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Same Qz as input

Started by naszdom, May 03, 2017, 02:41:57 pm

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naszdom

May 03, 2017, 02:41:57 pm Last Edit: May 03, 2017, 02:44:00 pm by naszdom
I came across
https://www.avidemux.org/admWiki/doku.php?id=tutorial:guide_to_encoding_types
when I was looking for something else. 

It mentions Same Qz as input as being useful for modifying an existing encoded file.  Just right for hard subtitles I thought.  However I just cannot find it in the configuration of version 2.6.21.  Does it exist in the Windows version for MKV files?

Jan Gruuthuse

May 03, 2017, 03:29:33 pm #1 Last Edit: May 03, 2017, 03:50:06 pm by Jan Gruuthuse
You are confusing container formats (mp4, mkv) with MPEG-4 encoding (h263, h264, ...)

mkv can contain a MPEG-4 encoded video

naszdom

The attached is what I see. I am not too concerned about the container. It could easily be an MP4 container.

What I want to do is "extract the 1-pass analysis information already stored in the video frames and reuse it, effectively avoiding a whole pass and saving time." as in the tutorial.  But I do not see how to set it for "Same Qz as input"

eumagga0x2a

In most cases, especially with hw accel enabled, Avidemux doesn't get the quantizing info from video. I don't think that this approach is viable.

naszdom

So does that mean that the avidemux admwiki needs correcting? (see link in first post)

eumagga0x2a

I can only guess that the article targeted xvid/divx as codec and was written with Avidemux 2.5.x in mind. Since then a lot of water has flowed under the bridge.

I'm not into the Avidemux wiki.

naszdom

Thanks for the clarification.

Jan Gruuthuse

May 04, 2017, 05:08:20 am #7 Last Edit: May 04, 2017, 05:12:51 am by Jan Gruuthuse
Time permitting the main developer does update the Wiki for big changes.

As you're using x264, this would be the place to look: guide_to_encoding_types ââ,¬Â¢ doctop ââ,¬Â¢ h.264
Qz is not mentioned there.

naszdom

Thanks - that will keep me going for a while.

mean

yes, it dates xvid/divx era
With more recent codecs we dont get that info at all