I am about to convert my old vhs home movies. I will be capturing using ati 128 aiw card and pentium 11. I have experimented with caturing and have sucessfully encoded and played back the vcd's on my pioneer dvd. No issues with the current set-up. My question is dvd burning is about to become a standard. Avi files are so large that I was condisering converting to mpeg (highest quality) for storage (data cd-r's) with the hope of being able to burn dvd's in the future from the mpeg's. Will the quailty of the those future recordings suffer without the original avi? Any suggestions? I only want to capture once.

-- John R. Murphy (murphy.john.r.1@worldnet.att.net), January 02, 2002

Answers

Your best option would be to convert to DVD format and burn that. I'm sure you know that DVD uses MPEG-2 video. Use a bit rate of somewhere between 3.5 and 4 Mbps. Current DVD-R/W discs only hold about 4 GB or so of data and you need to keep the bit rate at 4 Mbps or less to get 2 hours of recording time per disc. SVCD is not a very good option as the resolutions it uses (480x480 NTSC and 480x576 PAL) are not valid for DVD. VCD resolutions and MPEG-1 video itself are both valid for DVD as the spec was designed to provide for some degree of compatibility. Of course, at its low bit rates and resolutions, VCD is not the best choice today for long term storage. It has been my experience that if I use a constant bit rate of 3.6 Mbps and record 720x480 NTSC MPEG-2 video for DVD, I can get about 22-24 minutes to an 80 minute CD-R. Variable bit rate might up that a bit. I do know of a guy who records 356x480 NTSC MPEG-2 video at a variable bit rate of 3.5 Mbps or so and he can get about 44 minutes burned to either 90 or 99 minute CD-Rs. 352x480 is valid for DVD, but it's lower resolution than the normal 720x480. He is doing real-time MPEG-2 recording and he has to use this resolution because ATI cards will drop frames at 720x480 unless you do I-frames only or have a 2 GHz PC (even then it might drop frames). Lucky for you, you are doing encoding from AVI, so you don't have to worry about that. This is what I recommend: 1) Record AVI video using Huffy or another lossless codec at 720x480 NTSC or 720x576 PAL. 2) Split the AVI into 20-24 minute chunks. 3) Encode each chunk to MPEG-2 using something like TMPGenc or CCE (Cinema Craft Encoder - CCE is really the best) at a bit rate of 3.6 Mbps. If you use VBR instead of CBR, you might be able to get a few extra minutes burned to CD-R. 4) Make a DVD using some authoring software and burn to CD-R. Down the road, you will have DVD compatibile video you can burn to DVD-R discs at very good quality.

DVD does support bit rates of up to 9.something Mbps, but if you use a bit rate that high, you'll only get about 10-12 minutes of recording time to an 80 min. CD-R.

-- Jason (Jason.Shumate@equant.com), January 02, 2002.