64 bit version of libXvBAW.so.1?

I try to install mplayer-vaapi. Strace tells me mplayer tries to open /usr/lib/libXvBAW.so.1.

Unfortunately opensuse 11.3 doesn’t contain this file but only the version in /usr/lib

Any ideas?

I try to install mplayer-vaapi. Strace tells me mplayer tries to open /usr/lib/libXvBAW.so.1.

Unfortunately opensuse 11.3 doesn’t contain this file but only the version in /usr/lib

Any ideas?
So why do you need to install mplayer-vaapi? I show no such file when I search for mplayer and searching on vaapi finds some video accelerator. I have never needed such a thing to use mplayer. So again, what are you trying to do exactly?

Thank You,

mplayer-vaapi is a variant of mplayer that decodes films on a radeon graphics card. Thus even a HD film can be watched without much cpu percentage and the resulting noise from the fan.

Now there is no substitute for loading the best video driver for your video chipset and I do so for my nVIDIA video card. However, you don’t need any special accelerated video player to view video content in openSUSE. You just need to make sure all of your multimedia files are properly updated from the Packman repository. If you are not sure, check the just released How To about the mmcheck script file here:

MultiMedia Checker or mmcheck - Check Your openSUSE MultiMedia Setup in Just 16 Steps

I can view any and all content in full screen (Excluding Blue Ray movies or the older HDDVD Movies due to the copyright issues) including any standard DVD and even including viewing iTunes Movie Trailers seen here:

iTunes Movie Trailers

If you can not get an iTunes Movie Trailer to work on your PC, then you need to download and run the mmcheck script to find out just what is wrong.

Thank You,

Sorry, but it is my business what I install on my system So: How to get libXvBAW.so.1 for 64 bit?
Anyway, it’s supposed to be 64bit. So where’s the library?

Actually, in my view you are both right :slight_smile: … For a moderately aged computer, jdmcdaniel3’s view is accurate for all videos except those that are HD with high bit rate. HD videos with high bit rate (such as 1920x1080 @ 25 MB/sec) can not be played on a moderately aged PC without massive audio/video desyncronization, and video slow down.

To prove my point, jdmcdaniel3 take a look here: H.264 Demo Clips | H264info.com

Download the two “I Am Legend – 1080p Trailer” videos. Try to play them in Linux on an older PC.

I’ll bet you a virtual beer that any older PC you may have will struggle with that video (if you have an older PC).

Now I can play them on my old 32-bit athlon-2800 with mplayer and vdpau (using a nVidia GeForce 8400GS graphic card with the proprietary nVidia driver) , … but my older dual core P8400 Dell Studio 1537 with an ATI Radeon HD3450 with the proprietary ATI graphic driver in Linux struggles and has problems with the same video, even though it has SIGNIFICANTLY more CPU capability and what should be a faster graphic card. That is because with my athlon-2800 I am offloading the video processing from the CPU to the GPU. [Note in WinXP my Dell Studio 1537, with its superior ATI radeon driver, has NO PROBLEM with HD videos - the Linux driver simply is seriously lacking].

Hence IMHO juxal is also correct, if one can offload the decoding of the video from the CPU to the videocard GPU, then even an old PC can play the very high HD videos with a high bit rate. This is one reason why Linux nVidia users are so keen on using vdpau with mplayer, and are waiting patiently for vlc and xine to obtain same vdpau playback capability. Now one needs the proprietary nVidia driver to take advantage of Vdpau (note vdpau is called “pure video” in MS-Windows).

ATI graphic drivers in Linux have for the longest time lacked providing the capability to offload the decoding of the CPU to the videocard GPU. ATI cards have this capabilty in MS-Windows via AVIVO. But until recently there has been no Linux capability for ATI graphic cards similar to AVIVO. vaapi/xvba is a technology that Linux users hope will provide that CPU to GPU offload capability for ATI graphic cards. But other than see a few threads on this on openSUSE (asking for help) I have not read of anyone reporting success.

juxal, if you search on vaapi or xvba on our forum, you may find the threads I am refering to, such as: video players supporting vaapi/xvba for ATI cards … but unfortunately, no real answers. Those who have solved this (if any) are not sharing yet.

Juxal, other than my knowing some very general theory (from a bit of reading) I do not have any specifics. Did you look here:
software.opensuse.org: Search Results
in this repository:


and try the package xvba-video-amd-0.7.7-1.1.x86_64.rpm .

