What are the differences between OpenQuicktime and Quicktime 4 Linux ?
In fact, the two libraries have a different philosophy. Quicktime 4 Linux contains
everything a user needs but is limited to open source codecs, handles only local
files and works only on Intel Linux. OpenQuicktime is more complex, contains
no colorspace conversion, doesn’t support all the Quicktime 4 Linux codecs but
is easily extendable and fully portable. The two libraries are already completely
different and the differences will increase in future version of the libraries.
- OpenQuicktime library contains no embedded codecs but has a plugin system
to dynamically load audio and video codecs.
- OpenQuicktime contains no colorspace conversion algorithm.We think this
has nothing to do in a such library.
- OpenQuicktime is fully portable and fully configurable with all the autoconfigure
and automake magic we have been able to add.
- OpenQuicktime supports compressed headers (decoding only for the moment).
- OpenQuicktime supports Quicktime Sound System version 2.
- OpenQuicktime can support any inputs and outputs (file, HTTP, FTP, RTP,
...), in fact the functions used to read, write and seek are overloadable.
- OpenQuicktime has an overloadable plugin mechanism. This is a complexe feature
which enables any application to use its own codecs instead of the OpenQuicktime
ones. This feature is essential for the Gstreamer
I use Quicktime 4 Linux, should I change for OpenQuicktime ?
Even if both libraries have currently the same interface, we don’t recommend
you to change. Quicktime 4 Linux is much more simple to use than OpenQuicktime
because it contains codecs and colorspace conversion statically linked. Besides,
the OpenQuicktime interface is not finalized and could change. But be aware,
that in a near future, OpenQuicktime should support more codecs and should be
usable to play quicktime streams directly from the network.
OpenQuicktime is linked to 3ivx and is not really Open Source ?
Yes and no. Currently all the members of OpenQuicktime are also members of
the 3ivx project. 3ivx is, for the moment, not open source in any case but has
the ambition to be a really portable codec. To port the codec on any Unix, we
have decided to create what we needed and release it open source ... Of course,
a 3ivx OpenQuicktime plugin will be available soon. But because this library
is released under the LGPL, if Sorenson, or any other codec companies wants
to create plugins, and sell them, it is possible and we hope that they will
do so. That way, Linux users will not have to reboot on Windows to see their
favorite trailers. ;)
I want to write a codec for your library, is there any documentation somewhere
to help me ?
Yes, we’ve created a video plugin HOWTO.
We will create an audio plugin HOWTO soon as well. For the moment, you could
always look at the MP3 plugin as an example.
On which Unix has the library been successfully ported ?
For the moment, the library has been ported on Intel, Sparc and PPC Linux,
and Solaris as well. We are currently testing it on
Darwin. We plan to adapt
it also on Tru64.