diff --git a/sdk/include/logger.h b/sdk/include/logger.h
index 3011197..81a650b 100644
--- a/sdk/include/logger.h
+++ b/sdk/include/logger.h
@@ -15,9 +15,9 @@ extern "C"
 {
 #endif
 
-#define log_debug(x, ...)
+#define log_debug(x, format, ...) 
 
-#define log_info(x, ...)
+#define log_info(x, format, ...)
 
 #define log_notice(x, ...)
 
diff --git a/src/app.toml b/src/app.toml
index a801e28..28accdc 100644
--- a/src/app.toml
+++ b/src/app.toml
@@ -15,7 +15,7 @@
 # example3:
 RUN_MODE="PCAP_FILE_MODE"
 WORKER_THREAD_NUM=2                    # Prompt marsio how many threads to start to receive packets
-PCAP_FILE_PATH="/home/liuwentan/project/stellar/pcap_test" # if single file, specify dir+filename; if pcapfile directory, specify dir
+PCAP_FILE_PATH="/home/liuwentan/project/stellar/stellar/src/packet_io/test/pcap_sample" # if single file, specify dir+filename; if pcapfile directory, specify dir
 DELETE_WHEN_DONE=0                      # 0(false) 1(true), default 0, if delete it when the pcapfile is processed
 # BPF_FILTER="port 80 and udp"            # default null
 
diff --git a/src/main.cpp b/src/main.cpp
index ea71832..3c792a0 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -26,6 +26,7 @@
 #include "http.h"
 #include "utils.h"
 #include "util_errors.h"
+#include "packet_io_internal.h"
 
 struct worker_thread_ctx
 {
diff --git a/src/packet_io/pcap_file_mode/pio_pcap_file.cpp b/src/packet_io/pcap_file_mode/pio_pcap_file.cpp
index e57d3bf..7fec9a4 100644
--- a/src/packet_io/pcap_file_mode/pio_pcap_file.cpp
+++ b/src/packet_io/pcap_file_mode/pio_pcap_file.cpp
@@ -15,6 +15,7 @@
 #include <pthread.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
+#include <pcap/pcap.h>
 
 #include "utils.h"
 #include "util_errors.h"
@@ -25,6 +26,8 @@
 #include "packet_io_util.h"
 #include "packet_io_internal.h"
 
+#define MAX_RECV_BURST 64
+
 struct safe_pending_file_queue g_pending_file_queue;
 
 /**
@@ -63,26 +66,6 @@ static ssize_t validate_directory_or_file(const char *path, DIR **dir)
     return ret;
 }
 
-/**
- * @brief get the timestamp of the first packet and rewind
- *
- * @retval true(success), false(error)
- */
-static bool peek_first_packet_timestamp(struct pcap_plain_file_info *pfile_info) 
-{
-    int ret = pcap_next_ex(pfile_info->pcap_handle, &pfile_info->first_pkt_hdr, 
-                           &pfile_info->first_pkt_data);
-    if (ret <= 0 || (nullptr == pfile_info->first_pkt_hdr)) {
-        log_error(ST_ERR_PCAP_OPEN_OFFLINE, "failed to get first packet timestamp");
-        return false;
-    }
-
-    pfile_info->first_pkt_ts.tv_sec = pfile_info->first_pkt_hdr->ts.tv_sec;
-    pfile_info->first_pkt_ts.tv_usec = pfile_info->first_pkt_hdr->ts.tv_usec;
-
-    return true;
-}
-
 static ssize_t init_pcap_file(struct pcap_plain_file_info *pfile_info) 
 {
     char errbuf[PCAP_ERRBUF_SIZE] = "";
@@ -118,9 +101,6 @@ static ssize_t init_pcap_file(struct pcap_plain_file_info *pfile_info)
     }
 #endif
     pfile_info->data_link = pcap_datalink(pfile_info->pcap_handle);
-    if (!peek_first_packet_timestamp(pfile_info)) {
-        return -1;
-    }
 
     return 0;
 }
@@ -344,7 +324,8 @@ void pcap_file_pkt_callback_oneshot(char *user, struct pcap_pkthdr *pkt_hdr, u_c
     p->pkt_hdr = p;
     p->pkt_payload = (uint8_t *)p + CUSTOM_ZONE_LEN;
     p->pkt_len = pkt_hdr->caplen;
-    p->data_link = pfile_dev_ctx->entity.file->data_link;
+    //p->data_link = pfile_dev_ctx->entity.file->data_link;
+    p->data_link = 1;
     
     if (packet_copy_data((uint8_t *)p->pkt_payload, (uint8_t *)pkt, pkt_hdr->caplen)) {
         FREE(p);
@@ -361,80 +342,55 @@ void pcap_file_pkt_callback_oneshot(char *user, struct pcap_pkthdr *pkt_hdr, u_c
     pthread_mutex_unlock(&pfile_dev_ctx->pkt_queues[rxq_id].mutex_q);
 }
 
