This afternoon I found my way to a chat line on the internet and get a chance to speak with the best of the mpeg community. They show me a few things about Virtual Dub functions, Divx, and Mpeg4. I now can create hours of video/audio in mpeg4 (AVI) that is equivalent to the input source. The filesize is 1/2 of that of VCD! It is now possible to put a complete movie into one single CD that has video quality equal to DVD(if you have a DVD source). This is just great for computer playback, but not on stand alone DVD player since it does not support mpeg4. So I use panasonic encoder to re-encode it back to VCD, and behold the quality is just as good with a few ant like artifacts by using no filter and full pixel. Some day...someone is going to support mpeg4 format....

-- lnguyen (wingstarzz@hotmail.com), July 28, 2000

Answers

Virtual Dub, Huffyuv and VidCap. ;-) How is it working? PS: Your better of taking your original captured avi with huffyuv and running it through Tmpgenc instead of converting to Divx first and then re-encoding with Panasonic.

EG Marshall

-- EG Marshall (4me@schoolmail.com), July 29, 2000.

Hi EG,

I know what you are saying regarding the loss less codecs; However, that option does not work well with ATI AIW128. Believe me I've tried it out side by side and compared quality scene for scene in VHS (both composite and S-video). This is the best that i am seeing with the settings i have above. The loss less codecs may function better on other capture devices, but ATI likes its own internal mpeg raw codecs and mpeg4 much much better then YUY2 or divx. The result avi file is smaller so you don't have to deal with file size limitation and the quality is equivalent to input source...and the best is that you can fit a 2 hours movie into one single CD rom for archiving! You can run the AVI through panasonic, TMPEGen, or BBMPEG1.23, etc to make VCD without further filters or anything to make VCD. The quality of the VCD is a little less then the original AVI(typical mpeg1!), but is much better then what i can produced with my optibase or from ATI (realtime or highbitrate re- encoding or SVCD for that matter).

-- lnguyen (wingstarzz@hotmail.com), July 29, 2000.

Yea, the ATI card is a real pain for capturing. I have an older AIW and only use it as a video card now. I installed a WinTV card on the same system for the BT848 chip and it's ability to handle YUY2 (not YUY packed). It can also handle 6 or 7 other video formats that the ATI cannot. Just remember that MPEG4 will never be standalone supported and converting it to VCD will always have some deterioration in quality. Whether the quality loss is acceptable, is up to each individual. I personally prefer the lossless quality of Huffyuv and encoding the avi to mpeg1 VCD rate.

-- EG Marshall (4me@schoolmail.com), July 29, 2000.

for the record do not use the mpeg 4 or dixv codec if your converting a higherate mpeg clip (2900) to avi using the virtual dub, the codecs make the pic look horrible. So i guess though for the ways your using them your getting a diffrent pic then me. I do know people use these two codecs to fit an entire ripped dvd onto a single cd

-- Doug (mazinz@aol.com), July 29, 2000.

i know what "yuv" is, but what is "huffyuv"? is it a type of compression or a program? also, whenever i use MPEG4 compression, whether it is the official microsoft codec, or the divx one, i get these horizontal breaks in the picture, mainly during heavy movement. this happens regardless of the bitrate i use, or the rez, low-motion codec, or high motion codec. my capture card isnt dropping frames, it even does it if im converting from dvd2mpeg4 strictly with software. i dont think im dropping frames on playback either. any ideas?

-- ndumu (ndumu@hotmail.com), July 30, 2000.

Doug....

Mpeg4 is ASF and DivX. It compresses video with high quality output(equivalent to input) and the result file size is either equivalent to standard VCD or less depends on what data rate you want. I usually do 2/3 of the data rate so that the quality is still retained but the file size is much less then VCD. At 2/3 data rate the file size is also 2/3 of VCD as well (sweet). So a typical movie will fit into one single CD for archive. If i want VCD playback on stand alone, then I convert it to mpeg1 with little or no loss of quality at all.

Ndumm....

HuffYUY2 is a codecs similar to YUY2 codecs however it produces much bigger file size; Hence no quality loss! It is used for AVI capture so that you can convert it to mpeg1 for VCD later on.

-- lnguyen (wingstarzz@hotmail.com), July 30, 2000.

Ndumu,

I don't know what horizontal breaks you are talking about? I did not see it in my capture. Every capture cards behave differently with mpeg4. Furthermore, the compression on Mpeg4 is VBR and not CBR so you can't tell or estimate what the ending filesize gonna be. Best guess is one to one, data rate = file size (VCD file size is the reference at maximum file size @ 6000Kbps data rate).

-- lnguyen (wingstarzz@hotmail.com), July 31, 2000.

hello ! guys i need help please i have an ATI ALL in wonder but i don't no how to encode in divx ! if you could send me something it will be nice ! thx before

-- christ (c.gall@noos.fr), January 03, 2001.