[Mobile Replay]: Player flickering on Safari

[c298lee]

When watching replays on Safari, the video seems to flicker between clips. This is happening because the video clips itself have around a second in the beginning where it's empty. On Chrome, this is not an issue because the empty part of the video is never played, so if it's a 6 second clip and the first second is empty, the first second is skipped and only 5 seconds of that clip is played. However on Safari, the entire 6 second clip will be played, so it results in the video itself looking like it's flickering.

I've noticed this issue on all replays in the brustolin org but not the sentry-sdks org.
Example replay: https://brustolin.sentry.io/replays/c817d3d7daac4440a2788fd0cbf521b0
The third video clip in this replay and onwards contains around a second where the clip is just empty:

90_5579037_c817d3d7daac4440a2788fd0cbf521b0_2.video.mov

Note how Github doesn't let you play the empty first second of the clip. You'll be able to see the empty part if you download and play with Quicktime Player

We should fix this by ensuring that we don't have any empty parts in the video clips. However, this might take a while to fix so in the meantime, we will try to fix this in the player.

[bruno-garcia]

We should fix this by ensuring that we don't have any empty parts in the video clips.

We should fix the player on Safari regardless of how the video is make. The player should be lenient (that's why on GitHub and on Chrome this works) because it's hard to guarantee videos are made properly for reasons