[Ffmpeg-devel] Naming conventions

[Panagiotis Issaris]

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Hi,

I want to start a discussion regarding possible FFmpeg naming
conventions. I think the current situation is suboptimal and would like
to send some patches to enchance the situation. That's why I want some
input from others.

Currently, some public API functions are prefixed with avcodec_, some
with av_, some with avpicture_ some are not prefixed (such as
register_avcodec, dump_format, parse_image_size, parse_frame_rate,
parse_date, find_info_tag, video_grab_init, audio_init, dv1394_init,
dc1394_init), some with ffm_, some with avpicture_, ...

I think consistently named APIs are not only a pleasure to look at, but
really make a library much easier to use. With a truly consistently
named API you can nearly guess the name of the function you need to use,
when thinking of some stuff you need to do.

So, I'd like write some patches making the API more (hopefully fully)
consistent and therefore want to know what kind of naming conventions
libav* developers and users prefer.

In a previous thread [1] on this mailinglist, Michael Niedermayer and
Baptiste Coudurier made some remarks regarding naming conventions.


I think all agree that all public API functions should be prefixed with
at least "av" and possibly "av_".

Personally, I see various possibilities for structuring function names.

The names could in some way include:

* The name of the library: So, a prefix such as avc, avu and avf. It has
the disadvantage that if functions are migrated to another library,
they'll have to be renamed and thus cause ABI breakage. Libavcodec in
some way seems to use this convention: avcodec_thread_init,
avcodec_version, ... Libavformat and libavutil do not.

* The name of the type "it works on". Libavformat uses this for some of
its functions: av_parser_init, av_parser_parse, av_parser_change,
av_bitstream_filter_init, avpicture_alloc, avpicture_free, ...

* And of course the actual description of what the function does, the
action.

How should these possibly included parts be ordered? The previously
mentioned functionnames used the "type_action" order, but there also
appear functions which do not use this order:
av_init_packet, av_new_packet, av_get_packet, av_dup_packet,
av_free_packet, ...


_Personally_, I prefer the "type_action" type of names, and having all
of them prefixed with some FFmpeg specific part, so that the chance of
namecollisions is greatly reduced.


What do you think?


With friendly regards,
Takis

[1] http://article.gmane.org/gmane.comp.video.ffmpeg.devel/45682
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