Strange blocks in Mencoder

[TheCreamCrackerBoy]

Hello to all,

I'm trying to convert a movie trailer (avi format, divx codec) to SVCD format, using Mencoder. However, I noticed some white and black blocks like the scene below:
http://img182.imageshack.us/img182/7273/frame661whiteandblackblocks4au.jpg (http://imageshack.us)

These blocks don't appear if I compress the video with HCEnc or QuEnc - however, I still want to use Mencoder and I can't get rid of these blocks, even if I change matrices (Notch, AVAMAT6, etc).

If I change Mencoder version to mencoder-p4-cvs-20060323.7z (source: http://oss.netfarm.it/mplayer-win32.php), I can't encode neither 2nd and 3rd passes (error: "Cannot find codec matching selected -vo and video format 0x32315659")

I am using:
McBatch 0.0.8.0.4pb
Celtic Druid's Mencoder build (01-jan-2006)
AviSynth 2.56
Win2k
512MB RAM
Pentium 4 1.8GHz processor
Movie source: http://www.vistacodec.com/trailers/SilentHill_Trailer.zip

Video settings:
GOP=18
Bitrate=2200
MaxBitrate=2300
Matrix=NOTCH
Passes=3
No turbo, no PSNR
Aspect Ratio=4/3
DC Precision=8
Trellis=ON

Am I missing something...? Please, help me.

Thank you,

TheCreamCrackerBoy.

[hellfred]

Celtic Druid forces the use of SSE asembler code on the win32 platform for his builds, which is said to produce sporadic problems on win32 due to limitations of gcc/win32 platform. To make certain, the reason for your artefacts are not caused by the SSE instructions, try to use an mencoder build that will report not to use SSE.Stefan@SAGARA ~
$ /opt/mplayer/bin/mencoder
MEncoder dev-CVS-060420-19:19-3.4.5 (C) 2000-2006 MPlayer Team
CPU: Intel Pentium M Dothan (Family: 6, Stepping: 8)
CPUflags: Type: 6 MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 0 SSE2: 0
Compiled for x86 CPU with extensions: MMX MMX2 SSE SSE2

91 audio & 205 video codecs
No file given

Exiting... (error parsing cmdline)
E. G. try the binaries from MPlayerHQ.hu.
(http://www.mplayerhq.hu/MPlayer/releases/win32-beta/) If the problem still persists, get latest SVN build and try again (PM me for a binary if you can not finde one). If the artefacts still appear, read bugreport.html and send a bugreport to mplayer-users mailing list.

Hellfred

[dancho]

@TheCreamCrackerBoy

I did try to encode SilentHill .avi and this is error I am getting...
see the bold part plz...

==========================================================================
Opening video decoder: [raw] RAW Uncompressed Video
VDec: vo config request - 640 x 272 (preferred colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is undefined - no prescaling applied.
videocodec: libavcodec (640x272 fourcc=3267706d [mpg2])
[VE_LAVC] Using constant qscale = 3.000000 (VBR).
[mpeg2video @ 00A8AE08]MPEG1/2 does not support 2997/125 fps
Could not open codec.
FATAL: Cannot initialize video driver.
VDecoder init failed :(
Cannot find codec matching selected -vo and video format 0x32315659.
Read DOCS/HTML/en/codecs.html!
==========================================================================

VirtualDub avi info is saying that fps is 23.976 so this is solution:

-fps 24000/1001 -ofps 24000/1001

and my encoding with 3 passes went well....


:helpful:

P.S.

MCbatch file info : FPS=23.98

hehe,I must fix that....

[Mug Funky]

try it without the notch matrix and see what happens (custom matrices have been known to cause this sort of thing, not necessarily with mencoder)

[Abond]

Trellis make this. Simply disable trell. There were posts for these blocks in the old QuEnc treads.

[dancho]

trell on

http://img101.imageshack.us/img101/6272/trellon0yo.jpg (http://imageshack.us)

trell off

http://img101.imageshack.us/img101/1360/trelloff0li.jpg (http://imageshack.us)

@Abond
:goodpost:

btw
MCbatch has trell off by default...

[TheCreamCrackerBoy]

@Hellfred
Celtic Druid forces the use of SSE asembler code on the win32 platform for his builds, which is said to produce sporadic problems on win32 due to limitations of gcc/win32 platform. To make certain. (...) Try to use an mencoder build that will report not to use SSE.
This new build executes 3-pass processing ok.

@Abond & Dancho
Trellis make this. Simply disable trell. There were posts for these blocks in the old QuEnc treads.
It solved the problem! No more weird blocks!

Should I use Trellis no more with low bitrate MPEG-2 encodings with Mencoder, Quenc, HCEnc and other programs? Is it useful only for MPEG-4 low bitrate encodings?

Thanks again! :-)

TheCreamCrackerBoy.

[TheCreamCrackerBoy]

By the way, I use DGPulldown to change flags to 29.970fps (SVCD compliant) and when I mux video with audio, TMPGEnc give me this message:

http://img182.imageshack.us/img182/4023/tmpgengmultiplexingerror8ef.jpg (http://imageshack.us)

Otherwise, the video looks ok, even in my DVD player device. Should I ignore this warning?

Thanks,

TheCreamCrackerBoy.

[Mug Funky]

the underflows are probably due to libavcodec's slightly lax approach to max bitrate enforcement...

i think you can define your own ratecontrol string at the commandline, but i've no idea whether it gives enough control to stop those underflows.

[Inc]

Mencoder has been known to be very tricky in its bitrateallocation behaviours. Not mention very low bitrate encodings for (x)SVCDs where here even more tight speks regarding Bitrates have to be respected.

Imho sagiataire (was it the name?) offered HQ 3pass commandline settings where the Ratecontrol gets more under "control".

Or, try your encoding using Qenc and see if your (x)SVCD resulting streams do here respect the setted Bitratesettings as it comes with a different ratecontrol approach (XVID).