Get Frame Size from GstSample in new-sample callback

[Michiel Konstapel]

You can get the caps from the sample, which have the width and height. 
Python example:

caps = sample.get_caps()
width = caps.get_structure(0).get_value("width")
height = caps.get_structure(0).get_value("height")

Just a guess: the 1088 pixel height might be because it comes from a 
source that only deals with 16x16 pixel blocks? 
https://stackoverflow.com/questions/9259044/h264-stream-incorrect-height-8-pixels-taller

Cheers,
Michiel

On 26-09-2022 18:16, Dwight Kulkarni via gstreamer-devel wrote:
> Hi all,
>
> Have a gstreamer pipeline with:
> v4l2src device=/dev/video3 ! video x-raw, width-1920, height=1080, 
> framerate=15/1 !  ...
>
> This terminates in an appsink called jpegsink.
>
> I am accessing the new sample like so:
> g_signal_connect(G_OBJECT(jpegsink),"new-sample",G_CALLBACK(new_sample_jpeg),NULL);
>
> In the new_sample_jpeg(...)  function I access the sample, segment, 
> and buffer like so:
>
> GstSample* sample = gst_app_sink_pull_sample(GST_APP_SINK(sink));
> GstSegment* currsegment = gst_sample_get_segment(sample);
> GstBuffer* buffer = gst_sample_get_buffer(sample).
> GstMapInfo map;
> gst_buffer_map(buffer,&map,GST_MAP_READ);
>
> unsigned char* img = new unsigned char[map.size]
>
> My question is how do I get the size of the image in width and height 
> from the GstSample. The size property of map given is the length of 
> the array data but not the actual image size. When I saved the image 
> data to file, the size of the image is showing 1920 x 1088 even though 
> in the pipeline it is specified at 1920 x 1080.
>
>
>
> -- 
> Sincerely,
>
> Dwight Kulkarni
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