[aravis] understanding command events

  • From: Ran Shalit <ranshalit@xxxxxxxxx>
  • To: aravis@xxxxxxxxxxxxx
  • Date: Sun, 25 Feb 2018 10:53:19 +0200

Hello,

I am new with aravis.

I see it lists commands/ack in packet-gvcp.c:


/*
Command and acknowledge IDs
*/

#define GVCP_DISCOVERY_CMD (0x0002)
....
#define GVCP_EVENTDATA_ACK (0x00C3)
...

But searching these numbers in standard genTL, genCP , I didn't found
0xc3 in standard, instead I find 0xc00 defined as event command in
standard.

I did found in aruvcp.h in code:

typedef enum {
ARV_UVCP_COMMAND_READ_MEMORY_CMD = 0x0800,
...
ARV_UVCP_COMMAND_EVENT_CMD = 0x0c00
} ArvUvcpCommand;


Yet, I don't see that aravis use ARV_UVCP_COMMAND_EVENT_CMD , but
instead use the 0xc3 define.

I would please like to ask:
1. What is the meaning of 0xc3, and why I can't find it in standard ?
2. How does events are being recieved in host ? Does host required to
poll the events from device ? if yes - in which rate ?

Thank you,
ranran
I

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