bitrate vs filesize

[PkmoNk]

I've noticed how DivX uses bitrate to determine the output size, and XviD uses the filesize to determine the bitrate, but I wanted to know if XviD can implement this function because it makes batch encoding easier, because I don't have to do as many calculations. Unless there is a reason to keep this feature out?

[SiXXGuNNZ]

I personally think the way xvid does it is alot more accurate, considering I never had a divx come even close to what filesize it was supposed to me. I myself would love to see divx have an option to go by video filesize myself :)

[gldblade]

I don't see how figuring out filesize takes more steps than figuring out bitrate.

[PkmoNk]

I agree its more accurate.

But I'm chinese, and I like to watch my cultural films (hehe). And my chinese films come in VCDs(2discs), so this is my step to encoding:

1) Find durations of both CDs
2) Add them up
3) Put in NitroGen's XviD calculator
*[the duration and filesize (350MB), I fit 2 movies into one disc]
4) Open another instance of the calc
5) Put in duration of CD1 and adjust the filesize to match the bitrate of the one in instance1.
6) Encode in two-pass
7) Repeat 5 and 6 for CD2

Thats what I meant for easy on batch encoding, especially when i do 20+ episodes of a series. hehe.

Is it possible to implement the bitrate function and allow the user to choose if they want to put the bitrate or filesize? Just a suggestion :D

[droolian01]

Hi there.

So you want to put one movie (2 vcd's) onto one disc using xvid to recompress, is this right?

I would:-
1. calculate the total film length (totaltime) from the length of vcd1 (vcd1time) and vcd2 (vcd2time)

2. use a bitrate calc to give you the length of the video only part of the xvid (most ask for the audio mp3 bitrate and derive the video size from this. ecuadors is good http://ecuador.ebodyform.com/ ) say this gives 592mb, round it down to 680mb.


3. then encode vcd1 to xvid with a target filesize of -
580mb x (vcd1time/totaltime )

4. encode vcd2 to xvid with a target filesize of -
580mb x (vcd2time/totaltime)

Actually it would be better for you to copy both vcd1 and vcd2 as mpegs and just splice them together to give one large mpeg, then just convert this way - but you may have limited hd space - i don't know.

hope this is some use

droolian

[PkmoNk]

@droolian01:
I know the procedure to compress and calculate all the filesize and stuff. It's just the procedure is very time consuming, and I'm suggesting a thang to make it simple.