Custom Aspects/Resolutions on HD Extender?

[bialio]

Did you try the Letterbox AR defined in this post?

[Taddeusz]

When you mux into an MKV file mkvmerge must be told to keep the AR that's encoded into the video stream by using this command:

--engage keep_bitstream_ar_info

Otherwise mkvmerge strips it by default. The HD Extender only reads the stream AR and not the container AR so when it's been stripped out of the video stream it assumes the video has square pixels.

[Vox-uLaw]

Originally Posted by Taddeusz

When you mux into an MKV file mkvmerge must be told to keep the AR that's encoded into the video stream by using this command:

--engage keep_bitstream_ar_info

Otherwise mkvmerge strips it by default. The HD Extender only reads the stream AR and not the container AR so when it's been stripped out of the video stream it assumes the video has square pixels.

That did it,

Much thanks!


Now I just need to figure out how to get OGMRip to use that flag.

SOLVED: Used a wrapper script for mkvmerge and added the engage flag.

[ldavis]

I hate to dig up an old thread but I have read through this and searched this forum for answers and have found none that I can understand. Did anyone finally figure our how to vertically compress/expand a video (say an anamorphic video but w/o AR tagging). I have plenty of ways to crop a video but this is not what I am trying to do. With a client, this a trivial task but with HD extender (even after 5 hours of research and trial and error) I have no idea what almost any of the parameters do. Quite frankly, if the designers' goal was to make the this information uninteligible, then they have succeded as far as it concerns me !

[Rob]

This will vertically expand:

advanced_aspect_ratio_extra_modes=Taller|source\=2048,2048,4096,3580
,FrontEdgeToCenter,FrontEdgeToCenter,Relative,Relative,Relative,Relative
|blackstrip\=0,0|cutstrip\=0,516

[ldavis]

Originally Posted by Rob

This will vertically expand:

advanced_aspect_ratio_extra_modes=Taller|source\=2048,2048,4096,3580
,FrontEdgeToCenter,FrontEdgeToCenter,Relative,Relative,Relative,Relative
|blackstrip\=0,0|cutstrip\=0,516

Thanks. Unfortunately, expanding is all I have been able to do with any of the settings. Does anyone know how to "compress" the image.

[Opus4]

Originally Posted by ldavis

Does anyone know how to "compress" the image.

Try setting the source's w or h value larger than 4096. The output setting is ignored, btw.

- Andy

[Taddeusz]

Originally Posted by ldavis

Thanks. Unfortunately, expanding is all I have been able to do with any of the settings. Does anyone know how to "compress" the image.

What kind of video files are you having problems with? You mentioned anamorphic video files. Would they by chance be MKV's? MKVmerge by default strips the stream AR data out unless you put "--engage keep_bitstream_ar_info" on the command line.

If you need to redo the stream AR data you will need to demux the video from the MKV container and use mp4box to do so.

Using the settings like you're trying to do is sounds to me like you're going about it the wrong way. The HD Extender depends on the stream AR data to display the anamorphic video properly. Trust me, I have a couple hundred anamorphic MKV video files that all play fine on my HD Extender.

[ldavis]

No, they are AVIs that could me made into MKVs (using any number of programs and the time to remux about 360 files –including changing the aspect ratio of the video stream). I realize that AVI is outdated but the program that I used to compress the files only had AVI as an option. I have had nothing but flawless playback with AVC and AC3 in these files and every computer/program that I have put these on recognize the file types and playback easily with ffdshow installed. Thus, I have had no compelling reason to remux to MKV until possibly now.

I see that the aspect ratio information in the AVC stream is used by HD extender in source AR but for some reason the AR is not exactly correct (it is watchable though and really only barely stretched.). As far as the HD extender needing correct source information to display correctly, that is only true if you leave the AR in source mode – and I agree that is ideal. The other modes distort/zoom the picture to display whatever portions you want. How is that different than leaving a server/client in source mode – again, ideal if you can do that? But I can not – I have a need for both 16x9 and 2.35:1 AR (and that is regardless of whether the original video was anamorphic or not as the files were cropped). With server/client it takes about 30 seconds to modify an AR to do 2.35:1 – if you have more than 2 functioning brain cells and I just barely qualify . I just do not understand why HD Extender is so complicated in this area when everything else “just works”. (It took me longer to unbox the extender and plug it in than to actually set it up, except for AR issues.)

