Audio-Video Attainability
[Author: Bill Fischer]
Overview
Captions and audio descriptions are designed to take advantage of the built-in capabilities of video players. The best video players include features such as: resolution options, keyboard support, changing the speed of the video, setting how captions are displayed (e.g., text style, text size, colors, and position of the captions), and interactive transcripts. Here are two useful resources that contain detailed information about accessible video players.
Built-in settings for the YouTube player (external link). These incude many accessibility features like caption settings, and video speed, as well as screen reader and keyboard compatibility.
Internet Bandwidth Challenges
Playing high resolution videos over the internet requires a fast internet connection. Solutions for improving the attainability for persons without broadband internet access include:
Providing a downloadable copy that persons can access when they have broadband access. Once downloaded, they can watch the video anywhere without requiring any internet connection.
Use an online video service, like YouTube, that allows viewers to adjust the video quality to match their bandwidth. This changes the pixel dimensions. The lowest dimension is typically 240p, standard high definition is 1080p, and the highest definition is 4K.
Video Export Settings
It's important for videos to be compatible with modern web browsers. The most common video export settings for web media, whether uploading to YouTube, Google Drive, or your own server are:
Video
Video Format: H.264 (.mp4)
Video Pixel Dimensions: 1920 x1080 Full HD
Video Target bitrate: 8 Mbps
Video Streaming: on
Audio Codec: AAC
Audio Sample Rate: 48 Khz
Audio Channels: Stereo
Audio Bitrate: 128
Audio Only
Format and Codec: AAC
Sample rate: 48 KHz
Audio channels: Stereo