HD Encoding Stuttering

[Czanchez]

I've recently encoded 2 movies which stutter during playback, I'm using the default x264 Blu-Rayfast profile.

I encoded HD movies before using x264 and had no problems, but I reformated my computer and lost my old profiles.

program --pass 2 --bitrate 8000 --stats ".stats" --level 4.1 --keyint 24 --min-keyint 2 --ref 3 --mixed-refs --bframes 3 --weightb --direct auto --deblock -1:-1 --subme 5 --partitions p8x8,b8x8,i4x4,i8x8 --8x8dct --ipratio 1.1 --pbratio 1.1 --vbv-bufsize 40000 --vbv-maxrate 40000 --qcomp 0.5 --merange 12 --threads auto --thread-input --progress --no-psnr --no-ssim --output "output" "input" --mvrange 511 --aud --nal-hrd --sar 1:1

In the gui there is an option called VBV Buffer Size, which says that if can effect playback and cause stuttering if it is too low, but 40000 seems high to me. What does this number mean and is it my problem, if not what is, and what does that mean.

Thanks.

[linyx]

Did you by chance have a *good* decoder installed before (CoreAVC, DivX H.264 Decoder) but now you are using something else? Also, do your old encodes now play with or without stuttering?

[Czanchez]

Well I have a HTPC and a laptop, since the laptop has a faster core speed I use that for encoding, which cuts down on the times.

The computer that I use to play the files hasn't changed. The HTPC computer plays the older encodes fine, but the new ones stutter. Think like a music measure, the first three beats are at 160bpm athen the last beat is 200bpm, something like that.

I'm guessing that the new settings are made for a "better" computer, like there is nothing wrong with the settings but the computer is an older pentium 4 with an ok video card, but if I played it on a newer compute it would play fine, but I have no access to a better computer to try it out.

[Sharktooth]

P4 is not enough to play HD stuff, expecially if you enable some settings in the encoder that require more CPU cycles when decoding (higher bitrates also require more cycles).

[_DW_]

P4 is not enough to play HD stuff, expecially if you enable some settings in the encoder that require more CPU cycles when decoding (higher bitrates also require more cycles).

That is what I was thinking. You really need dual cores to decode any HD stuff. You can almost get by if you have a really high clock speed but almost doesn't cut it. I had AMD 4000+ that could almost play the nvidia pure demo, almost. My first htpc was a amd 3000+. I thought it was ready for HD. I was so wrong...:p

[Sagittaire]

I don't know for the playback but the VBV profil is false. Max for buffer is 30000 and max for maxrate is 40000. Inferior value are compliant too.

[Comatose]

A high clock P4 is enough for 720p, but with anything else...

[Czanchez]

Ya, the stuff is 720p because there is no need for 1080p since the tv that it's hooked up to isn't large enough for 1080p.

Is there anyway to analyze the previous videos and get the encoded settings, like the buffer size and all the thing that affects playback during decoding. That would be the easiest thing because whatever the settings were before, they worked fine.

One note that might help, the old videos take a while to buffer when skipping but the new ones buffer much quicker, almost instant.

[canuckerfan]

i have a p4 3.0 ghz. using ffdshow+halli splitter+coreavc+mpc, I can play 720p x264 stuff just fine. but that's the upper limit for what it can do. anything beyond that and it stutters.

[Czanchez]

I did some narrowing down to the problem. I now believe it is the AVS file I am using to process the file and not the encoder profile. I did too movies, both using the same profile but the first movie works fine, I just did it the other day. The second movie still skips. I checked the raw HD files from the disk and they work with no stuttering(I am using eac3to to dump the mkv). I am guessing that the megui avscript creator "analyze" function is the culperate by miss identifying the video quality. I'll do some more tests.