MeGUI: General Questions and Troubleshooting Thread

[Kurtnoise]

you should try to play your file with a decent player first and see if the subtitles are there.

[check]

FFDshow was the culprit...Would just like to add here that the culprit is most likely the configuration, rather than the tool -- unless you have an ancient version.

Well, now my problem has spawned a new buddy. While I solved the "filter graph won't talk to me" nonsense (by uninstalling ffdshow and forcing AC3Filter), NOW I get "unable to determine the duration of the audio."Can you please summarise your current setup which causes this issue again?

Output video has bitrate 1530 Kb/s (The length of video is 9 min, so the difference is very big)

Why can it be?I am guessing because you used 1pass ABR, and your video is a somewhat pathological case which screws up ratecontrol. I will delay judgement until I see the logfile though: Post the logfile output from MeGUI for this job. You can find it in the MeGUI\logs folder if you've closed the program since.

ABR stands for Average Bit-Rate. It doesn't mean you always get specified bitrate.The MeGUI default will only let this be 1% off. (http://mewiki.project357.com/wiki/X264_Settings#ratetol)

[mutha88]

Does MeGUI include the new experimental adaptive quantizer ? :)

One more question.. what does a "noise filter" mean? I am downscaling 1280x544 (720p) to 800x336 with MeGUI... do i need to add a noise filter? Is Lancsoz(Sharp) the most appropriate filter for me? Thank you for answering my question (in advance)!

[Atak_Snajpera]

Does MeGUI include the new experimental adaptive quantizer ?
Yes if you download special x264 build and add necesary commands

[Xodarap]

Would just like to add here that the culprit is most likely the configuration, rather than the tool -- unless you have an ancient version.

Can you please summarise your current setup which causes this issue again?


FFDshow went through several uninstalls / fresh reinstalls. That's including my watchful eye on the registry for leftovers. Newest version. I just hadn't tried it WHILE it was uninstalled (because I was thinking the problem was with something ELSE). Now, with the merit slider all the way down, things are working out. Honestly, AC3Filter has proven to be a much better normalizer, anyways...

As far as I know (using graphedit) EVERY dshow filter on my system underwent similar treatment. So I don't know what the setup was doing.


have you already thought to format and re-install windows? (joking)
however, try this one: use ds source for video (ensure you specify audio=false) and use nic ac3 source filter (it comes with megui) for the audio (the .ac3 file)

The nic filter thing -- tried that FIRST.

You THOUGHT you were joking. And guess what worked? A reformat! :P Really, I did it before reading it from you, and needed to anyways. God knows what was clogging everything up, but it all works beautifully now.


Except now I can't get subs on MPC, and it plays multiple audio tracks concurrently -- has me using WMP11 *shudder*... (Or MPlayer, I just like my ffdshow settings...) Sorry, that's for another thread.

I wish I knew what was causing the issues before...

[Xodarap]

Does MeGUI include the new experimental adaptive quantizer ? :)

One more question.. what does a "noise filter" mean? I am downscaling 1280x544 (720p) to 800x336 with MeGUI... do i need to add a noise filter? Is Lancsoz(Sharp) the most appropriate filter for me? Thank you for answering my question (in advance)!

Is your source noisy? IE: is it "grainy" or "flickery" or otherwise of a poor quality that moves around? A noise filter, to put it very simply, blurs the image to cover up defects. That includes blurring across time (to hold things still, like flickering or dustiness). However, your source may be "clean," in which case, you only might need a noise filter to provide additional encoding efficiency. I always throw in a temporalsoften(3,2,2,6,2) or (2,3,3,6,2) for good measure, even on a clean source...

[fleon]

so, if you have installed the vobsub package correctly, you need to fix your avs script like this:

DGDecode_mpeg2source("C:\FINAL_FANTASY_7\VIDEO_TS\New Folder\VTS_02_1.d2v",info=3)
ColorMatrix(hints=true,interlaced=true)
VobSub("C:\FINAL_FANTASY_7\VIDEO_TS\New Folder\VTS_02_0.idx")
tfm(order=1).tdecimate()
#crop
Spline36Resize(480,272) # Spline36 (Neutral)
#denoise
__film = last
__t0 = __film.trim(1, 130004)
__t1 = __film.trim(144862, 145135)
FadeOut(__t0, 23) ++ FadeIn(__t1, 23)

because this sub file is not a text file. The idx one (formely index) must be in the same .sub file folder.

