I too am getting stuttering but only when watching HD MKV files and not all of them. Mostly 1080p BD Rips cause the issue where by one of the CPU's would spike at 100% and you get a warning message saying "main warning: late picture skipped". This happens at the same places every time this file is played.
I have a Mac Pro 2006 2Ghz Quad 8GB RAM 2x1TB Samsung HDD in RAID 0.
Below is the log for viewing and below that the media info for the file:-
TIMER module_need() : 51.986 ms - Total 51.986 ms / 1 intvls (Avg 51.986 ms)
using video output module "opengl"
main debug: TIMER module_need() : 53.044 ms - Total 53.044 ms / 1 intvls (Avg 53.044 ms)
main debug: got 1 direct buffer(s)
main debug: pic render sz 1920x1080, of (0,0), vsz 1920x1080, 4cc I420, sar 1:1, msk r0x0 g0x0 b0x0
main debug: pic in sz 1920x1080, of (0,0), vsz 1920x1080, 4cc I420, sar 1:1, msk r0x0 g0x0 b0x0
main debug: pic out sz 1920x1080, of (0,0), vsz 1920x1080, 4cc UYVY, sar 1:1, msk r0x0 g0x0 b0x0
main debug: looking for video filter2 module: 15 candidates
main debug: using video filter2 module "i420_yuy2_sse2"
main debug: TIMER module_need() : 0.309 ms - Total 0.309 ms / 1 intvls (Avg 0.309 ms)
main debug: indirect render, mapping render pictures 0-24 to system pictures 1-25
avcodec debug: using direct rendering
main debug: using audio output module "auhal"
main debug: TIMER module_need() : 65.551 ms - Total 65.551 ms / 1 intvls (Avg 65.551 ms)
main debug: output 'f32l' 48000 Hz Stereo frame=1 samples/8 bytes
main debug: mixer 'f32l' 48000 Hz Stereo frame=1 samples/8 bytes
main debug: no need for any filter
main debug: looking for audio mixer module: 3 candidates
main debug: using audio mixer module "float32_mixer"
main debug: TIMER module_need() : 0.730 ms - Total 0.730 ms / 1 intvls (Avg 0.730 ms)
main debug: input 'dts ' 48000 Hz 3F2R/LFE frame=512 samples/2048 bytes
main debug: looking for audio filter module: 1 candidate
scaletempo debug: format: 48000 rate, 2 nch, 4 bps, fl32
scaletempo debug: params: 30 stride, 0.200 overlap, 14 search
scaletempo debug: 1.000 scale, 1440.000 stride_in, 1440 stride_out, 1152 standing, 288 overlap, 672 search, 2400 queue, fl32 mode
main debug: using audio filter module "scaletempo"
main debug: TIMER module_need() : 0.703 ms - Total 0.703 ms / 1 intvls (Avg 0.703 ms)
main debug: filter(s) 'dts '->'f32l' 48000 Hz->48000 Hz 3F2R/LFE->Stereo
main debug: looking for audio filter module: 14 candidates
main debug: using audio filter module "dtstofloat32"
main debug: TIMER module_need() : 1.355 ms - Total 1.355 ms / 1 intvls (Avg 1.355 ms)
main debug: found a filter for the whole conversion
main debug: filter(s) 'f32l'->'f32l' 52800 Hz->48000 Hz Stereo->Stereo
main debug: looking for audio filter module: 14 candidates
bandlimited_resampler debug: f32l/52800KHz/2->f32l/48000KHz/2
main debug: using audio filter module "bandlimited_resampler"
main debug: TIMER module_need() : 0.889 ms - Total 0.889 ms / 1 intvls (Avg 0.889 ms)
main debug: found a filter for the whole conversion
main debug: End of audio preroll
main debug: End of video preroll
main debug: Received first picture
main debug: Post-processing available
main warning: vlc_object_find_name(postproc) is not safe!
