NvSciStream Multicast 4 consumers lead to error


We update DriveOS to 5.2.6 vesion and we want to use NvSciStream multicast to build our image process pipeline.
When we test nvscistream_multicast_sample in SDK and start 4 consumers, got err below:

Module_id 24 Severity 2 :  Failed to set PreFence as the Max preFences are set already

It seems multicast mode has some limitation? Could you please give me some suggestions if we have more than 4 consumers in different process?

Looking forward your reply. Thanks !

Dear @yangyanlin,
Could you share the used command?

Hi, Nvidia. Thanks for reply.

My apology. I’ve modify the sample code lead to this error.

But I wanna ask the same question. It seems multicast mode has some limitation:

    // we necessarily need a channel name
    // and only for either producer or consumer
    if (isConsumerChannel == false &&
        (nConsumer < 1|| nConsumer > 4)) {
        // wrong the number of consumer.

If I delete the code upon, this will lead to this error

channel_producer.cpp (66), createBlocks: NvSci error 100

Is this means multicast has 4 consumers at most ?
If we really need more than 4 consumers, is there any other way to solve the problem ?

Dear @yangyanlin,
We support upto 4 consumers and can be seen even application parameters that allowed range is 1-4 for n(https://docs.nvidia.com/drive/drive-os-

Appreciate your reply.