Well, after encoding the video with that script and puting the muxed video(audio+video) on my psp I still cant see the subtitle, so what could be the problem? I wanna like burn them on the video, because I know that the psp cant render subtitles

you should try to play your file with a decent player first and see if the subtitles are there.
Well, in bsplayer I can see the video with the subtitles, on vlc player I cant, and on windows media player I get a black screen and the program starts to freeze up

[TheResidentEvil]

I tried to use Handbrake to make an .MKV file of a .mpg i have (I didn't know about MeGUI) and the file locks up in VLC. I want to create an H.264 mp4 of an .mpg .

I keep finding info that is more related to ripping from a DVD but I didn't have a DVD to start with. I am a avid AutoGK user so I don't know everything. The file I have is a 720p capture via OTA. Is there any guide for what I am looking to do or how to re-encode any file to H.264 ?

[Sharktooth]

there are plenty just :search:

[meatwad666]

i'm having a bit of a mysterious problem that i'm hoping someone can lend some insight. I recently upgraded my motherboard and videocard. The old motherboard was an agp model (biostar k8m800) with a 5700U agp card. the new board is pcie (pchips A33G) with a HD2600xt. the cpu, ram, and HD are all the same, although i recently got rid of running a seperate OS drive (on an old 9gig drive) from my capture drive, but I think the issue arose before I went to 1 HD.

Although i did forget to copy over my profiles, i'm pretty sure they're unchanged as I just use the ce-* profiles but running in ABR.

my issue is that my encoding speed seems to be roughly 1/2 of what it was on the old board; is there anything immediately obvious to people as to what could be causing the problem? prior to this I was using megui with tools current to about sept 07, now i am using the most recent updates.

the source material is HD captures in 1080i or 720p. I used to be able to convert 720p at 350meg/40 min in just about realtime (probably becuase i was just dumping frames to get 30fps with selecteven() ) and 1080 would take about 2.5-3hrs.

[mitsubishi]

Meatwad, the HD probably isn't the problem, it can affect speeds if being starved for bandwidth. Are your captures in lossless format? Is the source and destination on a different partition. Might be worth a defrag and checking for DMA (you installed the mobo drivers right?) anyway though.

But for such a speed drop, maybe somehow you are now only using one core (if you have a dual). Check your CPU usage.

[meatwad666]

Meatwad, the HD probably isn't the problem, it can affect speeds if being starved for bandwidth. Are your captures in lossless format? Is the source and destination on a different partition. Might be worth a defrag and checking for DMA (you installed the mobo drivers right?) anyway though.

But for such a speed drop, maybe somehow you are now only using one core (if you have a dual). Check your CPU usage.

cpu is a athlon 64 3500+ (one core), CPU usage is pegged, the captures are the raw transport streams, source and destination are always the same partition (and physical drive), IDE channel is uDMA-5. mobo drivers were installed, but this board is garbage, so maybe that can affect it. I just didnt expect it to affect it by 2x. (i also dont use a page file, so i dont think its the drive being hammered for page requests, and I have enough ram anyway)

thanks for the help

[audioffile]

I'm trying to encode the ac3 track from my DVD into aac with ndaac. The problem is that the output file is essentially empty (727 bytes). I noticed below that the there is no input file being passed to neroaacenc. Am I doing something wrong to cause this?

Input: Channels=6, BitsPerSample=16, SampleRate=48000Hz
Command line used: D:\Program Files\megui\tools\neroaacenc\win32\neroAacEnc.exe -ignorelength -q 0.5 -if - -of "L:\DVDs\FRIDAY_AFTER_NEXT\VIDEO_TS\English.mp4"

I also tried running the file through neroaacenc myself but i discovered that it wants wav input. So I guess MeGUI actually takes care of that for me... it converts my ac3 into wav and then feeds it into neroaacenc. Is that correct? If so, there appears to have a breakdown somewhere along the line. Any suggestions appreciated. Thanks.

[mroz]

Don't worry about the command line - the audio is processed by Megui internally using an AviSynth script (see the log if you're interested) and the output from that fed directly to the encoder (the equivalent of piping it, I imagine).

Try forcing Megui to use directshow to decode your audio source, rather than the NicAudio avs plugin it uses by default - click on the Config button in the audio input panel of the main megui window & check 'Force decoding via direct show'.

