diff --git a/gear-lib/libuvc/Makefile b/gear-lib/libuvc/Makefile
index a45cc4e..56e0100 100644
--- a/gear-lib/libuvc/Makefile
+++ b/gear-lib/libuvc/Makefile
@@ -30,7 +30,7 @@ TGT_LIB_SO	= $(LIBNAME).so
 TGT_LIB_SO_VER	= $(TGT_LIB_SO).${VER}
 TGT_UNIT_TEST	= test_$(LIBNAME)
 
-OBJS_LIB	= $(LIBNAME).o v4l2.o
+OBJS_LIB	= $(LIBNAME).o v4l2.o dummy.o
 OBJS_UNIT_TEST	= test_$(LIBNAME).o
 
 ###############################################################################
diff --git a/gear-lib/libuvc/dummy.c b/gear-lib/libuvc/dummy.c
new file mode 100644
index 0000000..b05a2ca
--- /dev/null
+++ b/gear-lib/libuvc/dummy.c
@@ -0,0 +1,308 @@
+/******************************************************************************
+ * Copyright (C) 2014-2020 Zhifeng Gong <gozfree@163.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ ******************************************************************************/
+#include "libuvc.h"
+#include <libthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <time.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/epoll.h>
+
+struct dummy_ctx {
+    int fd;
+    int rd_fd;
+    int wr_fd;
+    uint64_t seek_offset;
+    uint64_t first_ts;
+    uint64_t frame_id;
+    struct uvc_ctx *parent;
+    struct thread *thread;
+    bool is_streaming;
+    int epfd;
+    struct epoll_event events;
+};
+
+#define timespec2ns(ts) \
+    (((uint64_t)ts.tv_sec * 1000000000) + ((uint64_t)ts.tv_nsec))
+
+static void *uvc_dummy_open(struct uvc_ctx *uvc, const char *dev, struct uvc_config *conf)
+{
+    int fds[2];
+    struct dummy_ctx *c = calloc(1, sizeof(struct dummy_ctx));
+    if (!c) {
+        printf("malloc dummy_ctx failed!\n");
+        return NULL;
+    }
+
+    c->fd = open(dev, O_RDWR);
+    if (c->fd == -1) {
+        printf("open %s failed: %d\n", dev, errno);
+        goto failed;
+    }
+    c->frame_id = 0;
+    c->seek_offset = 0;
+
+    if (pipe(fds)) {
+        printf("create pipe failed(%d): %s\n", errno, strerror(errno));
+        goto failed;
+    }
+    c->rd_fd = fds[0];
+    c->wr_fd = fds[1];
+
+    memcpy(&uvc->conf, conf, sizeof(struct uvc_config));
+    c->parent = uvc;
+
+    return c;
+
+failed:
+    if (c->fd != -1) {
+        close(c->fd);
+    }
+    if (c) {
+        free(c);
+    }
+    return NULL;
+}
+
+static int msleep(uint64_t ms)
+{
+    struct timeval tv;
+    tv.tv_sec = 0;
+    tv.tv_usec = ms*1000;
+    return select(0, NULL, NULL, NULL, &tv);
+}
+
+static int uvc_dummy_enqueue(struct uvc_ctx *uvc, void *buf, size_t len)
+{
+    char notify = '1';
+    uint64_t delay_ms = 0;
+    struct dummy_ctx *c = (struct dummy_ctx *)uvc->opaque;
+
+    delay_ms = (1000)/(uvc->conf.fps.num/(uvc->conf.fps.den*1.0));
+    msleep(delay_ms);
+    if (write(c->wr_fd, &notify, 1) != 1) {
+        printf("Failed writing to notify pipe\n");
+        return -1;
+    }
+    return 0;
+}
+
+static int uvc_dummy_dequeue(struct uvc_ctx *uvc, struct video_frame *frame)
+{
+    int i;
+    ssize_t ret;
+    size_t len;
+    char notify;
+    struct timespec ts;
+    struct dummy_ctx *c = (struct dummy_ctx *)uvc->opaque;
+
+    if (read(c->rd_fd, &notify, sizeof(notify)) != 1) {
+        printf("Failed read from notify pipe\n");
+        return -1;
+    }
+
+    for (i = 0; i < frame->planes; ++i) {
+        len = frame->linesize[i]*frame->height;
+        ret = read(c->fd, frame->data[i], len);
+        if (ret != len) {
+            printf("read failed: ret=%lu, len=%zu, errno=%d, ptr=%p\n", ret, len, errno, frame->data[i]);
+            return -1;
+        }
+        c->seek_offset += len;
+        lseek(c->fd, c->seek_offset, SEEK_SET);
+    }
+    if (-1 == clock_gettime(CLOCK_REALTIME, &ts)) {
+        printf("clock_gettime failed %d:%s\n", errno, strerror(errno));
+        return -1;
+    }
+    frame->timestamp = timespec2ns(ts);
+    if (c->frame_id == 0) {
+        c->first_ts = frame->timestamp;
+    }
+    frame->timestamp -= c->first_ts;
+    frame->frame_id = c->frame_id;
+    c->frame_id++;
+
+    return frame->total_size;
+}
+
+static int uvc_dummy_poll_init(struct dummy_ctx *c)
+{
+    struct epoll_event epev;
+    memset(&epev, 0, sizeof(epev));
