.. | ||
main | ||
CMakeLists.txt | ||
player.py | ||
README.md | ||
sdkconfig.ci | ||
sdkconfig.ci.custom_format | ||
sdkconfig.ci.stream | ||
sdkconfig.defaults | ||
sdkconfig.defaults.esp32s2 | ||
sdkconfig.defaults.esp32s3 |
Supported Targets | ESP32-P4 | ESP32-S2 | ESP32-S3 |
---|
USB Camera Example
Overview
This example demonstrates how to:
- Capture video from a USB camera using the
libuvc
library. - Stream the video over WiFi by hosting a TCP server.
The example enumerates a connected USB camera, negotiates a selected resolution along with an associated FPS
, then starts capturing video. The frame_callback
function is then invoked after receiving each frame. Users can process the received frames according to their needs.
Optionally, the captured video can be visualized on a PC with help of the player.py
script provided in this example. After setting the Example Configuration->Enable streaming
option in menuconfig, the example will create a TCP server upon startup, and waits until player.py
connects to the server. Once a connection is established, the example streams each received frame to the PC for visualization. The network connection can be configured in menuconfig via Example Connection Configuration
.
Notice that libuvc
selects highest possible dwMaxPayloadTransferSize
by default. As a result, this example will manually overwrite this value to 512 bytes (the maximum packet size supported by ESP32-S2/S3).
(See the README.md file in the upper level 'examples' directory for more information about examples.)
How to Use Example
Hardware Required
- ESP with USB peripheral and external PSRAM
- Exposed USB host connector
- USB camera
Running this example on an ESP module without external PSRAM will fail on initialization. Please select your PSRAM configuration in menuconfig Component config->ESP PSRAM
. If you manually disable PSRAM, the required framebuffers might not fit into DRAM (especially on ESP32-S2).
Configure the project
Following configuration is needed for streaming video:
Open the project configuration menu (idf.py menuconfig
).
In the Example Connection Configuration
menu:
- Set the Wi-Fi configuration.
- Set
WiFi SSID
. - Set
WiFi Password
.
- Set
In the Example Configuration
menu:
-
Set the Example configuration
Enable streaming
-
Select one of UVC Protocol Mode
Auto
Custom
Optional: If you need, change the other options according to your requirements.
Additionally, the player.py
python script makes use of the opencv-python
and numpy
packages which are not included in the idf-env
environment by default. Run following command to install those packages:
pip install opencv-python numpy
UVC Protocol Mode: Auto
When the protocol mode is set to Auto, the example will make three attempts to negotiate the protocol with following parameters:
- Attempt: 640x480, 15 FPS, MJPEG
- Attempt: 320x240, 30 FPS, MJPEG
- Attempt: 320x240, first available FPS, MJPEG
If all three attempts result in an error, the example displays the error message and suggests to try another USB UVC Device.
UVC Protocol Mode: Custom
When the protocol mode set to Custom, the example tries to negotiate the protocol using user provided values for the following parameters: Attempts, Width, Height, FPS, and Frame Coding format. After all attempts result in an error, the example displays the error message and suggests to try another USB UVC device.
Build and Flash
Build the project and flash it to the board, then run the monitor tool to view the serial output:
Run idf.py set-target esp32xx
to set target chip.
Run idf.py -p PORT flash monitor
to build, flash and monitor the project.
(To exit the serial monitor, type Ctrl-]
.)
See the Getting Started Guide for all the steps to configure and use the ESP-IDF to build projects.
Known limitations
Having only a Full Speed USB peripheral and hardware limited MPS (maximum packet size) to 512 bytes, the ESP32-S2/S3 is capable of reading data at approximately 0.5 MB/s. When connected to Full Speed USB host, cameras normally provide resolution no larger than 640x480 pixels. The following two formats are the most commonly supported at Full Speed (both encoded in MJPEG):
- 320x240 30 FPS
- 640x480 15 FPS
Tested cameras
- Logitech C980
- Logitech C270
- CANYON CNE-CWC2
Example Output
...
I (1186) example: Waiting for USB UVC device connection ...
I (1606) example: Device found
DEVICE CONFIGURATION (0c45:6340/ S) ---
Status: idle
VideoControl:
bcdUVC: 0x0100
VideoStreaming(1):
bEndpointAddress: 129
Formats:
MJPEGFormat(1)
bits per pixel: 0
GUID: 4d4a5047000000000000000000000000 (MJPG)
default frame: 1
aspect ratio: 0x0
interlace flags: 00
copy protect: 00
FrameDescriptor(1)
capabilities: 00
size: 640x480
bit rate: 24576000-147456000
max frame size: 614400
default interval: 1/30
interval[0]: 1/30
interval[1]: 1/25
interval[2]: 1/20
interval[3]: 1/15
interval[4]: 1/10
interval[5]: 1/5
FrameDescriptor(2)
capabilities: 00
size: 352x288
bit rate: 8110080-48660480
max frame size: 202752
default interval: 1/30
interval[0]: 1/30
interval[1]: 1/25
interval[2]: 1/20
interval[3]: 1/15
interval[4]: 1/10
interval[5]: 1/5
FrameDescriptor(3)
capabilities: 00
size: 320x240
bit rate: 6144000-36864000
max frame size: 153600
default interval: 1/30
interval[0]: 1/30
interval[1]: 1/25
interval[2]: 1/20
interval[3]: 1/15
interval[4]: 1/10
interval[5]: 1/5
FrameDescriptor(4)
capabilities: 00
size: 176x144
bit rate: 2027520-12165120
max frame size: 50688
default interval: 1/30
interval[0]: 1/30
interval[1]: 1/25
interval[2]: 1/20
interval[3]: 1/15
interval[4]: 1/10
interval[5]: 1/5
FrameDescriptor(5)
capabilities: 00
size: 160x120
bit rate: 1536000-9216000
max frame size: 38400
default interval: 1/30
interval[0]: 1/30
interval[1]: 1/25
interval[2]: 1/20
interval[3]: 1/15
interval[4]: 1/10
interval[5]: 1/5
StillFrameDescriptor
bEndPointAddress: 00
wWidth(1) = 640
wHeight(1) = 480
wWidth(2) = 352
wHeight(2) = 288
wWidth(3) = 320
wHeight(3) = 240
wWidth(4) = 176
wHeight(4) = 144
wWidth(5) = 160
wHeight(5) = 120
END DEVICE CONFIGURATION
I (1796) example: Negotiate streaming profile 640x480, fps 15 ...
I (1816) example: Negotiation complete.
bmHint: 0001
bFormatIndex: 1
bFrameIndex: 1
dwFrameInterval: 666666
wKeyFrameRate: 0
wPFrameRate: 0
wCompQuality: 0
wCompWindowSize: 0
wDelay: 23469
dwMaxVideoFrameSize: 614400
dwMaxPayloadTransferSize: 512
bInterfaceNumber: 1
I (1836) example: Streaming...
I (4016) example: fps: 10, bytes per second: 69920
...
I (44916) example: fps: 9, bytes per second: 62928
E (45626) USBH: Device 1 gone
I (45636) example: Done streaming.