[FFmpeg-devel] [PATCH] metadata conversion API

Baptiste Coudurier baptiste.coudurier
Tue Mar 3 03:25:30 CET 2009

On 3/2/2009 5:36 PM, Michael Niedermayer wrote:
> On Mon, Mar 02, 2009 at 03:41:04PM -0800, Baptiste Coudurier wrote:
>> On 3/2/2009 3:32 PM, Michael Niedermayer wrote:
>>> On Mon, Mar 02, 2009 at 10:51:00PM +0100, Peter Eszlari wrote:
> [...]
>>>> Of course manpower is a different matter...suppose we had this
>>>> list with all options&ranges, how would we actually proceed?
>>>> Checking them one by one like it is done atm (see attached
>>>> patch for -aq/mp2 case)? This seems not practical, especially
>>>> if we want to prevent the user from doing really stupid things
>>>> like:
>>> The way to go (if we had the volunteers for it ...) would be to
>>> at the simplest level add an array of const char* name, float
>>> max, float min to AVCodec that can then include what options and
>>> what ranges each codec supports its easy to check then if
>>> everything is within range and if any other option has been
>>> changed from its default (there are also other ways then checking
>>> against the default from AVOptions to detect changed stuff.
>> I propose to add an array of tag/value pairs as "char*" in 
>> AVCodecContext, then encoder_init can check these values.
>> char* is definitely more flexible, and permits more advanced
>> treatment. Furthermore, it can be passed "as is" to libx264.
> [...]
> Also we are lacking volunteers to make such lists, are you
> volunteering?

Sorry, nope, I don't find this solution elegant nor flexible.
I need an option which only supports 2, 4 or 8 as param.

I however volunteer to add key/value as char* options to AVFormatContext
and AVCodecContext and use them.

I think user should only need to pass char * to libavcodec and
libavformat, nothing else.

Internally however, I think AVOption can be used if option permits it.

Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
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