groupwatch_sync

Automatically start and get back in sync with a group watch by adjusting playback speed.

Installation

Place groupwatch_sync.lua in your mpv scripts folder.

Usage

Set the group watch position at the beginning of the viewing.
Press k at any time to sync up with the group.

Default key bindings:

• k to sync by adjusting playback speed
• Ctrl+k to sync by jumping to group watch position
• Shift+k to set group watch position to the current playback time
• Ctrl+Shift+k to set a start timestamp from local time

Behavior

All syncing behavior is implicit based on the current position relative to the group, and the actions taken by the user during syncing.
This behavior is what I think is most useful, but may be confusing without first reading this.
If something doesn't behave as described, please file an issue.

You can prepend group position to osd messages with show_group_pos=yes.

Setting the group watch position (groupwatch_start, groupwatch_start_here):

• Playback is unpaused.

Setting an absolute group start timestamp (groupwatch_set_time):

• Existing start time is unset.
• If start timestamp is in the past, set group position. Playback is not unpaused.
• If start timestamp is in the future, defer setting group position to when the group starts.

Pressing the groupwatch_sync key:

• With no group position set: does nothing
• With group position set: initiate syncing if not already synced, see below

If behind:

• Playback is unpaused and speed is increased every second by speed_increase until max_speed is reached or group position is reached.
• Pausing, unpausing and seeking will not interrupt syncing, unless seeking past the group position.

If ahead:

• allow_slowdowns=no (default): Playback is paused until group position reaches playback position.
• allow_slowdowns=yes: Playback is unpaused and speed is decreased every second by speed_decrease until min_speed is reached or group position reaches playback position.
• Unpausing and seeking will interrupt syncing.
• Explicitly cancelling the current sync will unpause playback.

In both cases:

• subs_reset_speed=yes: Playback speed goes back to 1 when a subtitle is displayed then resumes speed increase/decrease.
• Pressing the groupwatch_sync key again will cancel the current sync ("explicitly cancelling" refers to this).

If synced:

• Playback is unpaused

Pressing the groupwatch_jump key:

• Any ongoing syncs are canceled
• Playback position is set to group position
• Playback is unpaused