Day 90 of 100DaysOfSpec, the video element, contd.

I am reading and taking notes on the HTML specifications for 100 days as part of #The100DayProject. Read the initial intent/backstory. I am a Microsoft employee but all opinions, comments, etc on this site are my own. I do not speak on behalf of my employer, and thus no comments should be taken as representative of Microsoft's official opinion of the spec. Subsections not listed below were read without comment.

Currently reading in 4.7.6 The video element

UAs = user agents = browsers, etc.

These notes extend the previous day’s post.

• If the UA can’t fetch a poster image by the URL stored in the poster attribute on video, there is no poster image. I assume the first frame of the video just gets used for preview?
• The video’s format has an impact on which frame is associated with a playback position.
• In UA’s implementation, the audio has to be synced up with video, “at the element's effective media volume”.
• The UA can choose to give visual cues on the video element as to the element’s status.
• If the UA can’t render the video, it can link out to another method of playback or the raw video data.
• Unless overridden by styling, the UA is beholden to rendering video content at its original aspect ratio, centered in the playback area, as large as possible without getting clipped in one direction or another.
• Intrinsic height and width of the playback area are determined from the poster frame, or the video resource as a backup, if available. Default “object size” is 300px x 150px (CSS pixels, since a device’s “effective” pixels is not a fixed value).

Didn’t get too far in today’s reading because somedays you just. aren’t. feelin’ it.