Re: Precision of #xywh=percent:...

On Thu, Apr 7, 2011 at 6:06 PM, Philip Jägenstedt <philipj@opera.com> wrote:
> On Thu, 07 Apr 2011 09:38:41 +0200, Silvia Pfeiffer
> <silviapfeiffer1@gmail.com> wrote:
>
>> On Thu, Apr 7, 2011 at 5:22 PM, Philip Jägenstedt <philipj@opera.com>
>> wrote:
>>>
>>> On Thu, 07 Apr 2011 02:54:24 +0200, Silvia Pfeiffer
>>> <silviapfeiffer1@gmail.com> wrote:
>>>
>>>> Oh, it hadn't occurred to me that we may need fractions of
>>>> percentages. I think we should allow that.
>>>>
>>>> Another use case may be: a video recording of a concert from the
>>>> distance with a camera that won't zoom any further and you know you
>>>> can focus in on a specific cropped region.
>>>
>>> In this situation, why not just use the #xywh=pixel:x,y,w,h grammar? This
>>> is
>>> more straight-forward if there is only one resolution of the video. If
>>> you
>>> have multiple resolutions of the video, then you can do the cropping
>>> while
>>> encoding those multiple versions and save bandwidth at the same time.
>>>
>>> This line of argument actually works against my 16:9 cropping as well --
>>> if
>>> there is only one version then you don't need percentages, but if there
>>> are
>>> several then you can do cropping while encoding.
>>
>>
>> I actually think that because things can go full-screen now, the
>> non-percent version is almost useless and an author would almost
>> always want to use percent, just to make sure that whatever display
>> size the user chooses, it will still display the same thing.
>
> The pixel syntax operates on the intrinsic size of the video, not the
> display size. The result would be the same regardless of fullscreen, modulo
> scale of course.


Is this how image maps work, too?


>>>> There are further use cases at
>>>> http://www.w3.org/2008/WebVideo/Fragments/WD-media-fragments-reqs/,
>>>> e.g.
>>>> 4.1.4 Scenario 4: Image Region of video over time
>>>
>>> MF doesn't allow for changing the highlighted/cropped region over time.
>>> Even
>>> so, it's not something you need the percent syntax for.
>>>
>>> I'm going to play the devil's advocate and suggest that we drop the
>>> percent
>>> syntax completely.
>>
>>
>> I think that would be a big problem.
>
> What are the use cases where all of the following are true:
>
> * You have multiple videos of different resolution.
> * Those videos are not the same video encoded at different resolutions.
> * You want to apply the same relative cropping to all of them.

I don't fully follow - probably better to discuss at the next conference call.

Silvia.

Received on Thursday, 7 April 2011 22:25:20 UTC