Reducing captured video file size

[DigitalDisney]

Hi
As some of you know, I am in the process of digitizing all of my home movies (VHS & 8mm). The goal is to put one tape per burned CD (2 hrs of audio and video into 700 MB). After doing the math, I have about 100KB/sec to play with.

After some trial and error, I think I've managed to get a decent setup for my video capture efforts. I'm using a MS ADPCM 22KB/sec stereo audio stream, which leaves around 75-80KB/sec for video. The current setup uses a CBR 3vix. DiVX was dropping frames, and WMP9 produces the best results but takes entirely too long to encode.

Any suggestions for reducing the file size while retaining a lot of the quality? What audio codecs do you recommend? I'm sure I can compress the audio more, which will give me more room for the video.

Since I have 50-100 tapes to go through, encoding time is a really big deal to me. On my current computer, I can only get about 2-3fps while encoding with the WMP9 codec, which means that a 2 hr tape is going to take 20+ hrs to encode. If I use 3vix or DiVX, I can encode at about 15-20fps.

 

[DigitalDisney]

It's been a while, but I thought I'd post my discoveries for all those who are interested

After doing a lot of research, I think I found an excellent method to digitize my movies.
1. Record video with MJPEG codec, 29.97fps, 640x480. This turns 2 hrs of film into about 6-8GB worth of high-quality video.
2. Apply Virtualdub's built-in resize (to 512x384) and de-interlace (blend) filters
3. Set up 2-pass DIVX encoding, with a rate of 684kbps (based on 100KB/s of data (120 mins in 700MB), minus 16KB/s for audio), and the highest quality setting
4. Configure the audio for LAME MP3 codec, 128bps stereo CBR
5. Do something else for a while

Recording the video is done in real time(of course)
Each encoding pass takes about 2.5-3 hrs

So, an entire video can be compiled in under 8 hours, and the quality is decent. I've been pretty impressed with the results I've gotten thus far. I used to record at 320x200 and expand it to 512x384, and this new high-res recording + the 2-pass encoding makes the result look very very good.

If you want to do it right, you could swap out VirtualDub's deinterlace filter for the awesome free Deinterlace MAP filter, but it would make each encoding pass 2-4 times slower. If you're encoding a TV show, then that may be fine. Since I'm encoding 50-100 2hr tapes, time is of the essence for me.

 

[PhotoDave219]

I falling in love with Vegas. That stuff rocks.

 

[NowInc]

Audio rate could save a lot of space. Im going to assume these arenbt 5.1 surround sound quality videos..so you could prob deal with a lower bitrate...try it

 

[DigitalDisney]

Audio rate could save a lot of space. Im going to assume these arenbt 5.1 surround sound quality videos..so you could prob deal with a lower bitrate...try it

I discovered that a while back. Switching to LAME has saved me many precious kbps.

I highly value my audio, so I think I'm going to stick to the 16KB/sec I'm using right now.

Also, I have recently switched to XviD instead of DivX. With one-pass encoding, DiVX wins, but in two-pass mode XviD kicks DivX's butt. Big time. XviD preserves detail better, and has fewer MPEG artifacts than DivX. When I play my compressed 512x384 movie at full screen, it almost looks just like the original source video, which is impressive.