Inconsistant DivX output file size

[benwhit]

Hi all.

I have been ripping DVD movies to DivX recently using FlasKMPEG & VBR DivX 5.02 Pro with the intention of getting a 1400Mb avi file as the output.

However, due to the VBR I assume, most of the movies I encode (particullaly sub 120min) come out far smaller than the 1400Mb which I calculated them to. for example;

Movie: Being John Malkovich
Length: 108 minutes
bitrate encoded at: 1675kbps (128k CBR MP3 audio)
output file size: 848Mb (should be 1400Mb!)

Longer movies with more action such as Minority Report and Black Hawk Down encoded just fine and I havn't changed any settings (other than the video bitrate of course) so I guess it has something to do with the variable bitrate encoding...

Anyways, If any of you have had similar problems or know how to get the desired output file size every time(preferable without resorting to constant bitrate) please reply.

Thanks for your help.
benwhit.

[crahak]

I never knew thatr flaskmpeg did VBR? Might be a new thing anyways.

My only recommendation: dump flask, and try Gordian Knot. You'll get the best rips you can get, fast, and they'll be the size you want.

[benwhit]

Yeah, the latest version of FlasKMPEG does a two pass VBR encoding but as you recommend, I thing I will look into Gordian Knot.

I'm still very interested in how to resolve the problem with FlasKMPEG though so if anyone has any ideas please reply.

Thanks.
benwhit

[benwhit]

Gordian Knot is great! but I still get movies well below the 1400Mb output size I'm setting it to. any more idears?

Thanks

[crahak]

How long is the movie exactly? How much bits/(pixel*frame) were you aiming for? Did you do a compressability test?

Also, note that the .avi will be smaller than 1400 at first, as audio is not into it yet (you have to multiplex it).

[benwhit]

Hi crahak

I'm currently encoding Being John Malkovich again using GordianKnot this time. The movie is 162248 frames at 25fps (108min 10sec) and is being encoded at 0.247 bits/(pixel*frame) the encoder has written to the log that it is encoding the movie at 1736kbits/sec. By doing the maths on that the output file should be 1343Mb (video only) but all my attemps so far have not produced what was expected so I am still doubtfull.

I have not carried out a compressability test and to be honest am not quite sure what this function does, can you advise me here?

as for the audio, FlaskMPEG and GordianKnot both interleave the audio for the final output file.

Thanks for any help you can provide me with.
benwhit