That's assuming you can play the ac3 track using a direct show based player.

The problem is almost certainly on the decoding side, so the above has a good chance of helping.

[audioffile]

audio is processed by Megui internally using an AviSynth script (see the log if you're interested)

I didn't see anything in my logs that showed how the piping would occur, but I did notice that even on successful encodes the -if parameter remains blank in the logs.

Try forcing Megui to use directshow to decode your audio source

That didn't seem to make any difference either.

Here's the log again:

Input: Channels=6, BitsPerSample=16, SampleRate=48000Hz
Command line used: D:\Program Files\megui\tools\neroaacenc\win32\neroAacEnc.exe
-ignorelength -q 0.5 -if - -of "L:\DVDs\FRIDAY_AFTER_NEXT\VIDEO_TS\English.m4a"

Error:
*************************************************************
* *
* Nero Digital Audio Reference MPEG-4 & 3GPP Audio Encoder *
* Copyright 2007 Nero AG *
* All Rights Reserved Worldwide *
* *
* Package build date: Aug 6 2007 *
* Package version: 1.1.34.2 *
* *
* See -help for a complete list of available parameters. *
* *
*************************************************************


ERROR: Could not open file

[duckdown]

Hello , no matter what I do this program still is creating incorrectly sized XviD segments for me.

I tell it to do a 4 minute segment around 750kbps, it was supposed to make a file sized 27.5 but instead just freely creates its own sized clip of a massive 40mb and a bitrate of like 1050

What is going on here? I have tried applying ALL of the proper settings found in the sticky regarding oversize/undersize yet this bloody program is still doing it.

If I use StaxRip it makes the properly sized segment so why is this so different?

I am extremely irritated with the unpredictable output of this program and its failure to achieve the specified bitrate/filesize.

What are my choices here?

Log for job job48

Job commandline: "C:\Program Files\megui\tools\xvid_encraw\xvid_encraw.exe" -i "C:\files\int16.avs" -pass2 "C:\files\int16.stats" -bitrate 744 -kboost 100 -ostrength 10 -oimprove 10 -odegrade 10 -overhead 0 -nopacked -vhqmode 4 -closed_gop -imin 1 -imax 3 -pmin 1 -pmax 3 -bquant_ratio 100 -par 1:1 -threads 0 -avi "C:\files\int16.avi"
xvid_encraw - raw mpeg4 bitstream encoder written by Christoph Lampert 2002-2003

Trying to retrieve width and height from input header
xvid [info]: Avisynth detected
xvid [info]: Input colorspace is YV12
xvid [info]: Input is 512 x 384, 29.970fps (30000/1001), starting from frame 0
xvid [info]: Number of frames to encode: 9211, Bitrate = 744kbps
xvid [info]: xvidcore build version: xvid-1.2.0-dev
xvid [info]: Bitstream version: 1.2.-127
xvid [info]: Detected CPU flags: ASM MMX MMXEXT SSE SSE2 TSC
xvid [info]: Detected cpus = 4, threads requested = 3, threads in use = 3
xvid [info]: Threaded input reading active

Tot: enctime(ms) =189265.00, length(bytes) = 41045501
Avg: enctime(ms) = 20.54, fps = 48.68, length(bytes) = 4455
I frames: 83 frames, size = 23585/ 1957611, quants = 2 / 2.66 / 3
P frames: 3270 frames, size = 8757/ 28637795, quants = 3 / 3.00 / 3
B frames: 5858 frames, size = 1783/ 10450095, quants = 5 / 5.89 / 6
desired video bitrate of this job: 744 kbit/s - obtained video bitrate (approximate): 1074 kbit/s


Wow. This one is even friggin worse..


Log for job job52

Job commandline: "C:\Program Files\megui\tools\xvid_encraw\xvid_encraw.exe" -i "C:\files\para01.avs" -pass2 "C:\files\para01.stats" -bitrate 900 -kboost 100 -ostrength 10 -oimprove 10 -odegrade 10 -overhead 0 -nopacked -vhqmode 4 -closed_gop -imin 1 -imax 3 -pmin 1 -pmax 3 -bquant_ratio 100 -par 1:1 -threads 0 -avi "C:\files\para01.avi"
xvid_encraw - raw mpeg4 bitstream encoder written by Christoph Lampert 2002-2003