main debug: looking for video blending module: 1 candidate
main debug: Decoder buffering done in 128 ms
main warning: PTS is out of range (-9942), dropping buffer
blend debug: chroma: YUVA -> UYVY
main warning: PTS is out of range (-19827), dropping buffer
main debug: using video blending module "blend"
main warning: PTS is out of range (-30742), dropping buffer
main debug: TIMER module_need() : 1.211 ms - Total 1.211 ms / 1 intvls (Avg 1.211 ms)
main warning: late picture skipped (60547 > -6908)
main warning: late picture skipped (18547 > -6908)
main warning: late picture skipped (5432 > -4933)
main warning: late picture skipped (12840 > -4604)
main warning: late picture skipped (15481 > -4455)
main warning: late picture skipped (12103 > -4455)
main warning: late picture skipped (21030 > -4222)
main debug: control type=4
main warning: early picture skipped
main warning: received buffer in the future
mkv debug: seek request to -1 (0.197135%)
mkv debug: seek got 1729978000 (20%)
main debug: b_seek=1 th*avg=946088 skip=5697044586
main debug: Buffering 0%
main debug: Buffering 0%
main debug: Buffering 16%
main debug: Buffering 28%
main debug: Buffering 14%
main debug: Buffering 55%
main debug: Buffering 41%
main debug: Buffering 80%
main debug: Buffering 83%
main debug: Buffering 69%
main debug: Stream buffering done (334 ms in 32 ms)
main debug: End of video preroll
main debug: Received first picture
main debug: Decoder buffering done in 341 ms
main debug: End of audio preroll
main warning: output PTS is out of range (79561), clearing out
main debug: audio output is starving (423667), playing silence
main warning: output date isn't PTS date, requesting resampling (-40550)
main warning: buffer is 40551 in advance, triggering downsampling
main warning: late picture skipped (5290 > -2250)
main warning: late picture skipped (10706 > -2242)
main warning: late picture skipped (17562 > -2162)
main warning: late picture skipped (21796 > -2077)
main warning: late picture skipped (30555 > -2001)
main warning: late picture skipped (277 > -2106)
main warning: late picture skipped (437 > -2102)
main warning: late picture skipped (2385 > -2055)
main warning: late picture skipped (3187 > -2055)
main warning: late picture skipped (17361 > -2025)
main warning: late picture skipped (6732 > -2075)
main warning: late picture skipped (7595 > -2097)
main warning: late picture skipped (9157 > -2041)
main warning: late picture skipped (13046 > -1994)
main warning: late picture skipped (13174 > -1994)
main debug: removing module "blend"
main debug: looking for video blending module: 1 candidate
blend debug: chroma: RGBA -> UYVY
main debug: using video blending module "blend"
main debug: TIMER module_need() : 0.332 ms - Total 0.332 ms / 1 intvls (Avg 0.332 ms)
main warning: resampling stopped after 6453382 usec (drift: -449)
main warning: late picture skipped (-27 > -2594)
main warning: late picture skipped (6689 > -2516)
main warning: late picture skipped (12403 > -2467)
main warning: late picture skipped (19384 > -2467)
main warning: late picture skipped (22163 > -2354)
main warning: late picture skipped (48639 > -2212)
main warning: late picture skipped (13839 > -2150)
main warning: late picture skipped (15929 > -2095)
main warning: late picture skipped (22895 > -2038)
main warning: late picture skipped (25954 > -2038)
main warning: late picture skipped (36147 > -2054)
main warning: late picture skipped (8415 > -2469)
main warning: late picture skipped (23031 > -2482)
main warning: late picture skipped (26214 > -2358)
main warning: late picture skipped (33019 > -2243)
main warning: late picture skipped (32947 > -2243)
main warning: late picture skipped (-2639 > -3061)
main warning: late picture skipped (11268 > -3074)
main warning: late picture skipped (5830 > -3044)
main warning: late picture skipped (7559 > -3044)
main warning: late picture skipped (2531 > -3061)
main warning: late picture skipped (9409 > -3136)
main warning: late picture skipped (1969 > -2766)
main warning: late picture skipped (7801 > -2610)
main warning: late picture skipped (12243 > -2506)
main warning: late picture skipped (17631 > -2506)
main warning: late picture skipped (20974 > -2447)
main warning: late picture skipped (930 > -2454)
main warning: late picture skipped (5398 > -2392)
