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Discussion Starter · #1 ·
After perusing the various forum postings on playback of x264 streams using hardware acceleration (DXVA), I learnt that DXVA works only if VideoWidth X VideoHeight X NumRefFrames is lesser than approximately 9 million (DPB - Decoded Picture Buffer limitation?), and the actual level specified (4.1 or 5.1) really doesn't make a difference.

My HTPC configuration is as below:

P4 3 GHz


Windows XP

MPC-HomeCinema with the CCCP (Combined Community Codec Pack) to take advantage of DXVA

ATI 3450 with HDMI out to Onkyo TX-SR606, with HDMI out to Toshiba Regza 37" 1080p TV

I have with me some sample MKV clips with x264 video streams with following specs:

Video 1: 1920 x 1040, 5 reference frames

Video 2: 1920 x 816, 5 reference frames

Video 3: 1920 x 1080, 5 reference frames

Video 4: 1920 x 1080, 16 reference frames

As expected, Videos 1,3 and 4 either stuttered or refused to play altogether with MPC-HC. Video 2 played back beautifully.

Videos 1 and 3 didn't play initially in the WDTV HD Media Player either, but after their firmware update, I was able to play them. I will be testing Video 4 on the WDTV HD Media Player shortly, but I don't have high hopes for that.

I seek the wisdom of fellow AVS forum members in the following issues:

1. Since Videos 1 and 3 could be played back on the WDTV HD media player with a firmware update, is it possible for a driver or software update on the HTPC which can enable the same files to be accelerated through DXVA?

2. Since MPC-HC operates in bitstream mode, I suspect that it is the ATI driver for 3450 which is at fault in not being able to handle 5 reference frames. Am I right in my understanding? If yes, where should this issue be posted? ATI Catalyst Forums or somewhere else?

3. How can we enable playback of Video 4 with 16 reference frames on a HTPC? Is there anything at all which can play a x264 stream encoded with that much complexity? Some specs would be really helpful.

4. I also have a spare S3 Graphics Chrome 530 lying around. Is it possible for XvMC and mplayer to playback the non-DXVA file? (I found out about XvMC from Wikipedia, and not much information anywhere else). What would be the best forum to know about this?

Thanks in advance for all your inputs!
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