+    printf("dummy_ctx=%p\n", c);
+    c->epfd = epoll_create(1);
+    if (c->epfd == -1) {
+        printf("epoll_create failed %d!\n", errno);
+        return -1;
+    }
+
+    epev.events = EPOLLIN | EPOLLOUT | EPOLLPRI | EPOLLET | EPOLLERR;
+    epev.data.ptr = (void *)c;
+    if (-1 == epoll_ctl(c->epfd, EPOLL_CTL_ADD, c->rd_fd, &epev)) {
+        printf("epoll_ctl EPOLL_CTL_ADD failed %d!\n", errno);
+        return -1;
+    }
+    return 0;
+}
+
+static int uvc_dummy_poll(struct uvc_ctx *uvc, int timeout)
+{
+    struct dummy_ctx *c = (struct dummy_ctx *)uvc->opaque;
+    int ret = 0;
+
+    int n = epoll_wait(c->epfd, &c->events, 1, timeout);
+    switch (n) {
+    case 0:
+        printf("poll timeout\n");
+        ret = -1;
+        break;
+    case -1:
+        printf("poll error %d\n", errno);
+        ret = -1;
+        break;
+    default:
+        ret = 0;
+        break;
+    }
+
+    return ret;
+}
+
+static void uvc_dummy_poll_deinit(struct dummy_ctx *c)
+{
+    if (-1 == epoll_ctl(c->epfd, EPOLL_CTL_DEL, c->rd_fd, NULL)) {
+        printf("epoll_ctl EPOLL_CTL_DEL failed %d!\n", errno);
+    }
+    close(c->epfd);
+}
+
+static void *dummy_thread(struct thread *t, void *arg)
+{
+    struct uvc_ctx *uvc = arg;
+    struct dummy_ctx *c = (struct dummy_ctx *)uvc->opaque;
+    struct video_frame frame;
+
+    if (uvc_dummy_poll_init(c) == -1) {
+        printf("uvc_dummy_poll_init failed!\n");
+    }
+    video_frame_init(&frame, uvc->conf.format, uvc->conf.width, uvc->conf.height, VFC_ALLOC);
+    c->is_streaming = true;
+    while (c->is_streaming) {
+        if (uvc_dummy_enqueue(uvc, NULL, 0) != 0) {
+            printf("uvc_dummy_enqueue failed\n");
+            continue;
+        }
+        if (uvc_dummy_poll(uvc, -1) != 0) {
+            printf("uvc_dummy_poll failed\n");
+            continue;
+        }
+
+        if (uvc_dummy_dequeue(uvc, &frame) == -1) {
+            printf("uvc_dummy_dequeue failed\n");
+        }
+        uvc->on_video_frame(uvc, &frame);
+    }
+    uvc_dummy_poll_deinit(c);
+    return NULL;
+}
+
+static int uvc_dummy_start_stream(struct uvc_ctx *uvc)
+{
+    char notify = '1';
+    struct dummy_ctx *c = (struct dummy_ctx *)uvc->opaque;
+
+    if (c->is_streaming) {
+        printf("dummy is streaming already!\n");
+        return -1;
+    }
+
+    if (write(c->wr_fd, &notify, 1) != 1) {
+        printf("Failed writing to notify pipe\n");
+        return -1;
+    }
+
+    if (uvc->on_video_frame) {
+        c->thread = thread_create(dummy_thread, uvc);
+    }
+
+    return 0;
+}
+
+static int uvc_dummy_stop_stream(struct uvc_ctx *uvc)
+{
+    struct dummy_ctx *c = (struct dummy_ctx *)uvc->opaque;
+    char notify = '1';
+
+    if (!c->is_streaming) {
+        printf("dummy stream stopped already!\n");
+        return -1;
+    }
+
+    if (write(c->wr_fd, &notify, 1) != 1) {
+        printf("Failed writing to notify pipe\n");
+        return -1;
+    }
+
+    if (uvc->on_video_frame) {
+        c->is_streaming = false;
+        thread_destroy(c->thread);
+    }
+
+    return 0;
+}
+
+static int uvc_dummy_query_frame(struct uvc_ctx *uvc, struct video_frame *frame)
+{
+    if (uvc_dummy_enqueue(uvc, NULL, 0) != 0) {
+        printf("uvc_dummy_enqueue failed\n");
+        return -1;
+    }
+    if (uvc_dummy_dequeue(uvc, frame) == -1) {
+        printf("uvc_dummy_dequeue failed\n");
+        return -1;
+    }
+    return 0;
+}
+
+static void uvc_dummy_close(struct uvc_ctx *uvc)
+{
+    struct dummy_ctx *c = (struct dummy_ctx *)uvc->opaque;
+    uvc_dummy_stop_stream(uvc);
+    close(c->fd);
+    close(c->epfd);
+    close(c->rd_fd);
+    close(c->wr_fd);
+    free(c);
+}
+
+struct uvc_ops dummy_ops = {
+    .open         = uvc_dummy_open,
+    .close        = uvc_dummy_close,
+    .ioctl        = NULL,
+    .start_stream = uvc_dummy_start_stream,
+    .stop_stream  = uvc_dummy_stop_stream,
+    .query_frame  = uvc_dummy_query_frame,
+};
diff --git a/gear-lib/libuvc/libuvc.c b/gear-lib/libuvc/libuvc.c
index f207a81..4cbbf6d 100644
--- a/gear-lib/libuvc/libuvc.c
+++ b/gear-lib/libuvc/libuvc.c
@@ -28,6 +28,7 @@
 #include <errno.h>
 #include <stdarg.h>
 
