Converted Filesizes: wonder of wonders ? comments please!

[Don4031]

Having too much time on my hands and using a program called Media Cope to convert, I selected a video clip wmv encoded HD size 262 Meg and converted it to:

vob same quality now sized 452 meg
avi 438
mpg 437
mp4 368
flv 425
mov 368

Then took the mov file and converted back to

wmv same quality now sized 686 meg

Stupid question why? What happened? Crapware software ? or

What information is on all those extra megs? Does this happen on all converters and cutters?

MY answer to stupid question 1 I noticed that filews whether cut or converted were always larger than the original? 1a answer I noticed that certain ra vid files were only 10% of same quality wmv files as measured by dpicolorcount.

Whats your answer? Whats your comment? Whats your suggestion for cutting out the unnecessary file size, not quality?

[aedipuss]

simple math. filesize = bitrate x time. that's it for all video. change one variable to change another. no further explanation required.

[Don4031]

Thanks for the reply, it certainly fits the category!

The question arises why then do all of the files take the same time from start to finish. the content should be unchanged no further comment required?

[aedipuss]

same amount of time but different encoding bitrates would give different file sizes.

[Nelson37]

Different codecs all have different efficiencies of compression, in addition to different bitrates used by the program when it is allowed to determine this. Pretty much all encoders will operate this way unless you give a specific bitrate.

Cutters are completely different as most do not re-encode the entire file.

[Don4031]

Thank you Nelson, I understand that but the comparison between converters was based upon same quality Hd, display bitrate is based upon single frame size, display rate of frames, refresh rates to give similar display quality color hue etc.

Bitrate as I understand it is the sum per unit time of the number of dots displayed, and should not be a determining factor if single display is used for comparison.

A program that takes a 25megabyte file that converts to a 252 megabyte file then to a 650 megabyte file just how big does it get and why etc

[redwudz]

Don4031, in the future please use a more descriptive subject title in your posts to allow others to search for similar topics. I will change yours this time. From our rules:

Try to choose a subject that describes your topic.
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Thanks,
Moderator redwudz

[manono]

A program that takes a 25megabyte file that converts to a 252 megabyte file then to a 650 megabyte file just how big does it get and why etc

I'll assume you're just setting a Quality. Because of that you have no idea at all what's going on under-the-hood, so to speak. If you were to go into the Custom Settings, there you'd find a way to set the bitrate and if all conversions were set to the same bitrate they'd all wind up with roughly the same size. Your questions so far are pretty meaningless and unanswerable. Maybe you'd have more luck asking the developer. It seems like a nice and easy to use program but I haven't (and perhaps no one else here, either) ever used it.

And although you're setting them all for the same 'quality', the quality always degrades from encode to encode because all of the codecs used are lossy.

[Nelson37]

To put this another way, if you set an arbitrary quality of say, "5", using mpg2 the prog might set a bitrate of 4000, using Divx or Xvid the bitrate might be 2000, and for h264 about 1000. These numbers are very approximate but the point being that using the same "quality" setting for different codecs will yield vastly different bitrates and thus filesize.

[videobruger]

Don4031 Have you tried to drag the files you made onto MediaInfo and seen whats actually in those containers ? Perhaps that would help with your questions

[Cornucopia]

If you want to compare the various overheads of the containers, you encode to a codec that is common to those containers and then remux into each of the containers. Any other method has too many confounding variables that you couldn't control for.

Scott