-static ssize_t pcap_directory_file_dispatch(struct pio_pcap_file_device_context *pfile_dev_ctx, uint32_t rxq_id, 
-                                            struct stellar_packet **pkts, size_t nr_pkts) 
+static ssize_t pcap_directory_file_pkts_dispatch(struct pio_pcap_file_device_context *pfile_dev_ctx, uint32_t rxq_id) 
 {
-    if (pfile_dev_ctx->entity.dir->current_file[rxq_id]->first_pkt_hdr != nullptr) {
-        pthread_mutex_lock(&pfile_dev_ctx->entity.dir->current_file[rxq_id]->handle_mutex);
-        if (pfile_dev_ctx->entity.dir->current_file[rxq_id]->first_pkt_hdr != nullptr) {
-            pcap_file_pkt_callback_oneshot((char *)pfile_dev_ctx, pfile_dev_ctx->entity.dir->current_file[rxq_id]->first_pkt_hdr, 
-                                  (u_char *)pfile_dev_ctx->entity.dir->current_file[rxq_id]->first_pkt_data);
-            pfile_dev_ctx->entity.dir->current_file[rxq_id]->first_pkt_hdr = nullptr;
-            pfile_dev_ctx->entity.dir->current_file[rxq_id]->first_pkt_data = nullptr;
-        }
-        pthread_mutex_unlock(&pfile_dev_ctx->entity.dir->current_file[rxq_id]->handle_mutex);
-    }
-
-    int packet_q_len = nr_pkts;
+    int packet_q_len = MAX_RECV_BURST;
     ssize_t res = -1;
 
-    pthread_mutex_lock(&pfile_dev_ctx->entity.dir->current_file[rxq_id]->handle_mutex);
     res = pcap_dispatch(pfile_dev_ctx->entity.dir->current_file[rxq_id]->pcap_handle, packet_q_len,
                         (pcap_handler)pcap_file_pkt_callback_oneshot, (u_char *)pfile_dev_ctx);
-    pthread_mutex_unlock(&pfile_dev_ctx->entity.dir->current_file[rxq_id]->handle_mutex);
     if (res < 0) {
         log_error(ST_ERR_PCAP_DISPATCH, "error code %ld %s for %s", res,
                   pcap_geterr(pfile_dev_ctx->entity.dir->current_file[rxq_id]->pcap_handle), 
                   pfile_dev_ctx->entity.dir->current_file[rxq_id]->file_name);
     } else if (res == 0) {
         log_info("reach end of pcap file %s (error code %d)", pfile_dev_ctx->entity.dir->current_file[rxq_id]->file_name, res);
-        //TODO: close pcap file
-    } else {
-        // success
-        struct pio_packet *p = nullptr;
-        size_t i = 0;
-        uint32_t q_len = 0;
-        pthread_mutex_lock(&pfile_dev_ctx->pkt_queues[rxq_id].mutex_q);
-
-        /* if pkt queue is empty */
-        if (pfile_dev_ctx->pkt_queues[rxq_id].len == 0) {
-            pthread_mutex_unlock(&pfile_dev_ctx->pkt_queues[rxq_id].mutex_q);
-            return 0;
-        }
-
-        do {
-            p = pio_packet_dequeue(&pfile_dev_ctx->pkt_queues[rxq_id]);
-            pkts[i] = (struct stellar_packet *)p;
-            q_len = pfile_dev_ctx->pkt_queues[rxq_id].len;
-            i++;
-        } while ((q_len != 0) && (i < nr_pkts));
-        pthread_mutex_unlock(&pfile_dev_ctx->pkt_queues[rxq_id].mutex_q);
-
-        if (q_len == 0) {
-            res = i;
-        } else {
-            res = nr_pkts;
-        }
     }
 
