[FFmpeg-devel] [PATCH] Stream specifier enhancement

[Marton Balint]

On Mon, 12 Oct 2015, Bodecs Bela wrote:

> Dear All,
>
> currently stream specifiers may contain stream index, stream type,
> stream id, program id, metadata key/value es usable config settings.
> But you can not combine them. In some case, mainly working with
> multiprogram mpeg-ts containers as input, this feature would be handy.
> This patch makes it possible to combine them.
> Examples: p:601:a  will select all audio streams of program 601,
> a:m:language:hun will select all audio streams marked by its metadata
> as hun language,
> p:604:v:0  will select first video stream of program 604,
> a:m:language:hun:0 will select 1st audio streams with hun language.
> p:403:s:0 will select the first avaiable sub_title tream of program 403,
> and p:403:s:m:language:hun:0  will select the first hungarian language
> sub_title stream of program 403.  To select first hungarian language
> audio stream a:m:language:hun:0
> The order of sub-specifiers (program/type/metadata/usable_config) is
> arbitrary. So, you may also write v:p:604:0 to select first video stream
> of program 604
>
> Please consider to put this enhancement into the official ffmpeg code.

I like the idea, but are you sure just concating the specifiers is 
a good approach?

For example, what will the following mean?

m:language:u

All usable streams with language metadata or streams where the language 
metadata is 'm'?

Regards,
Marton