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  1. Member
    Join Date: Feb 2008
    Location: Ireland
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    Hi,
    I'm having problems with the quality of my AVI files after I've converted them from MKV's.

    I'm using Xilisoft Video Converter Ultimate to convert my MKV files to XVID AVI's, but the problem is that I'm noticing pixilation issues in certain parts of the converted AVI's, mostly in scenes with red backgrounds, scenes with water, scenes with sparks, fireworks, explosions....

    Here's the usual settings I use when encoding...

    Source Properties / Output Settings

    File Name: pfa-raze.720p / pfa-raze.720p
    File Format: mkv / avi
    Duration: 01:32:00 / 01:32:00
    Bit Rate: 6775k / 3948k
    File Size: 4.35 GB / 2.54 GB


    Video Stream#1

    Video Codec: h264 / xvid
    Video Bitrate: 5265k / 3500k
    Video Size: 1280x528 / 1280x528
    Aspect Ratio: 2.42:1 / 2.42:1
    Frame Rate: 23.98fps / 23.98fps


    Audio Stream#1

    Audio Codec: dca / ac3
    Audio Bitrate: 1536k / 448k
    Channels: 6 / 6
    Sample Rate: 48000 / 48000


    Anyone know why I'm getting this pixilation issue, could it the encoding program I'm using? Can anyone shed some light on the issue please?
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  2. You're converting h.264 at 5265 kbps to Xvid at 3500 kbps. Of course you're getting losses. You're using a lower bitrate with a less efficient encoder. Blocky artifacts are to be expected.

    If you're not using 2 pass VBR mode in Xvid -- you should.
    Last edited by jagabo; 13th Jul 2014 at 08:19.
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  3. Member
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    Ok thanks, I haven't been using the 2 pass mode, so I'll give that a go.

    But is CBR not better then VBR?? Constant bit rate over variable bit rate.
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  4. Originally Posted by stoksyXL View Post
    But is CBR not better then VBR??
    No. You want to let the encoder use more bitrate on shots that require it, less on shots that don't need it. Why should a second of all black frames be encoded at 3500 kbps? You wouldn't be able to tell the difference between 3500 kbps and 100 kbps on that shot. The same is true for (nearly) still shots. Since high compression codecs get most of their compression from not repeating parts of the picture that don't change from frame to frame, you want to let them use lower bitrates to encode still shots so that bitrate can be shifted to high action shots. The only reason to use CBR is when you have a playback device that only supports CBR. Or if you're in a big hurry and don't want to wait for 2 passes.

    If you want the faster speed of single pass encoding and don't care exactly what the final file size is you can use Target Quantizer mode in Xvid. With Target Quantizer mode you pick the quality you want (the quantizer value) and the encoder uses whatever bitrate is needed to deliver that quality -- so you don't know what the file size will be. In short, With Target Quantier mode you know what the quality will be but you don't know what the file size will be. With bitrate mode you know what the file size will be but you don't know what the quality will be.
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  5. Member
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    Ok, I've tried the same settings as shown above but changed to 2 pass vbr mode, but I'm getting a way too big file size now.
    In Xilisoft Video Converter Ultimate it's saying that the output file size should be around 2.7gb but when it's finished encoding after around 2 hours, the output file size is 10gb.



    Am I doing something wrong or is the problem with Xilisoft Video Converter Ultimate?
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  6. Member Cornucopia's Avatar
    Join Date: Oct 2001
    Location: Deep in the Heart of Texas
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    Yes and yes.

    Filesize = Bitrate * Running time. With Vbr, this means resultant Average bitrate. Use an app that lets you correctly specify that (and sticks close to it in execution).

    Have you considered rather not re-encoding, but just remuxing from mkv to avi? Won't lose quality that way.

    Scott
    "When will the rhetorical questions end?!" - George Carlin
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  7. Member
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    Location: Ireland
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    I'm a bit of a noob with this encoding, so that's why I've been using video converter ultimate, I know the settings to usually type in and just press go and wait for it to convert.
    Is there a similar program that is better and will convert mkv to avi's for me?

    I don't really want to remux, what I'm trying to do is make my own smaller size 720p xvid rips from 1080p mkv's. So I'm just looking to re-encode.
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  8. I'm a Super Moderator johns0's Avatar
    Join Date: Jun 2002
    Location: canada
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    Any reason you are re-encoding mkv to avi/xvid in the same resolution?Most people resize down to 720x480/576 to save on size and to play through older devices and dvds that only play at that resolution.
    I think,therefore i am a hamster.
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  9. Member
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    Just want to make high quality 720p xvid rips. Size isn't really too much of a problem, I'm looking to make 720p rips around 3gb per video.

    I don't want large 5-7gb mkv files in 720p or 8-10gb 1080p mkv files.

    The 720p xvid rips are fine for me.
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  10. I'm a Super Moderator johns0's Avatar
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    It's better to re-encode as mkv/h.264 videos to a smaller file size,re-encoding to avi/xvid will just reduce quality even more if you want to reduce the file size.
    I think,therefore i am a hamster.
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  11. Member
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    Most of the bluray xvid rips available on the net have been all converted from 720 and 1080 mkv's and are fine quality.
    That's what I'm trying to accomplish too, just without the pixelation in certain scenes that I mentioned above.
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  12. Member
    Join Date: Sep 2007
    Location: Canada
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    Maybe they used a higher bitrate, or didn't have things like action, explosions (ie. more difficult to compress) etc... which require more bitrate

    You can get a clue from the h264 encode which use 5265 kbps video bitrate. You basically need more than that to make it look decent if you're using xvid. ie. larger filesize than that source. And remember you're not using even the original , original source . You're starting with a lower quality lossy copy to begin with

    If you're still having problems with some sections, you can use xvid zones. It allows you allocate more bitrate to defined sections

    Or another approach is to use degrainers/ denoisers to improve compressibility. e.g. if the AVC copy has lots of grain/noise, that's difficult on compression
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  13. Member
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    There's a sample of what settings they use when encoding and their xvid rips come out fine.....

