| Supported Targets | 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`. 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: ```bash 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: 1. Attempt: 640x480, 15 FPS, MJPEG 2. Attempt: 320x240, 30 FPS, MJPEG 3. 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. ```