Quick start fix

From Wikanual

Contents 1 The problem 2 The fix 3 Details 3.1 Header misplaced 3.2 Time code track 3.3 Clip status display 4 Bandwidth limit 5 History

The problem

Clips that are not encoded for quick start download to the clients computer completely before they start playing.

This creates an unnecessary delay.

Since the player remains empty during this time it might appear as if the page is not responding.

INTERDUBS analyses uploaded clips and checks if they are encoded for quick start.

The fix

INTERDUBS can fix such clips via the

 fix quick start 

function. It appears as a link for each clip that does not have the quicktime header in the right place.

You can also select affected clips with check boxes and use the function from the row of icons on top of the table.

The original source clips will be left in the folder. To avoid confusion INTERDUBS hides them and appends - before quickstart to their name.

The fixed clips are being created by a task. There is a slight delay before they will appear in the same folder. Fixed clips will only have a video and audio track. All other tracks like Time code etc will have been removed from the file.

The file has NOT been transcoded though: no changes the to actual video and audio content have been made.

Details

There are multiple causes for a clip not to play back right away in a web browser:

Header misplaced

Many encoders simply append the quicktime header in the end of the file. While clips can play on a local machine just fine since the player can seek to the end, they will only play in a browser when they have been downloaded entirely.

INTERDUBS detects this kind of clip during the upload, displays a message and marks it permanently so that the quick start message will be displayed next to it.

This message will only appear if the bandwidth of the clip is below a configured threshold. (see below)

Time code track

The existence of a timecode track can prevent quick start functionality. Since this is not always the case the message during upload will say: Timecode detected, but there will be no permanent message next to the clip.

When a clip shows that a time code track has been detected it is worth checking if it will play properly. If not then simply quick start fix it manually.

Clip status display

When you enter the

 edit file 

screen you will see a 'header misplaced' on top of the page, regardless if a bandwidth limit has been set.

Likewise you can see if a clip has a timecode track below the

EDIT file

button. This allows you to check the status of the clip and take measures should it not be playing.

Bandwidth limit

Large movie file that are never meant to be played in a browser have sometimes atttributes that would trigger warnings or auto processing.

Since it would pointless to fix these large files automatic ingest handling can be disabled for these files. When the bandwidth of the file in Mb/s is larger than the configured value for

upper MB/s limit for ingest warnings / processing

then no ingest handling is being performed. The default value for this is 25 Mb/s.

Files over 100MB will also not be auto processed.

History

Before September 2013 the quick start fix function only changed the header of the file. The icon of the function was a flag:

 fix quick start 

The updated function that also will remove extraneous tracks is being indicated by a new icon

 fix quick start 

and the slightly altered background color.