third-party-cam-requirements.md

Third-Party Camera Requirements for Pupil Capture

Third-party cameras - Pupil Capture supports third-party USB cameras that fulfill the following criteria:

1. UVC compatible (Chapters below refer to this document)
2. Support Video Interface Class Code 0x0E CC_VIDEO (see A.1)
3. Support Video Subclass Code 0x02 SC_VIDEOSTREAMING (see A.2)
4. Support for the UVC_VS_FRAME_MJPEG (0x07) video streaming interface descriptor subtype (A.6)
5. Support UVC_FRAME_FORMAT_COMPRESSED frame format

Access Pupil cameras via libuvc These are the steps that pyuvc uses to access Pupil cameras:

1. Use uvc_init() to create a context
2. Use uvc_get_device_list() to enumerate available devices
3. Use uvc_open() to create a device handle for a given device from step 2
4. Use uvc_get_format_descs() to enumerate available format descriptions
5. Enumerate available frame sizes and rates for format descriptions with the bDescriptorSubtype == UVC_VS_FRAME_MJPEG
6. Get a stream control handle by passing UVC_FRAME_FORMAT_COMPRESSED and a valid frame size/rate combination to uvc_get_stream_ctrl_format_size()
7. Open the stream with vc_stream_open_ctrl()
8. Start the stream with uvc_stream_start() passing 2.0 as bandwidth_factor
9. Use uvc_stream_get_frame() to access frames
10. Use uvc_stream_stop() to stop the stream
11. Use uvc_stream_close() to close the stream
12. Use uvc_close() to close the device handle
13. Use uvc_unref_device() to unrefence the selected device