     return res;
 }
 
-static ssize_t pcap_file_dispatch(struct pio_pcap_file_device_context *pfile_dev_ctx, uint32_t rxq_id, 
-                              struct stellar_packet **pkts, size_t nr_pkts) 
+static ssize_t get_pcap_file_pkts(struct pio_pcap_file_device_context *pfile_dev_ctx, uint32_t rxq_id,
+                                  struct stellar_packet **pkts, size_t nr_pkts)
 {
-    if (pfile_dev_ctx->entity.file->first_pkt_hdr != nullptr) {
-        pthread_mutex_lock(&pfile_dev_ctx->entity.file->handle_mutex);
-        if (pfile_dev_ctx->entity.file->first_pkt_hdr != nullptr) {
-            pcap_file_pkt_callback_oneshot((char *)pfile_dev_ctx, pfile_dev_ctx->entity.file->first_pkt_hdr, 
-                                  (u_char *)pfile_dev_ctx->entity.file->first_pkt_data);
-            pfile_dev_ctx->entity.file->first_pkt_hdr = nullptr;
-            pfile_dev_ctx->entity.file->first_pkt_data = nullptr;
-        }
-        pthread_mutex_unlock(&pfile_dev_ctx->entity.file->handle_mutex);
+    ssize_t res = -1;
+    size_t i = 0;
+    uint32_t q_len = 0;
+    struct pio_packet *p = nullptr;
+
+    pthread_mutex_lock(&pfile_dev_ctx->pkt_queues[rxq_id].mutex_q);
+    if (pfile_dev_ctx->pkt_queues[rxq_id].len > 0) {
+        do {
+            p = pio_packet_dequeue(&pfile_dev_ctx->pkt_queues[rxq_id]);
+            q_len = pfile_dev_ctx->pkt_queues[rxq_id].len;
+            pkts[i] = (struct stellar_packet *)p;
+            i++;
+        } while ((q_len != 0) && (i < nr_pkts));
+    }
+    pthread_mutex_unlock(&pfile_dev_ctx->pkt_queues[rxq_id].mutex_q);
+
+    if (q_len == 0) {
+        res = i;
+    } else {
+        res = nr_pkts;
     }
 
-    int packet_q_len = nr_pkts;
+    return res;
+}
+
+static ssize_t pcap_file_pkts_dispatch(struct pio_pcap_file_device_context *pfile_dev_ctx) 
+{
+    int packet_q_len = MAX_RECV_BURST;
     ssize_t res = -1;
 
     pthread_mutex_lock(&pfile_dev_ctx->entity.file->handle_mutex);
@@ -444,31 +400,8 @@ static ssize_t pcap_file_dispatch(struct pio_pcap_file_device_context *pfile_dev
     if (res < 0) {
         log_error(ST_ERR_PCAP_DISPATCH, "error code %ld %s for %s", res,
                   pcap_geterr(pfile_dev_ctx->entity.file->pcap_handle), pfile_dev_ctx->entity.file->file_name);
-    } else {
-        if (res == 0) {
-            log_info("reach end of pcap file %s (error code %d)", pfile_dev_ctx->entity.file->file_name, res);
-        }
-
-        // success
-        struct pio_packet *p = nullptr;
-        size_t i = 0;
-        uint32_t q_len = 0;
-        pthread_mutex_lock(&pfile_dev_ctx->pkt_queues[rxq_id].mutex_q);
-        if (pfile_dev_ctx->pkt_queues[rxq_id].len != 0) {
-            do {
-                p = pio_packet_dequeue(&pfile_dev_ctx->pkt_queues[rxq_id]);
-                q_len = pfile_dev_ctx->pkt_queues[rxq_id].len;
-                pkts[i] = (struct stellar_packet *)p;
-                i++;
-            } while ((q_len != 0) && (i < nr_pkts));
-        }
-        pthread_mutex_unlock(&pfile_dev_ctx->pkt_queues[rxq_id].mutex_q);
-
-        if (q_len == 0) {
-            res = i;
-        } else {
-            res = nr_pkts;
-        }
+    } else if (res == 0) {
+        log_info("reach end of pcap file %s (error code %d)", pfile_dev_ctx->entity.file->file_name, res);
     }
 
     return res;
@@ -569,6 +502,197 @@ static ssize_t pcap_directory_insert_file(struct pending_file *file_to_add)
     return 0;
 }
 
