[FFmpeg-devel] Hello,

Baptiste Coudurier baptiste.coudurier
Thu Jul 16 21:12:45 CEST 2009


On 07/16/2009 12:10 PM, M?ns Rullg?rd wrote:
> Jean-Daniel Dupas<devlists at shadowlab.org>  writes:
>
>> 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.
>>
>> Now, about what is missing in the current code. The actual code assume
>> the alias contains a path (either relative or absolute), but an alias
>> is more than that. It contains enough informations to locate a file
>> that was renamed and moved (as long as it remain on the same volume).
>> As this is an opaque struct, I never tried to look at what it does,
>> but I assume it is using FSVolumeRefNum, and nodeID (inode) under the
>> hood.
>> In fact, the alias manager is even able to resolve path on file that
>> are stored on remove volumes and to mount this volume if needed.
>
> Such a ridiculous feature is best left unsupported in my opinion.

Well, I'd like to support this feature, the patch is small and does not 
cause any harm IMHO.

-- 
Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
Key fingerprint                 8D77134D20CC9220201FC5DB0AC9325C5C1ABAAA
FFmpeg maintainer                                  http://www.ffmpeg.org



More information about the ffmpeg-devel mailing list