[theora] Black borders on resized videos

Michael Smith msmith at xiph.org
Sun Aug 23 22:09:15 PDT 2009

On Sun, Aug 23, 2009 at 9:31 PM, Christopher
Blizzard<blizzard at mozilla.com> wrote:
> On 8/22/2009 5:37 PM, Torrance wrote:
>> P.S. I can provide examples both of the commands given and the
>> resulting videos if necessary.
> What are you using for a player?  Theora video is required to be at
> sizes that are multiples of 16 pixels.  Videos not at those sizes are
> done by having black borders and the player is supposed to crop the
> video viewing area.  Some players don't support that.

Just to clarify this:

There's an internal detail of the format that means what actually gets
encoded is a multiple of 16 pixels. There is absolutely _not_ such a
constraint on the actual size of theora videos - any size is entirely

However, as Chris says - because of this internal format detail, it's
possible for buggy decoders/players to display some of the invalid


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