+#define	SWAPLONG(y) \
+    (((((u_int)(y))&0xff)<<24) | \
+     ((((u_int)(y))&0xff00)<<8) | \
+     ((((u_int)(y))&0xff0000)>>8) | \
+     ((((u_int)(y))>>24)&0xff))
+
+#define	SWAPSHORT(y) \
+     ((u_short)(((((u_int)(y))&0xff)<<8) | \
+                ((((u_int)(y))&0xff00)>>8)))
+
+/* Standard libpcap format. */
+#define TCPDUMP_MAGIC 0xa1b2c3d4
+
+/* Alexey Kuznetzov's modified libpcap format. */
+#define KUZNETZOV_TCPDUMP_MAGIC	0xa1b2cd34
+
+/*
+ * Normal libpcap format, except for seconds/nanoseconds timestamps,
+ * as per a request by Ulf Lamping <ulf.lamping@web.de>
+ */
+#define NSEC_TCPDUMP_MAGIC	0xa1b23c4d
+
+#define LT_RESERVED1(x)	((x) & 0x03FF0000)
+
+static ssize_t pcap_header_check(const uint8_t *magic, FILE *fp)
+{
+    int swapped = 0;
+    size_t amt_read;
+    uint32_t magic_int;
+    struct pcap_file_header hdr;
+
+    /*
+	 * Check whether the first 4 bytes of the file are the magic
+	 * number for a pcap savefile, or for a byte-swapped pcap
+	 * savefile.
+	 */
+    memcpy(&magic_int, magic, sizeof(magic_int));
+    if (magic_int != TCPDUMP_MAGIC && magic_int != KUZNETZOV_TCPDUMP_MAGIC && magic_int != NSEC_TCPDUMP_MAGIC) {
+		magic_int = SWAPLONG(magic_int);
+		if (magic_int != TCPDUMP_MAGIC && magic_int != KUZNETZOV_TCPDUMP_MAGIC && magic_int != NSEC_TCPDUMP_MAGIC) {
+                return -1;
+        }
+		swapped = 1;
+	}
+
+    /*
+	 * They are.  Put the magic number in the header, and read
+	 * the rest of the header.
+	 */
+	hdr.magic = magic_int;
+	amt_read = fread(((char *)&hdr) + sizeof hdr.magic, 1,
+	                 sizeof(hdr) - sizeof(hdr.magic), fp);
+	if (amt_read != sizeof(hdr) - sizeof(hdr.magic)) {
+		return -1;
+	}
+
+	/*
+	 * If it's a byte-swapped capture file, byte-swap the header.
+	 */
+	if (swapped) {
+		hdr.version_major = SWAPSHORT(hdr.version_major);
+		hdr.version_minor = SWAPSHORT(hdr.version_minor);
+		hdr.thiszone = SWAPLONG(hdr.thiszone);
+		hdr.sigfigs = SWAPLONG(hdr.sigfigs);
+		hdr.snaplen = SWAPLONG(hdr.snaplen);
+		hdr.linktype = SWAPLONG(hdr.linktype);
+	}
+
+	if (hdr.version_major < PCAP_VERSION_MAJOR) {
+		return -1;
+	}
+
+	/*
+	 * currently only versions 2.[0-4] are supported with
+	 * the exception of 543.0 for DG/UX tcpdump.
+	 */
+	if (! ((hdr.version_major == PCAP_VERSION_MAJOR &&
+		    hdr.version_minor <= PCAP_VERSION_MINOR) ||
+	       (hdr.version_major == 543 && hdr.version_minor == 0))) {
+		return -1;
+	}
+
+	/*
+	 * Check the main reserved field.
+	 */
+	if (LT_RESERVED1(hdr.linktype) != 0) {
+		return -1;
+	}
+
+    return 0;
+}
+
+
+#define BT_SHB            0x0A0D0D0A
+#define BT_SHB_INSANE_MAX 1024U*1024U*1U  /* 1MB should be enough */
+#define BYTE_ORDER_MAGIC  0x1A2B3C4D
+struct section_header_block {
+	uint32_t	byte_order_magic;
