Poor Xvid video from avi

[akkers]

I have PAL avi files that are from a camcorder. They are SD 720x576 PAL interlaced files.

When I convert them to xvid or divx files, the resulting video has a lot of artifacts or motion stutter.

I have tried converting the files in tmpgenc, dvix pro, autogordianknot in higher quality settings but I still get very poor results.

What am I doing wrong.

[poisondeathray]

are you encoding progressive? you might be using a poor quality deinterlacer (deinterlacing artifacts & "jaggies") & throwing out 1/2 the temporal information (deinterlacing to 25p instead of "bobbing" to 50p)

[akkers]

There is no option divx encoder for interlacing/progressive. In tmpgenc I am setting interlaced. in autogordiannow, I cannot see any setting for interlaced/progressive.

I have to say the video from autogordianknow looks ok quality-wise when played on the pc but stutters when played on a set-top box. That would indicated some problem with interlacing.

[poisondeathray]

hard to say without more information

what set top box? I'll be it probably doesn't understand interlaced xvid - are you getting combing (horizontal lines) when playing the tmpgenc encode ?

use mediainfo on the encoded file from autogk - is it 25p or 50p ? what bitrate ? what settings ?

or maybe your box can't handle certain encoding settings or higher bitrates

[akkers]

I ran mediainfo on the autogk file:

General
CompleteName : F:\Vids\divxpla\test_agk.avi
Format : AVI
Format/Info : Audio Video Interleave
FileSize/String : 700 MiB
Duration/String : 14mn 41s
OverallBitRate/String : 6 661 Kbps
Encoded_Application : VirtualDubMod 1.5.4.1 (build 2178/release)
Encoded_Library/String : VirtualDubMod build 2178/release

Video
ID/String : 0
Format : MPEG-4 Visual
Format_Profile : Advanced Simple@L5
Format_Settings_BVOP/String : No
Format_Settings_QPel/String : No
Format_Settings_GMC/String : No warppoints
Format_Settings_Matrix/String : Custom
CodecID : XVID
CodecID/Hint : XviD
Duration/String : 14mn 41s
BitRate/String : 6 528 Kbps
Width/String : 720 pixels
Height/String : 544 pixels
DisplayAspectRatio/String : 4:3
FrameRate/String : 25.000 fps
ColorSpace : YUV
ChromaSubsampling : 4:2:0
BitDepth/String : 8 bits
ScanType/String : Progressive
Compression_Mode/String : Lossy
Bits-(Pixel*Frame) : 0.667
StreamSize/String : 686 MiB (98%)
Encoded_Library/String : XviD 1.2.1 (UTC 2008-12-04)

Audio
ID/String : 1
Format : MPEG Audio
Format_Version : Version 1
Format_Profile : Layer 3
Format_Settings_Mode : Joint stereo
Format_Settings_ModeExtension : MS Stereo
CodecID : 55
CodecID/Hint : MP3
Duration/String : 14mn 41s
BitRate_Mode/String : Variable
BitRate/String : 120 Kbps
BitRate_Nominal/String : 128 Kbps
Channel(s)/String : 2 channels
SamplingRate/String : 48.0 KHz
Compression_Mode/String : Lossy
StreamSize/String : 12.6 MiB (2%)
Alignment/String : Aligned on interleaves
Interleave_Duration/String : 24 ms (0.60 video frame)
Interleave_Preload/String : 498 ms
Encoded_Library/String : LAME3.98r
Encoded_Library_Settings : -m j -V 4 -q 2 -lowpass 17 --abr 128

[poisondeathray]

What device are you using ?

~6.5Mb/s bitrate

Some set top players will "poop out" around 3-4Mb/s, and can't handle the higher bitrates . Of course PC playback can handle higher bitrates

25p will play more "jerky" than 50p , regardless of player

[akkers]

I am using a standard dvd player that plays divx and xvid files. It happily plays xvid files I download from net.

Should I be encoding progressive even though my original files are interlaced and my tv set is PAL?

[poisondeathray]

Most xvid compatible dvd players don't handle interlaced xvid/divx , so you don't have an option to encode interlaced if you are using divx/xvid . Otherwise you get combing (it doesn't deinterlace on the fly) - So you should be encoding progressive. Do some tests or check your manual

[akkers]

Ok, I will do some tests with small files.

[akkers]

I have done a few tests with reduced bit rates but the problem still persists.