Note again my knowledge is slim … very slim … and I am dearly hoping one of our ATI users share how to get this working for the rest of our forum to benefit.

So oldcpu, not sure how old a computer it takes. The slowest I can try it on is my two year Dell Laptop, a Latitude E6400 Intel Core 2 Duo 2.268 GHz Intel Mobile Processor. When running Windows XP, it barely can get out of its own way. It has Mobile 4 Integrated Graphics Controller. For Linux it is running at present, openSUSE 11.2, kernel 2.6.37-rc4, KDE 4.4.4 and I followed all of the recommendations per mmcheck. I tried mplayer and my favorite Kaffeine/KDE3, which allows me to take the picture full screen and for both movies it played just fine, as did my top computer using a nVIDIA graphics controller, which was no surprise.

So, I say bolderdash to need a better player or an addon to your video player if you followed ALL suggestions as per mmcheck, you can play most any video format. Now I must admit that if you are hobbled with a AMD video card, I can’t vouch for how well it will work, but surely it would be better than my Dell Laptop with its “unknown” 3D graphics driver? Why not show yourself it can really make a difference. Run mmcheck, update ALL of your multimedia files and then play that video on your lowest PC and see what happens. And, if you think the newer kernel gives me an advantage, then update your kernel, just as I have done. Ask me how!

As you know, I am honest as the day is long and if I am able to run these HIGH RESOLUTION movies on my slow, poor video laptop after following the mmcheck recommendations, I win, right? Now here is the type of beer I like. There are others that will do, but when drinking Virtual beer, why not go for the best. That is what I always say.


Disclaimer: I, nor any of my family work for Guinness and we always drink responsibly, and so should you. It is also best to not message in the forum while drinking beer. Don’t ask me how I know that.

Thank You,

First, I should say nice hardware and its GREAT to read of an Intel graphics processor success story.

I would need more detail on your Dell’s “Mobile 4 Integrated Graphics Controller”, but my guess is the Intel open source driver is likely offloading the decoding of the video from the CPU to the GPU, else your E6400 would be struggling. I tried finding your controller here: Intel GMA - Wikipedia, the free encyclopedia but I would need more detail to specifically point to which one it is, but please look at that chart. Look at the 3 columns on the right called “Hardware Acceleration”. Those columns are to tell us the capability of the Intel device to offload the processing of the CPU to the GPU (with the appropriate driver).

The h264 video examples I gave are NOT the most difficult HD videos to play. For example my Canon HF S10 records videos with a higher bit rate and a higher (slightly) resolution. Reference the Canon HF S10 I have, here is a sample of the resolution / bit-rate, but from a different Canon : http://av.watch.impress.co.jp/video/avw/docs/076/262/ez041.mts A caution, thats a large 30MB file, from a Japanese web site reviewing the camera so download may be slow. Also, the bit rate on that is still not the highest the camera can produce (at least not with that example scene).

Here is with NO vdpau - cpu is higher

Here is with vdpau - cpu load is lighter

But the example is not the best. Its on my Corei7, which does not need CPU to GPU off loading.

This weekend, I’ll upload a raw video from my Canon so you can download (if you wish) so as to make my point better. And I run an example on my 32-bit athlon-2800 (which pales in comparison to the ‘power’ of your slowest PC) …

Now reference the example I provided, I can play that back on my Dell Studio 1537 with a P8400 Dual Core CPU and an ATI radeon HD3450 graphics (proprietary ATI driver) but the video is disproportionally slow. Unfortunately one can not tell from that nature scene how badly the video lags the audio when played back without the video decoding being offloaded from CPU to GPU.

jdmcdaniel3, your script is wonderful, and I am most gratelful for the help you have provided others.

… but I have to say I’ve being doing the things in your script for years. This IS hardware, and fortunate for you, your hardware already offloads the decoding from CPU to GPU and has an adequate driver, or your CPU is so fast it does not need the offloading.

Do you NOT have a PC with nVidia or ATI graphics ? Because if you do, I am confident I can provide you with some suggestsions for a test to make my point.

Ahh … well, … no, … :slight_smile: … and that is what the OP is trying to sort. They want this CPU to GPU working with their ATI card.