main warning: late picture skipped (10213 > -2325)
main warning: late picture skipped (12568 > -2325)
main warning: late picture skipped (18495 > -2293)
main warning: late picture skipped (43530 > -2339)
main warning: late picture skipped (45265 > -2339)
main warning: late picture skipped (47936 > -2452)
main warning: late picture skipped (49494 > -2451)
main warning: late picture skipped (50674 > -2471)
main warning: late picture skipped (-2039 > -2489)
main warning: late picture skipped (92 > -2416)
main warning: late picture skipped (2965 > -2366)
main warning: late picture skipped (9514 > -2366)
main warning: late picture skipped (13037 > -2436)
main warning: late picture skipped (13171 > -2499)
main warning: late picture skipped (2653 > -3015)
main warning: late picture skipped (4882 > -3082)
main warning: late picture skipped (7774 > -3082)
main warning: late picture skipped (10900 > -3232)
main warning: late picture skipped (12822 > -3246)
main warning: late picture skipped (30361 > -3447)
main warning: late picture skipped (30798 > -3447)
main warning: late picture skipped (30638 > -3493)
main warning: late picture skipped (34874 > -3435)
main warning: late picture skipped (40751 > -3435)
main warning: late picture skipped (3425 > -3566)
main warning: late picture skipped (8100 > -3566)
main warning: late picture skipped (12474 > -3598)
main warning: late picture skipped (11812 > -3493)
main warning: late picture skipped (16566 > -3493)
main warning: late picture skipped (-1394 > -3377)
main warning: late picture skipped (37942 > -3363)
main warning: late picture skipped (40801 > -3464)
main warning: late picture skipped (44176 > -3539)
main warning: late picture skipped (49211 > -3439)
main warning: late picture skipped (51486 > -3439)
main warning: late picture skipped (-1210 > -3474)
main warning: late picture skipped (1304 > -3427)
main warning: late picture skipped (3174 > -3346)
main warning: late picture skipped (4764 > -3346)
main warning: late picture skipped (6744 > -3294)
main warning: late picture skipped (40417 > -3206)
main warning: late picture skipped (25810 > -2565)
main warning: late picture skipped (29828 > -2524)
main warning: late picture skipped (31150 > -2363)
main warning: late picture skipped (31707 > -2276)
main warning: late picture skipped (31792 > -2276)
main warning: late picture skipped (-1605 > -2651)
main warning: late picture skipped (-2219 > -2629)
main warning: late picture skipped (-2137 > -2678)
main warning: late picture skipped (-13 > -2667)
main warning: late picture skipped (31543 > -2667)
main warning: late picture skipped (30281 > -2791)
main warning: late picture skipped (32898 > -2855)
main warning: late picture skipped (29534 > -2855)
main warning: late picture skipped (32399 > -2823)
main warning: late picture skipped (-1646 > -2822)
main warning: late picture skipped (2795 > -2778)
main warning: late picture skipped (3836 > -2778)
main warning: late picture skipped (40067 > -2946)
main warning: late picture skipped (41682 > -2928)
main warning: late picture skipped (43833 > -2817)
main warning: late picture skipped (-1788 > -2480)
main warning: late picture skipped (35194 > -2408)
main warning: late picture skipped (36037 > -2353)
main warning: late picture skipped (38455 > -2353)
main warning: late picture skipped (39193 > -2292)
main warning: late picture skipped (40528 > -2292)
main warning: late picture skipped (21096 > -3541)
main debug: skipped big render time 220843 > 203541
main warning: late picture skipped (241415 > -3541)
main warning: late picture skipped (749663 > -3567)
main warning: late picture skipped (753765 > -3766)
main warning: late picture skipped (751983 > -3766)
main warning: late picture skipped (236079 > -3671)
main warning: late picture skipped (900 > -2376)
main warning: late picture skipped (1695 > -2289)
main warning: late picture skipped (-343 > -2289)
main warning: late picture skipped (2401 > -2269)
main warning: late picture skipped (5372 > -2264)
main warning: late picture skipped (6919 > -2239)
main warning: late picture skipped (9262 > -2239)
main warning: late picture skipped (13559 > -2313)
main warning: late picture skipped (-649 > -3458)
main warning: late picture skipped (496 > -3366)
mkv debug: Event Key
main debug: control type=1
main debug: removing module "blend"
