Don't know about MAC, but on a PC it is impossible. Logic dictates that it is impossible on a MAC too. And a setup like that will give you headaches in terms of performance, unless you are talking about dual teamed 1 Gb NIC's or faster backbones.
Dammm, I was hoping I wouldnt hear that. Harm, you said imposible, but what about the link I posted in the original message- http://www.virtualvtr.com/pictureready/index.html ?
Do you have any other suggestions to accomplish the task? I just need aspects of the file thats being captured available for immediate playback, without stopping the capture.
Im planning on buying this in the future- http://www.bhphotovideo.com/c/product/405919-REG/Sony_DSRDR1000A_DSRDR1000A_DVCAM_HDD.html
but i'm looking for a solution to work with for now.
The problem is that you want to write to a file (capturing) and at the same time read this file. You just can't do that at the same time. The OS does not allow it. You may have to look at a method to have the player, that is used to capture from, connected to a TV during the capture, but then physical distance can be a bottleneck.
The Sony you linked to has its own harddisk to create a copy of the file you capture, but still you have to wait for the writing to be finished before you can read it.
Your problem is comparable to early adopters of CS5.5. When they download CS5.5, it initially creates a .part file and when the download is complete, it creates an .iso file. During the download you can't access the .part file, you can only access the file after the download is complete.