DXVA limits? MPC

[invisible]

I've seen some limits on what dxva can accept using the 'media player classic' way of playing h264. I do have it working in general. It might be hardware dependent, too. That's another thing I'd like to know. For me it's on an nvidia geforce 9600 gso. I get just fine playback on most content, including "regular" 1080p content in mov, such as apple trailers (note: installing itunes/quicktime breaks this). But some movies fall back on software decoding no matter what. This is an example. (http://www.mediafire.com/?myxjzkmjmvm) From the file properties and some light testing, it looks like it's the frameref number, which is 16 on that one. Does anyone know if the limit is 15, or is it lower? Or am I incorrect in the frameref assesment? Or maybe it depends on the hardware? Every other h264 movie that I tried played with dxva, but I don't have tons and tons of them. However, the example is the only one with 16 reference frames from the ones I have.

[ronnylov]

High profile level 4.1 should work.
The limit of frameref number then depends on resolution and framerate.
I have not checked your example but ref 16 is probably too high.

Some info here:
http://www.avsforum.com/avs-vb/showthread.php?t=972503
http://en.wikipedia.org/wiki/H.264/MPEG-4_AVC

[Ingram]

My HD3200 has issues with MPC-HC playing back HD-DVD Evo files. Yet they play perfect in PDVD8.

*Shrug*

[invisible]

There are issues attached to that, I'm sure. All I care about is just the h264 playback on dxva, which can only be done openly with mpc-hc, as far as I know. I also don't care about profiles or anything like that, even if I'm well aware of them. I wouldn't use 16 frameref on regular content -- that's insane. But in some cases, like in really small videos with a lot of still video, it can make some difference.

Anyways, it looks like the limit is not 15 as some encoders suggest, but lower. Some videos with 15 seem to start playing but freeze while the audio continues. It's more like 12 or 13. I haven't been able to pinpoint it. The trouble is that if you set, for example, frameref=12, it will actually dip 1 to 11. Same for 13. Now I'm left to try 14, although for my use at least, it seems frameref=13 is a fairly safe bet. I just wish I had an ati video card to test this.

[littleD]

My HD3200 has issues with MPC-HC playing back HD-DVD Evo files. Yet they play perfect in PDVD8.

*Shrug*

It may be interlaced

[invisible]

I have figured out that the max seems to be 13 real frame ref, which seems to mean that passing frameref=14 to the encoder will do it. I guess this is what I will use, ati cards notwithstanding. Unless somebody with this mix of mpc and dxva on ati is willing to test some videos for me.

anyway, here's one video with 13 real ref frames video (http://www.mediafire.com/?mcdmzye0ozn)

[invisible]

On Windows 7 the limit is down to 11.

[tetsuo55]

The limits are different for each brand, model, driver and windows version.
MPC-HC has code to detect what combination you have and redirect the video to software decoding when DXVA will not work properly.

Commercial products have full access to the hardware specifications, we suspect their code contains many hacks to work around the many bugs in DXVA and bitstreaming hardware/drivers. This is probably also the reason why even the newest hardware still has bugs.

If you want to have 16 ref frames working all the time you will need a newish nvidia card.

[invisible]

Newer than a GTX 460m? Because I tested a laptop with that and w7 x64 and the 16 frameref video wasn't accelerated (no chance to test 11). Also, I got the same 11 frameref limit on at least two PCs using windows 7 but different cards.

Anyway, that's besides the point. The point is there are limits. It would actually be more helpful to me to know the absolute minimum number across all dxva compatible cards. But if there is a chart it would be helpful.

[tetsuo55]

L4.1 compatible files will always work. Assuming full-HD that means 4 ref frames.

[invisible]

Yes, I know. Oh, and forgot to say thanks. :)