Reducing output file sizes and video/audio out of sync

[myleftshoe]

Hello,

New to encoding, grateful if someone can help.

1. Would like to decrease the size of the created DVD e.g. I converted a 720Mb 2hr movie using QuEnc and it created 4 VOB files in the VIDEO_TS folder with a total of around 3.5 Gb. I guess I need to adjust the QuEnc options in the encoding tab but which ones? I want an output file roughly the same size and quality as the avi.

-2. I used FreeEnc for a job and the DVD produced had the audio and video out-of-sync. I had subtitles too which were in-sync with the audio but obviously not the video. I used only 1 pass for the encoding. Don?t know what multiple passes does but does this sound like a symptom of only using one pass.

ta

[H.Ammer]

I'm sorry that you can't achieve your first thought. It's all to do with compression, reducing the file size with little expense on quality. AVI files are highly compressed and the picture size may be smaller, say 650 pixels X 325 pixels. DVDs use MPEG2 which is less compressed and requires to be, for PAL, 720 pixels X 576 pixels and for NTSC, 704 pixels X 420 pixels approximately. VOB file sets are basically advanced MPG (MPEG2) files in nominal 1Gb chunks. It is totally impossible to have DVD VOB file set anywhere near the size of the original compressed AVI file.

The conversion from AVI video to MPG video is a compromise of quality and speed. The longer it takes, the better the quality. Two or multiple pass encoding provides superior results than a single pass. Think of it as laying a garden path. You will get better results if you survey the route and calculate the materials required rather than just laying one slab after the next without looking ahead. Encoding is the same, the first pass merely checks the file to see where the compression of the final file requires to be adjusted for optimum results.

I would recommend using Henc as your default encoder and have it set for best quality. It will be slower (depending on your computer specifications) but the results are regarded as being the best for a free encoder.

Avi2Dvd is designed to provide only the minimum of adjustable setting for the whole process, so there are no real changes you can make to the way the encoder works other than those in "step 3".

The synchronization of audio, video and subpicture (subtitle) streams is an issue that can be quite complicated to fault as it is dependent on the original video/audio source. Even if the source is playable as a AVI or other file, does not mean that when it is encoded to MPG/VOB files there will not be sync issues.

This situation is exploited by Studios to deter illegal copying of copyright material. Have a look at this post for some details http://www.trustfm.net/phpBB2/viewtopic.php?t=2152
You may wish to look at this as well http://www.trustfm.net/phpBB2/viewtopic.php?t=2114.

I hope this is of some use to you, please post if you have any further questions. Don't forget to check the rest of the forum for possible help and have a look at www.Videohelp.com.

[myleftshoe]

Thanks for the responses and the reading list. Will take a look.