[Theora-dev] Re: [ogg-dev] OggYUV
ogg at illiminable.com
Tue Nov 8 15:38:09 PST 2005
> For a lossless codec, the luxury of a "small number of useful formats"
> may not be advisable. I can't tell you how many times I've had some raw
> data and been completely unable to play it with e.g., mplayer, because
> mplayer did not have an apporpriate fourcc. And mplayer has made up many
> of their own non-standard fourcc's (which not even all of mplayer
> support) to cover for the gaping holes left after counting illi's
> supposed "90% of cases on one hand". It is a common but deadly mistake
> to assume that what is important to you is what is important to everyone
> else. Creating a video format system around the fourcc model has always
> struck me as a very, very bad idea.
Well i guess it depends what it's being used for. My understanding is the
usefullness of such a raw format is to firstly get raw data from some
hardware device, be it a video camera/webcam etc... which correct me if i'm
wrong, all output raw data in a fourcc format or one of the common rgb
Secondly be able to store that raw data, for the purposes of either
inputting it to another codec, or to a hardware display device. As to
displays, again correct me if i'm wrong, but most don't support arbitrary
formats of video buffers, they support some subset of fourcc and rgb types.
To me the idea of a raw format, is for a time-efficient method to store and
display raw data and/or input it it somewhere else. It seems to me, if you
want the fully-specified-arbitrary model, then there's a lot of extra
processing work that has to be done in between.
And just from a MS/directshow perspective, all the input devices, output
devices and codecs support a fourcc, or common rgb model. It's all well and
good to represent accurately some other colourspace, but considering no
codec or output device will display it exactly as is, nor will it ever
generate such data, i'm not sure i see the point in these implementations.
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