Secrets of Converting Cine Film to DVD
A Great factor in cine conversions is encoding. Encoding is the transfer of the images into a digital data stream like MPEG / AVI / .MOV which can be burned and read by a DVD. To understand this you will need to understand that a Commercial DVD or VCD like cinema movies in the shops are factory made using a special pressing and mastering process, the same goes with CD. Many DVDs hold up to 9GB of info.
Custom DVDs like yours, are made in small runs and are mastered onto a blank recordable DVD (DVD-R, DVD+R the ''R'' meaning recordable). Such DVDs hold half the data (4.7GB) Here is the problem. Many video companies attempt to match the commercial DVD by offering a 'tempting' two hours on to one DVD. This can only be possible by a reduction in the Data Rate, this is like putting your Video Recorder on long-play to get 4 hours of TV on a 2 hour tape subsequently reducing quality.
Standard MPEG encoding gives you 90 minutes of top class video on a single 4.7 GB DVD. Any firm offering over 90 minutes will simply be reducing the quality of your final film. This is however, unless your videos are transferred to DLT for mass production (1000 copies) on DVD. This brings us to the next aspect to affect quality - the QUALITY of the Encoder (the kit which transfers movies to DVD).
Cheap Encoders will skip an essential process, what we mean is that they convert your cines images and audio (for super 8 films) directly to MPEG 2 (DVD). Such Direct transfer will make your DVDs appear much darker than the original film footage. Once your films are encoded and nothing can be done to rectify it. Poorly lit faces on the original movie go even darker and they stay like this forever. Any attempt to adjust contrast (lighten them) will result in detail loss. All these problems can be avoided by Professional Encoding. We professionals import your film images to AVI clips or DV (Digital Videos) before encoding them to MPEG2 (DVD). It's at this stage that the better studios like us watch your Cine Film whilst converting to it to Digital Video MPEG / AVI / .MOV and then make adjustments that are (on average) the optimum for your movie. This is similar photo processing labs. The cheaper ones do a one size fits all and the expensive ones carefully review your films, optimising quality. This extra process takes a little longer and the equipment is also much more expensive.
The cheapest MPEG encoders cost around £1,500 and fit into your Computer called RTCC or Real Time Conversion Cards. Such cards come in two types Variable Bit Rate (VBR) or Constant Bit Rate (CBR) encoding. The Variable Rate being the better and a lot more expensive. In summary you don't want a film Studio which encodes your video film movies direct to MPEG 2. How will you know? Just ask them if they can convert AVIs to DVD or Cine to AVI. If they can not do either then they are utilising these simple domestic encoders (RTCC) we have just mentioned. You could purchase these yourself online for around £1,500 plus a good computer. With 10 orders of £150 such equipment has paid for itself. Saying that, the quality is however, still no match for Professional Transfer Equipment like our. If you do want your Cine Films on DVD, AVI or Video without any loss of quality, then you must use a Professional Cine Film Transfer Studio and pay for professional rates. Having said that we have documentary evidence that some transfer amateurs are charging twice our conversion rate producing half the quality.
Remember we talked about Constant Rate and Variable Rate. Using Variable Bit Rate (VBR) Encoding varies the encoding rate depending on how little each frames changes. E.g. This is a like creating a TV cartoon of Mickey Mouse. If Mickey simply needs to close his eyes in the next scene then all the cartoonist needs to do is draw his closed eyes, not the whole picture. He can copy the body and background over as it does not change. Therefore 98% of the frame stays exactly the same and therefore needs much less data for this image. Hence Less Data means a much lower bit rate, and therefore you are varying the bit rate.
VBR, why then do we vary the bit rate? The easiest way to explain this is to try and understand that a DVD-R will only hold 4.7GB of data. Imagine this 4.7GB space is a weeks budget of cash then you know it is better to have more money at the weekends when you have time to spend it and less money on work days. Eg Your spending is yes "VARIABLE". By Varying this bit rate, by giving a much higher bit rate to faster changing frames (Mickey Mouse jumps), at the expense of a much lower bit rate for frames that change a lot less (Mickey Mouse winks) optimises the data required (eg optimising the money spent).
We use the very latest innovations in electronics technology our high end VBR encoders use a 2 pass operation, whereas most of our competitors are stuck with traditional Single Pass Encoders.
1. The first Pass 'looks' at the source images and then determines the best bit rate for each image sequence, (sequences can be defined as being comparatively similar pieces of film footage).
2. The second Pass 'Encodes' the footage using this info and then Varies the bit rate accordingly so it is at the highest possible quality for each individual sequence.
The same too goes for sound clips on Super-8 films. These Super8 films replaced 8mm films as they recorded sound.
We hope this review of different methods help you.