Why do some video formats take so long to load and play - FLV, MP4, MOV, WMV
There are a couple of things worth mentioning about some video formats - FLV, MP4, MOV, WMV as it will affect how they playback online.
When rendering and producing your video for online viewing, keep in mind that making the filesize as small as possible isn't just a cost saving for you, it means faster downloads for your viewers!
You might already know that the most popular online video format is Flash (FLV or MP4 format) (In fact at eZs3, we have over ten times more Flash players than Windows and Quicktime combined)
But there are a couple of things which are worth noting:
The first is MetaData.
These are the instructions for the player, i.e.:
Play, pause, rewind, fast forward and stop
The file can't begin playback until these instructions have been downloaded.
For Windows Media (WMV) and Apple QuickTime (MOV) much of the file has to download before playback will start.
For Flash (MP4) we have discovered that many editing suites place the metadata at the end of the file - so again the viewer has to wait for playback.
So, for some MP4 videos, it seems as though nothing is happening - but in fact the file is downloading and will start just as soon as the player information gets through!
We have found a solution to move the metadata for MP4 files, if you are using this format.
Flash (FLV) Here the metadata is at the start of the file and so playback is quicker.
2. Filesize or Bitrate
The overall size of the file divided by the length of playback gives you a 'bitrate' - This is the amount of data that needs to be downloaded into your viewers cache. If it is too high - the video will stall.
So having a larger file will cost you more and will hit a 'bottle-neck' as your viewer downloads it.
We recommend 5 Mb/sec as a rule-of-thumb - as this is about average.
Also IMPORTANT info on File Management