[video_player_avfoundation] fix playback speed resetting #7657
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misos1
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...on/darwin/video_player_avfoundation/Sources/video_player_avfoundation/FVPVideoPlayerPlugin.m
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Sorry, this fell off my review queue. @hellohuanlin can you take a look as well? |
| // status changes to AVPlayerItemStatusReadyToPlay. | ||
| float speed = _playbackSpeed.floatValue; | ||
| if (speed > 2.0 && !_player.currentItem.canPlayFastForward) { | ||
| if (_player.currentItem.status != AVPlayerItemStatusReadyToPlay) { |
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what if we call updateRate with speed < 2.0? should we also check the status here? Should this status check be moved to top of the fucntion?
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That check is to confirm whether canPlay... returned false because it cannot be played at speed>2 instead of because status was not ready to play. There is no need to check status for speeds for which is not needed canPlay.... But as I am thinking about it now maybe status should be fetched before canPlay... to avoid a false positive when status becomes ready right after canPlay....
| @@ -397,7 +399,15 @@ - (void)updatePlayingState { | |||
| return; | |||
| } | |||
| if (_isPlaying) { | |||
| [_player play]; | |||
| // Calling play is the same as setting the rate to 1.0 (or to defaultRate depending on ios | |||
| // be played at these speeds, updatePlayingState will be called again when | ||
| // status changes to AVPlayerItemStatusReadyToPlay. | ||
| float speed = _playbackSpeed.floatValue; | ||
| bool readyToPlay = _player.currentItem.status == AVPlayerItemStatusReadyToPlay; |
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BOOL since this is Obj-C code.
| @@ -82,6 +82,8 @@ @interface FVPVideoPlayer () | |||
| @property(nonatomic) CGAffineTransform preferredTransform; | |||
| @property(nonatomic, readonly) BOOL disposed; | |||
| @property(nonatomic, readonly) BOOL isPlaying; | |||
| // Playback speed when video is playing. | |||
| @property(nonatomic, readonly) NSNumber *playbackSpeed; | |||
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It would be more accurate to call this targetPlaybackSpeed (and document it as something like "The target playback speed requested by the plugin client."), since it's entirely possible for the playback speed to not be this value while playing.
| @@ -406,6 +416,30 @@ - (void)updatePlayingState { | |||
| _displayLink.running = _isPlaying || self.waitingForFrame; | |||
| } | |||
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| - (void)updateRate { | |||
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This needs a declaration comment, per the style guide.
Calling play is the same as setting the rate to 1.0 (or to
defaultRatedepending on ios version, documentation in this first link is clearly not updated because it does not mentiondefaultRate):https://developer.apple.com/documentation/avfoundation/avplayer/1386726-play?language=objc
https://developer.apple.com/documentation/avfoundation/avplayer/3929373-defaultrate?language=objc
The second link contains a note about not starting playback by setting the rate to 1.0. I assume this is because of the introduction of
defaultRate(which can be different than 1.0) and not becauseplaymay do something more than just settingrateas that wording is explicit about setting rate to 1.0, it says nothing about any other value.This is also why flutter/plugins#4331 did not work well. It was setting
rateto 1.0 (throughplay) then immediately to the value set bysetPlaybackSpeed. One of them or both caused change toplaybackLikelyToKeepUpwhich triggeredobserveValueForKeyPathwithplaybackLikelyToKeepUpContextwhich in turn called againupdatePlayingStatewhere wasrateagain changed first to 1.0 then to another value and so on. In this PR the rate is changed only once and then to the same value, seems whenrateis assigned but not really changed it does not trigger anything.In issues below
seekTocan triggerplaybackLikelyToKeepUpchange which will callupdatePlayingStateand resetrateto 1.0 throughplay. When the speed is set in dart before initialization then the dart side will set it right after callingplaybut even some time after initialization there is still a flood of events callingupdatePlayingStateand it is likely that some of them will call it aftersetPlaybackSpeed. Actually even whensetPlaybackSpeedwas not called on dart side it (dart side) will always change speed after play to 1.0 so it ignores this newdefaultRatefeature.Pre-launch Checklist
dart format.)[shared_preferences]pubspec.yamlwith an appropriate new version according to the pub versioning philosophy, or this PR is exempt from version changes.CHANGELOG.mdto add a description of the change, following repository CHANGELOG style, or this PR is exempt from CHANGELOG changes.///).If you need help, consider asking for advice on the #hackers-new channel on Discord.