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  1. Having problem with Winff, trying to change bitrate for xvid avis. Winff sometimes wont re-encode to values set in video tab or command line.

    I have some avi's that are around 4000 bitrate and re-encoding to 1800-1600 xvid avis. Usually have no problems re-encoding to lower bitrates, but sometimes winff will ignore any bitrate values entered and will encode to a value not entered like 1000. Have tried changing bitrate value in video tab and also the command line. Was wondering why it does this only on some videos and if there is a way to force it to encode at certain bitrate. Weird because sometimes can enter 1800 and it will encode at that rate, but other times it will ignore and encode at a lower bitrate and will not change no matter what I try.

    using winff on XP
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  2. Member
    Join Date: Oct 2004
    Location: Freedonia
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    Try Xvid4PSP. It's free. It will obey the bitrate values you give it.
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  3. You might be entering too high a bitrate at times, especially if you're reducing the resolution when encoding. ie once a bitrate achieves Xvid's maximum quality, it probably won't go any higher.

    One way to tell might be to encode a "problem" video using single pass, constant quantizer (CQ) encoding and an Xvid target quantizer of 2. That's 100% quality for Xvid. It's filesize/bitrate should be about the maximum you'll get, assuming all Xvid's other settings are the same.

    If asking for too high a bitrate is the problem (without knowing how much winff lets you change Xvid's settings), when you configure Xvid you can try changing all the minimum quantizers to 1 (if they're all set to 2). A value of 1 allows Xvid to achieve larger file sizes or higher bitrates than it otherwise would, although I don't think it improves the quality. Or you could reduce the number of B frames allowed, or even disable them.

    If you're re-encoding AVIs (or DVDs), AutoGK might be worth a look. It has two encoding modes. Single pass, constant quantizer mode just gives you a quality rather than bitrate or file size. AutoGK displays it as a percentage. 100% uses a target quantizer of 2 for Xvid. The default of 75% equates to a target quantizer of 2.67 (from memory). Of course you have no say when it comes to bitrate or file size. In 2 pass mode you select the desired file size, but AutoGK is the only encoder GUI I know of which tells you roughly what the quality will be in 2 pass mode (it runs a compression test first).
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  4. thanks for the suggestions, will try those programs. Liked winff because of it's easy to use gui. Just wondering why some avis winff will not encode to bitrates specified. For instance have an avi with 4000 bitrate and winff will only encode to 1100, eventhough I'm trying to encode to 2000. anyways wil try those other encoders and see how difficult they are to learn to use.
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  5. Often I'd run a single pass encode using AutoGK's 75% quality setting (70% to 75% is generally considered the optimum quality/compression ratio for Xvid), then use the resulting file size for a 2 pass encode. 2 passes ensures 100% AVI capable DVD player compatibility as Xvid's video buffer control only works in 2 pass mode, plus Xvid's single pass constant quantizer mode isn't really a true constant quality mode (as the x264 encoder has).

    I recommend AutoGK simply because it tells you what sort of quality to expect after it runs it's compression test.
    HDConvertToX is about the only other GUI I can think of which will still runs a compression test before encoding (and like AutoGK it may no longer be actively developed, but it still works). It goes about it differently to AutoGK. Instead of selecting a file size and then running the compression test, and having to adjust the file size and run it again if you're not happy, HDConvertToX lets you select the desired quality, it runs a compression test, then it'll suggest the appropriate file size to use.

    I guess the difference is AutoGK won't let you configure Xvid manually (it adjusts Xvid's settings according to the compression test result) whereas HDConvertToX just uses Xvid's default settings, or however you've configured it.

    Either way, both methods to me seem better than picking a bitrate and hoping for the best when it comes to quality, or using a bitrate which is likely to be excessive simply to ensure the quality is okay.