+	u_short		major_version;
+	u_short		minor_version;
+	uint64_t	section_length;
+	/* followed by options and trailer */
+};
+
+struct block_header {
+	uint32_t	block_type;
+	uint32_t	total_length;
+};
+
+static ssize_t pcapng_header_check(const uint8_t *magic, FILE *fp)
+{
+    uint32_t magic_int;
+    uint32_t total_length;
+    uint32_t byte_order_magic;
+    size_t amt_read;
+    struct block_header *bhdrp;
+	struct section_header_block *shbp;
+
+    /*
+	 * Check whether the first 4 bytes of the file are the block
+	 * type for a pcapng savefile.
+	 */
+	memcpy(&magic_int, magic, sizeof(magic_int));
+	if (magic_int != BT_SHB) {
+		return -1;
+	}
+
+	/*
+	 * OK, they are.  However, that's just \n\r\r\n, so it could,
+	 * conceivably, be an ordinary text file.
+	 *
+	 * It could not, however, conceivably be any other type of
+	 * capture file, so we can read the rest of the putative
+	 * Section Header Block; put the block type in the common
+	 * header, read the rest of the common header and the
+	 * fixed-length portion of the SHB, and look for the byte-order
+	 * magic value.
+	 */
+	amt_read = fread(&total_length, 1, sizeof(total_length), fp);
+	if (amt_read < sizeof(total_length)) {
+        return -1;
+	}
+
+	amt_read = fread(&byte_order_magic, 1, sizeof(byte_order_magic), fp);
+	if (amt_read < sizeof(byte_order_magic)) {
+		return -1;
+	}
+	if (byte_order_magic != BYTE_ORDER_MAGIC) {
+		byte_order_magic = SWAPLONG(byte_order_magic);
+		if (byte_order_magic != BYTE_ORDER_MAGIC) {
+			return -1;
+		}
+		total_length = SWAPLONG(total_length);
+	}
+
+	/*
+	 * Check the sanity of the total length.
+	 */
+	if (total_length < sizeof(*bhdrp) + sizeof(*shbp) + sizeof(total_length) ||
+            (total_length > BT_SHB_INSANE_MAX)) {
+		return -1;
+	}
+
+    return 0;
+}
+
+static ssize_t validate_pcap_file(struct pio_pcap_file_device_context *pfile_dev_ctx, const char *file_name)
+{
+    uint8_t magic[4];
+    char abs_path[PATH_MAX] = {0};
+    
+    snprintf(abs_path, sizeof(abs_path), "%s/%s", pfile_dev_ctx->entity.dir->dir_name, file_name);
+    FILE *fp = fopen(abs_path, "r");
+    if (nullptr == fp) {
+        return -1;
+    }
+
+    size_t ret = fread(&magic, 1, sizeof(magic), fp);
+    if (ret != sizeof(magic)) {
+        return -1;
+    }
+
+    if (pcap_header_check(magic, fp) == 0) {
+        return 0;
+    } else if (pcapng_header_check(magic, fp) == 0) {
+        return 0;
+    }
+
+    return -1;
+}
+
 static ssize_t pcap_directory_collect_pending_files(struct pio_pcap_file_device_context *pfile_dev_ctx, struct timespec *deadline)
 {
     if (nullptr == pfile_dev_ctx) {
@@ -594,6 +718,11 @@ static ssize_t pcap_directory_collect_pending_files(struct pio_pcap_file_device_
             continue;
         }
 
