AnimeSuki Forums

skystrife · 2007-07-06, 16:24

I'm interested in encoding using VFR, but I'm very new to the encoding scene and I have no idea of how to go about it. I read the VFR thread in here, but it's mainly a guide of what to do if you encounter a VFR raw (which I just recently did). I'm curious about the most accurate way of creating a VFR encode from a CFR raw. Say, taking a 23.975fps raw and getting rid of duplicate frames in still areas and (if there are any) when the image is moving. I think if I do this I'll be able to squeeze out slightly higher quality video while keeping the filesize down. I'm wanting to do this to a HD raw in order to keep the filesize down to 233MB while still having quality somewhere similar to a crf-18 pass.

Harukalover · 2007-07-06, 16:47

Make VFR out of CFR?

You would use something like DeDup or mode 3 in Yatta. Both won't really decrease filesize that much and both put you at risk for softsubs playback if you decide to use them. Most modern codecs will compress duplicate frames fairly well.

Either you can let DeDup gather dup metrics and do it automatically. (Be careful with how high you set thresholds or you may lose non-dups)

Or you can do it in Yatta by decimating frames manually. (takes lots of time though)

DeDup

Yatta

martino · 2007-07-06, 16:52

So you have a CFR raw, and want to forcibly make it VFR? Using DeDup to remove duplicate/similar frames and output a matroska timecodes format will only give you and the rest of the team trouble. So, for that matter try Dup. It replaces similar/duplicate frames with exact duplicates, and from what I've been told a modern codec (like h264, XviD and such) can compress a such frames down to 8 bytes. So there you go, saves some bitrate which can be used in other areas where it's needed.

P.S. Just make sure to set a good threshold for Dup, otherwise it could end up replacing frames that you don't want it to (hint: show=true is your friend).

Edit: Harukalover got there first...

TheFluff · 2007-07-06, 17:47

Yes, don't use DeDup. Even its author, pengvado (also x264 developer) says it's pretty pointless and only creates a lot of extra work. Use temporal softening and/or the normal dup instead.

Nicholi · 2007-07-06, 20:28

Truly if the RAW already is CFR, best to leave well enough alone. You only use VFR to preserve motion because of differeing framerates. Dropping duplicate frames though as with DeDup has proven to have little effect on filesize which is really only the real reason to use it.

2007-07-06, 16:24	Link #1
skystrife Encoder Fansubber Join Date: Jun 2007 Location: Illinois	VFR Question I'm interested in encoding using VFR, but I'm very new to the encoding scene and I have no idea of how to go about it. I read the VFR thread in here, but it's mainly a guide of what to do if you encounter a VFR raw (which I just recently did). I'm curious about the most accurate way of creating a VFR encode from a CFR raw. Say, taking a 23.975fps raw and getting rid of duplicate frames in still areas and (if there are any) when the image is moving. I think if I do this I'll be able to squeeze out slightly higher quality video while keeping the filesize down. I'm wanting to do this to a HD raw in order to keep the filesize down to 233MB while still having quality somewhere similar to a crf-18 pass. Last edited by skystrife; 2007-07-06 at 16:41.

2007-07-06, 16:47	Link #2
Harukalover In exile Join Date: May 2006 Location: There! Not there! There! Age: 36	Make VFR out of CFR? You would use something like DeDup or mode 3 in Yatta. Both won't really decrease filesize that much and both put you at risk for softsubs playback if you decide to use them. Most modern codecs will compress duplicate frames fairly well. Either you can let DeDup gather dup metrics and do it automatically. (Be careful with how high you set thresholds or you may lose non-dups) Or you can do it in Yatta by decimating frames manually. (takes lots of time though) DeDup Yatta __________________ "Brainpower without willpower is no power."

2007-07-06, 16:52	Link #3
martino makes no files now Join Date: May 2006	So you have a CFR raw, and want to forcibly make it VFR? Using DeDup to remove duplicate/similar frames and output a matroska timecodes format will only give you and the rest of the team trouble. So, for that matter try Dup. It replaces similar/duplicate frames with exact duplicates, and from what I've been told a modern codec (like h264, XviD and such) can compress a such frames down to 8 bytes. So there you go, saves some bitrate which can be used in other areas where it's needed. P.S. Just make sure to set a good threshold for Dup, otherwise it could end up replacing frames that you don't want it to (hint: show=true is your friend). Edit: Harukalover got there first... __________________ "Light and shadow don't battle each other, because they're two sides of the same coin" Last edited by martino; 2007-07-06 at 17:09. Reason: corrected term

2007-07-06, 17:47	Link #4
TheFluff Excessively jovial fellow Join Date: Dec 2005 Location: ISDB-T Age: 37	Yes, don't use DeDup. Even its author, pengvado (also x264 developer) says it's pretty pointless and only creates a lot of extra work. Use temporal softening and/or the normal dup instead. __________________ \| ffmpegsource 17:43:13 <~deculture> Also, TheFluff, you are so fucking slowpoke.jpg that people think we dropped the DVD's. 17:43:16 <~deculture> nice job, fag! 01:04:41 < Plorkyeran> it was annoying to typeset so it should be annoying to read

2007-07-06, 20:28	Link #5
Nicholi King of Hosers Join Date: Dec 2005 Age: 41	Truly if the RAW already is CFR, best to leave well enough alone. You only use VFR to preserve motion because of differeing framerates. Dropping duplicate frames though as with DeDup has proven to have little effect on filesize which is really only the real reason to use it.