… as noted, I’ve been doing the sort of things that mmcheck proposes for years. It does NOT make a difference.

I have to rush to work, but I tell you what, I’ll do screen prints of top with my PC (athlon-2800 with nVidia 8400GS) playing a HD video with vdpau functionality (offloading decode of video from CPU to GPU) with mplayer, and I’ll do the same with vdpau switched OFF in mplayer. And you will either be surprised, or you simply will not believe me having done this correctly when I show you the difference in CPU overhead.

lol ! Thanks for the suggestion. It is NOT kernel difference, unless the Kernel gives your Intel hardware graphic driver better functionality (such as the capability to offload the video decoding from CPU to GPU).

Well, no, … but I’ll send the virtual beer anyway, because I think our chat here will be educational to others.


Disclaimer: I do like Guinessess but it is not my like of Guiness that is having me send a virtual beer back, but rather its your post that motivated me.

… as an aside, I think if you surf the web on this and look for keywords such as “vdpau”, “pure video” , and “avivo” you will understand better what the user’s request in this thread is all about. … all the best and hope we can continue a technical thread on this.

Later today, or this weekend, I’ll create a test for you to run on any PC with nVidia graphic hardware that supports Pure Video (called vdpau in Linux) with two different terminal commands to run the application mplayer against the HD videos I asked you to examine. One command will use mplayer with vdpau switched ON, and the other command will use mplayer with vdpau switched OFF. You should see a signficant difference in CPU load.

This demo I plan to provide will only work with nVidia proprietary graphic driver installed, but I assume you do have it installed.

More to come later today or this weekend …

I documented some of this in this old out of date wiki page: Video editing/avchd - openSUSE and I am guilty for not maintaining it.

Here are some examples for your PC’s with nVidia graphic cards and the proprietary nVidia graphic card driver installed. I assume here that you have re-installed vdpau (from packman) AFTER your last proprietary graphic card update (that IS important). …

So lets say you have an HD h264 encoded video. Open a terminal and type “top” so as to monitor the CPU load. Try this to play back one of the videos without vdpau:

mplayer my-h264-video.avi 

where “my-h264-video.avi” is the name of your video (substitute it there).
Make a note of CPU load.

Now launch same video with vdpau:

 mplayer -vo vdpau -vc ffh264vdpau my-h264-video.avi 

and as long as you do not have ‘vdpau’ in your ~/.mplayer config file as the default video output mode, you should see a massive difference in CPU load.

You can also do same with mpeg2 encoded video:

 mplayer -vo vdpau -vc ffmpeg12vdpau my-mpeg2-video.mpg 

and for a wmv3 encoded video:

 mplayer -vo vdpau -vc ffwmv3vdpau my-wmv3-video.wmv 

and for a VC1 encoded video:

 mplayer -vo vdpau -vc ffvc1vdpau my-wmv-video.wmv 

where in each case you need to compare the CPU load of the video played with just ‘mplayer’ and no options, against the CPU load when playing the video with mplayer and the various ’ -vo’ and ’ -vc’ options.

Again this is only for a nVidia card that supports Pure Video (called vdpau in Linux) with the proprietary nVidia driver.

Now the OP in this thread is looking to conceptually do something similar with ATI graphics.

Your example of a moderately aged PC with Integrated Graphics has hardware acceleration built in, so this until now has all been transparent to you (because of your hardware selection and because of the reasonably good state of the Intel graphic driver for your hardware).

I think we need to increase that bet, like double or nothing on the virtual beer. It is early Friday morning and no time for downloading large videos but I will try everyone you put in front of me tonight. Now we may need to document that we have in fact setup all of your multimedia properly, though the results of mmcheck can not be posted on SUSE Paste I have discovered. This is due to the large number of URL’s in the test output which SUSE Paste thinks makes you are a spammer.

Also, in a separate note, I am actually working at a new nVIDIA Data Center here in Austin, setting up their environment control system. It also includes a large what I call Brainiac center with some very unusual architecture, for an office. I have a big meeting with the folks that run the Data Center. I am kind of excited to work there, though it is hard to know what it means to my use of their video cards in Linux.

Thank You,

lol !