main debug: looking for video blending module: 1 candidate
blend debug: chroma: YUVA -> UYVY
main debug: using video blending module "blend"
main debug: TIMER module_need() : 0.391 ms - Total 0.391 ms / 1 intvls (Avg 0.391 ms)
main debug: removing module "blend"
main debug: looking for video blending module: 1 candidate
blend debug: chroma: RGBA -> UYVY
main debug: using video blending module "blend"
main debug: TIMER module_need() : 0.328 ms - Total 0.328 ms / 1 intvls (Avg 0.328 ms)
main debug: removing module "blend"
main debug: looking for video blending module: 1 candidate
blend debug: chroma: YUVA -> UYVY
main debug: using video blending module "blend"
main debug: TIMER module_need() : 0.255 ms - Total 0.255 ms / 1 intvls (Avg 0.255 ms)
main debug: removing module "blend"
main debug: looking for video blending module: 1 candidate
blend debug: chroma: RGBA -> UYVY
main debug: using video blending module "blend"
main debug: TIMER module_need() : 0.321 ms - Total 0.321 ms / 1 intvls (Avg 0.321 ms)
main debug: removing module "blend"
main debug: looking for video blending module: 1 candidate
blend debug: chroma: YUVA -> UYVY
main debug: using video blending module "blend"
main debug: TIMER module_need() : 0.209 ms - Total 0.209 ms / 1 intvls (Avg 0.209 ms)
main debug: removing module "blend"
main debug: looking for video blending module: 1 candidate
blend debug: chroma: RGBA -> UYVY
main debug: using video blending module "blend"
main debug: TIMER module_need() : 0.383 ms - Total 0.383 ms / 1 intvls (Avg 0.383 ms)
main debug: removing module "blend"
main debug: looking for video blending module: 1 candidate
blend debug: chroma: YUVA -> UYVY
main debug: using video blending module "blend"
main debug: TIMER module_need() : 0.219 ms - Total 0.219 ms / 1 intvls (Avg 0.219 ms)
main debug: skipped big render time 425479 > 203670
main debug: removing module "blend"
main debug: looking for video blending module: 1 candidate
blend debug: chroma: RGBA -> UYVY
main debug: using video blending module "blend"
main debug: TIMER module_need() : 0.320 ms - Total 0.320 ms / 1 intvls (Avg 0.320 ms)
main debug: removing module "blend"
main debug: looking for video blending module: 1 candidate
blend debug: chroma: YUVA -> UYVY
main debug: using video blending module "blend"
main debug: TIMER module_need() : 0.208 ms - Total 0.208 ms / 1 intvls (Avg 0.208 ms)
main debug: removing module "blend"
main debug: looking for video blending module: 1 candidate
blend debug: chroma: RGBA -> UYVY
main debug: using video blending module "blend"
main debug: TIMER module_need() : 0.310 ms - Total 0.310 ms / 1 intvls (Avg 0.310 ms)
main debug: removing module "blend"
main debug: looking for video blending module: 1 candidate
blend debug: chroma: YUVA -> UYVY
main debug: using video blending module "blend"
main debug: TIMER module_need() : 0.204 ms - Total 0.204 ms / 1 intvls (Avg 0.204 ms)
main debug: removing module "blend"
main debug: looking for video blending module: 1 candidate
blend debug: chroma: RGBA -> UYVY
main debug: using video blending module "blend"
main debug: TIMER module_need() : 0.286 ms - Total 0.286 ms / 1 intvls (Avg 0.286 ms)
main debug: removing module "blend"
main debug: looking for video blending module: 1 candidate
blend debug: chroma: YUVA -> UYVY
main debug: using video blending module "blend"
main debug: TIMER module_need() : 0.200 ms - Total 0.200 ms / 1 intvls (Avg 0.200 ms)
main debug: removing module "blend"
main debug: looking for video blending module: 1 candidate
blend debug: chroma: RGBA -> UYVY
main debug: using video blending module "blend"
main debug: TIMER module_need() : 0.382 ms - Total 0.382 ms / 1 intvls (Avg 0.382 ms)
main debug: removing module "blend"
main debug: looking for video blending module: 1 candidate
blend debug: chroma: YUVA -> UYVY
main debug: using video blending module "blend"
main debug: TIMER module_need() : 0.218 ms - Total 0.218 ms / 1 intvls (Avg 0.218 ms)
main debug: skipped big render time 453050 > 203763
main debug: removing module "blend"
main debug: looking for video blending module: 1 candidate
blend debug: chroma: RGBA -> UYVY
main debug: using video blending module "blend"
main debug: TIMER module_need() : 0.337 ms - Total 0.337 ms / 1 intvls (Avg 0.337 ms)
MediaInfo Export
* * * MediaInfo Mac 0.7.33.4 file analysis report.
