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[whatwg] Video : Slow motion, fast forward effects

From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
Date: Wed, 15 Oct 2008 05:37:52 +1100
Message-ID: <2c0e02830810141137u7c1fb3a7o3b6299ec61f94a23@mail.gmail.com>
On Wed, Oct 15, 2008 at 5:28 AM, Peter Kasting <pkasting at google.com> wrote:
> On Tue, Oct 14, 2008 at 8:00 AM, Eric Carlson <eric.carlson at apple.com>
> wrote:
>>  Some media formats and/or engines may not support reverse playback, but I
>> think it is a mistake for the spec to mandate this behavior. Why is reverse
>> playback different from other situations described in the spec where
>> different UAs/ media formats will result in different behavior, eg. pitch
>> adjusted audio, negotiation with a server to achieve the appropriate
>> playback rate, etc?
>>  I think the current sentence that talks about audio playback rate:
>>  When the playbackRate is so low or so high that the user agent cannot
>> play audio usefully, the corresponding audio must not play.
>> could be modified to include reverse playback as well:
>>  When the playbackRate is such that the user agent cannot play audio
>> usefully (eg. too low, too high, negative when the format or engine does not
>> support reverse playback), the corresponding audio must not play.
> Agree wholeheartedly.
> Mandating silence during reverse playback seems bizarre in the abstract,
> unnecessary if authors have a way to mute, and potentially detrimental to
> future applications which may _want_ to be able to do this in a controlled
> fashion (e.g. a virtual turntable application).
> PK

Also in the case of a caption/subtitle authoring application: being
able to scrub through the audio forwards/backwards is a very important
means for captioners to identify the time points to start/end a
caption segment. I disagree with mandating silence and would rather
deal with an intermediate inconsistent browser landscape for lack of
the audio scrubbing feature in some browsers.

Received on Tuesday, 14 October 2008 11:37:52 UTC

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