最終更新:2014-09-30 (火) 21:58:25 (2185d)  

bStillCaptureMethod
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0x00None
0x01Medhod 1
0x02Medhod 2
0x03Medhod 3

Method 1

  • The host software will extract the next available video frame from the active video pipe in the relevant VideoStreaming interface upon receiving the hardware trigger event.
  • The hardware does not interrupt or alter the video stream in this case.
  • For this method, the still image frame is always the same size as the video frames being streamed.

Method 2

  • If the device supports higher-quality still images, it has the option of streaming still-image-specific packets across the active video pipe.
  • In this case, the host software will temporarily suspend video streaming, select the optimal bandwidth alternate setting based on the still probe/commit negotiation (subject to bandwidth availability), send a VS_STILL_IMAGE_TRIGGER_CONTROL Set request with the "Transmit still image" option, and prepare to receive the still image data.
  • The device transmits the still image data marked as such in the payload header. Once the complete still image is received, the host software will then revert back to the original alternate setting, and resume video streaming.

Method 3

  • This method enables the capture of higher-quality still images from a dedicated bulk still image pipe.
  • By doing so, the active streams would continue uninterrupted.