DAR set for avs4x264mod encoding

yup · 21st November 2013, 07:52

Hi all!

Before i am using MeGUI and use DAR signaling in my script

Code:

global MeGUI_darx=4
global MeGUI_dary=3

Now i am go to batch file with

Code:

avs4x264mod --level 4.1 --preset veryslow --crf 20 --keyint 24 --b-pyramid strict --ref 4 --weightp 0 --slices 4 --qpmin 10 --qpmax 51 --vbv-bufsize 30000 --vbv-maxrate 40000 --aud --nal-hrd vbr --tff --output file.mp4 file.avs

What I need make, add --sar option for avs4x264mod or during muxing mkvmerge change to DAR 4:3.
Please advice.

yup.

sneaker_ger · 21st November 2013, 11:43

H.264 "SAR" and DAR are two different things. It is recommended to set --sar, mkvmerge will then automatically read and use that info for the container as well.

DAR = (width/height) * SAR

yup · 21st November 2013, 13:14

sneaker_ger

But If encoded without --sar, mkvmerge solving problem, if I change to 4:3?
I have some files encoded without --sar and question easy can I use mkvmerge for patching or need reencoding.
yup.

sneaker_ger · 21st November 2013, 14:04

If you put an H.264 stream into an mkv container there can be two locations in which aspect ratio information is stored:
1. within the H.264 bitstream
2. within the mkv header

Some players rely on 2 and some players rely on 1. The x264 paramter --sar will only write 1, mkvmerge will only write 2. You cannot use mkvmerge to patch 1.

There is a tool which can change 1 without re-encoding but it's neither trivial to use nor stable:
http://forum.doom9.org/showthread.php?t=152419

yup · 21st November 2013, 14:33

sneaker_ger!
I try patched from mkvmerge files on VLC and two my mediabox it is work.
I read that mkvmerge remove AR info from bitstream.
I try suggested direct264 tool.
yup.

sneaker_ger · 21st November 2013, 14:56

Quote:

Originally Posted by yup

I try patched from mkvmerge files on VLC and two my mediabox it is work.

If your players rely on 2 you could of course leave it at that.

Quote:

Originally Posted by yup

I read that mkvmerge remove AR info from bitstream.

That information is very outdated. Mkvmerge has not been doing that anymore by default for years.

yup · 21st November 2013, 15:41

sneaker_ger!

I extract from mkv bitstream.
I try

Code:

"C:\Video\ff\ffmpeg.exe" -i "T1_Video - .h264" -vcodec copy -acodec copy -vbsf h264_changesps=sar=12:11 "T1_Video - ow.h264"

and after mux back to mkv.
Now Mediainfo show only DAR 4:3.
My video PAL 720x576.
It is right way for processing? I have near 300GB video which I could remake.
Please advice.
yup.

yup · 22nd November 2013, 11:07

Hi all!
Before I am using wrong SAR, now

Code:

ffmpeg.exe -i chapter13.mkv -vcodec copy -acodec copy -vbsf h264_changesps=sar=16:15/fps=50:2 chapter13cd.mkv

work on mkv without demuxing, but I add fps parameter because without this I get video with 1000 fps.
yup.

21st November 2013, 07:52	#1 \| Link
yup Registered User Join Date: Feb 2003 Location: Russia, Moscow Posts: 854	DAR set for avs4x264mod encoding Hi all! Before i am using MeGUI and use DAR signaling in my script Code: global MeGUI_darx=4 global MeGUI_dary=3 Now i am go to batch file with Code: avs4x264mod --level 4.1 --preset veryslow --crf 20 --keyint 24 --b-pyramid strict --ref 4 --weightp 0 --slices 4 --qpmin 10 --qpmax 51 --vbv-bufsize 30000 --vbv-maxrate 40000 --aud --nal-hrd vbr --tff --output file.mp4 file.avs What I need make, add --sar option for avs4x264mod or during muxing mkvmerge change to DAR 4:3. Please advice. yup.

21st November 2013, 15:41	#7 \| Link
yup Registered User Join Date: Feb 2003 Location: Russia, Moscow Posts: 854	sneaker_ger! I extract from mkv bitstream. I try Code: "C:\Video\ff\ffmpeg.exe" -i "T1_Video - .h264" -vcodec copy -acodec copy -vbsf h264_changesps=sar=12:11 "T1_Video - ow.h264" and after mux back to mkv. Now Mediainfo show only DAR 4:3. My video PAL 720x576. It is right way for processing? I have near 300GB video which I could remake. Please advice. yup.

22nd November 2013, 11:07	#8 \| Link
yup Registered User Join Date: Feb 2003 Location: Russia, Moscow Posts: 854	Hi all! Before I am using wrong SAR, now Code: ffmpeg.exe -i chapter13.mkv -vcodec copy -acodec copy -vbsf h264_changesps=sar=16:15/fps=50:2 chapter13cd.mkv work on mkv without demuxing, but I add fps parameter because without this I get video with 1000 fps. yup.

21st November 2013, 11:43	#2 \| Link
sneaker_ger Registered User Join Date: Dec 2002 Posts: 5,565	H.264 "SAR" and DAR are two different things. It is recommended to set --sar, mkvmerge will then automatically read and use that info for the container as well. DAR = (width/height) * SAR

21st November 2013, 13:14	#3 \| Link
yup Registered User Join Date: Feb 2003 Location: Russia, Moscow Posts: 854	sneaker_ger But If encoded without --sar, mkvmerge solving problem, if I change to 4:3? I have some files encoded without --sar and question easy can I use mkvmerge for patching or need reencoding. yup.

21st November 2013, 14:04	#4 \| Link
sneaker_ger Registered User Join Date: Dec 2002 Posts: 5,565	If you put an H.264 stream into an mkv container there can be two locations in which aspect ratio information is stored: 1. within the H.264 bitstream 2. within the mkv header Some players rely on 2 and some players rely on 1. The x264 paramter --sar will only write 1, mkvmerge will only write 2. You cannot use mkvmerge to patch 1. There is a tool which can change 1 without re-encoding but it's neither trivial to use nor stable: http://forum.doom9.org/showthread.php?t=152419

21st November 2013, 14:33	#5 \| Link
yup Registered User Join Date: Feb 2003 Location: Russia, Moscow Posts: 854	sneaker_ger! I try patched from mkvmerge files on VLC and two my mediabox it is work. I read that mkvmerge remove AR info from bitstream. I try suggested direct264 tool. yup.