About AVI Video Quality

The AVI format is not a standard and it is designed by Microsoft for use on Windows platforms. AVI does not specify a Video compression format, but instead specifies methods to utilize any format. You need to use a CODEC (Coder-Decoder pair) to store video in AVI files. In #1 DVD Ripper you may select the video codec for AVI output from a list of available (installed and compatible with the source video) codecs. Each codec has it's own settings and quality parameters, and you must set them from the codec's windows and dialogs. You can reach to the selected codec's settings window from the Setup button on the output' setting window (please refer to the Video Codec setting section in this help for further information.) Since each codec has a different set of settings, you must refer to the codec's help system to find out the best settings for your target quality/filesize.

Since in AVI the video resolution as well as the encoding settings are set by the user, the output quality may be disappointingly low if they codec and its settings are not selected carefully. As a rule lowering the video resolution almost always results in higher-quality output than leaving the default full-size resolution.

When encoding in DivX remember to select the appropriate profile for the source video. If you are converting at the highest video resolution, the 'Home Theater' or 'High Def' profiles must be selected. Also, depending on the type of video (fast motion, action movie or slow motion movie) you will need to select the bitrate. Faster-motion video require higher-bitrates, while slower-motion ones can be encoded in lower bitrates. But for the highest video resolution, setting the bitrate to 2000 or 2500Kb/s or higher will give good output quality. Also, remember that setting the 'Performance / Quality' bar toward the right (slowest) will give better results, especially if the video resolution is high and/or the bitrate is low. For the best results please refer to the DivX help files and to any of the multitude online forums for help.

When encoding in XviD using the default settings, selecting an appropriate bitrate will usually give very good quality output, even for high video resolution. Although for best results an understanding of the different settings is usually necessary. Please refer to the help files and to any of the multitude online forums for help.

In all events, when blockiness, or pixerlization is noticed in the output video, it is usually solved by highering the bitrate. Regardless of all other settings, the highering the bitrate will result in higher quality output.

Choose a proper Codec

By far,DivX codec is the most popular codec for encoding AVI file. Since its inception, DivX has been among the world's most popular video technologies and has been downloaded over 200 million times. DivX is helping to redefine the media experience by enabling anyone to create, share and play highly-compressed, high-quality video content. DivX technology now powers an entire ecosystem of interoperable products and services, from a secure digital video distribution solution to tens of millions of consumer electronics devices and popular video software applications. But DivX isn't just a technology. It's a global community informed by creativity and passion for all that is possible with digital media, and that community is growing in strength and number every day.
We strongly recommend you install Divx codec,download it at http://www.divx.com/divx/windows/

Choose output resolution

The standard resolution for DVD movie is 720 x 480 for NTSC DVD and 720 x 576 for PAL DVD. If you want to keep video quality as original DVD you'd better keep original DVD resolution.Select output resolution at output tag of settings dialog.
However, DVD has a concept of aspect ratio,like 16:9 for wide screen TV and 4:3 for standard TV but AVI format does not has such parameter. Aspect ratio effects the final display size of DVD movie. So if you do not use "Crop" setting to crop video source some DVD movies will result in black bar in final DivX video.Please see Crop source video for details.

Use 2-pass encoding

Using multipass technique when encoding video into another format means basically that the video encoder analyzes the video many(mostly 2) times from the beginning to the end before the actual encoding process. While scanning the file, encoder writes information about the original video to its own logfile and uses that log to determine the best possible way to fit the video within the bitrate limits user has set for the encoding process -- this is why multi-pass encoding is only used in VBR encoding (the CBR encoding doesn't offer any flexibility for the encoder to determine the bitrate for each frame). Best way to understand why this is used is to think of a movie -- when there are shots that are totally, absolutely black, like scene changes, normal 1-pass CBR encoding uses the exact same amount of data to that part as it uses for complex action scene. But by using VBR and multi-pass, encoder "knows" that this piece is Ok with lower bitrate and that bitrate can be then used for more complex scenes, thus creating better quality for those scenes that require more bitrate.

To use 2-pass encoding please goto output tag of settings dialog, Check "Enable 2-pass encoding", Click "setup 1st pass" and select 1st pass as "Multipass 1st pass", Click "Setup 2nd Pass" and select 2nd pass as "Multipass Nth Pass" in the configuration window of DivX codec. 2-pass encoding takes double time to encode compare to 1 pass mode but result in best video quality.

Conclusion

Install DivX codec, select "High Definition Profile" of DivX Codec, enable 2-pass mode, Crop Video source if needed.