Is it possible to add more than one GstVideoRegionOfInterestMeta metadata to a single buffer?

[José Carlos Cazarin Filho]

Thanks for the example, really helpful! But in the end, the problem was in my code, I'm able to get multiple ROIs metadata now

-----Original Message-----
From: Nicolas Dufresne <nicolas at ndufresne.ca> 
Sent: Thursday, February 17, 2022 6:53 AM
To: Discussion of the development of and with GStreamer <gstreamer-devel at lists.freedesktop.org>
Cc: José Carlos Cazarin Filho <jose at au-zone.com>
Subject: Re: Is it possible to add more than one GstVideoRegionOfInterestMeta metadata to a single buffer?

Le mercredi 16 février 2022 à 18:06 +0000, José Carlos Cazarin Filho via gstreamer-devel a écrit :
> Hello! I'm trying to do something which I'm not sure it is supported. 
> I'm writing a plugin in which I call 
> gst_buffer_add_video_region_of_interest_meta
> in a loop, adding (presumably) more than one 
> GstVideoRegionOfInterestMeta to a single buffer.
> In another plugin that consumes the output of the previous plugin, I 
> call gst_buffer_iterate_meta in a loop to try to retrieve the 
> information. But I can only retrieve the first metadata successfully. 
> After the first one, gst_buffer_iterate_meta returns NULL.
> So, my question is: is it possible to have multiple 
> GstVideoRegionOfInterestMeta metadata in the same GstBuffer?

Yes, you can add multiple ROI. Here's an example of iterating of them:

https://gitlab.freedesktop.org/gstreamer/gstreamer/-/blob/main/subprojects/gst-omx/omx/gstomxvideoenc.c#L2951

> Thanks!
>