Strange X264 Playback

[dimzon]

Hi!
I encoded video using x264 rev 265:

x264 --progress --pass 1 --bitrate 700 --stats "\x264_1.stats" --8x8dct --merange 32 --subme 6 --ref 16 --filter -2:-2 --keyint 300 --min-keyint 10 --direct temporal --sar 1:1 --bframes 3 --weightb --b-pyramid --ipratio 1.40 --pbratio 1.30 --qcomp 0.75 --me "umh" --analyse "all" -o NUL "C:\dvd\ga\ga.avs"
x264 --progress --pass 3 --bitrate 700 --stats "\x264_1.stats" --8x8dct --merange 32 --subme 6 --ref 16 --filter -2:-2 --keyint 300 --min-keyint 10 --direct temporal --sar 1:1 --bframes 3 --weightb --b-pyramid --ipratio 1.40 --pbratio 1.30 --qcomp 0.75 --me "umh" --analyse "all" -o "C:\dvd\ga\ga.mp4" "C:\dvd\ga\ga.avs"


I used MP4Box by Celtic_Druid from 11 June 2005 to mux it with audio:
MP4Box.exe -new my.mp4 -ismax -add C:\dvd\ga\ga.mp4 -fps 25 -add C:\dvd\ga\g.m4a -sbr

I'm using Haali Media Splitter 12/06/2005 and FFDSHOW 19/06/2005 from Celtic_Druid to decode my video.

Problem
All frames are in right order, CPU is around 70% BUT sometimes motion is jerky (looks like framedrops).
Any suggestions?

[DeeGee]

Well if you would have used nero decoder I might have suspected that the large ammount of reference frames is the problem, but I haven't noticed the same problem on ffdshow when using 15 reference frames.

[dimzon]

I might have suspected that the large ammount of reference frames is the problem
If I reduce max amount of reference frame down to 8 - how much quality loss will it be?

[Sharktooth]

You'll loose almost nothing coz Reference frames > 5 = OVERKILL!!!
Me range > 16 = useless too.

[DeeGee]

Is there any kind of quide for x264 settings? I usually use quite large ammount of reference frames and big motion estimation range as i haven't bothered doing tests of my own to decide what kind of settings are good enough.

[dimzon]

You'll loose almost nothing coz Reference frames > 5 = OVERKILL!!!
Me range > 16 = useless too.
Can You tell me NeroAVC <-> x264 settings mapping. Bcz I have some little expirience with NeroAVC.

[Sharktooth]

well, theres no guides but default settings works pretty well with some slight modifications.
me range = 16 is ok 99.9% of times (note: this is not mv range!!!)
my preferred settings are:
subme 5 or 6
2 or 3 bframes
3 refs
uhm
8x8dct
analyze all
deblocking alpha -5: beta -5 (for bitrates around 1000-1200kbps)
ratetol 1
weighted b-prediction
cabac
chroma ME
b-pyramid
other settings left to default.

[dimzon]

well, theres no guides but default settings works pretty well with some slight modifications.
me range = 16 is ok 99.9% of times (note: this is not mv range!!!)
ratetol 1

Can you tell me about this 2 parameters - what they mean and how they affect on video quality?

Thanx!

[Sharktooth]

ratetol is the bitrate variability control. the more you set it the more the bitrate is NOT allowed to vary. if you want a more "constant" quality use high ratetol.
merange is the number of iterations for motion vector extimation (search). 16 is a safe value.

[dimzon]

ratetol is the bitrate variability control. the more you set it the more the bitrate is allowed to vary. Since i prefer keeping about the same quality over the whole movie i use ratetol = 1.
Is it something like Curve Compression in XviD?

merange is the number of iterations for motion vector extimation (search). 16 is a safe value.
Thanx a lot!

[Sharktooth]

Is it something like Curve Compression in XviD?
not properly but it helps averaging (or not) the bitrate variability.

[DeeGee]

Is uhm worth the slowdown it causes? I thought that it was just rotated hex that isn't optimized.

[Sharktooth]

it depends on the source.

[bond]

ratetol is the bitrate variability control. the more you set it the more the bitrate is allowed to vary. Since i prefer keeping about the same quality over the whole movie i use ratetol = 1.

constant quality means varying bitrate means high ratetol

[IRMA1024]

is there any detailed explanation (with technical stuff) for each x264 option?

what it does, what it affected, the result, encoding speed affected,etc..

[berrinam]

At the moment, there is no single comprehensive guide for the options, but the mplayer man page (http://www.mplayerhq.hu/DOCS/HTML/en/menc-feat-x264.html) is a very good explanation for some of the features, and others can be found by searching on this forum.

[Sharktooth]

constant quality means varying bitrate means high ratetol
right... post edited.