So ultimately, I am left with three choices:

-Live with it as is – not a really bad choice.

-Modify the existing files – I am guessing days and weeks of file manipulations. You mentioned mp4box. Is there a guide to use YAMB or some other front end program do exactly what you are saying, including changing the video stream AR. To be honest unless there is some batch method, I will probably leave it as is before I do this, or I might do it slowly over a long period of time.

-Find a way to set up a 16x9 and 2.35:1 AR as I do with server/client. Though less than ideal (I agree changing the video stream AR is the best choice), it is not ideal to spend as much time as I expect it will take to modify those files. That makes this the best choice at this point if possible.

To that end, I will try Opus’ suggestion when I get home. BTW, would you leave the blackstrip and cutstrip the same? Any way, I will give it a try

[Taddeusz]

I guess the difference is that I don't crop. At least not my SD DVD rips. BD rips are cropped only vertically but are not anamorphic so they don't need any special AR consideration.

I've tried cropping a couple times but the trouble with getting the AR just right isn't worth it. And if you're using CQ mode the size difference between uncropped and cropped really isn't that much. On the one major test I did the difference was something like 6MB with the larger video being around 700MB. The difference wasn't worth the work in getting the AR to be correct. And I'm certainly not going to convert to square pixels.

[ldavis]

Originally Posted by Taddeusz

I guess the difference is that I don't crop. At least not my SD DVD rips. BD rips are cropped only vertically but are not anamorphic so they don't need any special AR consideration.

I've tried cropping a couple times but the trouble with getting the AR just right isn't worth it. And if you're using CQ mode the size difference between uncropped and cropped really isn't that much. On the one major test I did the difference was something like 6MB with the larger video being around 700MB. The difference wasn't worth the work in getting the AR to be correct. And I'm certainly not going to convert to square pixels.

With regard to cropping, I agree totally with your comment on space savings. I have not really tested it, but it seems unlikely that a modern codec would not be able compress black space down to nothing. I did it for two reasons:

1. Compression was faster – only smaller portions of each frame needed to be scanned
2. Marginal machines could play back the video. I have several marginal clients that this helped as each frame had fewer pixels to decode. That consideration is moot with HD extender.

I used/use FairUse. That is probably not the best program but it was simple and produced fairly transparent results (albeit at just over twice the file size that you are reporting). I noticed right off that the AR within the video stream was not correct (bear in mind that this is also true for uncropped anamorphic files such as 1.85:1 video where I kept all 720 x 480 pixels, so the cropping did not produce the problem, the incorrect AR in the video stream did) but it has never been any issue until now, and I do not think it will be an issue for long

[Taddeusz]

Originally Posted by ldavis

I used/use FairUse. That is probably not the best program but it was simple and produced fairly transparent results (albeit at just over twice the file size that you are reporting). I noticed right off that the AR within the video stream was not correct (bear in mind that this is also true for uncropped anamorphic files such as 1.85:1 video where I kept all 720 x 480 pixels, so the cropping did not produce the problem, the incorrect AR in the video stream did) but it has never been any issue until now, and I do not think it will be an issue for long

Ah.. yea, I think some people who write those video conversion front-ends don't fully understand the calculations needed to get proper PAR data on an anamorphic video inserted into the video stream. I use AutoMKV and the guy who writes it is very thickheaded about the whole issue. I've tried to explain it to him on a couple occasions be he still doesn't seem to get it. A few months ago I had to give myself a crash course on the topic because I had some anamorphic video files that I was trying to get playing correctly on the HD Extender. After long last I finally understood the process and was able to get the correct PAR into the stream using mp4box and then muxed into an MKV container. I've since found a web site that can do all the calculations for you.

I use mp4box on the command-line so I don't know of any front-ends to make it easier.

And no, AVI isn't a proper container for AVC/H.264 video. I personally had issues with the HD Extender and choppy video when I was starting off using AVI. In the process I discovered that the very same video played fine from an MKV but gave me chop from AVI on the HD Extender. Very strange.

I know MKV is more or less in it's infancy and isn't that well supported. Hopefully Frey will get subtitle support into SageTV some time in the near future. MKV itself also needs support for high definition subtitle streams such as PGS (.sup files). But it's still a better option than MP4 since it supports AC3 and DTS. I still have yet to get ts or m2ts files to play properly on my HD Extender so I'm not really holding my breath there.

