Page 3 of 4: DivX 5.0.x Setup

Select the "DivX Pro 5.0.x Codec" (depending on your version of the DivX codec - eg. "DivX Pro 5.0.3 Codec") in the "Choose Videocompressor" window (note that you can select any codec you want here, if you don't want to convert to DivX). Press the "Configure" button, and you should see the window below (slightly modified to make the picture smaller). We'll go through each of the sections, and describe what each setting does. Please refer to the official DivX guide for more detailed and technical information on these feature.

Profiles Setup :

New in version 5.0.3

DivX 5.0.x - Profiles Setup
1. Choose your Profile
DivX 5.0.3 introduces the notion of profiles (or standards). Basically, these are pre-programmed settings for the DivX 5.0.3 codec that conform to standards set by DivX.com. This will be more helpful in the future, when DivX enabled devices are available, and you want to make sure your DivX encodings will playback on these devices.

The four profiles currently available are Handheld, Portable, Home Theatre and High Definition.
2. What is the resolution of your video?
Enter the resolution of your video here and the DivX codec will test and see if this resolution conforms to the profile/standard you have selected.
3. What is the framerate of your video?
Enter the framerate of your video here and the DivX codec will test and see if this framerate conforms to the profile/standard you have selected.
MPEG4 Tools :
These options allows you to select the three special encoding methods that will try to improve the quality of the encoding, while decreasing the file size.

DivX 5.0.3's use of profiles now limits the use of these tools, and you may only be able to select some of these options if you disable the use of profiles.

Use Quarter Pixel - This feature is not working properly in build 413 of the DivX 5.0 codec, so disable it. Not available when profiles are used

Use GMC - Global Motion Compensation (GMC) is useful in improving the quality of scenes where lots of movement (especially panning, zooming) occur. You should enable this option. Not available when profiles are used

Use Bidirectional Encoding - Bidirectional encoding allows for the use of B frames in the encoding, in addition to the I-frame (data for this frame is completely stored) and the P-Frame (predicted frame). This option also increases quality, so enable it as well. Not available for the "Handheld" profile

Bitrate Control Setup :

DivX 5.0.x - DivX Codec Setup
Variable bitrate Mode
Choose the type of encoding method for this codec. "1-pass" encoding is similar to DivX 3.11 Alpha's "low motion" encoding. "1-pass quality based" encoding is basically constant bitrate encoding (same bitrate used for every frame), and is similar to the compression used in MPEG-1 movies (ie. crappy compression). "2-pass" is the best encoding option (for smallest file size, and best quality) - unfortunately, it takes twice the time of "1-pass" encoding, but the results may be worth it - 2-pass uses the bitrate you selected as appropriately as possible, to give you both an accurate file size (good if you are using bitrate calculators - make sure you get a DivX 4.x/5.0.x compatible calculator) and the best possible looking picture given that bitrate.

New in Version 5.0.3 : DivX 5.0.3 Pro adds Nth pass encoding. Previously, only 2-passes were available. Now, you can have as many passes as you want, with each pass giving the DivX codec more information to work with, and hence, achieve a higher quality encoding (at the expense of time, of course).

Using Nth pass encoding is similar to using 2-pass encoding : you have a common first pass using the "Multipass - 1st pass", and then subsequent passes can be performed using the "Multipass - nth pass" settings.

DivX 5.0.x - Variable bitrate mode
Max bitrate : - New in Version 5.0.3 (for profile-less "Multipass - nth pass" mode only)
The maximum bit-rate to use during encoding - required by certain DivX/MPEG-4 devices that cannot handle large bit-rates. Max bitrate is not yet implemented in the DivX 5.0.3.
Encoding bitrate :
This is the bit rate setting for the video. A setting of 1500 will produce very good quality video (lower will mean a smaller file size, but poorer quality). Don't go below 650 (650-1000 for 1 CD movies), and there is probably not too much point in going over 2000 (1300-2000 for 2 CDs).
Bitrate modulation : - New in Version 5.0.3 (for "Multipass - nth pass" mode only)
This allows you to tell how much motion your source video has, and let the DivX codec decide on the best way to encode this video source. Drag the slider towards "high-motion" or "low-motion" depending on your source.
Multipass encoding log files :
Log file - 2-pass encoding requires the information in the first pass to be stored in a LOG file - you can specify the location to store the log file by using this option. You can also specify whether to update this log file (the log file only needs to be updated if you plan on doing another pass after the current pass).

