pixelated macro-blocks on videosink with hardware-acceleration

[Saurabh Bora]

Hi,

Could you anyone please help me understand these issues and point in the
right direction?


On Tue, Oct 15, 2019, 02:34 Saurabh Bora <saurabh9bora at gmail.com> wrote:

> Hi Experts,
>
> I have a gstreamer pipeline to send VP8 encoded data using hardware
> acceleration:
> videotestsrc is-live=yes ! aspectratiocrop aspect-ratio=4/3 ! vaapivp8enc
> ! rtpvp8pay !application/x-rtp,media=video,encoding-name=VP8,payload=96  !
> udpsink host-127.0.0.1 port=5000
>
> On the other hand, following pipeline is used to decode the data and
> display on a videosink:
> udpsrc port=5000 caps = "application/x-rtp, media=video, clock-rate=90000,
> encoding-name=VP8, payload=96" ! rtpvp8depay ! decodebin ! videoconvert !
> autovideosink
>
> When a specific event happens, I change the "aspect-ratio" property on
> "aspectratiocrop" element to 1/1. I achieve this by using below code:
>
>   GstElement* cropStream = gst_bin_get_by_name(GST_BIN(pipeline),
> "aspectRatio");
>   if (cropStream == NULL)
>   {
>       return -1;
>   }
>   //Set aspect-ratio property as 1/1.
>   g_object_set(cropStream, "aspect-ratio", 1, 1, NULL);
>
> The property is successfully changed and aspect ratio changes to "1/1".
> However, for a second or so, macro-blocks of pixels with pink color appear
> on the videosink. These macro-blocks are really ugly and not desired.
>
> I have tried few things and observations were as follows:
>
>    1. Modified all the default properties on "vaapivp8enc" element --> *still pixelated
>    macro-blocks appear*
>    2. Do not change aspect-ratio property  --> *pixelated macro-blocks do
>    not appear*
>    3. Replace hardware accelerated vaapi encoding - "vaapivp8enc" element
>    with normal software enabled encoding - "vp8enc" element --> *pixelated
>    macro blocks do not appear*
>
> Please help me understand if
>
>    1. The way I am setting the "aspect-ratio" property directly is
>    correct and why does it impact the encoder? *OR* Ideal way to set
>    property in a running pipeline is - pause pipeline, unlink element, create
>    element with right property, link element, play the pipeline again?
>    2. Are there any specific combination of property values that can be
>    used with "vaapivp8enc" to solve this issue?
>
>
> Kindly guide me in right direction..
>
> --
> Thanks and Regards,
> Saurabh Bora
>
> PH NO : 7038166900
> EMAIL : saurabh9bora at gmail.com
>              saurabh9bora at outlook.com
>
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