I have a better home video you could test. It is 10 seconds of video, and it is 29 MB in size (approx). Location is here on our family ftp site (right click and download): oldcpu family video 00178.mts

Reference the output of mmcheck, again look here (right click and download) : 32-bit athlon-2800 mmcheck output … ignore the " code ] " and " / code ] " you see in it. I was preparing it for posting on the forum, and then changed my mind. [note I do not like the vlc plugin for mozilla and we are not chatting here about mozilla]. This is from my old 32-bit athlon-2800 running openSUSE-11.3 KDE-4.4.4. Graphic card nVidia 8400GS with proprietary graphic driver from nVidia.

When I play that video 00178.mts on my 32-bit athlon with vdpau, it plays back ok with 11.6% mplayer load on the cpu. Command was this:

mplayer -vo vdpau -vc ffh264vdpau 00178.mts

Image WITH vdpau and 11.6% mplayer cpu load:

But when I play that 00178.mts on my 32-bit athlon withOUT vdpau, it plays back poorly (with video drag) with 97.4% load on the cpu. Command was this:

mplayer 00178.mts

Image withOUT vdpau and 97.4% mplayer cpu load:

why the difference ? Because vdpau offloads the video decode from CPU to GPU.

THAT is the sort of improvement that the OP is trying to achieve by asking for the library (albeit IMHO that is only one of a number of steps they will have to do in order to get this working with ATI hardware).

I had a heck of a time trying to set this up. On my Best computer, running the terminal mode mplayer as the GUI one is gmplayer I discovered, I had 7% CPU usage. On my slowest computer, my Laptop, I had 44 % usage. In both cases, the video played just fine with no visible issues I could see. Now, surely I could find a computer that is slow enough that it would not work, but since I don’t use AMD video cards, I can not check anything else out. Added acceleration can surely help crappy video cards, but my slowest computer does not seem to need it. Also, I was getting tired of watching you drink out of that pineapple. Surely you have something longer and more interesting to look at. Where do we go from here?

Thank You,

Your hardware is pretty good. I think your oldest PC is newer than the best PC of most people I know!

On your oldest PC you have an Intel Graphics that appears to have the capability to offload the video processing from CPU to GPU. And the PC with your nVidia card is probably so fast it does not need to offload the video from CPU to GPU.

Still, on your PC with the nVidia card, IF you run ‘mplayer’ exactly as I specified (with and without the vdpau option) and compare the % cpu load, I believe you will see a difference in cpu load dependent on whether you use vdpau or not use vdpau.

I think your slowest computer already has it. I know that a P8400 Dual Core with an ATI HD3450 struggles with the 00178.mts video.

lol ! I can provide longer videos that are more interesting, BUT they are not as good for illustrating an audio to video desync, and hence it not possible to tell that the audio has lagged.

Here is a link to a couple of HD videos of similar HD quality:

The above 2 are not from my camera, but were on the web.

I can play those with no problem with ‘vdpau’ option in mplayer (on my old 32-bit athlon-2800). But if I do not specify vdpau with mplayer they won’t play properly on that old PC.

I don’t think you have an old PC, so you likely won’t have a trouble with HD playback.

OK, here is a longer video, but it is much larger in size (130MBytes) : Watching Mountain climbing video](http://rijira.net/oldcpu/00094.mts)

The test I have in mind is for you to play this on your PC that has a nVidia card. First play with this command:

mplayer 00094.mts 

and in “top” note the typical CPU load.

Then play that video again on your PC that has a nVidia card. Play with this command:

mplayer -vo vdpau -vc ffh264vdpau 00094.mts 

and again in “top” note the typical CPU load.

I am assuming you have the nVidia proprietary driver installed, and you have re-installed libvdpau1-0.4-5.6.x86_64 since the last time you installed the nVidia proprietary graphic driver.

I confess if you find identical mplayer load in top between the two commands I would be surprised. There should be a big difference if vdpau is working with your nVidia card.

So, on my best machine, using the command “mplayer -vo vdpau -vc ffh264vdpau 00178.mts” seems to produce a 3% CPU load as opposed to 7% without the acceleration. When I try this command on my Dell Laptop, I get no video.

The error(s) say, “VDPAU backend libvdpau_nvidia.so: cannot open shared object file: No such file or directory” and “[vdpau] Error when calling vdp_device_create_x11: 1”, “Error opening/initializing the selected video_out (-vo) device.”

But my Dell laptop did play just fine without the hardware acceleration command.

