comskip max_repair_size setting

[johnsonx42]

In another thread, pBS said:

there is only 1 part of files comskip can sometimes alter, the pts timeline can be 'fixed' by comskip up to 200 frames by default..
set max_repair_size=0 in comskip.ini to turn that off completely...

This setting is described in the comskip.ini file thusly:

Code:

max_repair_size=200    ; Will repair maximum 200 missing MPEG frames in the timeline, set to 0 to disable repairing for players that don't use PTS.

Can anyone tell me precisely what this does to the file? Could leaving it enabled throw off the data in the file relative to the NPVR Timing.Info? I've become EXTREMELY frustrated trying to use comskip with NPVR lately; the skip points are sometimes so far off I have to manually skip back through the commercial break to catch 10-20 seconds of show that I missed when it skipped. I'm almost ready to throw in the towel on using comskip (yet without it I would start to question (again) why I bother with all this). Comskip itself works perfectly: if I bring up a problem file in the comskip debugger display, the detected skip points are frame-perfect from its point of view. NPVR and comskip just can't agree on the timeline in a lot of files, so NPVR skips in the wrong place half the time.

I've just set the max_repair_size to 0, but I won't know for sure right away since some recordings do seem to skip pretty accurately.

Can anyone say whether this could in fact have anything to do with this issue, or what else might cause it?

[mvallevand]

Even if it was perfect, I have never found comskip to be worth the cpu time, but regardless in my testing I've found the new timeline seeking to be extremely good on the NMT except when there is a comskip at the very beginning of file especially when mixed with a resume. How is it for you from the video library?

Martin

[BrettB]

I've been getting pretty good results with comskip on my HD QAM recordings of broadcast TV channels in the US with NPVR.

There was a problem with GBPVR when there was a skip at the beginning of a recording, so I still have my comskip.ini setup to never have a skip within the first 90 seconds. (I think that's the value. I'm not at home right now, so I can't check my .ini file for the exact setting.)

The one problem that I have is that internally, during processing, comskip uses frame numbers. If you want an edl file output (which is what I use for NPVR), then comskip will convert from frame numbers to edl timings based upon the frame rate at the END of the recording file. When the frame rate is fixed/constant, this method works fine. However, with digital, HD broadcasting these days, it seems the frame rate is sometimes changed (either for commercials or for different shows). I typically see this problem with CBS recordings, and it can be seen when you display the timeline in NPVR and all of the commercial breaks are in the 1st half of the timeline. Erik indicated that this is a known problem, but fixing it is not a simple matter.

[pBS]

the pts are presentation time stamps..[basically the timeline] so i can see how it could affect it..
apparently comskip removes missing frames and tightens up the timeline to make it all continuous..
and if he means mpeg picture frames, then 200 is enough to mess it up good..

now if yours is skipping prematurely by a couple of secs, then that could just be lag..
try going back to the skip point and see if it doesn't skip better second time, data being cached and more instant..usually better by half second..
also, .ts seems less precise overall when seeking...seems like more tricks are needed for it over mpg2..
is this on digital or analog recordings?
it should affect digital more than analog..
a properly running analog shouldn't have any missing frames..
digital is subject to signal dropouts..

[pBS]

i haven't seen any oddities with my CBS recordings yet...
but maybe that's cuz i'm on antenna atsc..

[johnsonx42]

I will check to see if the problem recordings are starting out with a skip. I don't think it's the case, but we'll see. I may want to set that option anyway to disallow skips during the first 90 seconds, as I often find that if it does skip that soon it's probably skipping the opening scene of the show.

As to the possibility of just being random variance due to lag or whatever, no that's not it. I do find if I go back and let it skip again there is a slight variance of a 1/2 second or so sometimes, but no, I'm talking skipping 10 to 20 seconds early (and again, this is after I've verified that from comskip's point of view the skip points are accurate down to the frame).

I am using antenna ATSC as well. I really don't see any evidence of drop-outs in the problem recordings.

I have turned off the repair function in comskip, so I'll see if that does affect anything.

[Reddwarf]

I saw the recomendation a while ago and zeroed the value because I saw lots and lots of "repairing timeline" messages while comskip was running, and the skipping wad far from accurate. It has improved, and I'm quite satisfied with comskipping now, but for HD recordings it's not worth yhe cpu-time. It takes "forever" and the skipping is not as good as SD recordings.

Besides, I'v learned how long the commercials are on both Nat.geo HD and Discovery HD Showcase so I can easely skip them with my remote :p.

[johnsonx42]

Wow, major improvement with timeline repair in comskip turned off. I viewed 3 recordings made this evening, and all autoskipped pretty good. The skip points aren't quite frame perfect, but within a second or two at worst. I'll be sure after watching a couple night's recordings, but it seems pretty definite already. Finally, I can move on to something else.

The moral of the story is: "Don't let comskip screw around with your recordings!"

[johnsonx42]

Nevermind.

