the remaining DMA packet consisting of %u bytes, ignoring broken data...", bufsize);
 	    return PCILIB_STREAMING_CONTINUE;
 	}
     }
@@ -213,11 +237,11 @@ static int ipecamera_data_callback(void *user, pcilib_dma_flags_t flags, size_t
     if (ctx->cur_size + bufsize > ctx->roi_raw_size) {
         size_t need;
 	
-	for (need = ctx->roi_raw_size - ctx->cur_size; (need + CMOSIS_FRAME_HEADER_SIZE) <= bufsize; need += sizeof(uint32_t)) {
+	for (need = ctx->roi_raw_size - ctx->cur_size; (need + CMOSIS_ENTITY_SIZE) <= bufsize; need += sizeof(uint32_t)) {
 	    if (!CHECK_FRAME_MAGIC(buf + need)) break;
 	}
 	
-	if ((need + CMOSIS_FRAME_HEADER_SIZE) <= bufsize) {
+	if ((need + CMOSIS_ENTITY_SIZE) <= bufsize) {
 	    extra_data = bufsize - need;
 	    eof = 1;
 	}