[mhdebokx]

Recently I discovered that during playback of HD video's there is a hugo rate of dropped frames. As a result the video is stuttering and doesn't look pretty. It is not wilh all my HD movies. I discovered that 720p movies are OK, and some 1080i and 1080p also rendered OK. Looking to the codec info (used MediaInfo) I think the stuttering appeares when the decoded bit rate is above 28 Mbps.

Do other macmini users also experience the same problems ?

And is it thru Mac OS X version 10.6.5 is the dissatisfier on the older macmini version ?

And what happens if I upgrade to the new 2010 model of the macmini using the NVIDIA GeForce 320M.

Below are all technical aspects:

The macmini is 2 years old, Darwin Kernal Version 10.5.0, release i386 (I think it's model Mid 2007).
running Mac OS X, version 10.6.5
CPU: 2GHz Intel Core 2 Duo T7200
memory: 2GB 667 MHz DDR2 SDRAM
GPU: Intel GMA 950 OpenGL Engine, VRAM 64MB

Running XBMC Dharma RC2 (R35567)

This is the mediainfo from the video containter:

General
ID : 1
Complete name : Victoria's Secret Fashion Show (2010).ts
Format : MPEG-TS
File size : 10.1 GiB
Duration : 40mn 47s
Overall bit rate : 35.5 Mbps

Video
ID : 65 (0x41)
Menu ID : 1 (0x1)
Format : MPEG Video
Format version : Version 2
Format profile : 4:2:2@high
Format settings, BVOP : Yes
Format settings, Matrix : Default
Format settings, GOP : M=3, N=15
Codec ID : 2
Duration : 40mn 47s
Bit rate mode : Variable
Bit rate : 33.5 Mbps !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Nominal bit rate : 35.5 Mbps !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate : 29.970 fps
Standard : Component
Color space : YUV
Chroma subsampling : 4:2:2
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Bits/(Pixel*Frame) : 0.539
Stream size : 9.54 GiB (94%)

[mhdebokx]

I did some additional experiments.

Using a bitrate of 35.5Mbps I had a drop rate of about 700 drops in 1 minute
Using a bitrate of 17.0Mbps I had a drop rate of about 300 drops in 1 minute

I changed 'advancedsettings' with <skiploopfilter>8</skiploopfilter>

The 35.5.Mbps had still a lot off drops, still choppy vieuwing :mad:
The 17.0Mbps had only a few drops

Unformunatly I can't get it better today

[idioteque]

The mini you own does not have a nvidia graphics chip
Therefore you cannot use VDA or hardware acceleration for Playing h264 files
So the CPU has to do all the work and the CPU is to slow for high bitrates

[snowdrift]

I did some additional experiments.

Using a bitrate of 35.5Mbps I had a drop rate of about 700 drops in 1 minute
Using a bitrate of 17.0Mbps I had a drop rate of about 300 drops in 1 minute

I changed 'advancedsettings' with <skiploopfilter>8</skiploopfilter>

The 35.5.Mbps had still a lot off drops, still choppy vieuwing :mad:
The 17.0Mbps had only a few drops

Unformunatly I can't get it better today

What idioteque said

I think that's probably the best you're going to get unfortunately, without upgrading the hardware to a newer Mac Mini with the nVidia 9400M graphics (I have a late 2009 model running 10.6.4 - which incidentally works like a dream on everything H264 with the hardware VDA decoding). You could play with the skiploopfilter values to get a reasonable balance between smooth(ish) playback vs frame drops.

And what happens if I upgrade to the new 2010 model of the macmini using the NVIDIA GeForce 320M.

There are various threads in this forum about the relative merits and demerits of the 2010 Mac Mini, such as this one. General consensus seems to be that hardware accelerated playback is fine so long as the latest OS X you have installed is 10.6.3.

[mhdebokx]

thanks @snowdrift and @idioteque for the reply's. I think I have a special request for Santa Clause now ...