[Ffmpeg-devel] [PATCH] Enhance genre, year and track tag support

Michael Niedermayer michaelni
Tue Sep 12 20:19:51 CEST 2006


On Mon, Sep 11, 2006 at 04:28:46PM +0200, Panagiotis Issaris wrote:
> Hi,
> Op donderdag 7 september 2006 15:03, schreef Michael Niedermayer:
> > [...]
> > > Hmm. Sorry, but I don't really get it. qscale is defined in both, and "b" (OptionDef) and 
> > > "bit_rate" (AVOption) seem to have the same meaning, don't they?
> > 
> > yes, some are duplicated as a large part of the AVOptions have been created
> > automatically from the structs with grep & sed, the duplicated ones should be
> > removed from OptionDef and in some cases the names of the AVOption ones should
> > be renamed ...
> In trying to do so, I stumbled upon several issues:
> * Some AVOptions and OptionDefs used different units. As the OptionDef structure provided
> a function for parsing parameters, these options were sometimes scaled in this function:
>   2119 static void opt_video_bitrate(const char *arg)
>   2120 {
>   2121     video_bit_rate = atoi(arg) * 1000;
>   2122 }
> AVOption sets the values using a generic function and does not provide such a specific
> callback hook per option. So, either the commandline usage would change, or code using
> the parameter should be modified to do the scaling, or some init function called for all codecs
> could do the scaling (which seems the best solution to me).

while i dont know if we will or will not need some init function, i somehow
think that it that it would be best to not do any scaling but instead
support SI postfixes (k,m,g) and maybe bit/byte too ...

> * Some AVOption names are a lot longer then the corresponding OptionDef names. For example 
> the parameter for setting the video bitrate would change from "b" to "bit_rate". I think
> this would annoy a lot of users. Are the AVOption parameter names already used? By external
> projects like MPlayer or VLC? If not, I could start renaming the AVOption names to the shorter
> ffmpeg.c/OptionDef names.

yes, rename them

> * The AVOption default values differ from the defaults given to the same parameters in the
> ffmpeg.c file. I think it would be best to not change the current behavior and so take
> the defaults from the ffmpeg.c file, right?

probably ...


Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In the past you could go to a library and read, borrow or copy any book
Today you'd get arrested for mere telling someone where the library is

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