    File: Independence.Day.1996.MULTiSubs.BRRip.XviD-BLiNK.avi
    Size: 2717919232 bytes (2.53 GiB), duration: 02:24:47, avg.bitrate: 2503 kb/s
    Audio: ac3, 48000 Hz, 5:1, 448 kb/s
    Video: mpeg4, yuv420p, 720x304, 23.98 fps(r)



    INFORMATION
    ===-- P R E S E N T S: --===
    Independence.Day.1996.MULTiSubs.BRRip.XviD-BLiNK
    RELEASE INFO
    Source.............: 720p.BluRay.DTS.x264-CtrlHD
    Year...............: 1996
    Release.Size.......: 2.53 GB
    Video.Codec........: XviD
    Video..............: 720x304 | 2 044 Kbps | 23.976 fps
    Aspect.Ratio.......: 2.35:1
    Audio..............: Dolby Digital AC3 5.1 ch | 48.0 KHz | 448 kb/s
    Runtime............: 145 min
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  14. Member
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    Video..............: 720x304 | 2 044 Kbps
    Lots of action in independence day, but that is 2044kbps for 720x304. Like johns0 said, most people reduce the dimensions when using xvid

    1280x528 is quite a bit larger frame size, requires more bitrate to look a similar level of frame quality. That's > 3x more pixels. The realtionship for required bitrate isn't linear, but 3x bitrate would be about 6Mb/s
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  15. Member
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    This is what I'm trying to do.....

    http://www.sb-innovation.de/f209/how-create-xvid-brrip-720p-mkv-19364/

    Is this the best way or is there any easier way?
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  16. Originally Posted by stoksyXL View Post
    Ok, I've tried the same settings as shown above but changed to 2 pass vbr mode, but I'm getting a way too big file size now.
    In Xilisoft Video Converter Ultimate it's saying that the output file size should be around 2.7gb but when it's finished encoding after around 2 hours, the output file size is 10gb.
    Does that program run both passes automatically? Some programs require that you manually run each of the two passes. First you set up for 2-pass first pass then save. Whan that's done you set up for 2-pass second pass then save again. The result you want to keep is the one from the second pass.
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  17. Member
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    No, don't think so. Does it all at once as far as I can tell. Before I checked the 2 pass mode option it took around 40 mins to re-encode the mkv to avi, now it takes around 2 hours and ends up with a 10gb file when I set the bitrate to around 3600kps.
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  18. vanished El Heggunte's Avatar
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    Forget Xilisoft, problem solved
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  19. Member
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    Ok, so any other similar programs I can use?
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  20. Member
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    What makes you think 3600kbps is going to be enough? Do you think +100kbps and 2pass VBR will "fix" everything? I can tell you right now its not enough
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  21. Member Cornucopia's Avatar
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    10GB / 92 min = ~14.8Mbps. So either you didn't set things right, the app didn't execute things right, or both.

    However, again, your assumption that you can achieve a nonpixellated copy, using a LESS efficient lossy codec, and at a LOWER bitrate, is seriously flawed.

    Scott

    P.s. YES!! Germany scores!
    "When will the rhetorical questions end?!" - George Carlin
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  22. Member
    Join Date: Nov 2003
    Location: West Texas
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    Buy the Blu-ray, rip uncompressed to the hard drive and start with that rather than an already compressed copy in mkv format.

    If you absolutely have to have Xvid avi, there are several programs that can output in that format, like VideotoVideo or Xvid4PSP, but for small file sizes and correspondingly smaller bitrates, you're better off using H264 and mkv or mp4.
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  23. Member
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    I'm following the guide here to make my xvid rips.....
    http://www.sb-innovation.de/f209/how-create-xvid-brrip-720p-mkv-19364/

    But I'm stuck on the 3rd part, I can't figure out what resolution settings to enter?

    3) Once finished you have the encoded audio and need to encode the video and combine the two.
    Create a new text document which will be our avisynth script in the mkv directory.

    It will say:
    DirectShowSource("Source.mkv", fps=SourceFPS, convertfps=true)
    Lanczos4Resize(NEW,RES)
    "Source.mkv" = full path to your MKV file.
    SourceFPS = the FPS of the original MKV file (can be found with Media Player Classic, G Spot, or MediaInfo)
    (NEW,RES) = specify here the resolution of your choice.


    The video I have now is 1920x1080 and I want to resize it to 1280x720, so what size do I enter here....
    DirectShowSource("Source.mkv", fps=SourceFPS, convertfps=true)
    Lanczos4Resize(NEW,RES)
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  24. Originally Posted by stoksyXL View Post
    This is what I'm trying to do.....

    http://www.sb-innovation.de/f209/how-create-xvid-brrip-720p-mkv-19364/

    Is this the best way or is there any easier way?
    That's not a bad guide. However, he isn't making 720p XviD AVIs, but is downsizing them for standalones that can play XviDs. In addition, you're using a crap program and are expecting the same results as someone that actually knows what he's doing.

    The video I have now is 1920x1080 and I want to resize it to 1280x720, so what size do I enter here....
    1280x720. The guy explains how to figure the new resolution. It requires maybe a third grade education.

    Or are you asking for the filesize for good results? No way to tell without knowing more about the kind of movie it is. If you can figure it out just do a single VBR pass for quant 3.
    Last edited by manono; 14th Jul 2014 at 05:55.
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  25. Lanczos4Resize(1280, 720) if you want 1280x720.
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