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  1. Member
    Join Date: Oct 2007
    Location: United States
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    If I am going to convert avi files to DVD using DVDflick, how do I know how much quality loss there will be. What do I use as a gauge or guideline. Should I be looking at the bitrate and dimensions of my source. If gspot tells me my source is 897kbps and dvdflick tells me the average bitrate will be 8000kbps, what does that really mean since the quality will not improve, it will probably just get a little worse. My goal is to get as much video on a disk as possible without unnecesarry data loss. I hope that makes sense.
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  2. Member yoda313's Avatar
    Join Date: Jun 2004
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    Don't use the max bitrate if you want to squeeze a lot of video on it. 8000kpbs will fill up a disc quckly.

    Your best option is to simply burn as avi and use a divx compatible settop dvd player to play it back on. Assuming the player can play the codec than you just burn the file as an avi. Then you don't have to convert and retain the original quality of the file.
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  3. You typically need 2 to 4 times the source bitrate when converting MPEG4 ASP (Divx/Xvid) to MPEG2 for DVD. But this varies depending on many factors like frame size (AVI source and DVD), frame rate, which MPEG encoder you use, etc. If your MPEG encoder supports a constant quality mode you should use that unless you need to maximize the running time on the DVD. That way you'll always be assured of the quality of the resulting MPEG file.
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  4. Member
    Join Date: Oct 2004
    Location: Freedonia
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    Originally Posted by marioval
    If I am going to convert avi files to DVD using DVDflick, how do I know how much quality loss there will be.
    It's impossible to answer that question. If your film is an hour or less and you intended to put only it on a single layer DVD, you can use a bit rate of 8000 Kbps and you may not notice any difference between the Divx original and your DVD. The longer your Divx source and lower the bit rate used on it (897 isn't exactly great for the Divx original), the more likely you will have visible quality loss on the conversion to DVD. You probably should just do some tests yourself to get a feel for this.
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  5. Member
    Join Date: Oct 2007
    Location: United States
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    My dvd player does not play divx/xvid files and I am not in the market to buy one right now. Also I use DVDflick to convert so the bitrate adjusts as I add more videos. 8000kbps would be for 1 hour of video, if I put another video on there it would go down to 3000 or 4000 (examples only). Jagabo, are you saying that if my source file is 1000kbps then my resulting DVD will begin to loose quality if I go below 4000kbps (as a general rule of thumb, I know these are not set in stone)? if so, thats good to know.
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  6. Always Watching guns1inger's Avatar
    Join Date: Apr 2004
    Location: Miskatonic U
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    bitrate is only part of the equation. You also have to look at what else you are doing to the file - resizing, for example - and what you will be playing it back on.

    Re-encoding will change the original file, regardless of bitrate, if you use a lossy codec like mpeg2. That is just how the codec works, and even with a very high bitrate, the data will be altered. However, at a running time of 90 - 120 minutes, the differences will be visually minimal if you use a good encoder. DVD Flick does a good job, FAVC can do even better, but is slower as a consequence.

    The real problem is that your source, if it is the usual download type file, is not as good as you would like to believe it is, and has already been very heavily compressed and is full of artifacts before you start re-encoding. For the nmost part these are small, and because of the different way in which computer monitors work versus TVs, much of the damage is not readily visible.

    However, when you convert to DVD and watch it on your TV, things are suddenly different. The usually has to be resized, to begin with. Suddenly, all the small artifacts that aren't so annoying become big blocks on your screen. Computer monitor gamma settings, especially on CRT monitors, are also generally a lot darker than most TVs. This hides a lot of the colour banding and artifacts inherent in darker scenes. Play the same file back on a TV, and these become very visible.

    So there is a lot more to it than just bitrate. Bitrate is easy - what bitrate do I need to fit this movie to this disc ? Any calculator can tell you that.
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