x264vfw, handbrake, different file size output?

[whatsisname]

Hi all,

I have a 165mb avchd lite mts file.

When I encode it in handbrake using High Profile avg bitrate 7000, I get a 42mb file. Mediainfo tells me this:

Bit rate mode :Variable
Bit rate : 3437 Kbps
Nominal bit rate : 7000 Kbps


Using x264vfw within vegas 9 pro, again setting avg bitrate 7000, I get a file that is 82mb. Mediainfo tells me this:

Bit rate mode :Variable
Bit rate : 6972 Kbps
Maximum bit rate : 14.7 Mbps

What I want is the result from handbrake but using x264vfw in vegas. What am I doing wrong with the settings in x264vfw?

Any help gratefully appreciated!

Gary.

[nurbs]

A good start would be posting the settings you used. Handbrake has a log IIRC and I think you can get x264vfw to show the command line somehow. Version of both encoders is also important.

From the mediainfo it looks like the Handbrake file is using only half the bitrate.

[sneaker_ger]

I don't really get your problem. You set an average bitrate of 7000 kbit and that's what you got using x264vfw. :confused:
Question would rather be: what did you do wrong that made the Handbrake encode not end up using 7000 kbit.

[Dark Shikari]

I don't really get your problem. You set an average bitrate of 7000 kbit and that's what you got using x264vfw. :confused:
Question would rather be: what did you do wrong that made the Handbrake encode not end up using 7000 kbit.6972 looks a lot like 7000 to me.

[sneaker_ger]

6972 looks a lot like 7000 to me.

Yes, but that's what he got using x264vfw, which is what he asked for and that's why I don't really get what his problem is.

[whatsisname]

Hi guys, thanks for your replies.

The reason I want the result that handbrake produces is that those files will playback ok on an older laptop that I have, and the files produced by 264vfw won't, presumably because of the bitrate issue.

I'm trying to understand what is happening with the two different encoding methods. I've attached the two mediainfo files from the two different files with the encoding settings...

Looking at the readout, I'm wondering if it is something to do with the frame rate? The source file is 50fps from a panasonic tz7, but its actually 25fps with each frame repeated (double pal?). Is handbrake treating this differently than x264vfw somehow?

[whatsisname]

Ok I had another look at this this evening, and analysed the files with Bitrate Viewer. Seems to me that basically the complication is induced by handbrake and not vfw. Altho I am setting 7000 variable in handbrake, actually it is coming out at 3500 or so. Don't understand why, but as it stands, that is what I think is going on...

[nm]

Seems to me that basically the complication is induced by handbrake and not vfw. Altho I am setting 7000 variable in handbrake, actually it is coming out at 3500 or so.

It's probably related to the duplicate frames in the source video. It's hard to say what goes wrong since we can't see your attachments until they are approved. Upload your logs to pastebin.com or some similar service instead.

You should make sure that the duplicate frames aren't fed to the encoder and that the input framerate is 25 fps. Then you can use x264's "--pulldown double" feature to make the video appear 720p50, or slow down to 720p24. That way the output can be made Blu-ray/AVCHD-compatible with minimal loss in compression efficiency, but you also need to set VBV and other required parameters.