Action Details
Requirements and how-to articles for Twitch's action:

Requirements
You need this to get it done:

Video (Third-Party Served) (VAST)
Video file requirements: (see previous video file specs)
Recommended video transcodes:
1920 x 1080 - 5,500 Kbps (required)
1280 x 720 - 3,100 kbps (required)
1024 x 576 - 1,750 kbps
888 x 500 - 1,316 kbps
854 x 480 - 1,200 kbps (required)
720 x 406 - 866 kbps
640 x 360 - 550 kbps (required)
480 x 270 - 384 kbps
320 x 180 - 200 kbps
284 x 160 - 180 kbps (required)
VAST 3.0 only.
SSL Compliance
Twitch requires all ads and third party vendors to be SSL compliant. All components of video and display ads including creative and tracking must be able to serve via SSL (https).
Video (Ad Server Hosted)
Maximum video length: 30 seconds (unskippable) (can have up to 60 seconds in mid-roll with extra charge)
Minimum resolution: 1280 x 720 (1920 x 1080 recommended)
Minimum bitrate: 1000 Kbps
Peak Audio: -9dB
Video file format: .mp4 (h.264 encoded)
Maximum FPS (frames per second): 30
Third Party Tracking Events (Video)
Impressions, clicks, quartiles, completes.
Requirements missing or found errors? Report

How-To Articles
A list of useful links for you:

0
Twitch Advertising - Mobile Video
Twitch help section covering the Mobile Video ad products.
Official
Link missing here or found errors? Improve How-Tos