change bitrate in SmartCutter

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bumper2007
Posts: 13
Joined: Fri Jan 07, 2011 9:22 am

change bitrate in SmartCutter

Post by bumper2007 »

hi, Is there way to set or alter the bitrate when generating the output file. Actually i tried Smartcutter to cut a short section from a long MP4 video. the output file is obviously larger than that I got from TotalMedia Extreme 2. What I have done in the experiment is:

I have HDPVR box connected to a recorder which plays the recorded video file, and try to capture a short video section in 2 ways:

1st method:
when playing the video file, I used TotalmediaExtreme2 to capture the whole length of about 3 hours, in MP4 format. Then I used Smartcutter v1.4.1 to cut the big file and get the wanted section, the output file size is ~26MB (length: 1min 10s)

2nd method:
when playing the video file, I used TotalmediaExtreme2 to capture the wanted section directly, the output file size is ~16MB (length: 1min 17s)

when I compare the properties of these 2 small video files, i found main differences at,
General, Overall bit rate: the output file from SmartCutter is 3036 Kbps, while TME2 output is 1505 kbps
Video, bit rate: 2261Kbps by Smartcutter, TME2 used 1505 Kbps only

so I wonder if Smartcutter output file bit rate can be set to 1500 kbps? My purpose is to reduce the output file size.
Could someone help? Your advice is much appreciated.

thanks.
admin
Site Admin
Posts: 740
Joined: Mon Jun 01, 2009 12:54 pm

Re: change bitrate in SmartCutter

Post by admin »

Dear bumper2007:
Thanks for your message.
bumper2007 wrote:if Smartcutter output file bit rate can be set to 1500 kbps?
We raise the bitrate of the output so as to maintian a better video quality, as much as we can. 1500 Kbps is some how low for regular video encoding. It may produce a poor video output.

Please feel free to send us your further advice and suggestion.
Thank you very much.

Best Regards,
FameRing Support Team
bumper2007
Posts: 13
Joined: Fri Jan 07, 2011 9:22 am

Re: change bitrate in SmartCutter

Post by bumper2007 »

hi support team, thanks for your reply.

I have to change to bit rate if possible, it is due to the trade off between output file size and video quality.
Please kindly advise.

thanks a lot.
bumper2007
Posts: 13
Joined: Fri Jan 07, 2011 9:22 am

Re: change bitrate in SmartCutter

Post by bumper2007 »

admin wrote:Dear bumper2007:

We raise the bitrate of the output so as to maintian a better video quality, as much as we can. 1500 Kbps is some how low for regular video encoding. It may produce a poor video output.
seems that i'm the only one to have such issue / question.
further to your reply above, I suppose SmartCutter won't alter the format or bit-rate. That's what I see as "split without re-encoding". if you can raise the bitrate, why not having the option to disable bit-rate change or even with the bit-rate tuning?

Thanks for your attention.
JohnnyB
Posts: 13
Joined: Mon Jan 02, 2012 5:11 pm

Re: change bitrate in SmartCutter

Post by JohnnyB »

My understanding of how SmartCutter works, which is one of its primary features, is that it achieves high processing rates and maximum video quality by NOT re-encoding the video stream and only re-encodes the frames near where edit cuts are made. In order to change the bit-rate of the entire video file, the entire stream would have to be re-encoded. This would degrade the video quality by another de-code / en-code process.

If you desire to change the bit-rate (i.e.: compression level) of the video file, I believe you are looking for a function best served by a different software package.
bumper2007
Posts: 13
Joined: Fri Jan 07, 2011 9:22 am

Re: change bitrate in SmartCutter

Post by bumper2007 »

JohnnyB wrote: If you desire to change the bit-rate (i.e.: compression level) of the video file, I believe you are looking for a function best served by a different software package.
hi JohnnyB, thanks for your advice. But as per admin's reply above, "We raise the bitrate of the output so as to maintian a better video quality, as much as we can....". And as per my experience, when my source file is 1500kbps, the output file from Smartcutter could be ~2000kbps. That's why I said Smartcutter alters the bitrate.
JohnnyB
Posts: 13
Joined: Mon Jan 02, 2012 5:11 pm

Re: change bitrate in SmartCutter

Post by JohnnyB »

bumper2007 wrote:
JohnnyB wrote: If you desire to change the bit-rate (i.e.: compression level) of the video file, I believe you are looking for a function best served by a different software package.
hi JohnnyB, thanks for your advice. But as per admin's reply above, "We raise the bitrate of the output so as to maintian a better video quality, as much as we can....". And as per my experience, when my source file is 1500kbps, the output file from Smartcutter could be ~2000kbps. That's why I said Smartcutter alters the bitrate.
I think you may have mis-understood my reply. Since Smart Cutter only re-encodes the few frames of video near where the cuts are made, the bit rate at which Smart Cutter encodes those few frames is probably indeed set to be higher than the bit rate of the original video in order to avoid significantly degrading the quality of those re-encoded frames. However, the other 99% of the frames in the video is not touched by Smart Cutter and therefore the bit rate of those frames are not changed.

Since it appears that in your examples you are using pretty small files (< 2 minutes), the ratio of the number of Smart-Cutter re-encoded frames to the total number of frames is much higher that if you were working with a much larger file, so the overall effect on the filesize is a little more dramatic than if you just trimmed off the beginning and end of a 2 hour movie file.

If your desire is to take an existing video file and "resize" it to fit within a smaller amount of disk space, I do not believe Smart Cutter was designed to do that. This operation would require a decode / re-encode-at-a-lower-bitrate function that Smart Cutter was not designed to do.
bumper2007
Posts: 13
Joined: Fri Jan 07, 2011 9:22 am

Re: change bitrate in SmartCutter

Post by bumper2007 »

hi JohnnyB, thanks for your explanation, i understand now.
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