With the price of hard drives continuing to fall, I figure that I might as well begin the process of digitizing and backing up my dvd collection. I expect this process to last months and/or years and so I want to plan properly so that I only have to go through it once.
My goal is to put the file on disk once in a size and format that can be used over a variety of devices even though the eventual primary purpose will be to stream it over a Home Media Network (HMN) to large screen HDTV’s.
This is going to be the first of many posts on this subject and I’m going to talk it through as I do it. I want to solicit input from those of you that are interested and I also want to leave a record of how and why I did what I did so that you can eventually do it yourself.
That said, with this post I want to discuss file formats, file size and file quality.
File Requirements
I anticipate watching my media files over a home network on an HDTV. At times, I’m sure that I’ll want to watch them on an ipod or something, but the primary use for these files will be in the living room.
Requirement Number 1: File quality must be good enough to use on a large screen HDTV.
I am reasonably tech proficient, but I can’t write code. I am willing to go open source but whatever I do can’t be too technical on the front end. First and foremost, I require ease of use on the front-end.
I have not begun to explore what the front end of my HMN will look like. I haven’t tested AppleTV or an XBOX. I haven’t tried any Open Source projects. I am a blank slate. I’m not even sure if what I eventually want exists right now. Consequently, my digitization project needs to be forward looking. As I rip DVD’s, I want to put them into a format that is mostly future proof and universal.
Requirement Number 2: File format should be reasonably future-proof and nearly universally accepted by today’s devices.
I anticipate using different ratios of picture quality to storage size depending on the individual movie. I have different expectations when I’m watching Tommy Boy than I do when I’m watching Lord of the Rings. That said, since I will retain the original disks as backups, I will be able to pop them in if I’m in need of best quality for any particular viewing.
Requirement Number 3:File size should be as small as possible but is less important than the other requirements.
The system I ultimately envision involves a home media server with several terabytes of storage streamed over a G or N standard Wi-fi network. I would expect to run a minimum of three home media streams at any given time in addition to having enough excess capacity for two people to surf the internet.
Requirement Number 4:File bit rate should be small enough to allow for five data streams across a Home Media Network.
If you have any thoughts I’d love to hear them.
Just some thoughts for now as I don’t have a lot of time for specifics right now.
1. File quality good enough for a 42″ HDTV (or larger) will mandate large file sizes. This will make storage on a device like an ipod challenging and tedious (transfers will be time consuming). Currently, best in class compression (mp4/h.264/etc) results in about 350MB for 1 hour of SD resolution video. At this size, you WILL see loss of quality on a big HDTV. For DVD quality video on a big HDTV, expect to use at least 600MB for 1 Hour of SDTV, more for something like LotR or something with really fast action (explosions) as the bit rate on fast action movies is significantly higher. That being said 350MB per hour is probably ok for Tommy Boy.
2. Right now, in the video codec world, MP4/H.264 (divx/xvid) is about as close to a standard as you can get (its what the pirates use). I think using this family of codecs will ensure non-proprietary devices can play the file, however, there will almost certainly be improvements to and possibly replacements of these formats in a 5 year window.
3. File size is utterly dependent upon the viewing media. If you want to play it on an ipod, you can get it really small. 52 in plasma? Not so much. I personally don’t know of any ripping technique that can satisfy these two diametrically opposed objectives. Although, Ipods are getting pretty big nowadays, so maybe a movie that clocks in at 1.5GB compressed is acceptable for ipod viewing and will still look decent on all but the largest HDTVs.
4. In theory, these compressed videos should be able to fit into a 6Mb/s data stream. 5 such streams would be completely consuming the capacity of a typical G home network, and hitting an “n” network pretty hard. I think this might be your biggest limiting factor. The average router you get at Best Buy may say it’s “G” or “N” or whatever, but they are notorious for only having the ability to pass about half the advertised traffic. I have several wireless networks running at home, one for video(videogames) and one for the internet (which is a second option for you there) and my “B” network using enterprise class hardware easily outperforms my “G” network using a cheapo Netgear. I have a really nice Cisco wireless network that handles all my video and gaming data. I have a crappy netgear router for my internet traffic. Someday this may not be necessary.