Re: Presets and profiles

[Stefan Kost <ensonic hora-obscura de>]

David Joaquim schrieb:
> Stefan Kost a écrit :
>> Please consider encoding and transcoding as a special case for decoding and
>> encoding (or just remuxing). Applications like pitivi,jokosher,buzztard & co
>> would like to benefit from the whole profile&preset work too.
>>
>> Stefan
>>   
> 
> Interresting!
> I didn't thought about that.
> 
> The difficult part is to provide a convenient way to encode from
> raw-video/audio to the specified profile.
> Am I right ?

Jep, you have n-audio and m-video tracks and you want to offer the user a
convinient way to encode into for archival or for a specific device or service.

> 
> We can develop something like an encodebin :)
> The transcodebin will use a decodebin and an encodebin.
> 
> I mean, for transcoding, the decoding part is "just" a decodebin, with
> no additionnal work.

Almost. The transcodebin would need to be smart to stop decodebin from decoding
streams if remuxing is enough. And an encodebin does not make too much sense as
you need to specify encoders and muxers anyway. We coudl have a function in the
library altough, that given the specs, creates and ordinary bin and adds the
requested elements there. We would need to define the needed info for doing that:
- Transcoding: you get media-specs from deodebin
- Encoding: the application provides it
These media-specs could e.g. be a list of pads.
Now we let the user choose a format that can handle the spec. (like if there is
video, we don't offer wav).
When you have the target format, create a bin for it and link pads. In case of
transcoding if would eventualy restart the decodebin to avoid the decoders.


> 
> Let's say an encoding library then.
> With an optional direct from file encoding.
> 
> It can be a good idea to make a list of all application that may want to
> use theses libraries and define a set of use cases!
> 
> * Converters (transcoders)
> * Extractors (sound-juicer, music players)
    Thoggen for DVDs :)
> * Multimedia editors / authoring tool
I think its really two things Encoding (kind of transcoding from raw) and
Transcoding.

> 
> Do I forget someone ?

Stefan