    Oh..... and HDConvertToX also has a calculator for calculating aspect ratio distortion as you crop and resize. When I'm ruler of the world, which will probably happen any day now, that'll be compulsory for every encoder GUI.
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  6. thanks for all the info and tips. Helped me out a lot. AutoGK seems pretty simple to use. But I did get 'audio not supported' errors on some avi's. Any tips on what's the best way to demux/convert audio (wma2 usually) and remux without audio/video sync issues. thanks
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  7. AutoGK should support MP3, AC3 and DTS and PCM. If there's another audio type..... well to be honest I've not worked with an AVI containing WMA audio.... probably ever...... and WMA isn't well supported by many (older) free programs. However.....

    I guess the first thing to do would be to convert the audio to MP3, replace the existing audio with the MP3 version and resave it as a new AVI. AutoGK will then convert the video but simply copy the new MP3 audio.

    An easy way to do it..... ffcoder is a video converter which will let you convert just the video, or just the audio, while copying the other etc. You could open the "problem" AVIs (or other file types AutoGK doesn't natively support) using ffcoder, select AVI as the output container, "Copy" for the video mode, MP3 or AC3 etc for the audio, then when it's done use AutoGK to convert the new AVI.
    Some of the one-click, all in one type converters such as AnyVideoConverter or FormatFactory or Super probably do the same thing.

    I'd probably use foobar2000 as it's my audio player and also a good converter. It'll play/convert the audio in AVI, MP4, MKV, WMA files without needing to demux it. It uses LAME for MP3 which you'll need to download if you don't already have it (along with the other usual encoders if you want to convert to other formats).

    MeGUI, which is the GUI I use for x264 encoding, will happily accept common video containers as the input for it's audio encoding section.

    There's probably lots of ways to go about it. Once you have the audio converted to MP3 it's just a matter of replacing the existing AVI audio with the MP3 version for AutoGK to open (unless you used a program like ffcoder to do it for you). Alternatively you can deselect the audio when opening an AVI with an unsupported audio type using AutoGK, convert the video only, then add the converted MP3 audio to the AVI AutoGK produces manually later on. Instructions for replacing/adding audio in an AVI:

    Navigate to the AutoGK installation folder and the VDubMod sub-folder.
    Run VirtualDubMod.exe
    Open the AVI using VirtualDubMod.
    From the Streams menu select Streams/Streams List. A window will open displaying the audio streams (mostly there's only one of them).
    Highlight the existing audio and hit the Disable button to disable it.
    Hit the Add button to add the converted/new version of the audio to the AVI.
    Hit Okay to close the Streams Window.
    Use the File/Save As menu to save a new copy of the AVI with the replacement/added audio.
    MOST IMPORTANT: Choose "Direct Stream Copy" as the video mode when the Save window opens or VirtualDubMod will try to re-encode the video rather than just copy it.
    Open the new copy of the AVI using AutoGK for encoding.

    One VirtualDubMod tip..... it'll always have a little cry if you open an AVI containing VBR audio, or if you try to add VBR audio to an AVI and ask if you want to rewrite the MP3 header. You don't, so always select "no". It's a VBR paranoia left over from the dark ages.

    Most sync problems will generally happen if the original AVI had it's audio delayed, but generally the video and audio in AVIs tends to start together. MediaInfo should tell you the delay amount used in an AVI (html view). When converting AVIs I don't think AutoGK automatically applies an audio delay so you'd need to do it manually. Using VirtualDubMod to open the AVI AutoGK produces as described above.... once you have the Streams window open it's just a matter of right clicking on the audio stream, selecting "Interleaving" and specifying the correct delay amount in the window which opens, then resaving a new version of the AVI, once again using Direct Stream Copy for the video.

    If you're really keen, as I still use AutoGK for any Xvid/AVI encoding I do, I worked out my own system for getting it to convert file types it doesn't natively support (mainly MP4 and MKV). Just as when converting AVIs containing "unsupported audio" it's necessary to convert the audio using a different program, then let AutoGK just copy it. I wrote a guide explaining how to do it here:
    http://doom10.org/index.php?topic=325.0
    It's long and probably appears complicated a first, but it explains in detail how to install and use the utilities which eventually semi-automate the process and make it nice and easy to encode other file types using AutoGK.
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