Now, I think that my original argument was that you did not need accelerated video to play these videos if you followed the mmcheck guide. All videos have played just fine without hardware acceleration from the video player. I don’t think I was making any CPU usage statement. Further, I guess, we did not establish just what an old computer was, but I try to get rid of anything over three years old. So, just what is an old computer and if it is older than three years old, then what?

For reference, I just sold off a three year old AMD Athlon 64 X2 5000+ computer for $200 US (less monitor, keyboard or mouse) to a friend at work in order to get him into using openSUSE. He has been out of town working all of this week, so I have not yet got an update of just how he was doing with it, but he was excited with its performance, after passing the mmcheck multimedia setup.

So, you have NEVER said if you are able to go to the iTunes Web Site and play a movie trailer there with your new PC. Have you tried to do that? It is one of the tests of a properly setup PC for multimedia setup. Now I have been watching you suck on that pineapple all night. Surely you can make one visit to the iTunes Web site and complete this one request.

Thank You,

vdpau ONLY works with nVidia graphic hardware and with the nVidia proprietary driver, and not with all nVidia hardware.

I guess 2 points here from my perspective. Your PCs are all new. You do not have an older PC. So from your perspective what you noted makes sence in terms of raw playback.

Most people that I know do not have PCs as new as yours, so from my perspective, people who can not afford a newer PC, can use HD acceleration play back and some MUST have it (for HD playback).

Also with HD acceleration, the CPU load is decreased to a greater or lessor extent dependant on one’s PC.

On any PC that is an average dual core or slower, one NEEDS HD acceleration else the top resolution / top bit-rate videos will not play back. I’ve proven that to my satisfaction categorically on my Dell Studio 1537 with a dual core P8400 and an ATI Radeon HD3450 graphics (which with the proprietary ATI Linux driver does NOT use the cards HD acceleration).

Your slowest PC has HD acceleration with its Intel card. So you are in effect using HD acceleration, which IMHO makes it harder for you to assess how that PC would perform without HD acceleration.

There was a time when I used to visit iTunes Web Site all the time to look at the trailers. Not any more. Now I just go to Youtube and play back trailers from there. They have a wider selection.

But since you requested :slight_smile: … I did go there (iTunes Web Site) a few minutes ago and played back a video with no problem with my newest PC which is 2 years old (which is an Intel Core i7 920). My wife has a new PC with an Intel Core i7 860, but from what I have read it is about the same speed as a i7 920.

So, I am not sure where videos are going in the future, but we can play most anything without added acceleration and the situation is only getting better and not going backwards (3D not with standing as I am unsure if that will really take everything over or not). Low CPU usage is not a bad thing, but when I play a video I am seldom trying to do something else to use up that extra power being saved. And by that I mean, once you are able to perform the task, well it just already works. Also, in your case, it was not all that long ago you were unsure that you could play a video on iTunes.

I can say that it (playing an iTunes movie Trailer) did not used to work for me either until I got interested in the correct multimedia setup while working on mmcheck. I did get it to work ever so often on one PC but not on another, but I was unable to understand why now and not so later. What did that really mean? How did you get to it? I have looked through the guides you have written, trying to make sense of them (though not always paying close enough attention I guess, such as just what VDPAU did). mmcheck was a collection of recommendations put together by many openSUSE experts such as yourself. It was evident to me that many many people just did not get what the correct setup was supposed to be.

As for new PC’s, I have one i7 870, but the next one down is just a Intel 9450. You have a i7 920 and 860. It would seem the Intel i7 line is way better than most anything else by AMD which I used to buy most of the time because of the lower price I could pay, not that I was unable to do most anything that I needed to do with AMD. Anyway, hardware acceleration does reduce CPU usage I will give you, but I was not betting on that aspect of the game. If you setup your multimedia properly and have a PC newer than three years old, you can play any video you want without adding in acceleration you did not even know that you had. What were we betting on again? lol!

Thank You,

Some time back, my method to get the Apple movie Trailers on iTunes to work was to use the “User Agent Switcher” in Firefox and have my PC identified as another device. That seemed to work to get Apple to stream the video to my PC. But it was not consistent, and some times it would cause Firefox to freeze and sometimes it would not. That was not a big thing for me, as noted I use YouTube to get my movie Trailers.