Trying to retrieve width and height from input header
xvid [info]: Avisynth detected
xvid [info]: Input colorspace is YV12
xvid [info]: Input is 624 x 352, 29.970fps (30000/1001), starting from frame 0
xvid [info]: Number of frames to encode: 5926, Bitrate = 900kbps
xvid [info]: xvidcore build version: xvid-1.2.0-dev
xvid [info]: Bitstream version: 1.2.-127
xvid [info]: Detected CPU flags: ASM MMX MMXEXT SSE SSE2 TSC
xvid [info]: Detected cpus = 4, threads requested = 3, threads in use = 3
xvid [info]: Threaded input reading active

Tot: enctime(ms) =187904.00, length(bytes) = 35870179
Avg: enctime(ms) = 31.70, fps = 31.55, length(bytes) = 6050
I frames: 145 frames, size = 24749/ 3588606, quants = 2 / 2.49 / 3
P frames: 2382 frames, size = 11223/ 26734765, quants = 2 / 2.99 / 3
B frames: 3399 frames, size = 1631/ 5546808, quants = 3 / 5.75 / 6
desired video bitrate of this job: 900 kbit/s - obtained video bitrate (approximate): 1457 kbit/s <--- WTF?

[check]

duckdown, your profile limits the min/max quantizers too much. Either change these by hand or use a more relaxed profile.

[mutha88]

1.Is spline36 the best downmixing (from 720p to 800x336 res.) filter? Or is spline64 better?!

2. When i see some blocks, should i use for "Deblocking Strenght" -2 (minus 2) and for "Deblocking Treshold" -1 (minus 1) ?

3. For this downmixing/downscaling encoding should i use "HQ-Slow/Slower" profile? I am downscaling with "CE-High Profile" now :).

:thanks: for all of your answers!

[fleon]

hi, I have a problem with megui that i have never had before, you see I have encoded some videos to be compatible with my psp with the PD-psp profile and until now they have work, but recently I have encoded one I tried some things like encoding the audio on differents bitrates and also on a bitrate that have worked with other videos but nothing, the video before converted was a xvid/mp3 file, and i used this script:

AviSource("C:\Documents and Settings\Leon\Desktop\Nuevo para pasar al disco duro\abc.avi")
TextSub("C:\abc.srt")
#deinterlace
#crop
Spline36Resize(480,272) # Spline36 (Neutral)
#denoise
and this is what gspot tells me about the muxed video
http://img293.imageshack.us/img293/1017/abcdb9.th.jpg (http://img293.imageshack.us/my.php?image=abcdb9.jpg)

[Ranguvar]

@fleon: Make sure you place the videos in ms0:\VIDEO\, where ms0 is your PSP drive letter, and your firmware is >= 3.30. You probably have those, but I'm not sure... is the video black, does it say Unsupported, or what?

@mutha88:
1.) Technically Spline64 is better. But the difference is nigh-impossible to see. Even me, a quality freak, only uses 36.

2.) No. Negative values will decrease deblocking, so for cases in which you have a lot of bitrate/options on and you want sharper, more detailed video. You'd use positive values for less blocks, but you'll get 'softer' video, and slightly less details.

3.) Downscaling doesn't make a difference in that regard.

:)

[saint-francis]

If I am wanting to queue up two movies to encode using 2 passes for each using the same x264 profile can I set a different bitrate for the second one while it's still on it's first pass or will the new modified profile change the settings for the second pass of the first encoding? I know that the command gets sent to x264.exe only at the beginning but since both passes are queued up as individual jobs I don't know if the new profile will be applied.

[mitsubishi]

Saint-Francis.

Yeah that's fine, the jobs are stored as jobs. once set they do not look at the profiles.

There does seem to be a bug I noticed though, that if you are encoded the same source twice it can go awry since it uses the source filename for the stats file rather than the output, but two different movies, no problem.

[saint-francis]

Thanks for the speedy reply mitsubishi.

:thanks:

[mutha88]

Thank you Ranguvar! Didn't know the stuff you've wrote here :)

[blazo]

Don't know if this has been answered yet...
I'm trying to convert my DVD to MP4 (AVC/AAC) using MeGUI and sticking with anamorphic setting (CleverTM anamorphic encoding). AVS file has proper AR, but resulting MP4 file plays at 720x576 (1:1 DAR). I use RAWAVC for video (x264 encode) and MP4Box for muxing. Any ideas how to get proper (16:9) DAR?

