Another strange video-convertion issue

[monteverde]

Hello everybody,

I'm converting some MOD video to the MP4 format, using the free Video-To-Video converter. The convertion works bad.
I tryed with "Same As Source" and "Highest" quality options and I always got some artifacts:

in motion scenes, I can see frames crossed by some horizontal lines. It seems that odd horizontal lines and even horizontal lines have been misplaced of a little.

Is it a convert options problem? That is: can I resolve my issue with a convenient choice of convertion options?

Thanks you for care

[DB83]

Not making much sense.

Upload a short sample which illustrates the problem.

[smrpix]

MOD files are standard definition interlaced files. Sounds like you are converting to progressive mp4 without properly deinterlacing.

(edit: this sentence is wrong -- Based on a quick perusal of their website, your software does not appear to have the option to do this.)

Try a different software such as handbrake.

[monteverde]

Thank you for answers.

I uploaded two frames from the original and converted videos. In the last one you can see:

- fuzzy edges;
- a wrong aspect ratio: indeed, the original video size is 770 x 430, while the converted video size is 720 x 580.

Do you think I can solve these issues changing convertion options?

Here are the actual convertion options:

Convert to: MP4 movie (*.mp4)
Extension: *.mp4
Length: 4:01.888

Quality: "7-highest" (this option changed by me: the default value was "custom")

Video codec: mpeg4
Extension: *.mp4
Video size: original
Video aspect: auto
Video bitrate: 4680
Video framerate: auto

Audio codec: aac
Audio bitrate: 128
Audio sampling: 44100
Audio channels: 2 stereo
Audio disable: no
Sync A/V: no
Audio stream index: default
Volume: 1/8

Target filesize: unlimited
Two pass encoding: no
Deinterlace: no
Keep aspect: yes
Spin: no
Flip: no

Thanks for care

[DB83]

When I said 'sample' I really meant an actual video sample but, if I understand you correctly, you wish to keep the video's subjects anonomous. Fair enough.

The combing artifact is the visual representation of interlacing - I see you did not de-interlace when you converted. You can either convert as de-interlaced or simple de-interlace at playback. If you still see the artifact when you de-interlace at playback I recc that you follow the above suggestion and use a different converter.

The original videos paraeters is odd - did you really mean 770 or should that be 720 ?. Then it is closer to 16:9 and you should convert to 16:9.

[smrpix]

Change the deinterlacing option from no to yes. Done.

[monteverde]

Video sizes I wrote are based on rough pixel measurements I took on frames I updated.

Do you think it would be useful operate on:

"Deinterlace: no" option?

I search the web about the MOD video format: it's a JVC proprietary format. See at http://www.fileinfo.com/extension/mod

where you can read some tech info that I can't understand.

Thanks for care

[DB83]

No need to guess the video size. Install mediainfo and load the videos in to it.

Post the report here.

[monteverde]

Ok, I tried "deinterlace=yes". Convertion stops with error:

#2140.0: Access violation at address 6252A4D7 in module 'avfilter-3.dll'. Read of address 00000000
ERROR: Access violation at address 6252A4D7 in module 'avfilter-3.dll'. Read of address 00000000...

[monteverde]

I can post now other tech info about source file. Now I'll try to install MediaInfo...

General
Complete name : C:\Users\.....\MOV00a.MOD
Format : MPEG-PS
File size : 265 MiB
Duration : 4mn 1s
Overall bit rate mode : Variable
Overall bit rate : 9 181 Kbps
Video
ID : 224 (0xE0)
Format : MPEG Video
Format version : Version 2
Format profile : Main@Main
Format settings, BVOP : Yes
Format settings, Matrix : Custom
Format settings, GOP : M=3, N=12
Duration : 4mn 1s
Bit rate mode : Variable
Bit rate : 8 615 Kbps
Maximum bit rate : 8 900 Kbps
Width : 720 pixels
Height : 576 pixels
Display aspect ratio : 16:9
Frame rate : 25.000 fps
Standard : PAL
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.831
Stream size : 248 MiB (94%)
Color primaries : BT.470-2 System B, BT.470-2 System G
Transfer characteristics : BT.470-2 System B, BT.470-2 System G
Matrix coefficients : BT.470-2 System B, BT.470-2 System G
Audio
ID : 189 (0xBD)-128 (0x80)
Format : AC-3
Format/Info : Audio Coding 3
Mode extension : CM (complete main)
Muxing mode : DVD-Video
Duration : 4mn 1s
Bit rate mode : Constant
Bit rate : 384 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Compression mode : Lossy
Delay relative to video : -80ms
Stream size : 11.1 MiB (4%)

[DB83]

Try de-interlace under playback. What player are you using ? Try mpc-hc or vlc

[smrpix]

I search the web about the MOD video format... you can read some tech info that I can't understand.

Thanks for care

Or you can just re-read my post (#3). Why don't you try handrake?

[DB83]

Ok. I did not see the mediainfo report when I posted my last reply.

There is nothing wrong with that MOD file. It is just the way you have processed it. The video is essentially 16:9 stored in the same format as a dvd ie 720*576. When it is displayed, the video is stretched to show the correct display aspect ratio.

What is uncertain is the detail of the converted file. Pls post the mediainfo report of that. I guess you ignored the 16:9 flag and simply converted 'as is'. If the converting program did not recognise the flag and just assumed the video to be 720*576 (hence the squashed picture) or you did not make the appropiate setting, you have no choice but to use another converter.

You see if we had an actual video example* - we are not concerned with the people in the vid and really this looks quite harmless - we could test this ourselves in the various tools and suggest the best (and easiest) one for you.

