[whatwg] Video with MIME type application/octet-stream

[Silvia Pfeiffer]

On Sat, Sep 11, 2010 at 8:51 AM, Roger Hågensen <rescator at emsai.net> wrote:

>  On 2010-09-09 09:24, Philip Jägenstedt wrote:
>
>> On Thu, 09 Sep 2010 02:15:27 +0200, David Singer <singer at apple.com>
>> wrote:
>>
>>  On Wed, Sep 8, 2010 at 3:13 PM, And Clover <and-py at doxdesk.com> wrote:
>>>>
>>>>> Perhaps I *meant* to serve a non-video
>>>>> file with something that looks a fingerprint from a video format at the
>>>>> top.
>>>>>
>>>>
>>>> Anything's possible, but it's vastly more likely that you just made a
>>>> mistake.
>>>>
>>>
>>> It may be possible to make one file that is valid under two formats.
>>>  Kinda like those old competitions "write a single file that when compiled
>>> and run through as many languages as possible prints "hello, world!" :-).
>>>
>>
>> For at least WAVE, Ogg and WebM it's not possible as they begin with
>> different magic bytes.
>>
>>
> Then why not define a new "magic" that is universal, so that if a proper
> content type is not stated then a sniffing for a standardized universal
> magic is done?
>
> Yep, I'm referring to my BINID proposal.
> If a content type is missing, sniff the first 265 bytes and see if it is a
> BINID, if it is a BINID check if it's a supported/expected one, and it is
> then play away, all is good.
> If a content type is given, then just in case sniff the first 265 bytes and
> see if it is a BINID, if it is a BINID check if it's a supported/expected
> one, and it is then play away, all is good.
> If a content type is missing, and the sniffing of the first 265 bytes shows
> it is not a BINID or not a supported one, then it can only be treated as
> unknown binary and would fail (though in the case of a unsupported BINID the
> user would be shown what the BINID is so they won't be fully stuck if they
> miss a particular codec or the browser doesn't support it).
> If a content type is given, and sniffing the first 265 bytes shows it's not
> a BINID or not a supported one, then treat it as per the context (video or
> audio) and hope the video or audio codec layer is able to find out what it
> is (what "should" happen currently right?).
>
> It would be very easy to add support for something like BINID as it can be
> output at the start of a file or stream as the server sends it, a script
> could even output it or it could be at the start of the actual file itself,
> and in the case of live streaming a server could easily add it to the start
> of the stream even if it's mid-stream. Even a wrongly configured webserver
> wouldn't be able to mess up the handling of this.
> The benefit is that the browser would see that, Oh, this is a BINID and
> it's Webm, I'll pass this on to the video codec then.
> Or if <audio> and the browser sees it is a BINID and it's MP3 it would pass
> it to the mp3 audio codec.
> In time something like BINID might even propagate elsewhere beyond just
> <video> and <audio>.
>
> I'm not saying that BINID must be used, but at least something very close
> to it (as unknown formats can be shown to a human user and make sense and be
> searchable), and maybe the first 8 bytes should be constructed slightly
> differently?.
> Oh and although I haven't tested this, I suspect that most current codecs
> would ignore the first 265 bytes when they sniff for the start of the data
> anyway so a BINID would be partially backwards compatible,
> and in any case certainly easy to patch in support for quite easily.
> And the best part is that the browser could easily strip or skip past the
> BINID when passing the data to the OS or codecs (if such do not support
> BINID at all), or if saving the audio or video locally per user request.
>
> Something like BINID (short for Binary Identification actually) is needed,
> and there is nothing wrong with HTML5 and <video> <audio> standard defining
> it,
> it wouldn't be the first time a web standard has been adopted elsewhere
> later, it would surely see adoption outside of this, I certainly would use
> it elsewhere.
>
> I invented BINID for a reason, because .*** file extensions just isn't good
> enough, and sniffing binary files is a real pain, the same pain as the
> <video> and <audio> discussion here is pointing out right now.
>
> So if sniffing is bad, but sniffing can't be avoided, then why not simply
> standardize the sniffing by defining a universal, simple and end user
> friendly (the BINID can be displayed to the user, even if
> unknown/unsupported),
> and the sniffing would be limited to the first 265 bytes (in the case of
> the BINID proposal), and this limited sniffing can't determine what
> something is and the context and extra info (like content type) does not
> clarify what it is or what to do with it then simply fail and inform the
> user, it doesn't have to be more complicated than that.
>
> As simple as possible, but no simpler. Isn't that the ideal mantra of all
> coders here?
>
> Remember, I'm not saying you must use BINID (but hey it's there and fleshed
> out already), if you must change the name, do so, if you must change the 8
> byte sequence, do so, just make sure it has a max length, and the "ID" is
> humanly disaplayable if the format is unsupported. Just make it into an RFC
> or something, and spec it in the HTML standard that it must be supported,
> and spec how to behave if it's not present (like I pointed further above)
> and it's solved as best as is possible. (unless somebody have an even better
> idea here that is?)
>
> And yeah, this kinda stretched beyond the scope of HTML5 specs, but you'd
> be swatting two flies at once, solving the sniffing issue with <video> and
> <audio>, but also the sniffing issue that every OS has had for the last
> couple of um... decades?! (poke your OS/Filesystem colleagues and ask them
> what they think of something like this.)
> Then again, HTML5 is kinda a OS in it's own right, being a app platform
> (not to mention supporting local storage of databases and files even), so
> maybe it's not that far outside the scope anyway to define something like
> this?
>
> --
> Roger "Rescator" Hågensen.
> Freelancer - http://EmSai.net/
>
>
Is there a link to your BINID proposal? From reading this I wonder: Would it
entail having to re-write all existing files with an extra identifier at the
start?

Silvia.
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