[mroz]

If you let Megui invoke mp4box to do the muxing it should have the correct aspect. If you generate raw avc with Megui & mux externally, you'll have to explicitly tell mp4box the correct PAR, since the PAR info isn't embedded in the raw avc data afaik.

[blazo]

I let MeGUI invoke MP4Box and the result was not anamorphic. Nevertheless I have figured out where the problem was.
http://forum.doom9.org/showthread.php?t=133124

It's in RAWAVC (.264) which I was using. Now I switched to MP4 and everything is OK.

[dolphinjet]

hi, please allow me to ask a newbie question
Does AutoEncode use the profile I chose in the Input > Video interface? I'm in doubt as the Autoencode window did not show up what profile.

[Ranguvar]

@dolphinjet: I think so. Try and see :)

@blazo: Yeah, if you encode as raw AVC stream, it won't even know the framerate, let alone the anamorphic settings :p

@mutha88: Welcome :) What do you mean?

[Zergrinch]

Am I doing something wrong? Any attempt to click AutoEncode with meGUI 3 produces this error window:

http://upload.jetsam.org/meguierror.jpg

[Carpo]

heres a strange one for you.

I have a film Abyss Special Edition, which on the back of the box says 2:35:1 and widescreen 4:3, there are two different versions on the same disc, Theactrical and Extended.

In the ifo it shows

VTS overview:

Menu attributes:
Video: MPEG-2 720x576 (PAL) (PAL 625/50) (16:9) (pan-scan)
Audio 1: Not Specified (Dolby AC-3) 2ch 48Kbps DRC
SubPicture 1: Not Specified (2-bit rle )

Title Set (Movie) attributes:
Video: MPEG-2 720x576 (PAL) (PAL 625/50) (4:3) (not specified perm.display)
Audio 1: English (Dolby AC-3) 6ch 48Kbps DRC (ID: 0x80)
SubPicture 1: English (2-bit rle ) (ID: 0x20)
SubPicture 2: English (2-bit rle ) (ID: 0x21,0x20)

dvd2avi picks it up as 4:3, question i have is do i encode it as 4:3 then tell the mux tools its 16:9, or do i tell megui to override dvd2avi and select 16:9 there ?

[mroz]

Firstly, are you having any problems selecting the version of the film which you want? If they're in distinct VTS it isn't a problem with D2V Creator, however sometimes distinct PGCs exist in one VTS & you need an extra step to pull out the one you want as Megui doesn't currently parse IFOs itself.

In this case I use DVD Decrypter from the original dvd, or if I only have a VIDEO_TS folder by that point, PGCDemux (http://download.videohelp.com/jsoto/dvdtools.htm).

Let's assume you have the version you want.

Assuming it's letterboxed 4:3, accept the above & when you crop the letterboxing off, Megui will get the aspect correct.

Or are you saying the aspect info above is wrong? In that case just override the DAR setting within the AVISynth Script Creator window.

[Carpo]

i have ripped the extended version i can tell that as its longer, and i have got the info in my post above from the ripped ifo, when i play it in a dvd player it comes up as 16:9

edit: when i play the vobs i ripped to disc it plays as letterboxed 4:3

edit: little Q about audio, i am backing up a lot of dvds i have to x264, i would like to use ac3 but some of the ac3 files are 300meg plus, which if i want to keep them to a 2 disc backup the picture quality suffers, i have seen that it is best to use 128 abr aac, and anything above 160 is a waste, if that is so why does megui have 192 and 256 options, and which should i use HC or LC, seeing as i want to keep the best audio i can?

Should i go with 128 even on something like lord of the rings, which is near 3 hours ?

[audioffile]

edit: little Q about audio, i am backing up a lot of dvds i have to x264, i would like to use ac3 but some of the ac3 files are 300meg plus, which if i want to keep them to a 2 disc backup the picture quality suffers
Assume that you mean two CDs, 1400MB.
i have seen that it is best to use 128 abr aac, and anything above 160 is a waste, if that is so why does megui have 192 and 256 options, and which should i use HC or LC, seeing as i want to keep the best audio i can?

