- Generated by
1.12.0
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PipeWire 1.5.0
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Absolute time reporting. More...
#include <spa/node/io.h>
Data Fields | |
| uint32_t | flags |
| Clock flags. | |
| uint32_t | id |
| Unique clock id, set by host application. | |
| uint64_t | nsec |
| Time in nanoseconds against monotonic clock (CLOCK_MONOTONIC). | |
| struct spa_fraction | rate |
| Rate for position/duration/delay/xrun. | |
| uint64_t | position |
| Current position, in samples @ rate. | |
| uint64_t | duration |
| Duration of current cycle, in samples @ rate. | |
| int64_t | delay |
| Delay between position and hardware, in samples @ rate. | |
| double | rate_diff |
| Rate difference between clock and monotonic time, as a ratio of clock speeds. | |
| uint64_t | next_nsec |
| Estimated next wakeup time in nanoseconds. | |
| struct spa_fraction | target_rate |
| Target rate of next cycle. | |
| uint64_t | target_duration |
| Target duration of next cycle. | |
| uint32_t | target_seq |
| Seq counter. | |
| uint32_t | cycle |
| incremented each time the graph is started | |
| uint64_t | xrun |
| Estimated accumulated xrun duration. | |
Absolute time reporting.
Nodes that can report clocking information will receive this io block. The application sets the id. This is usually set as part of the position information but can also be set separately.
The clock counts the elapsed time according to the clock provider since the provider was last started.
Driver nodes are supposed to update the contents of SPA_IO_Clock before signaling the start of a graph cycle. These updated clock values become visible to other nodes in SPA_IO_Position. Non-driver nodes do not need to update the contents of their SPA_IO_Clock. Also see Driver architecture and workflow for further details.
The host generally gives each node a separate spa_io_clock in SPA_IO_Clock, so that updates made by the driver are not visible in the contents of SPA_IO_Clock of other nodes. Instead, SPA_IO_Position is used to look up the current graph time.
A node is a driver when spa_io_clock::id and the ID in spa_io_position::clock in SPA_IO_Position are the same.
The flags are set by the graph driver at the start of each cycle.
| uint32_t spa_io_clock::flags |
Clock flags.
| uint32_t spa_io_clock::id |
Unique clock id, set by host application.
| uint64_t spa_io_clock::nsec |
Time in nanoseconds against monotonic clock (CLOCK_MONOTONIC).
This fields reflects a real time instant in the past, when the current cycle started. The value may have jitter.
| struct spa_fraction spa_io_clock::rate |
Rate for position/duration/delay/xrun.
| uint64_t spa_io_clock::position |
Current position, in samples @ rate.
| uint64_t spa_io_clock::duration |
Duration of current cycle, in samples @ rate.
| int64_t spa_io_clock::delay |
Delay between position and hardware, in samples @ rate.
| double spa_io_clock::rate_diff |
Rate difference between clock and monotonic time, as a ratio of clock speeds.
A value higher than 1.0 means that the driver's internal clock is faster than the monotonic clock (by that factor), and vice versa.
| uint64_t spa_io_clock::next_nsec |
Estimated next wakeup time in nanoseconds.
This time is a logical start time of the next cycle, and is not necessarily in the future.
| struct spa_fraction spa_io_clock::target_rate |
Target rate of next cycle.
| uint64_t spa_io_clock::target_duration |
Target duration of next cycle.
| uint32_t spa_io_clock::target_seq |
Seq counter.
must be equal at start and end of read and lower bit must be 0
| uint32_t spa_io_clock::cycle |
incremented each time the graph is started
| uint64_t spa_io_clock::xrun |
Estimated accumulated xrun duration.
1.12.0