[FFmpeg-devel] Hello,

Alex Converse alex.converse
Thu Jul 16 21:29:47 CEST 2009

On Thu, Jul 16, 2009 at 2:54 PM, Jean-Daniel
Dupas<devlists at shadowlab.org> wrote:
> Le 16 juil. 09 ? 20:26, M?ns Rullg?rd a ?crit :
>> Jean-Daniel Dupas <devlists at shadowlab.org> writes:
>>> Hello,
>>> I'm new to this list and to this project. I'm looking to use
>>> libavformat & libavcodec in some application and would like to
>>> contribute to improve ffmpeg.
>>> And so, to try to get into the code, I did a little patch to improve
>>> alias support in dref in mov files on OS X. This patch uses native Mac
>>> OS X API to resolve the alias if possible instead of trying to infer
>>> the path from opaque data.
>> I'd rather improve our own code if it is incomplete. ?Can you
>> elaborate on what it's missing?
>> <big elephant in the room> Why native Mac OS X API? </big elephant in the
>> room>
> I will answer the two questions.
> First, an alias as defined by the Mac OS File Manager reference is a blob of
> "data that is private to the Alias Manager". There is absolutely no
> guarantee about what it contains. And so, the native API is the only futur
> proof and reliable way to resolve it. That why I suggest to use it when
> available.
> [...]
> I'm not again the idea to improve the actual code to get support for
> relative path (and maybe inode) (by reverse engineering the content of the
> blob), but I thought it would be fine to use the most reliable way when
> possible.

Do you know how QuickTime for Windows deals with such files?

Also 14496-12:2008 defines dref so it must exist in some sort of
portable manner. Or is the MOV version of it some sort of crazy
extended version with lots of Apple specific craziness?

Also, thanks for your work thus so far.

Alex Converse

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