Intel® Media SDK 2014 for Clients

[gmb]

What is the Intel Media SDK?

The Intel® Media Software Development Kit (Intel® Media SDK) is a cross-platform application programming interface (API) for developing consumer and professional media applications, including video editing and processing, media conversion, streaming and playback, and video conferencing. The SDK makes it easy for developers to optimize applications for Intel® HD Graphics' fixed-function hardware acceleration, currently part of the 2nd, 3rd and 4th generation Intel® Core™ and new Intel® Atom™ processors.

What is new in Intel® Media SDK 2014 for Clients?

The SDK is optimized to utilize the power of 4th generation Intel® Core™ processors, codenamed "Haswell," and Intel® Atom™ processor-based tablets for a consistently high-quality media experience. In addition to supporting accelerated H.264 encode and decode and video processing filters, the new SDK includes access to the Media Solutions Portal where developers can access new tools and products to make developing media applications easier and faster. Use of Intel Media SDK 2014 for Clients also includes free licensing and source for integration with Open Source projects and OpenCL* video workloads. The SDK is available as a free download here.

http://software.intel.com/en-us/vcsourc ... /media-sdk


The new AAC stuff is included in a dedicated library and isn't for free it seems. I see a couple of new encoding features in the new SDK. BRefControl, LookAheadDS, EncoderROI, ICQQuality, HEVC level codec, RATECONTROL_ICQ, RATECONTROL_LA_ICQ and some more.

[Deleted User 11865]

Looks pretty cool. ICQ in particular sounds pretty cool, if it is what I'm guessing it is.

Too bad about HEVC and AAC (still, will look into the specifics), but since HEVC is probably software-only at this point, it's not a big deal (there are and/or will be other software-based alternatives).

[gmb]

I think so too, h264 should have priority. HEVC could be interesting nervertheless for quality comparisons with h264. I guess we won't see hardware support before Skylake. ICQ means intelligent constant quality algorithm...can be combined with LookAhead.

[Deleted User 11865]

Yeah, I guessed as much. Intel's answer/alternative to x264's CRF… IMO, a very nice addition to MediaSDK.

[gmb]

Intel released a new driver which supports API 1.8.


https://downloadcenter.intel.com/Detail ... ldID=23644
https://communities.intel.com/message/226042#226042

[Deleted User 11865]

Oh, reached Beta, nice.

Feel free to play with the latest nightly, it should support most of the new features, but hasn't been tested against the driver so far.

[Deleted User 11865]

Nto really meant for testing QSV it seems though. Whether Intel will accept bug reports for QSV against that particular driver, no idea. Not going to bother personally until/unless the release notes mention MSDK 1.8 specifically.

[gmb]

API 1.8 itself should be final. I have a slightly older WHQL driver with API 1.8 from some OEM. The QuickSyncOptions wiki isn't updated it seems, I don't know what to do in the new nightly.

[Deleted User 11865]

Right, still haven't done that.

[Rezal]

I have played around with the new ICQ settings, but so far it seems VBR with LA produces still much better results. Dark scenes still look extremely blocky with (I)CQ. Is there an explanation what downsampling does with the lookahead mechanism?

[gmb]

Depends on the input video. I have seen much better results with ICQ in two videos and a much worse result in one video with QSTranscode at the same bitrate. For the worse video I had to use ICQ 28 whilst the other two I could use ICQ 21 to achieve the same bitrate of 5000 Kbps.

[Rezal]

With no actual documentation from Intel, I have a hard time figuring out when DS even activates... I can turn it on according to the logs, but most of the time the output 100% identical to DS off. Does anybody know more about this?

[Deleted User 11865]

It could be unimplemented - because the API lets you set the option doesn't necessarily meant it'll work. But no, I don't have any more info on this.

[Rezal]

It did make differences occasionally and then helped with scene changes.

