Comparing the NV12 image with the RGB I can readily see it is the color-space conversion that causes the distortion--not libva or the intel driver. My apologies for the diversion.
On Wed, Oct 8, 2014 at 7:35 PM, Zhao, Yakui <[email protected]> wrote: > On Wed, 2014-10-08 at 10:02 -0600, Matt Pekar wrote: > > I've examined the behavior on Intel(R) Core(TM) i3-4130 and Intel(R) > > Core(TM) i5-2400. We target resolutions as low as 224x64 and up to > > 720P. > > > > Another thing I'm noticing is that the colors used seem to matter. I > > put some white on black text up and it looks great. Maybe there is an > > issue with how I do my colorspace conversion from BGR to NV12... > > > > Hi, Matt > > In order to narrow down the issue, Will you please help to remove the > extra color-space conversion of NV12 -> RGB and instead use the NV12 > image directly for the encoding? > > After the encoding is finished, you can calculate the corresponding PSNR > with the original reference YUV and then see whether the PSNR can meet > with your requirement. > > Thanks. > Yakui > > > I'm going to attempt to attach two pictures of what I'm seeing. They > > show the original .png image and what the encoder delivers side by > > side. > > > > > > On Wed, Oct 8, 2014 at 10:41 AM, Chris Healy <[email protected]> > > wrote: > > Hi Matt, > > > > > > I've been using the libva with the Intel driver to encode and > > stream myself for quite some time now. There are a number of > > visual artifacts that I have encountered along the way, though > > the fuzziness you describe is not one of them. With the Intel > > driver, I would expect different visual behaviour depending on > > the particular HW you are using as each one is different. I'm > > using an i7-3517U to encode 1280x720 H.264 at 4Mbps. What are > > you working with? > > > > Chris > > > > > > On Wed, Oct 8, 2014 at 7:18 AM, Matt Pekar > > <[email protected]> wrote: > > > > We use libva with the Intel driver to do live video > > streaming. In the encoding process we dynamically > > ramp the QP up and down as different content flows > > through. > > > > > > There are cases where we display simple text messages > > for many seconds. In these cases I'd like to send my > > QP down to 1--highest quality--and get as close to a > > lossless encode as possible. > > > > > > What I'm seeing is that on fonts and sharp lines a > > little bit of encoding will be done regardless, > > leaving the text slightly fuzzy. I tried the > > new VAEncMiscParameterTypeQualityLevel setting, but it > > only had two levels (1 and 2) and they didn't seem to > > affect the picture at all. > > > > > > Are there any settings I might try to ramp the quality > > up even further? Is the fuzziness I'm seeing in the > > text inherent to the h264 standard, or is this just > > what Intel's implementation happens to do? > > > > > > > > > > > > _______________________________________________ > > Libva mailing list > > [email protected] > > http://lists.freedesktop.org/mailman/listinfo/libva > > > > > > > > > > > > >
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