+        /* ignore non pcap file */
+        if (validate_pcap_file(pfile_dev_ctx, dir->d_name) < 0) {
+            continue;
+        }
+
         file_to_add = find_pending_file_to_add(pfile_dev_ctx, dir, deadline);
         if (nullptr == file_to_add) {
             continue;
@@ -609,14 +738,14 @@ static ssize_t pcap_directory_collect_pending_files(struct pio_pcap_file_device_
     return 0;
 }
 
-static ssize_t pcap_directory_dispatch(struct pio_pcap_file_device_context *pfile_dev_ctx, uint32_t rxq_id, 
-                                   struct stellar_packet **pkts, size_t nr_pkts) 
+static ssize_t pcap_directory_files_dispatch(struct pio_pcap_file_device_context *pfile_dev_ctx, uint32_t rxq_id) 
 {
     ssize_t res = -1;
     struct timespec deadline;
 
     memset(&deadline, 0, sizeof(struct timespec));
     get_current_timespec(&deadline);
+
     /* the newest file which can be processed */
     deadline.tv_sec = deadline.tv_sec - pfile_dev_ctx->entity.dir->delay;
 
@@ -632,6 +761,7 @@ static ssize_t pcap_directory_dispatch(struct pio_pcap_file_device_context *pfil
     /* not open file yet */
     if (nullptr == pfile_dev_ctx->entity.dir->current_file[rxq_id]) {
         pthread_mutex_lock(&g_pending_file_queue.queue_mutex);
+
         /* file_queue is empty */
         if (TAILQ_EMPTY(&g_pending_file_queue.file_queue_head)) {
             pthread_mutex_unlock(&g_pending_file_queue.queue_mutex);
@@ -654,24 +784,24 @@ static ssize_t pcap_directory_dispatch(struct pio_pcap_file_device_context *pfil
 
         res = strncpy_safe(pfile_info->file_name, current_file->file_name, sizeof(pfile_info->file_name));
         if (res < 0) {
-            log_error(ST_ERR_STR_COPY, "pfile_info file name copy failed.");
-            FREE(current_file);
             FREE(pfile_info);
+            FREE(pfile_dev_ctx->entity.dir->pending_file[rxq_id]);
+            log_error(ST_ERR_STR_COPY, "pfile_info file name copy failed.");
 		    return -1;
         }
 
         pfile_info->shared = &pfile_dev_ctx->shared;
 
         if (init_pcap_file(pfile_info) < 0) {
-            log_error(ST_ERR_PIO_PCAP_FILE_DEVICE, "init_pcap_file failed.");
-            FREE(current_file);
             FREE(pfile_info);
+            FREE(pfile_dev_ctx->entity.dir->pending_file[rxq_id]);
+            log_error(ST_ERR_PIO_PCAP_FILE_DEVICE, "init_pcap_file failed.");
             return -1;
-        } else {  
+        } else {
             pfile_dev_ctx->entity.dir->current_file[rxq_id] = pfile_info;
-            res = pcap_directory_file_dispatch(pfile_dev_ctx, rxq_id, pkts, nr_pkts);
+            res = pcap_directory_file_pkts_dispatch(pfile_dev_ctx, rxq_id);
             if (res < 0) {
-                FREE(current_file);
+                FREE(pfile_dev_ctx->entity.dir->pending_file[rxq_id]);
                 return -1;
             }
             log_info("processed file %s, processed up to %" PRIuMAX,
@@ -684,13 +814,14 @@ static ssize_t pcap_directory_dispatch(struct pio_pcap_file_device_context *pfil
             if (res == 0) { // reach the end of the file
                 cleanup_pcap_plain_file_info(pfile_dev_ctx->entity.dir->current_file[rxq_id]);
                 FREE(pfile_dev_ctx->entity.dir->current_file[rxq_id]);
-                FREE(current_file);
+                FREE(pfile_dev_ctx->entity.dir->pending_file[rxq_id]);
             }
         }
     } else {
         /* file has been opened */
-        res = pcap_directory_file_dispatch(pfile_dev_ctx, rxq_id, pkts, nr_pkts);
+        res = pcap_directory_file_pkts_dispatch(pfile_dev_ctx, rxq_id);
         if (res < 0) {
+            FREE(pfile_dev_ctx->entity.dir->pending_file[rxq_id]);
             return -1;
         } else if (res == 0) {
             cleanup_pcap_plain_file_info(pfile_dev_ctx->entity.dir->current_file[rxq_id]);
@@ -718,10 +849,20 @@ ssize_t pio_pcap_file_device_receive(struct packet_io_device *pdev, uint32_t rxq
     ssize_t res = -1;
     if (pfile_dev_ctx->is_dir == 0) {
         log_info("Start reading file:%s", pfile_dev_ctx->entity.file->file_name);
-        res = pcap_file_dispatch(pfile_dev_ctx, rxq_id, pkts, nr_pkts);
+
+        /* read pcap file and dispatch pkts to pkt_queue */
+        pcap_file_pkts_dispatch(pfile_dev_ctx);
+
+        /* get pkts from pkt_queue */
+        res = get_pcap_file_pkts(pfile_dev_ctx, rxq_id, pkts, nr_pkts);
     } else {
         log_info("Start reading directory:%s", pfile_dev_ctx->entity.dir->dir_name);
-        res = pcap_directory_dispatch(pfile_dev_ctx, rxq_id, pkts, nr_pkts);
+
+        /* read directory pcap files and dispatch pkts to pkt_queue */
+        pcap_directory_files_dispatch(pfile_dev_ctx, rxq_id);
+
+        /* get pkts from pkt_queue[rxq_id] */
+        res = get_pcap_file_pkts(pfile_dev_ctx, rxq_id, pkts, nr_pkts);
     }
 
     return res;
diff --git a/src/packet_io/pcap_file_mode/pio_pcap_file.h b/src/packet_io/pcap_file_mode/pio_pcap_file.h
index c02caec..24641e4 100644
--- a/src/packet_io/pcap_file_mode/pio_pcap_file.h
+++ b/src/packet_io/pcap_file_mode/pio_pcap_file.h
@@ -65,11 +65,6 @@ struct pcap_plain_file_info {
     int data_link;
     struct bpf_program filter;
 