My theory is that instead of the next N frames, the lookahead will analyze the next N*DS frames, but not consecutively, instead skipping 1 or 3 frames. So it would look ahead 80 instead of 40 frames with 2x DS, but skip every second.

[Deleted User 11865]

That doesn't seem to match what's in the reference manual PDF (publicly available, part of the Media SDK software install - see page 151).

[Rezal]

Thanks for pointing me to that... So it is just plain downsampling of the image.

[gmb]

Did you try ICQ with Handbrake, does Handbrake support it?

[Deleted User 11865]

It's enabled by default (instead of CQP) if detected as available. I didn't test it though.

ICQ vs. ICQ_LA is controlled via the "lookahead" option (like VBR vs. LA).

You can use CQP via the "force-cqp" option. Sorry for not updating the documentation.

[gmb]

encqsvInit: MBBRC on

Even with mbbrc=0 the log says it's enabled when using ICQ. Afaik mbbrc doesn't work with ICQ nevertheless.

ICQ_LA requires +3-7 higher QP values to match the ICQ bitrate. Quality is better though and it isn't slower so I recommend to use ICQ_LA instead ICQ without LA. Compared to the old CQP quality is a different world.


@Rezal

By default Handbrake is using a very low GopPicSize of 30, SDK default is 256. You should try gop-ref-dist=0:gop-pic-size=0 and TU4 is also the best tradeoff.

[Deleted User 11865]

encqsvInit: MBBRC on

Even with mbbrc=0 the log says it's enabled when using ICQ. Afaik mbbrc doesn't work with ICQ nevertheless.

I would guess so for ICQ_LA, but how about lookheadless ICQ?

Note: we print the MBBRC value unless the lookahead is enabled, it's possible that Media SDK just ignores its value.

ICQ_LA requires +3-7 higher QP values to match the ICQ bitrate. Quality is better though and it isn't slower so I recommend to use ICQ_LA instead ICQ without LA. Compared to the old CQP quality is a different world.

I assume you mean better, correct?

[gmb]

There is no MBBRC in the log with ICQ_LA. I don't think MBBRC is working with ICQ, there wasn't any difference when I compared it with QSTranscode, so most likely SDK ignores it. ICQ is much better than the old CQP yes. ICQ+LA works better than VBR+LA it seems.

[Deleted User 11865]

There is no MBBRC in the log with ICQ_LA.

Yeah but that's just the logging code (controlled by HandBrake, not Media SDK). We don't print the MBBRC value when lookahead or CQP are enabled, because they have no effect.

Since I have no idea whether MBBRC has an effect on lookaheadless ICQ, I left it alone (value gets printed), but that doesn't mean it's been sanitized or will be honored by the encoder.

I don't think MBBRC is working with ICQ, there wasn't any difference when I compared it with QSTranscode, so most likely SDK ignores it.

Actually, one way to test it is to try two encodes with identical settings except MBBRC enabled/disabled, and compare the output (I usually look at the byte count for the video track in the encode log, that quickly shows whether there's any difference).

[gmb]

Output size is exactly the same.

[Deleted User 11865]

Then it has no effect. I'll probably wait until a non-Beta driver is available to confirm this and adjust the settings printing code though.

[Rezal]

@Rezal

By default Handbrake is using a very low GopPicSize of 30, SDK default is 256. You should try gop-ref-dist=0:gop-pic-size=0 and TU4 is also the best tradeoff.

Thanks for the tip to increase gop-pic-size. As of now, I'm striving for maximum encode quality using QSV, so I will stick with tu=1 and trellis=3. QSV is still faster than x264 verfyast, yet produces better looking output (objectively verified). Now it is closing in to x264 faster.

I've also tried the new CQ modes some more, ICQ_LA can definitely produce some good output, depending on your source. I also noticed you have to set QP much higher to get similar bitrates to ICQ. Unfortunately, the variation in bitrate in ICQ and ICQ_LA is very high, making it useless for uploading, so standard VBR with LA is the way to go for that.