+extern struct uvc_ops dummy_ops;
 #if defined (OS_LINUX)
 extern struct uvc_ops v4l2_ops;
 #elif defined (OS_WINDOWS)
@@ -35,15 +36,16 @@ extern struct uvc_ops dshow_ops;
 #endif
 
 static struct uvc_ops *uvc_ops[] = {
+    [UVC_TYPE_DUMMY] = &dummy_ops,
 #if defined (OS_LINUX)
-    &v4l2_ops,
+    [UVC_TYPE_V4L2]  = &v4l2_ops,
 #elif defined (OS_WINDOWS)
-    &dshow_ops,
+    [UVC_TYPE_DSHOW] = &dshow_ops,
 #endif
-    NULL
+    [UVC_TYPE_MAX] = NULL,
 };
 
-struct uvc_ctx *uvc_open(const char *dev, struct uvc_config *conf)
+struct uvc_ctx *uvc_open(enum uvc_type type, const char *dev, struct uvc_config *conf)
 {
     struct uvc_ctx *uvc;
     if (!dev || !conf) {
@@ -55,7 +57,11 @@ struct uvc_ctx *uvc_open(const char *dev, struct uvc_config *conf)
         printf("malloc failed!\n");
         return NULL;
     }
-    uvc->ops = uvc_ops[0];
+    uvc->ops = uvc_ops[type];
+    if (!uvc->ops) {
+        printf("uvc->ops %d is NULL!\n", type);
+        return NULL;
+    }
     uvc->opaque = uvc->ops->open(uvc, dev, conf);
     if (!uvc->opaque) {
         printf("open %s failed!\n", dev);
diff --git a/gear-lib/libuvc/libuvc.h b/gear-lib/libuvc/libuvc.h
index 011f868..bb58b96 100644
--- a/gear-lib/libuvc/libuvc.h
+++ b/gear-lib/libuvc/libuvc.h
@@ -31,12 +31,19 @@
 #include <sys/ioctl.h>
 #endif
 
-#define LIBUVC_VERSION "0.1.0"
+#define LIBUVC_VERSION "0.2.0"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+enum uvc_type {
+    UVC_TYPE_DUMMY = 0,
+    UVC_TYPE_V4L2,
+    UVC_TYPE_DSHOW,
+    UVC_TYPE_MAX,
+};
+
 struct uvc_ctx;
 struct uvc_ops;
 typedef int (video_frame_cb)(struct uvc_ctx *c, struct video_frame *frame);
@@ -78,7 +85,7 @@ struct uvc_ops {
     int (*query_frame)(struct uvc_ctx *c, struct video_frame *frame);
 };
 
-struct uvc_ctx *uvc_open(const char *dev, struct uvc_config *conf);
+struct uvc_ctx *uvc_open(enum uvc_type type, const char *dev, struct uvc_config *conf);
 int uvc_ioctl(struct uvc_ctx *c, unsigned long int cmd, ...);
 void uvc_close(struct uvc_ctx *c);
 
diff --git a/gear-lib/libuvc/test_libuvc.c b/gear-lib/libuvc/test_libuvc.c
index 2900989..e39a798 100644
--- a/gear-lib/libuvc/test_libuvc.c
+++ b/gear-lib/libuvc/test_libuvc.c
@@ -31,7 +31,8 @@
 #define VIDEO_DEV       "/dev/video0"
 #define VIDEO_WIDTH     640
 #define VIDEO_HEIGHT    480
-#define OUTPUT_FILE     "uvc.yuv"
+#define OUTPUT_V4L2     "v4l2.yuv"
+#define OUTPUT_DUMMY    "dummy.yuv"
 
 static struct file *fp;
 