* Of the original, non-converted video

[monteverde]

Thanks all for answers.
Unfortunately I can't understand words as "16:9 flag" and other technical expressions. I'm just a newbie.

Now I post one video, it's a 47.3 MB (43 secs).

I hope you can play this video (download can need some minutes, please wait).

Thanks for care.

http://expocabrini.it/materiale/gatto.MOD

[DB83]

I notice that vlc does not recognise the AR flag - sorry to be technical but when you deal with video you have to learn the terms.

I have done a quick conversion using avidemux. The only filtering I have done is to de-interlace.

Take a look at this and see if it solves your issues.

[smrpix]

The deinterlace function causes VTV to freeze. Get rid of VTV. VTV is broken. Use handbrake, avidemux or something similar.

[monteverde]

I'm amazed looking your convertion: it's good!

Now I'm discarding my convertion tool (Video - to - Video) and I'm installing one of tools you have reported.

Only a question: comparing your converted video with the original one, I can see that quality is (slightly) got worse. Look at the gray can on the lower left of the frame I uploaded.

Do you think I will be able to improve video quality using convertion tool you suggested?

Thank for care.

[jagabo]

If you want smooth motion and good deinterlacing you should use QTGMC() in AviSynth. But that has a pretty steep learning curve. And it's pretty slow. Video only h.264 MKV attached.

[poisondeathray]

The problem illustrated in your screenshots is mainly from the bitrate used. DB83 just did a quick example for demonstration purposes - notice the filesize of original was 47.3MB vs 16.4MB . If he had used a higher bitrate (lower crf value) resulting in larger filesizes - those details would have been retained

But you will get higher quality results with avisynth and QTGMC as jagabo suggested

[monteverde]

Thanks for answers.

Is quality control easy in handbrake or avidemux ?

NB: Matrioska format is out for me: my TV set only read MP4 format.

[DB83]

I really suggest that you try out avidemux. It can be as easy or as complicated as you want it to be. Try it out and post any specific issues you have with it.

[jagabo]

NB: Matrioska format is out for me: my TV set only read MP4 format.

I uploaded MKV because that's what I usually use. The tools I used can also output MP4. Or you could easily remux into MP4 with free tools.

[monteverde]

I finally discarded Video to Video, but I noted that another program was installed on my PC with it. It's name is:

LAV Filters 0.55.3 (Hendrik Leppkes)

I discarded it too.

Now I have Avidemux 2.6.6

I run the program and loaded my MOD video, then I...

- changed output format from AVI Muxer to MP4 Muxer
- changed Video output to Mpeg4 AVC (x264)
- changed Audio output to AAC (Faac)

Then I saved the video (MP4 extension)

Well, the combing artifact is still present.

Must I change any other options?

[smrpix]

Deinterlace?

[DB83]

If you read my reply when I posted the sample, I mentioned that the only filtering I did was to de-interlace. Go to the Video Menu, chose filters and one of the options under 'interlacing'. If memory serves me I simply selected the top one which works very quickly. Some of the others are probably better but are very slow. You must also chose the field-order of your source which in your case is 'Top'

You can go straight to filters by clicking the icon under the video selection.

You must also go into the x264 confiruration menu, select the Output 1 tab and change the Pixel Aspect Ratio to 16:9 otherwise you still end up with a square picture.

[monteverde]

Thanks for your useful tips.

I tried your options set, but convertion was wrong. Here there is what I did:

- Opened the MOD file
- Video Output: Mpeg4 AVC (x264)
- Filters: Interlacing - Decomb decimate - [+] - Ok - Close the window
- Configure: Output 1 tab - Aspect ratio: PAL 16:9
- Audio Output: AAC (lav)
- Output Format: MP4 v2 muxer
- Saved with a new name

Combinig artifact is still there.

However I don't understand your sentence: "set the fiels-order of source: Top"

Very thanks for your care

[DB83]

It is quite possible that you are using a later version of avidemux to mine. My top selection is 'DGBob'

When I click the '+' button to add that filter to the project I get another window where I have to select the field-order of the source.It defaults to 'bottom' but your source is top field so it must be changed. Interlaced video is made up of two fields and you must ensure that you have selected the field that is displayed first else you have display issues.

You get the field-order from the mediainfo report.

DeComb decimate does not have that option. Someone with more knowledge of interlacing could explain why.

[monteverde]

Yes, now it works! Thank so much.

I selected the dgbob filter and I left default options:

Top Field First: checked
Mode: Keep nb frames and fts
Threshold: 12
Extra: not checked

I'm grateful to you.

Now another question about Avidemux and convertion quality.

If I open Configure Video - General tab, I can set the Quality scroll bar, from 0 (high quality) to 51 (low quality).

All I want is that: "converted file quality" has to be equal (or slightly lower) than "source file quality".

Is it a bad question?

Have I to set cursor to "high quality" or I have to go by trials and errors?

Thanks for your care

[manono]

- Filters: Interlacing - Decomb decimate - [+] -

I don't use AviDemux, but to me Decomb Decimate doesn't mean deinterlacing at all, but frame removal. If the original framerate was 25fps, did it become 20fps afterwards?

[monteverde]

Well, I've done some test. All has gone bad around quality.

I post a report with a detail of my video (the gray tank on the bottom left corner, at the 39-th second).

All of my guesses are worst than original.

Also note the increasing file sizes while quality has (slightly) improved.

At the maximum quality level I get a file size that is x4 than original file size, yet quality is too less.

Must I surrender and lose my original quality?

Alas, the MOD format is only read by my camcorder and by Windows Media Player, not by my TV set and other devices.

Thanks for care.