The video plays very well with good picture quality. However, when there is movement or panning, there is a lot of stutter.

[poisondeathray]

Is the "stutter" there on the PC playback? 25p is supposed to look juddery , just like 24p

25p pan will look "jerky" compared to 50p pan . 50p pan will look silky smooth . Your original file had 50 fields per second - that is 50 moments in time are represented per second. Cutting that in 1/2 will naturally make it look comparatively jerky

If it's not a playback issue, what you see maybe normal 25p "stutter" . Do your pans more controlled and slowly

If you upload a sample clip, someone will verify what is going on

[akkers]

I am not too hot on the 25/50p stuff. Basically I have PAL SD footage from a camcorder.

How do I convert it to 50p? Basically what is the best way to convert basic SD PAL footage to XVID/DIVX?

I did'nt know DIVX/XVID was that complicated and cant do a basic PAL conversion.

[poisondeathray]

how do I convert it to 50p?

You double rate deinterlace to convert to 50p

25p conversion means you throw out 1/2 the frames (i.e discard half the temporal information)

Basically what is the best way to convert basic SD PAL footage to XVID/DIVX?

There is no "best" way . There are pros/cons to any method .

For example there are high quality motion compensated deinterlacers, but they are very CPU intensive (= slow) . That's a trade off you decide if you want to make. The lower quality deinterlacers leave jaggy deinterlacing artifacts but process much faster

One of the better deinterlacers is QTGMC in avisynth. It's quite slow on default settings, but you can use one of the faster presets and it still produces much better quality than your typical deinterlacers

[manono]

The problem, as pdr guessed earlier, is the bitrate spikes - there are many places where the bitrate jumps way too high for your player, hence the stutters and maybe short freezes.

I have to say the video from autogordianknow looks ok quality-wise when played on the pc but stutters when played on a set-top box. That would indicated some problem with interlacing.

It indicates no such thing, since AutoGK will deinterlace it.

One answer is to use AutoGK with the ESS chipset option turned on. You can install it as such, or you can turn it on in the Hidden Options. This will limit the bitrate spikes and the resulting AVI should play smoothly. You might also want to lower the resolution to 640x480 or even lower. Also, post the AutoGK log so we can see the settings you used. Your average bitrate is absurdly too high. Very few standalones can handle that kind of bitrate, especially during the spikes.

It happily plays xvid files I download from net.

Which have average bitrates of what - 800-1500 or so? Yours is over 6000.

[jagabo]

If your player has problems with bitrate peaks it's not likely to play 50p encoded files.

This post:

https://forum.videohelp.com/threads/307004-Best-framerate-conversion-%28eg-23-97-to-30-...=1#post1888926

contains a 60p encoded file you can try out. You can convert it to 50p by changing the frame rate with AviFrate.

[Bjs]

akkers, run mediainfo on the original file not what was created ... then you might get somewhere.

Also dump using vbr audio ... pc's handle it fine but other devices are more sensitive to spikes in this stream (lockups / pausing)

Use media info on the files that played fine on the topset unit ... the vast majority if not all use cbr in audio encoding.

As for understanding the problems faced when dealing with interlaced footage > neuron2 ... ins and outs

[hech54]

akkers, run mediainfo on the original file not what was created ... then you might get somewhere

My thoughts exactly. Why the hell hasn't anybody asked what the original file is?

[manono]

... the vast majority if not all use cbr in audio encoding.

Nonsense. 'Scene' releases actually require VBR encoding. You really think his problem might be VBR (ABR if from AutoGK) audio when its bitrate is 120 Kbps and the video bitrate averages 6528 Kbps? Not a chance.

Why the hell hasn't anybody asked what the original file is?

Why? What difference does that make? He's creating something that'll play in his standalone which means XviD/DivX AVIs. My guess is the source is DV AVI but, again, so what?

[hech54]

My guess is the source is DV AVI but, again, so what?

Because 3 days of guessing has gotten him/us nowhere?

[jagabo]

He should open his AVI file with Bitrate Viewer and see if bitrate spikes coincide with the problems he's having.

And he should post a short sample that shows the problems he's having.

[poisondeathray]

I would think DV-AVI is a pretty good guess. Not very many other options for SD 720x576 interlaced PAL AVI files from a camcorder

[akkers]

Yes, the footage is from a PAL DV camcorder.

[jagabo]

Post a short sample of your converted file. One that shows the problems.