Takashi Sakamoto wrote:
Currently, in duplex streams with synchronization mode, this module just pass 'presentation timestamp' from in-packets to out-packets. This is enough to handle actual device but logically the timestamp should include 'transfer delay' and 'processing time'. This means the timestamp in out-packet should be at future.
To be simple, this commit add only 'transfer delay'.
*syt += (s->transfer_delay / TICKS_PER_CYCLE) << 12;*syt += s->transfer_delay % TICKS_PER_CYCLE;*syt &= CIP_SYT_MASK;
The transfer delay is the offset between the frame in which the packet is transmitted and the intended presentation time. This delay was already added by the device when it sent the input packets, so we don't need to send it again.
The frame in which the out-packet will be sent is QUEUE_LENGTH frames later than that of the in-packet, so we need to adjust the SYT by that amount. (However, 48 % 16 == 0.)
Regards, Clemens