Should i go with 128 even on something like lord of the rings, which is near 3 hours ?
If I run the audio as VBR q=.31 I typically get my audio file to be about 65-70% or the size of the AC3. Obviously it's not always going to be perfectly predictable. I have never noticed any degradation in the audio with the above settings. I would recommend cutting the audio down the q=.25 or even lower to see what kind of AAC file size you get. Anyway, the final answer with audio is always your ears, cut it down until you notice the difference.

Strangely, using q=.5 has given me AAC files that were larger than the original AC3, which didn't make a lot of sense to me.

Another thought, since LOTR is a very long movie (twice as long as average) you might just bit the bullet and split it across 3 CDs. Good luck.

[Carpo]

i have decided to go with 50% of the original ac3 - i cant really notice a difference in quality, i went with LC 192k, yes for lotr discs i was going down the 3cd route (2100M), although after reading what you have put i will give q.3(1) i go on a few tests :) thanks

[delxd]

im trying to convert a .mkv file to .mp4 and i cant sucess either converting the audio or the video.. thats what i get in my log :

MeGUI Version: 0.2.6.1040
OS used: Microsoft Windows XP Professional Service Pack 2
.Net Framework installed: 2.0.50727.42

------------------------------------------------------

Looking for job processor for job...

Processor found!



------------------------------------------------------


Starting job job4 at 04:55:25

Starting preprocessing of job...

Preprocessing finished!

successfully started encoding

Processing ended at 04:55:27

------------------------------------------------------

Log for job job4



Error:

------------------------------------------------------

End of log for job4
------------------------------------------------------


And when i try to load the avisynth script i get a window saying :
Avisynth script error : DirectShowSource: Couldn't Open the file
C:/.............. mkv
Wasnt possible to find a combination of filters to the flux (?)
something like that.. sorry for my bad english.. but thats the first time i get this error working with a .mkv file..

my avisynth script : for audio [ DirectShowSource("C:\Lorhan\[ZetSub] Lupin III - S01E02 [AD9B51F0].mkv", fps=23.976, convertfps=true)
DelayAudio(+0.0)

ConvertToYV12() ]

Video : DirectShowSource("C:\Lorhan\[ZetSub] Lupin III - S01E02 [AD9B51F0].mkv", fps=23.976, convertfps=true, audio=false)
ConvertToYV12
DeGrainMedian(limitY=2,limitUV=3,mode=1)

Hope that can help solve my prob

[check]

delxd: can you play the video in windows media player?

[delxd]

delxd: can you play the video in windows media player?

Actually i cant... i can play it just in the other players such as Media Player Classic,BsPlayer..

[check]

sounds like you need to clean up your directshow environment before you can use directshowsource() then.

[delxd]

sounds like you need to clean up your directshow environment before you can use directshowsource() then.

and how i do that exactly? uninstalling all my codecs or something like that? i got only CCCP installed on my system..

[weaver4]

Most of the time I want to take one of my new movies and make a backup for my Media Player (Popcornhour) and make a copy for my iPod. I use one-click profiles. But when my queue is running I get a File-Already-Exist error dialog after it runs DGIndex on the first copy and starts the second copy. Any way to fix this? I like to start this process off before I go to bed and have it done in the morning.

[pak_sunny]

Hi,
I hope i find a solution to my problem here i am using a amd turion 64 laptop with vista premium . the thing is that after installing megui it wont install al thee updates ( Codecs, eg. MP4Box ) I mean non of them and says error installing them,????

[Selur]

the thing is that after installing megui it wont install al thee updates ( Codecs, eg. MP4Box ) I mean non of them and says error installing them,????
running megui as administrator should help there;)

[check]

and how i do that exactly? uninstalling all my codecs or something like that? i got only CCCP installed on my system..
Grab the CCCP Insurgent and post a test render on the non working file.

[MKVCrazy]

Hi, I have been on the board for quite long and when I tried to encode my new videos, it still has a bug or I don't know but it crashes every time when I try to open something in AviSynth Script Creator.

I read a few threads about this before I post and someone said it has been solved! but I couldn't understand/see the final answer.

here is what I get when I load a file:
http://i28.tinypic.com/suym2h.png



What I have:

-MeGUI 2.6xxx (Stable Version)
-AviSynth 2.5.7 (Stable Version)
-K-Lite Codec Pack (Full Version)
-.NET Framework 3.0 Installed


What else might be causing the problem?

MKVCz.

[mroz]

Is Megui's aviscript preview sufficiently accurate?