-    /* get the first packet timestamp */
-    const u_char *first_pkt_data;
-    struct pcap_pkthdr *first_pkt_hdr;
-    struct timeval first_pkt_ts;
-
     struct pcap_file_shared_info *shared;
 };
 
diff --git a/src/packet_io/pcap_live_mode/pio_pcap_live.cpp b/src/packet_io/pcap_live_mode/pio_pcap_live.cpp
index 3b7f2a8..cb60221 100644
--- a/src/packet_io/pcap_live_mode/pio_pcap_live.cpp
+++ b/src/packet_io/pcap_live_mode/pio_pcap_live.cpp
@@ -212,23 +212,21 @@ ssize_t pio_pcap_live_device_receive(struct packet_io_device *pdev, uint32_t rxq
     if (res < 0) {
         log_error(ST_ERR_PCAP_DISPATCH, "error code %ld %s",
                   res, pcap_geterr(plive_dev_ctx->pcap_handle));
-    } else if (res == 0) {
-
     } else {
         struct pio_packet *p = nullptr;
         size_t i = 0;
         uint32_t q_len = 0;
 
+        pthread_mutex_lock(&plive_dev_ctx->pkt_queues[rxq_id].mutex_q);
         if (plive_dev_ctx->pkt_queues[rxq_id].len > 0) {
-            pthread_mutex_lock(&plive_dev_ctx->pkt_queues[rxq_id].mutex_q);
             do {
                 p = pio_packet_dequeue(&plive_dev_ctx->pkt_queues[rxq_id]);
                 q_len = plive_dev_ctx->pkt_queues[rxq_id].len;
                 pkts[i] = (struct stellar_packet *)p;
                 i++;
             } while ((q_len != 0) && (i < nr_pkts));
-            pthread_mutex_unlock(&plive_dev_ctx->pkt_queues[rxq_id].mutex_q);
         }
+        pthread_mutex_unlock(&plive_dev_ctx->pkt_queues[rxq_id].mutex_q);
 
         if (q_len == 0) {
             res = i;
diff --git a/src/packet_io/test/gtest_packet_io.cpp b/src/packet_io/test/gtest_packet_io.cpp
index 0d0eb47..d3eae75 100644
--- a/src/packet_io/test/gtest_packet_io.cpp
+++ b/src/packet_io/test/gtest_packet_io.cpp
@@ -458,7 +458,7 @@ TEST(PACKET_IO_PIO_PCAP_LIVE_Test, pio_pcap_live_device_open_and_close) {
 	FREE(pio_instance);
 }
 
-TEST(PACKET_IO_PIO_PCAP_LIVE_Test, pio_pcap_live_device_send) {
+TEST(PACKET_IO_PIO_PCAP_LIVE_Test, pio_pcap_live_device_receive_and_send) {
 	struct packet_io_instance *ppio_inst_file = packet_io_instance_create("stellar_file", PACKET_IO_RUN_MODE_PCAP_FILE);
 	EXPECT_NE(ppio_inst_file, nullptr);
 	struct packet_io_instance *ppio_inst_live = packet_io_instance_create("stellar_live", PACKET_IO_RUN_MODE_PCAP_LIVE);
@@ -475,6 +475,10 @@ TEST(PACKET_IO_PIO_PCAP_LIVE_Test, pio_pcap_live_device_send) {
 	ssize_t res = packet_io_device_tx(pdev_live, 0, tx_pkts, 64);
 	EXPECT_EQ(res, 0);
 	
+	struct stellar_packet *rx_pkts[64];
+	res = packet_io_device_rx(pdev_live, 0, rx_pkts, 64);
+	EXPECT_EQ(res, 0);
+
 	packet_io_device_close(pdev_file);
 	packet_io_device_close(pdev_live);
 	packet_io_fini(ppio_inst_file);