* * * MediaInfo Mac is ©2010 by Diego Massanti -
http://mediainfo.massanti.com
* * * MediaInfoLib by Jerome Martinez -
http://mediainfo.sourceforge.net
Created on: 26 Jul 2010 15:53:32 GMT+01:00
Report for file: Angels_and_Demons.mkv
General / Container Stream #1
Total Video Streams for this File.................1
Total Audio Streams for this File.................1
Total Subtitle Streams for this File..............3
Video Codecs Used.................................AVC
Audio Codecs Used.................................DTS
SubTitle Codecs Used..............................S_HDMV/PGS / S_HDMV/PGS / S_HDMV/PGS
Available Sutbitle Languages......................English / English / English
File Format.......................................Matroska
Play Time.........................................2h 26mn
Total File Size...................................26.3 GiB
Total Stream BitRate..............................25.7 Mbps
Encoded with......................................MakeMKV v1.5.3 beta darwin(x86-release)
Encoding Library..................................libmakemkv v1.5.3 beta (0.7.7/0.8.1) darwin(x86-release)
Video Stream #1
Codec (Human Name)................................AVC
Codec (FourCC)....................................V_MPEG4/ISO/AVC
Codec Profile.....................................High@L4.1
Frame Width.......................................1 920 pixels
Frame Height......................................1 080 pixels
Frame Rate........................................23.976 fps
Total Frames......................................210406
Display Aspect Ratio..............................16:9
Scan Type.........................................Progressive
Color Space.......................................YUV
Codec Settings (Summary)..........................CABAC / 2 Ref Frames
QF (like Gordian Knot)............................0.476
Codec Settings (CABAC)............................Yes
Codec Settings (Reference Frames).................2
Video Stream Length...............................2h 26mn 15s 692ms
Video Stream BitRate..............................23.7 Mbps
Bit Depth.........................................8 bits
Video Stream Size.................................24.2 GiB (92%)
Audio Stream #1
Codec.............................................DTS
Codec (FourCC)....................................A_DTS
Audio Stream Length...............................2h 26mn 15s 692ms
Audio Stream BitRate..............................1 510 Kbps
Audio Stream BitRate Mode.........................CBR
Number of Audio Channels..........................6
Audio Channel's Positions.........................Front: L C R, Side: L R, LFE
Sampling Rate.....................................48.0 KHz
Bit Depth.........................................24 bits
Audio Stream Size.................................1.54 GiB (6%)
Audio Stream Title................................3/2+1
Audio Stream Language.............................English
Subtitle Stream #1
Language..........................................English
Format............................................PGS
Codec ID..........................................S_HDMV/PGS
Codec Info........................................The same subtitle format used on BDs/HD-DVDs
Subtitle Stream #2
Language..........................................English
Format............................................PGS
Codec ID..........................................S_HDMV/PGS
Codec Info........................................The same subtitle format used on BDs/HD-DVDs
Subtitle Stream #3
Language..........................................English
Format............................................PGS
Codec ID..........................................S_HDMV/PGS
Codec Info........................................The same subtitle format used on BDs/HD-DVDs
Menu / Chapters Stream #1