I'll explain what I mean. I'm currently having a problem & I'm not sure if the issue is down to how Megui renders, or rather lets Windows render, the script, or if it's the result of a filter problem on my machine.

I have a source mpg that's far too bright. When I transcode it using Megui the resulting mp4 is faithful & so equally too bright. However, the preview window shows the video with desirable brightness.

There seem to be two issues here. One is with my source & concerns the question of how I modify the levels to get the output I want - that isn't a matter for this thread.

The other however might be. It being, why doesn't the preview window show my overly bright video?

I've had a play with graphedit & it seems the avs is rendered with the chain:
SummerCollection.avs
AVI Decompressor
Color Space Converter
Video Renderer

And it is the Color Space Converter that's correcting the brightness. I can confirm this by removing it from the chain & replacing it with an ffdshow raw video filter which I can easily configure to leave the colour levels & space alone.

This automatic conversion might well be desirable for general playback, but clearly not when one is trying to preview the direct output of the script.

If I render the source mpg, the converter isn't involved, which explains why it displays faithfully. Similarly, when the script is passed as input to x264, the converter mustn't be involved (thankfully, as this isn't easily within the user's control), resulting in a faithful but overly bright output mp4. Finally, playback of the mp4 is faithful & the converter is once more not involved (as checked with graphedit).

Does this indicate a problem with Megui's preview rendering? Could it be made more faithful by controlling the graph used to render the script? I guess this must be possible as x264 gets to see the faithful unmodified video.

Or is there some problem unique to my setup that I need to correct?

For now I'm having to resort to previewing my avs in graphedit, manually removing the converter for each test, which is really annoying.

Lastly, if anyone wants to take pity on me, any clues as to how I perform an accurate conversion to fix the brightness issue with my source? I was going to just tweak gamma until I realised there must be a colourspace issue. It's embarrassing when Windows can do a better job of rendering the video than I can with avisynth.

Edit: Ok, now I'm more confused, but am inclined to think this isn't in any way a Megui issue, so if you agree & wish, please delete or move this post.

For the record, I think I was seeing different behaviour in Megui's preview window purely as by chance it involved a different sequence of colourspace conversions; specifically the filters in the chain on that occassion performed a converstion to rgb32, but didn't when feeding x264 for example. I can mimic the former by adding a ConvertToRGB32() to the end of the script, whenceforth I get the darker more appropriate rendering.

Of course colourspace conversions shouldn't produce significant changes in the video (certainly not when converting to a more accuate space), unless the assumed colour coefficients are wrong at any step. However, the script looks correct. If I read the hint info from mpeg2source via info=1, I see the expected Rec.709 (my source is from a dvd originally), thus the ColorMatrix call should be converting Rec709 to Rec601, which is as expected. Furthermore, the ConvertToRGB32 should work correctly as that assumes an input using Rec601. So, I shouldn't be seeing any problems...

Unless the Rec.709 info concerning the source material is itself wrong. In which case the source is at fault & it's no wonder something like this is going wrong somewhere. In other words, the inconsistent behaviour isn't Megui's fault.

Does that make any sense? Or am I on the wrong track or indeed completely off the rails? I considered deleting this post, but would rather not until someone confirms this has nothing to do with Megui & I should remove it. Thanks for the patience ;)

[check]

Is Megui's aviscript preview sufficiently accurate?
Yes. Inaccuracies will arise due to the video renderer in use in other places, but MeGUI and VirtualDub should basically be considered authoritive.

[mroz]

Thanks. I've since found The bright cases were seemingly the deviant renderings, as they only occurred in Zoomplayer, which I had been trusting to be accurate, as it has always proved most reliable & I've never seen this issue before despite years of use.

Switching the renderer away from overlay mixer to /any/ other option cured it.

Still seems strange I've never seen this issue before. It was roughly equivalent to a gamma correction by 0.69, which is huge.

[saint-francis]

Could someone please explain to me what exactly clever anamorphic encoding does? Does it keep the original aspect ratio and signal x264 to resize? All I know is that when it's used avisynth doesn't resize and there are some commands which I don't understand that somehow signal resizing later on.

[mroz]

The original pixel aspect ratio is left unaltered. Resizing might not be necessary at all, typically. The commands you're referring to are just Megui setting a couple of variables so it can later keep track of what the display aspect ratio is; these are used subsequently to embed the aspect ratio information into the video stream (rather than to resize it).