x264's SAR or MKV's DAR?

elguaxo · 30th July 2008, 15:07

If I encode with x264 to MKV and use a custom SAR is it really stored in the AVC stream or is MKV's DAR used instead?

I did an anamorphic encode via MeGUI which resulted in a weird AR (it's a documented bug of the MeGUI version I'm currently using). I wanted to fix it via MKVToolnix remuxing and setting the correct DAR. Then I thought something weird might happen if the stream has one SAR and the container is specifying a different AR via DAR. But if I extract the rawstream out of the MKV with weird AR and open it via DGAVCIndex I get: SAR: Unspecified. So I wonder if the AR was stored just at the container level.

Sharktooth · 30th July 2008, 15:17

in the avc stream.
mkvmerge removes the AR from the stream and places it into the container.

martino · 30th July 2008, 15:20

Does it really remove it? I was in the through that it is kept, so even after doing AVC (w/ --sar) -> MKV/MP4 -> AVC -> MKV/MP4 the correct AR would be still kept since it's present in the AVC stream... Or is my memory going bad. :/

elguaxo · 30th July 2008, 15:21

Quote:

Originally Posted by Sharktooth

mkvmerge removes the AR from the stream and places it into the container.

that solves the mystery! thanks.

buzzqw · 30th July 2008, 15:32

or you can use the --engage keep_bitstream_ar_info in mkvmerge

BHH

elguaxo · 30th July 2008, 15:35

good to know. thanks buzzqw!

Sharktooth · 30th July 2008, 15:42

Quote:

Originally Posted by martino

Does it really remove it? I was in the through that it is kept, so even after doing AVC (w/ --sar) -> MKV/MP4 -> AVC -> MKV/MP4 the correct AR would be still kept since it's present in the AVC stream... Or is my memory going bad. :/

it removes the AR from the bitstream and places it in the container, how many times i have to repeat that?
you can do as buzzqw sugested to change the default behaviour

martino · 30th July 2008, 15:50

Quote:

Originally Posted by Sharktooth

it removes the AR from the bitstream and places it in the container, how many times i have to repeat that?

Ugh calm down... I was merely saying something, nothing more... :V

Sharktooth · 30th July 2008, 15:53

k, np. sorry. however search before posting. that info is already available in other threads too.

Brother John · 31st July 2008, 00:34

The removal doesn’t happen for all input types, though, as mosu explained some time ago in the German forum. I’m sure about raw AVC input and I think it was MP4 as well, but not other formats.

30th July 2008, 15:07	#1 \| Link
elguaxo Registered User Join Date: Jun 2006 Posts: 260	x264's SAR or MKV's DAR? If I encode with x264 to MKV and use a custom SAR is it really stored in the AVC stream or is MKV's DAR used instead? I did an anamorphic encode via MeGUI which resulted in a weird AR (it's a documented bug of the MeGUI version I'm currently using). I wanted to fix it via MKVToolnix remuxing and setting the correct DAR. Then I thought something weird might happen if the stream has one SAR and the container is specifying a different AR via DAR. But if I extract the rawstream out of the MKV with weird AR and open it via DGAVCIndex I get: SAR: Unspecified. So I wonder if the AR was stored just at the container level.

30th July 2008, 15:17	#2 \| Link
Sharktooth Mr. Sandman Join Date: Sep 2003 Location: Haddonfield, IL Posts: 11,768	in the avc stream. mkvmerge removes the AR from the stream and places it into the container. __________________ MPEG-4 ASP Custom Matrices: EQM V1(old), EQM AutoGK Sharpmatrix (aka EQM V2), EQM V3HR (updated 01/10/2004), EQM V3LR, EQM V3ULR (updated 04/02/2005), EQM V3UHR (updated 17/12/2004) and EQM V3EHR (updated 05/10/2004) Info about my ASP matrices. MPEG-4 AVC Custom Matrices: EQM AVC-HR Info about my AVC matrices My x264 builds. Mooo!!!

30th July 2008, 15:32	#5 \| Link
buzzqw HDConvertToX author Join Date: Nov 2003 Location: Cesena,Italy Posts: 6,552	or you can use the --engage keep_bitstream_ar_info in mkvmerge BHH __________________ HDConvertToX: your tool for BD backup MultiX264: The quick gui for x264 AutoMen: The Mencoder GUI AutoWebM: supporting WebM/VP8

30th July 2008, 15:53	#9 \| Link
Sharktooth Mr. Sandman Join Date: Sep 2003 Location: Haddonfield, IL Posts: 11,768	k, np. sorry. however search before posting. that info is already available in other threads too. __________________ MPEG-4 ASP Custom Matrices: EQM V1(old), EQM AutoGK Sharpmatrix (aka EQM V2), EQM V3HR (updated 01/10/2004), EQM V3LR, EQM V3ULR (updated 04/02/2005), EQM V3UHR (updated 17/12/2004) and EQM V3EHR (updated 05/10/2004) Info about my ASP matrices. MPEG-4 AVC Custom Matrices: EQM AVC-HR Info about my AVC matrices My x264 builds. Mooo!!!

31st July 2008, 00:34	#10 \| Link
Brother John (schein)heilig Join Date: Jun 2003 Location: Germany Posts: 512	The removal doesn’t happen for all input types, though, as mosu explained some time ago in the German forum. I’m sure about raw AVC input and I think it was MP4 as well, but not other formats. __________________ Brother John When lost in BeSweet's options, have a look at the Commandline Reference. DVD nach MPEG-4 klappt nicht? Verzweifelt? Auf zum Encodingwissen!

30th July 2008, 15:20	#3 \| Link
martino masktools2 (ab)user Join Date: Oct 2006 Location: PAL-I :( Posts: 235	Does it really remove it? I was in the through that it is kept, so even after doing AVC (w/ --sar) -> MKV/MP4 -> AVC -> MKV/MP4 the correct AR would be still kept since it's present in the AVC stream... Or is my memory going bad. :/

30th July 2008, 15:35	#6 \| Link
elguaxo Registered User Join Date: Jun 2006 Posts: 260	good to know. thanks buzzqw!

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