Get the pts that was before the current byte in the adapter.
When distance
is given, the amount of bytes between the pts and the current position is returned.
The pts is reset to GST_CLOCK_TIME_NONE and the distance is set to 0 when the adapter is first created or when it is cleared. This also means that before the first byte with a pts is removed from the adapter, the pts and distance returned are GST_CLOCK_TIME_NONE and 0 respectively.
this |
a Adapter |
distance |
pointer to location for distance, or |
The previously seen pts. |