-
H.264 image quality issue during stills
Hello,
I’m experiencing a kind of “pulsing” (probably of macroblocks) going from blurry and crisp, on imagery with tiny details. It happens rarely but is very visible and distracting when it does. The “pulses” happen at a steady frequency, possibly 1 second (keyframes?).
I was hoping i could fix it with a higher bitrate, but that doesn’t seem to be the issue. If i separately render out the specific section of my project, where the error occurs, the issue is gone.
The bitrates actually turn out lower in the separately rendered section, so that really isn’t the issue.
samples:
– pulsing blurriness (notice the clouds)
– crisp render (what the blurriness recovers to, and what it looks like when exporting a short section)Any ideas welcome. I would really like to use AE’s H.264 codec (MainConcept i think) for this, as it is, that issue aside, very well performing for me.
-
6 Replies
-
The source is only still imagery of high quality, no imported video. But if i understand you right, H.264 codecs aren’t as robust as desirable yet.
My former project with comparable content has a 640×480 resolution and didn’t show these issues, even at bitrates around 1Mbit/s.
-
if you used cineform’s codec, it would have converted inter to intraframe and you’d keep compression and have no problems.
-
Yes, the latter is the case, AE’s export causes these problems. I will follow your advice and try to compress it in VDub or so. The thought of a lossless movie at that resolution makes me cringe though, i hope it fits on my drive 🙂
x264 (another h.264 codec) offers a “lossless” codec option, i’ll see how much smaller that is and and if it holds up to the name.
Thanks for the help!
-
They really do come cheap nowadays.
I tried exporting it with x264’s lossless mode and it’s tons smaller than e.g. a PNG image sequence. The image (quality) is indistinguishable from AE’s workspace, so it’s definitely good enough for my hobbyist needs.
So i’ll export [Video] -> [h264 “lossless”], [Audio] -> [MS-PCM WAV] and merge the two in VDub for the final encode. That gets the job done alright.
Thanks again!
Adrian -
I have this same “pulsating” problem around keyframes… here goes my workflow which is different:
I use PP3 to edit my HDV footage from a Canon HV20 (MT2 files). I export from PP3 via DebugModeFrameserver through AviSynth into VirtualDub and save a deinterlaced and downscaled image (to 640×360) AVI, using Lagarith Lossless for the AVI. The resulting footage is excellent. (would this method still have the interframe issues mentioned above??)
I import the AVI into Sorenson Squeeze for Flash 5.0.2.8 and I ONLY see these pulsations when I compress with MainConcept H.264 (have tried all available settings and keyframe spacings) – bottom line – the MP4 has pulsations on the keyframes, no matter how far/near they are spaced.
My solution was to use another provided H.264 compressor that was in Squeeze – no pulsations, but the quality isn’t quite as good.
I don’t think this problem is with AE… it’s with MainConcept being used in Squeeze and AE.
Thoughts??
-
There are two solutions I’ve found for this problem. One is to increase the keyframe distance which at least makes the problem less common. The second is to use Apple H.264 codec which produces error-free video but is generally not as good and versatile a codec as MainConcept is.
I think the problem is with MainConcept codec but it’s only readily visible on still footage.
I use TMPGENC to encode my videos, which uses MainConcept like After Effects does. Sorenson Squeeze supports Apple H.264.
Reply to this Discussion! Login or Sign Up