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<p>I guess the main problem is that YUV generally defines the range
as 16-235.<br>
And so most of the available colorspaces have limited range
quantization.</p>
<p>As far as I can see only the JPEG colorspace defines full range
quantization:<br>
<a class="moz-txt-link-freetext" href="https://www.kernel.org/doc/html/v4.10/media/uapi/v4l/pixfmt-007.html#colorspace-jpeg-v4l2-colorspace-jpeg">https://www.kernel.org/doc/html/v4.10/media/uapi/v4l/pixfmt-007.html#colorspace-jpeg-v4l2-colorspace-jpeg</a></p>
<p>Perhaps you can see if it could be used.</p>
<p><br>
</p>
<p>Though is not the same issue I have previously run into a related
problem with videoconvert:<br>
<a class="moz-txt-link-freetext" href="https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/issues/868">https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/issues/868</a></p>
<p>Which might give some clues.</p>
<p><br>
</p>
<p>Otherwise you could make a simple contrast/intensity stretch
filter to put the range back to 0-255 (and possibly fix the
colorimetry CAPS as well).<br>
</p>
<p><br>
</p>
<div class="moz-cite-prefix">On 14.05.2022 14.00,
<a class="moz-txt-link-abbreviated" href="mailto:gstreamer-devel-request@lists.freedesktop.org">gstreamer-devel-request@lists.freedesktop.org</a> wrote:<br>
</div>
<blockquote type="cite"
cite="mid:mailman.25.1652529603.5253.gstreamer-devel@lists.freedesktop.org">
<blockquote type="cite" style="color: #007cff;">
<pre class="moz-quote-pre" wrap="">GStreamer team,
I am capturing video using a BlackMagic Video device, sending out using a VP9
encoder, and then using a payloader for use with webRTC. When I view the
stream, my blacks and whites are mapped 16-235 instead of 0-255. Is there a
way to correct this? WIth ffmpeg, I can use a filter graph and and set the
input and output scale ?scale=in_range=limited:out_range=limited?.
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">I don't think our converters current handle this, but the range is part of the
colorimetry= filed in caps. Would be nice to fix this of course, range
conversion seems pretty handy.
</pre>
<blockquote type="cite" style="color: #007cff;">
<pre class="moz-quote-pre" wrap="">Thanks,
Patrick
</pre>
</blockquote>
</blockquote>
<pre class="moz-signature" cols="72">--
Best regards / Med venlig hilsen
“Marianna Smidth Buschle”</pre>
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