yarpdataplayer playback slow

[arrenglover]

When playing back the data saved by yarpdataplayer, the output can seem to be slower than the original data. My hypothesis is that it is caused by the yarpdataplayer having a minimum time between when it can send out bottles that is currently 1 or 2 ms. The current zynqGrabber outputs vBottles as fast as it can, often with periods between packets of less than 1 ms. Therefore the yarpdataplayer won't play the dataset in real-time.

This issue won't affect off-line processing, but could give misleading results to measuring algorithm speed or processing capacity.

A solution:

• would be to have a switch to allow the zynqGrabber to send larger bottles at slower rates (which is typically worse for on-line operation).
• an offline processing script that converts a normal saved dataset to one which is compatible with the yarpdataplayer packet sending protocol. Packets withing 1 ms periods would be combined into a single vBottle.
• update the yarpdataplayer itself to allow faster packet sending.

[arrenglover]

we've implemented option 2, in which any recorded dataset needs to be processed before replaying through yarpdataplayer. If in the future we want to update yarpdataplayer to play at sub-millisecond the issue should be opened on yarp.