@@ -42,7 +43,7 @@ static int on_frame(struct uvc_ctx *c, struct video_frame *frm)
     return 0;
 }
 
-int main(int argc, char **argv)
+int v4l2_test()
 {
     struct video_frame *frm;
     struct uvc_config conf = {
@@ -50,7 +51,7 @@ int main(int argc, char **argv)
         .height = VIDEO_HEIGHT,
         .fps    = {30, 1},
     };
-    struct uvc_ctx *uvc = uvc_open(VIDEO_DEV, &conf);
+    struct uvc_ctx *uvc = uvc_open(UVC_TYPE_V4L2, VIDEO_DEV, &conf);
     if (!uvc) {
         printf("uvc_open failed!\n");
         return -1;
@@ -64,13 +65,54 @@ int main(int argc, char **argv)
     printf("%s %dx%d@%d/%d fps format:%s\n", VIDEO_DEV, uvc->conf.width, uvc->conf.height,
         uvc->conf.fps.num, uvc->conf.fps.den, pixel_format_to_string(uvc->conf.format));
     //uvc_ioctl(uvc, UVC_GET_CAP, NULL, 0);
-    fp = file_open(OUTPUT_FILE, F_CREATE);
+    fp = file_open(OUTPUT_V4L2, F_CREATE);
     uvc_start_stream(uvc, on_frame);
     sleep(5);
     uvc_stop_stream(uvc);
     file_close(fp);
     video_frame_destroy(frm);
     uvc_close(uvc);
-    printf("write %s fininshed!\n", OUTPUT_FILE);
+    printf("write %s fininshed!\n", OUTPUT_V4L2);
+    return 0;
+}
+
+int dummy_test()
+{
+    struct video_frame *frm;
+    struct uvc_config conf = {
+        .width  = 320,
+        .height = 240,
+        .fps    = {5, 1},
+        .format = PIXEL_FORMAT_YUY2,
+    };
+    struct uvc_ctx *uvc = uvc_open(UVC_TYPE_DUMMY, "sample_yuv422p.yuv", &conf);
+    if (!uvc) {
+        printf("uvc_open failed!\n");
+        return -1;
+    }
+    frm = video_frame_create(uvc->conf.format, uvc->conf.width, uvc->conf.height, VFC_NONE);
+    if (!frm) {
+        printf("video_frame_create failed!\n");
+        uvc_close(uvc);
+        return -1;
+    }
+    printf("%s %dx%d@%d/%d fps format:%s\n", VIDEO_DEV, uvc->conf.width, uvc->conf.height,
+        uvc->conf.fps.num, uvc->conf.fps.den, pixel_format_to_string(uvc->conf.format));
+    fp = file_open(OUTPUT_DUMMY, F_CREATE);
+    uvc_start_stream(uvc, on_frame);
+    sleep(5);
+    uvc_stop_stream(uvc);
+    file_sync(fp);
+    file_close(fp);
+    video_frame_destroy(frm);
+    uvc_close(uvc);
+    printf("write %s fininshed!\n", OUTPUT_DUMMY);
+    return 0;
+}
+
+int main(int argc, char **argv)
+{
+    v4l2_test();
+    dummy_test();
     return 0;
 }
diff --git a/gear-lib/libuvc/v4l2.c b/gear-lib/libuvc/v4l2.c
index 2e74a60..6a3cb3e 100644
--- a/gear-lib/libuvc/v4l2.c
+++ b/gear-lib/libuvc/v4l2.c
@@ -92,7 +92,6 @@ struct v4l2_ctx {
     int req_count;
     bool qbuf_done;
     uint64_t first_ts;
-    uint64_t prev_ts;
     uint64_t frame_id;
     struct v4l2_capability cap;
     uint32_t ctrl_flags;
@@ -463,7 +462,6 @@ retry:
     frame->frame_id = c->frame_id;
     c->frame_id++;
 
-    c->prev_ts = frame->timestamp;
     start = (uint8_t *)c->buf[qbuf.index].iov_base;
 
     if (frame->flag == VFC_NONE) {//frame data ptr
@@ -492,7 +490,6 @@ static int uvc_v4l2_poll_init(struct v4l2_ctx *c)
     }
 
     epev.events = EPOLLIN | EPOLLOUT | EPOLLPRI | EPOLLET | EPOLLERR;
-    epev.data.fd = c->fd;
     epev.data.ptr = (void *)c;
     if (-1 == epoll_ctl(c->epfd, EPOLL_CTL_ADD, c->fd, &epev)) {
         printf("epoll_ctl EPOLL_CTL_ADD failed %d!\n", errno);