Custom Bitrates

[rckowal]

Would some one please help me to better understand the relationship between bitrates & (apparent) video quality? Below is a grab of a DVD Flick option.

"Target bitrate" is more easy to use as "Auto fit". This option will calulate bitrate for encoding automatically, depends on DVD "Target size" and will be set as maximum possible value. If you have some advanced expirience with DVD ecoding, you can set "Custom bitrate".

The Auto Target Bitrate is a no brainer, but I would like to take advantage of any possible benefit using the Custom option.

My task is an FLV video that has a resolution of 8 bits. First, is this the same as Mbit/s? Regardless, it could stand some improvement. What Mbit/s rate should I use to get the best possible quality from the FLV?

[MilesAhead]

If you have a very short clip and set the output dvd to DVD9 then Flick should set the bit rate to the maximum for DVD. If you have a 3 hour clip, it's going to fall short of the max. Clips with run times somewhere between those 2 extremes you should slice off a piece and try it with various bit rates and see how the output looks.

The "most bang per bit" is going to be a subjective determination. Quality is in the eye of the beholder to some extent.

Since you give no clue how long the video is, I have to starting point to guess what bit rate you could use..

I would look at some bit rate calculators for various types of video but cut off a piece and try it is the best advice.

[rckowal]

MilesAhead, Thanks for the reply.

The master clip(s) I'm working with are 27 minute long FLVs from a TV show series. Although I've been experimenting with a single clip, the end objective is to have at least two of them, (preferably three or four, if practical) on a DVD5. Could you please suggest a "starting point" based on these criteria?

I'm unclear about your comment "slice off a piece". Are you saying to use a small portion of the video clip (maybe 2 minutes?) to conduct custom bit rate tests? I've used this technique before - it sure saves a lot of time.

I've also tinkered with bit rate calculators but evaluating the final result always comes down to "the eye of the beholder".

[MilesAhead]

I have no experienced with flv. I believe AviDemux handles it. That should make it easy to cut a section for tests. Also 8x DVD+RW erasables are a great help. You can burn a full DVD5 in a reasonable time for test burns.

If you want better quality than DVD Flick you may want to look at HC encode. It's a free video encoder. The input is an AviSynth script. If you're not familiar with AviSynth you may want to use AvsPmod. It's a specialized editor for AviSynth scripts. Just makes it easier since it has auto completion for many of the filters.

AviSynth seems weird at first since it's a dll and you don't run it directly. But there are tons of filters. You can do almost anything from noise clean-up to jaggies removal, resizing, sharpening etc..

HC encode is one of the best free mpeg2 encoders. It comes with its own gui but there are many front ends to make it easier to use. AvsToDVD is one.

The color space color correction stuff is an area I haven't gotten into. So usually what I do is use a tool that generates an .avs(AviSynth) script and copy/paste the stuff to do with that and maybe cropping or whatever, then add my own lines or input it to the encoder I want to use.

DVD Flick is more of a one click solution. If you want to tune the encode in depth get into AviSynth and the tools that use it.

You can ask questions about AviSynth usage here:

http://forum.doom9.org/forumdisplay.php?f=33

Other links:

http://avisynth.org/mediawiki/Main_Page

http://www.neuron2.net/