So the IAB's announced a new standard for video ads and members agree to become compliant.
The guidelines are posted online, but basic rules are:

• In-stream commercials may be up to thirty seconds long for pre and mid-roll commercials.
• Publishers may offer custom lengths for post roll. A recommended minimum of 200 Kbps for encoded bit rates.
• The minimum player controls present should be Start/Stop and Volume On/Off and Softer/Louder Control.
• Other recommended and acceptable buttons include Fast Forward/Rewind, Pause, Zoom and other Interactive buttons as needed.
• All buttons should be enabled throughout the play, with the exception of Fast Forward.