When you modified your excellent script sometime back to include Totem, I checked out the change (as I try to keep up with your script changes) and I immediately noted then that by adding Totem and its associted apps (such as totem-browser-plugin) that the iTunes would stream ok and I no longer needed “User Agent Switcher”. So you could say you showed me a different more stable method via your EXCELLENT script updates.

Until the Intel Core i7 line came out, I was also mostly an Intel user.

Reference PCs, we have a mix of old an new PCs in our apartment, with the list being (from old to new):

  • 32-bit AMD Athlon-1100
    w/1GB RAM (MSI KT3 Ultra motherboard) w/AGP nVidia GeForce FX5200 graphics [age ~10-years] running 32-bit openSUSE-11.3 LXDE - this is my “sandbox” PC
  • 32-bit Intel 1.5 celeron
    w/1.256 GB RAM (Fujitsu-Siemens Amilo 7400M Laptop) with Intel i855 graphics [age ~7 years] running 32-bit openSUSE-11.1 Gnome
  • 32-bit AMD Athlon-2800
    w/2GB RAM (Asus A7N8X Deluxe motherboard) w/ PCI nVidia GeForce 8400GS graphics [age ~6 years] running 32-bit openSUSE-11.3 KDE-4.4.4 (and also a version of SLED-11.1 SP1 that I boot to occasionally). This is my PC for vdpau testing
  • 64-bit Intel P8400
    w/4GB RAM (64-bit Dell Studio 1537 Laptop), w/ATI Radeon 3450HD graphics [age ~2+ years] running 64-bit openSUSE-11.3 KDE-4.4.4 (this is the laptop I use for business trips, and also take on vacations)
  • 64-bit Intel Core i7 920
    w/6GB RAM (Asus P6T Deluxe V2 motherboard) w/ PCI-e nVidia GeForce GTX260 graphics [age ~2 years] runing openSUSE-11.3 KDE-4.4.4 (this is my main PC).
  • 64-bit Core i7-860
    w/6GB RAM (Asus P7H55-M, H55 motherboard) w/GeForce G210 graphics [age ~2 months] (my wife’s new PC) running openSUSE-11.3 KDE-4.4.4 (but my wife mainly boots direct to winXP on this PC).

There is also my 84 year old mother’s PC a continent away (in Canada), which I maintain remotely from here in Europe, and logging in typically a couple of times/month:

  • 64-bit HP P6510F w/AMD Athlon II X4 630
    cpu w/4GB RAM, w/ATI Radeon 4200 graphics [age ~3 months] (my mother’s PC) [which is using the open source radeon driver to make my remote updates less risky] running openSUSE-11.3 KDE-4.4.4

And we gave away to our maid (less than 1 month ago) my wife’s old

  • 32-bit AMD Sempon-2600
    w/1GB RAM (Epox EP-8K7A motherboard) w/AGP ATI RV280 (Radeon-9200Pro) graphics [age ~6 years]. My wife had me clean Linux OFF the hard drive before we gave it away. And my wife installed a new (unused until now) legal copy of German WinXP on the PC as part of the ‘gift’.

Of those I consider only the following 3 as new PCs

  • my Intel Core i7 920,
  • my wife’s Intel Core i7 960, and
  • my mother’s Athlon II X4 630.

Those three relatively new PCs have CPU’s powerful enough such that offloading of the video decoding from the CPU to the GPU is not needed.

My Dual Core P8400 (Dell laptop) can ‘almost’ play the highest HD video, but not quite. I’m hoping either the upcoming kernel enhancements in the 2.6.37 kernel packaged by SuSE-GmbH (which has slightly superior performance to older kernels) or a future version of the ATI proprietary driver will provide what is needed for this P8400 laptop w/Radeon HD3450 graphics to play the highest quality HD videos.

My 32-bit athlon-2800 is the only 32-bit PC in the above PC list that can play HD videos, thanks to the nVidia 8400GS with the proprietary nVidia graphic driver providing vdapu (and mplayer that uses vdpau). There is work ongoing to modify vlc and also xine to be able to play HD videos using vdpau but those apps are not yet provided on Packman (as they are not yet mature).

But I note kdenlive (the video editing software) does use some of the capabilities that vdpau provides for displaying HD videos on the timeline.

I think the bet was for a virtual versions of a specific beverage, which I am sending two virtual versions your way for having the patience to chat with me about a subject that is interesting to me.