This commit brings significant improvements to the video cache feature.
Previously, the cache would merely download the video when requested, in
parallel with AVPlayer which also triggers a video download.
The video cache has been updated to tap into the AVPlayer loading
process, removing the download duplication.
Here is how that works:
1. The player requests an AVAsset from the cache.
2. The cache will return a cached asset if possible, or a special AVURLAsset with a custom `AVAssetResourceLoaderDelegate`.
3. The video player will start sending loading requests to this loader delegate.
4. Upon receiving the first request, the loader delegate begins to download the video data on the background.
5. Upon receiving these requests, the loader delegate will also record the requests, so that it can serve them once possible
6. The loader delegate keeps track of all video data chunks as it receives them from the download task, through the `URLSessionDataDelegate` and `URLSessionTaskDelegate` protocols
7. As it receives data, it checks all pending loading requests from the AVPlayer, and fulfills them as soon as possible
8. If the download fails (e.g. timeout errors, loss of connection), it attempts to restart the download.
9. If the download succeeds, it saves the video to the cache on disk.
Closes: https://github.com/damus-io/damus/issues/1717
Changelog-Added: Add video cache to save network bandwidth
Signed-off-by: Daniel D’Aquino <daniel@daquino.me>
Link: 20240411004129.84436-4-daniel@daquino.me
Signed-off-by: William Casarin <jb55@jb55.com>
This commit implements a simple but functional video cache.
It works by providing a method called `maybe_cached_url`, where a video
URL can be passed in, and this method will either return the URL of a
cached version of this video if available, or the original URL if not. It also
downloads new video URLs on the background into the cache folder for use
next time.
Functional testing
-------------------
PASS
Device: iPhone 15 simulator
iOS: 17.4
Damus: Approximately this commit
Setup:
- Debug connection
- Expiry time locally changed to 5 minutes
Steps:
1. Basic functionality
1. Go to a profile with lots of videos
2. Scroll down
3. Filter logs to only logs that start with "Loading video with URL"
4. Check that most videos are being loaded from external URLs. PASS
5. Now restart the app and go to that same profile
6. Scroll down and watch logs. Videos should now be loaded with an internal file URL. PASS
2. Automatic cache refresh after expiry
1. Go to the video-heavy profile, make note of the external URL.
2. Go to a different screen and then come back to that video. Make sure the file was loaded from cache. PASS
3. Now go to a different screen and wait 5 minutes.
4. Come back to the same video. It should be loaded from the external URL. PASS
3. "Clear cache" button functionality
1. Go to the video-heavy profile, make note of the external URL.
2. Go to a different screen and then come back to that video. Make sure the file was loaded from cache. PASS
3. Now quit the app (to ensure file is not in use when trying to delete it)
4. Clear cache in settings
5. Go back to the same video. It should now be loaded from the external URL. PASS
Performance testing
-----------------------
Device: iPhone 13 mini
iOS: 17.3.1
Damus: This commit
Baseline: 87de88861adb3b41d73998452e7c876ab5ee06bf
Setup:
- Debug connection
- Expiry time locally changed to 5 minutes
- Running on Profile mode, with XCode Instruments
Steps:
1. Start recording network activity with XCode Instruments
2. Go to a video-heavy profile (e.g. Julian Figueroa)
3. Scroll down to a specific video (Make sure to scroll through at least 5 videos)
4. Stop recording and measure the "Bytes In" from "Network connections"
5. Repeat this for all test configurations
Results:
- Baseline (No caching support): 26.74 MiB
- This commit (First run, cleared cache): 40.52 MiB
- This commit (Second run, cache filled with videos): 8.13 MiB
Automated test coverage
------------------------
PASS
Device: iPhone 15 simulator
iOS: 17.4
Damus: This commit
Coverage:
- Ran new automated tests multiple times. PASS 3/3 times
- Ran all other automated tests. PASS
Signed-off-by: Daniel D’Aquino <daniel@daquino.me>
Link: 20240411004129.84436-3-daniel@daquino.me
Signed-off-by: William Casarin <jb55@jb55.com>
The DamusAVPlayerView (along with other classes) play or pause based on
their Y position relative to the user's viewport. This is ideal for a
vertical feed of notes.
However, this does not work well on a horizontal carousel, such as when
viewing videos on the full-screen carousel and swiping left/right.
This commit adds a new tracking method based on onAppear/onDisappear
triggers from a lazy stack (which only loads when it is visible), and
applied it to videos shown on a full screen carousel, so that videos
pause when we swipe away from the video.
Incidentally, this also fixes an issue I was seeing where a full screen
video would disappear as soon as I rotated the phone to landscape mode.
Testing
--------
Device: iPhone 13 Mini
iOS: 17.3.1
Damus: This version
Coverage:
1. Scroll down a feed full of videos and make sure videos still autoplay when passing through them. PASS
2. Check videos on the feed are muted by default. PASS
3. Check mute button on the video still works. PASS
4. Check clicking on the video brings it to a full-screen carousel view. PASS
5. Check that videos play unmuted by default on full-screen carousel view. PASS
6. Check that all playback controls work on the full-screen carousel view. PASS
7. Check that clicking outside the video shows/hides the carousel overlays. PASS
8. Check that a summary of the note shows up. PASS
9. Check that clicking on that note takes the user to the thread view. PASS
10. Check that changing phone orientation between portrait and landscape on both full-screen carousel AND full-screen video modes will work as expected. PASS
11. Check close button on full-screen carousel works. PASS
12. Check that swiping the video away exits full-screen carousel. PASS
13. Check that full-screen carousel works with images. PASS
14. Check that a carousel with multiple images/videos can be swiped left and right. PASS
15. Check that swiping away from a video on a full-screen carousel will pause it. PASS
16. Check that clicking on an unmuted video on the feed won't cause double-audio issues. PASS
17. Check that full-screen carousel view looks good on both dark and light modes. PASS
Closes: https://github.com/damus-io/damus/issues/1530
Signed-off-by: Daniel D’Aquino <daniel@daquino.me>
Link: 20240318222048.14226-6-daniel@daquino.me
Signed-off-by: William Casarin <jb55@jb55.com>
This commit includes several UX changes to give users better control
over video playback. It also, by design, work arounds a SwiftUI quirk*
Here are the changes to the UX:
1. Videos on the feed only have a mute/unmute button
2. When the user clicks on the video, they are taken to a full screen carousel view (similar to when you click on an image)
3. The full-screen carousel view shows all video playback controls (through a specific SwiftUI hack)
4. If the carousel has multiple videos/images, the user can swipe between them normally as expected
Other UI changes that were made:
- The full screen carousel now uses dark mode (black background, white close button)
* The SwiftUI quirk is that when video views are placed within a TabView with ".page" tab view style, the tabview consumes most of the user gestures, making the video playback controls unusable.
Changelog-Changed: Improve UX around video playback
Signed-off-by: Daniel D’Aquino <daniel@daquino.me>
Link: 20240318222048.14226-3-daniel@daquino.me
Signed-off-by: William Casarin <jb55@jb55.com>
