DIVP Q&A

Q：What is the use of creating DIVP with ChnId=6?

When the DIVP used by the current branch is initialized, chn6 is created by default, which is used for Snapshot of VDEC (such as the introduction of Snapshot Realization). If the function is disabled, the buffer will not be occupied.

Snapshot Realization

As shown above:

  1. APP sets the width and height of VDEC Port0 to be the same as DISP.

  2. In normal playback, the frame obtained from port 0 of the stream data frame is used for FW decoding. Then it is transmitted by SYS to DISP for output.

  3. Create a channel with DIVP chanelID=6 at the moment of taking the picture, and create and open VDEC Port1.

  4. The frame of the code stream data frame obtained from port 1 (apply to MI SYS with the width and height of the original code stream) is used for FW decoding.

  5. There are two types of processing for the data frame decoded from port1. One is for snapshot realization function, and the other is packed from MI DIVP to VDEC port0 first and then to MI DISP. As shown below

  6. The Input Port and Output Port config of DIVP chanelID=6 is not set by APP. Input Port is automatically configured by DIVP from the Frame Buffer information of VDEC Output Port 1; Output Port is automatically configured by DIVP from the Frame Buffer information of VDEC Output Port 0.