MV file - DivX 5.0.x adds MV files, which contains Motion Vector data. Having a MV file will speed up the 2-pass encoding process, as motion compensation is performed during the first pass, and will not need to be done on the second pass again.

MPEG4 Tools :
The MPEG-4 Tools (Quarter Pixel, GMC, Bidirectional Encoding) have been moved to the "Profiles" setup area (see above) in version 5.0.3.


General Parameters Setup :

DivX 5.0.x - General Parameters Setup


Enable Crop :
Cropping allows you to remove a part of the picture that you don't want encoded - for example, the black bars on widescreen movies (they will be added back by your DivX player anyway, so there is no point wasting bitrate on them). Generally, your conversion tool will have a similar feature, so you should just disable and ignore this section.
Enable Resize :
Same deal as cropping, except this is for resizing the overall picture - you should just disable and ignore this section.
Psychovisual Enhancement :
Just like how MP3 encoding removes bits that the human ear can't hear, to decrease file size, psychovisual enhancement does the same with the video.
Pre Processing Source :
This option should really be renamed to "Noise Reduction", as this is what it really does. Unless your source has lots of noise in it (which shouldn't be the case if you are converting from a DVD), so you should just disable it.
Keyframe :
Max Keyframe interval - Keyframes helps you to skip forward/backwards (seek) through the movie (when you skip, the picture has to land on a keyframe first). Keyframe are automatically inserted at scene changes, but in case you have a movie where the scene never changes, then set this to a reasonable value to avoid having no keyframes. For example, you can insert a keyframe every 10 seconds by multiplying the framerate of the movie (eg. 23.976 or 25 or 29.97) by 10 (eg. 240, 250, 300), and entering it here.

scene change threshold - Set this to 50%
Performance/quality :
Determines tradeoff between performance and quality. Leaving it as Slowest gives you the best possible picture, and this is what I would set it at, since the speedup in compression is not reason enough to lose all that quality.
Source Interlace :
This option has been drastically changed for version 5.0.3.

You can now encode the video as progressive or interlaced. If your original source is interlaced, then encoding it as interlaced may result in a better looking picture, although it may increase file size. Similarly, encoding the video as progressive if the source is progressive will be benefitial. There are many ways to check if your video source is interlaced or progressive, but using DVD2AVI and checking for the "Frame Type" is a good way to achieve this.

The last option allows you to "Deinterlace all frames", which is just a way to convert the interlaced source into a progressive one. This is not really recommended, as it can lower picture quality.

DivX 5.0.x - Source Interlace


Advanced Parameters Setup :

No longer available through version 5.0.3's graphical setup - can only be changed via the Windows Registry

DivX 5.0.x - Advanced Parameters Setup


Date Rate Control(RC) :
Below are very important settings in determining quality. These settings are now only accessible through the Windows Registry, at the location HKEY_CURRENT_USER\Software\DivXNetworks\DivX4Windows. Do not change these settings unless you know what you are doing, as it can mess up your encoding, or worse, destroy your Windows registry.

Maximum Quantizer - A higher setting (eg. 20) will mean a more compression, hence less picture quality. Lowering the value will increase the file size.

Minimum Quantizer - A lower setting (eg. 2) will mean a more clear picture (less blocky), but will increase the file size.

RC averaging period, frames - This setting determines how the bitrate should be averaged out (eg. if there was a spike in bitrate used in previous frames). Leaving this at 2000 seems to work fine, but experiment by increasing this value, may bring better quality.

RC reaction period, frames - This setting determines how fast the codec should react the scene changes. The default value seems to work fine.

Rate control down/up reaction - The default value also seems to work fine here.

Use data partitioning :
Useful for video streaming, but otherwise, leave it disabled.
Performance/quality :
This setting has been moved to the "General Parameters" setup area (see above) in version 5.0.3.
DivX MP4 Creator :
As mentioned before, MPEG-4 writing does not yet support audio, so ignore this section. No longer available in version 5.0.3

 

 


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