[whatwg] <video> application/octet-stream

Philip Jägenstedt philipj at opera.com
Wed Jul 21 07:04:28 PDT 2010

On Wed, 21 Jul 2010 15:55:24 +0200, Mike Shaver <mike.shaver at gmail.com>  

> On Wed, Jul 21, 2010 at 9:51 AM, Philip Jägenstedt <philipj at opera.com>  
> wrote:
>> On Wed, 21 Jul 2010 15:15:18 +0200, Mike Shaver <mike.shaver at gmail.com>
>> wrote:
>>> Could you be more specific about the incorrect information?  My
>>> understanding, from this thread and elsewhere, is that video formats
>>> are reliably sniffable, and furthermore that the appropriate MIME type
>>> for ogg-with-VP8 vs ogg-with-theora isn't clear (or possibly even
>>> extant).  It seems like reliance on MIME type will result in more of
>>> the guessing-and-stupid-switches than sniffing.
>> The MIME type for both of those would be video/ogg. It wouldn't be hard  
>> or
>> very error-prone to use only the MIME type, Firefox already does that.  
>> It's
>> also not very hard to rely on sniffing, which all the other browsers do,
>> although Opera still checks the MIME type first.
> Indeed, so it seems that sniffing is always required, unless we expect
> reliable use of the "codecs" parameter to become widespread.  (I
> confess that I do not expect this, even if this group and the W3C
> exhort authors to do so.)

I can quite confidently say that the codecs parameter won't be used like  
this. Even if it were always correct, setting up the media pipeline isn't  
helped the slightest bit by it, as connecting the demuxer to the decoder  
needs much more than just the types involved. At most one could reject  
files that don't have the correct codecs parameter, but that seems rather  

>> * Configuring the MIME type is an extra step that seemingly many authors
>> don't know that they need. That it is easy to configure doesn't really  
>> help.
> It may or may not be easy to configure the MIME type correctly, if we
> are to include codec details.
>> * Ignoring the MIME type will lead to more videos served as text/plain,
>> which will render as huge amounts of garbage text in current browsers if
>> opened directly (i.e. in a top-level browsing context).
> Ignoring the MIME type *and* not sniffing those cases, you mean?

Right, sniffing is currently only done in the context of <video>, at least  
in Opera. The problem could be fixed by adding more sniffing, certainly.

Philip Jägenstedt
Core Developer
Opera Software

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