DVP Video_transfer

[Chinese]

1 Overview

The function of image transmission is mainly to compress and encode the original data collected by the dvp sensor through the jpeg encode module, and then send the data to the mobile phone by means of WiFi connection. The packet is parsed, and then the encoded video data stream is displayed in real time.

2 Code Path

demo path：./components/demos/media/video/video_transfer/video_transfer.c

3 Client command

The commands support by demo

Command	Param	Description
dvp set_cfg param1 param2 param3	param1:dev_id	the type of using dvp
	param2:image resolution	the resolution output
	param3:frame rate	the frame rate output
video_transfer param1 param2 [param3]	param1:connect method	wifi connecttion type
	param2:ssid	ssid
	param3:ssid_key	key

The macro configuration that the demo runs depends on:

NAME	Description	File	value
CONFIG_JPEG_ENCODE	support hw jpeg encode	middleware\soc\bk7256\bk7256.defconfig	y
CONFIG_CAMERA	suport use dvp camera	middleware\soc\bk7256\bk7256.defconfig	y
CONFIG_USE_APP_DEMO_VIDEO_TRANSSER	support video transfer	middleware\soc\bk7256\bk7256.defconfig	y
CONFIG_NET_WORK_VIDEO_TRANSFER	support wifi transfer	middleware\soc\bk7256\bk7256.defconfig	y
CONFIG_COMPONENTS_P2P	support p2p transfer	middleware\soc\bk7256\bk7256.defconfig	n
CONFIG_CAMERA_USE_I2C1	suport use I2C1	middleware\soc\bk7256\bk7256.defconfig	y

4 Presentation Introduction

The steps performed by the demo are as follows:

1. Prepare the dvp camera, the connection method is shown in Figure 1:

   The camera used in position 1 in the figure is gc0328c, dev_id=3, and supports a resolution of 640*480

1. When only the app image transmission command is executed, the operation is as follows:

2. Send the following commands in sequence:

   dvp set_cfg 3 480 20

   video_transfer -a test 12345678

3. Connect the mobile phone wifi to the route of the test name, the password is: 12345678

4. After the connection is successful, open the image transmission app.

The camera used in position 2 in the above picture is hm1055, dev_id=6, and supports 1280*720 resolution

1. If you use the hm1055 camera to start image transmission, send the following commands in sequence:

   dvp set_cfg 6 720 15

   video_transfer -a test 12345678

2. The mobile phone wifi is connected to the route of the test name, the password is: 12345678

3. After the connection is successful, open the app of the image transmission. The operation of the image transmission app is shown in Figures 2, 3 and 4.

Figure 1. sensor connect evb

Figure 2. WiFi Camera app

Figure 3. WiFi Camera app set

As shown in the figure above, when you want to perform image transmission, after connecting to the ssid set in the image upload command, position 1 will prompt 使用UDP广播指定的IP地址和端口, otherwise the image transmission will not take effect; After seeing prompt 1, click position 2 to enable image transmission. The effect of image transmission is shown in Figure 4.

Figure 4. WiFi Camera effect drawing

5 Detailed configuration and its description

1. Set dvp parameters: dvp set_cfg param1 param2 param3

• param1:0-7, corresponding to the following types of dvp cameras, currently only 3 and 6 are supported.

  PAS6329_DEV 0

  OV_7670_DEV 1

  PAS6375_DEV 2

  GC0328C_DEV 3

  BF_2013_DEV 4

  GC0308C_DEV 5

  HM_1055_DEV 6

  GC_2145_DEV 7

param2:resoultion

GC0328C_DEV：480(640*480)，240(320*240), 272(480*272)

HM_1055_DEV: 720(1280*720)

param3:frame rate

GC0328C_DEV：5、10、20、25

HM_1055_DEV：5、10、15、20

2、wifi connection type

1.video_transfer -a ssid key

• The development board is used as an AP, and the mobile phone is connected to this AP, which is similar to the mobile phone connecting to other wifi devices.

2.video_transfer -s ssid key

• Use the development board as a station to connect to the mobile phone. The mobile phone needs to open the wifi hotspot. At this time, the mobile phone is equivalent to a router.

3.video_transfer -p ssid key

• Use the direct connection method of the mobile phone, similar to the AP, on the mobile phone: WLAN–>Advanced settings–>WLAN direct connection, after searching for the device of the board, click connect.

Note

Note: In the first method, the bandwidth of the board may be insufficient, and the displayed video is not clear enough; in the second method, the effect of image transmission is the best because the bandwidth of the mobile phone is very sufficient; the third method has not yet been implemented.

3. Supports dynamic setting of resolution and frame rate, and does not support setting and replacing dvp devices

• After exiting the video transmission, send the dvp set_cfg param1 param2 param3 command, param1 cannot be changed, but param2 and param3 can be modified.

4、video transfer software process

Figure 5. video transfer function call

5、Calling between video transfer modules

Figure 6. video transfer modules communicate