[ldavis]

Well, don’t keep me in suspense here. Obviously you had AVI (AVC/AC3) files with the wrong aspect ratio data. Tell me the command line inputs/steps to demux, change the AR and remux to MKV. If you are doing this from a command line possibly a script could be written to convert files in masse. At least give some links to where you got the information.

When you say choppy video with AVI are you talking about slightly choppy video or terribly choppy. I am using extender only on secondary small monitors so slight choppiness might not be very noticeable for me.

[Taddeusz]

I use the mkvextract gui to demux the video to elementary streams but only because I use MKV. I think it might actually work to demux with tsmuxer. It supports all kinds of formats. BTW, both those programs are actually command-line so that they could actually be batched somehow. Since I use the gui's I don't know what commands are used.

When using elementary AVC streams the frame rate is unknown so that has to be taken into account also.

With mp4box I use a command something like:

mp4box -add video.264:fps=23.976:par=32:27 -new video.mp4

That par value is based on a 16:9 720x480 video so obviously you'd fill that with whatever the proper par is based on the display aspect ratio and resolution of your source video.

The web site I found to do the calculations is:

http://resizecalc.somestuff.org/?css=false

If you do the calculations by hand this site is handy for reducing the fraction:

http://www.analyzemath.com/Calculato...alculator.html

[Opus4]

I'm curious: has anyone playing around with the custom AR modes ever changed any other 'source' settings besides the width and height? Did you find the other options for 'source' useful & kept the results?

Thanks.

- Andy

[ldavis]

Originally Posted by Opus4

Try setting the source's w or h value larger than 4096. The output setting is ignored, btw.

- Andy

No joy on that. That seems to have no effect - like it is ignoring the extra lines. Got an other ideas?

[bialio]

I haven't played with this for a while, but my experience was that any operation that requires changing the geometry (as opposed to just cropping) that this parameter is necessary :

nonlinearmode\=0,0

[stanger89]

Originally Posted by ldavis

I hate to dig up an old thread but I have read through this and searched this forum for answers and have found none that I can understand. Did anyone finally figure our how to vertically compress/expand a video (say an anamorphic video but w/o AR tagging). I have plenty of ways to crop a video but this is not what I am trying to do. With a client, this a trivial task but with HD extender (even after 5 hours of research and trial and error) I have no idea what almost any of the parameters do. Quite frankly, if the designers' goal was to make the this information uninteligible, then they have succeded as far as it concerns me !

So (for a concrete example) you've got a 16:9 encoded video, with a 1.5:1 pixel ratio (720x480), and you're displaying it on a 4:3 TV and want it letterboxed?

What does this do:

Letterbox|source\=2048,2048,4096,4096,FrontEdgeToCenter,FrontEdgeToCenter,Relative,Relative,Relative,Relative|output=2048,2048,4096,3072,FrontEdgeToCenter,FrontEdgeToCenter,Relative,Relative,Relative,Relative;

-edit, nevermind, I see Andy said output is ignored.

Originally Posted by Opus4

I'm curious: has anyone playing around with the custom AR modes ever changed any other 'source' settings besides the width and height? Did you find the other options for 'source' useful & kept the results?

Thanks.

- Andy

You mean like this:

Letterbox|source\=2048,2048,4096,3072,FrontEdgeToCenter,FrontEdgeToCenter,Relative,Relative,Relative,Relative;

[Opus4]

Originally Posted by stanger89

You mean like this:

Letterbox|source\=2048,2048,4096,3072,FrontEdgeToCenter,FrontEdgeToCenter,Relative,Relative,Relative,Relative;

In that setting, only the height has been changed form the default value. So far, I've only seen the width & height being modified, but I'm wondering if anyone has found a use for the option setings on that line -- things like x, y, and the various options that could replace FrontEdgeToCenter or Relative.

I'm of the opinion that only width & height are really useful to us, but I want to see if someone thinks otherwise.

- Andy

[ldavis]

Originally Posted by bialio

I haven't played with this for a while, but my experience was that any operation that requires changing the geometry (as opposed to just cropping) that this parameter is necessary :

nonlinearmode\=0,0

I have played around with that some. Everything that I do results in an expanded image.

Stanger89,

Your AR attempt with the output set was the first thing I thought of. That would make too much sense to say, in effect, "Take the entire input frame and fit it into this smaller frame". But of course, the output parameter is ignored.