(I removed the Chromium related list as I am not subscribed there.)
On Fri, 21 Jan 2011 21:35:53 +0100, Adam Malcontenti-Wilson
<[email protected]> wrote:
XHR2 is one part of the APIs required for my use case as that is the
easiest way to download for example a music file. However, while
downloading, there's no way to pipe the download(ing) blob to the
HTML5 Audio element as to play Audio it requires an object URL, and an
object URL can (currently) only point to a static Blob, as well as the
fact that a Blob cannot be appended. This would be important for
listening streaming audio that needs to be processed in JavaScript or
cached to persistant storage using the Filesystem APIs without having
to wait for the entire file to be downloaded into an ArrayBuffer or
Blob.
There is a plan of allowing direct assigning to IDL attributes besides
creating URLs.
I.e. being able to do:
audio.src = blob
(The src content attribute would then be something like "about:objecturl".)
I am not sure if that API should work differently from creating URLs and
assigning those, but we could consider it.
My suggestion was for another alternative version of Blob and/or
createObjectUrl that mimicks how a HTTP request can be parsed and (in
the case of audio or video) start playing before it has finished
downloading (e.g. got to the content-length or had a connection close)
by pushing content when it is appended to the blob and then the
"virtual connection" can be closed when the Blob has finished being
built by calling a close() function. I've also thought of other
alternatives, but I'd make sure that there isn't already a way to do
this with the current (specified) APIs, and I think this has the most
other use cases as any data that takes a while to process can be
streamed to the user or other parts of the browser.
Is there actually a good reason for the URL API to have behave in this way?
--
Anne van Kesteren
http://annevankesteren.nl/
