Seeking Within Video

HTTP Progressive Download supports seeking within H.264 encoded videos (i.e., MP4, F4V, and MOV). Clients may seek to a particular position in the video, regardless of whether the video has already been cached by the user agentRefers to software that acts on behalf of a user. For example, a web browser (e.g., FireFox, Chrome, and Internet Explorer) is a user agent. A web browser will make HTTP/HTTPS requests based on user actions (e.g., requesting a web site or clicking a link). that requested it. Additionally, it allows you to programmatically start and/or end a video at a particular point in time.

Key information:

Defining Seek Parameters (Media Player)

HTTP Progressive Download supports the following seek parameters:

Rename the above parameters to match the name of your player's native parameter via Rules Engine's H.264 Support Video Seek Params feature.

Both of the above parameters are optional. However, the seek end parameter (i.e., ec_end) requires the seek start parameter (i.e., ec_seek).

Seek Start Parameter

A video player may be implemented with a scrubber bar (aka seek bar). A user can jump to a particular position in the video by clicking on the desired position in the scrubber bar.

Setting up this functionality requires either of the following:

The "ec_seek" parameter is unnecessary when using JW Player 6.

Once you have configured your video player to use the "ec_seek" parameter, a user can jump ahead to portions of the video that have not yet been downloaded to his/her computer. This can be performed using a player-specific seeking parameter. For example, JW Player uses "start" as can be seen in the following code fragment:

file: "http://wpc.0001.omegacdn.net/000001/Video01.mp4",

'http.startparam': 'ec_seek',

start: 30

The above sample code assumes that the requested video was encoded using H.264 format. It will seek 30 seconds into an H.264 encoded video.

The above scenario assumes that a user chose to skip ahead to a portion of the video that had not been already downloaded to his/her computer. However, you may also configure a link to always start at a certain position. In such a case, our CDN will always generate truncated video content that starts at the specified position.

Seek End Parameter

By default, seeking within a video will allow the viewer to view the entire video from that point forward. Alternatively, define the seek end parameter (i.e., ec_end) to stop playback before the end of the video. Our CDN service will only serve the content that falls between the specified seek start and end time.

Calculating a Start/End Position for H.264 Encoded Videos

Define a starting and ending position for an H.264 encoded video (i.e., MP4, MOV, and F4V) by setting the ec_seek and ec_end parameters to the desired position. Calculate a starting or ending position by the number of seconds elapsed from the beginning of the video to the desired point in time.

Seek start syntax:

ec_seek = Seconds

Seek end syntax:

ec_end = Seconds

Implementing Seek Support

Implement seek support on a custom media player by setting it up as indicated below.