I spoke too soon; a later recording was as bad as ever. It was on the same channel as an earlier recording that was really good. One of the skips near the end was a full 17 seconds early. There's no visible evidence of a poor signal or dropped frames.

[pBS]

are you using .edl or .txt?
using very latest ver of comskip?

since you're in US, maybe you can try this .ini file on some problem ones to see if any better..

Code:

detect_method=43            ;1=black frame, 2=logo, 4=scene change, 8=fuzzy logic, 16=closed captions, 32=aspect ration, 64=silence, 128=cutscenes, 255=all
validate_silence=1            ; Default, set to 0 to force using this clues if selected above.
validate_uniform=1            ; Default, set to 0 to force using this clues (like pure white frames) if blackframe is selected above.
validate_scenechange=1        ; Default, set to 0 to force using this clues if selected above.
verbose=0                ;show a lot of extra info, level 5 is also OK, set to 0 to disable
max_brightness=60                  ;frame not black if any pixels checked are greater than this (scale 0 to 255)
test_brightness=40              ;frame not pure black if any pixels checked are greater than this, will check average brightness (scale 0 to 255)
max_avg_brightness=25            ;maximum average brightness for a dim frame to be considered black (scale 0 to 255) 0 means autosetting
max_commercialbreak=600         ;maximum length in seconds to consider a segment a commercial break
min_commercialbreak=25            ;minimum length in seconds to consider a segment a commercial break
max_commercial_size=125            ;maximum time in seconds for a single commercial or multiple commercials if no breaks in between
min_commercial_size=4           ;mimimum time in seconds for a single commercial
min_show_segment_length=185     ; any segment longer than this will be scored towards show.
non_uniformity=500            ; Set to 0 to disable cutpoints based on uniform frames
max_volume=500                ; any frame with sound volume larger than this will not be regarded as black frame
min_silence=12                ; Any deep silence longer than this amount  of frames is a possible cutpoint
ticker_tape=0                ; Amount of pixels from bottom to ignore in all processing
logo_at_bottom=0            ; Set to 1 to search only for logo at the lower half of the video, do not combine with subtitle setting
punish=0                    ; Compare to average for sum of 1=brightness, 2=uniform 4=volume, 8=silence, 16=schange, set to 0 to disable
punish_threshold=1.3        ; Multiply when amount is above average * punish_threshold
punish_modifier=2            ; When above average * threshold multiply score by this value
intelligent_brightness=0         ; Set to 1 to use a USA specific algorithm to tune some of the settings, not adviced outside the USA
logo_percentile=0.92            ; if more then this amount of logo is found then logo detection will be disabled
logo_threshold=0.75
punish_no_logo=1            ; Default, set to 0 to avoid show segments without logo to be scored towards commercial
aggressive_logo_rejection=1
connect_blocks_with_logo=1        ; set to 1 if you want successive blocks with logo on the transition to be regarded as connected, set to 0 to disable
logo_filter=0               ; set the size of the filter to apply to bad logo detection, 4 seems to be a good value.
cut_on_ar_change=1            ; set to 1 if you want to cut also on aspect ratio changes when logo is present, set to 2 to force cuts on aspect ratio changes. set to 0 to disable
delete_show_after_last_commercial=0    ; set to 1 if you want to delete the last block if its a show and after a commercial
delete_show_before_or_after_current=0    ; set to 1 if you want to delete the previous and the next show in the recording, this can lead to the deletion of trailers of next show
delete_block_after_commercial=0    ;set to max size of block in seconds to be discarded, set to 0 to disable
remove_before=0                ; amount of seconds of show to be removed before ALL commercials
remove_after=0                ; amount of seconds of show to be removed after ALL commercials
shrink_logo=5                ; Reduce the duration of the logo with this amount of seconds
after_logo=0        ; set to number of seconds after logo disappears comskip should start to search for silence to insert an additional cutpoint
padding=1
ms_audio_delay=5
volume_slip=20
skip_b_frames=0                ; Set to 1 to force Comskip to skip frames for higher processing speed.
max_repair_size=0            ; Will repair maximum 200 missing MPEG frames in the timeline, set to 0 to disable repairing for players that don't use PTS.
disable_heuristics=4        bit pattern for disabling heuristics, adding 1 disables heristics 1, adding 2 disables heristics 2, adding 4 disables heristics 3, 255  disables all heuristics
delete_logo_file=1            ; set to 1 if you want comskip to tidy up after finishing
output_framearray=0            ; create a big excel file for detailed analysis, set to 0 to disable
output_data=0                ; create a dump of the user data channel, used for CC and XDS (such as V-Chip info). Can be use together with output_framearray to remote debug CC decoding
output_videoredo=0
output_womble=0
output_mls=0            ; set to 1 if you want MPeg Video Wizard bookmark file output
output_cuttermaran=0
output_mpeg2schnitt=0
output_mpgtx=0
output_dvrcut=0
output_zoomplayer_chapter=0
output_zoomplayer_cutlist=0
output_edl=1
output_edlx=0
output_vcf=0
output_bsplayer=0
output_btv=0                ; set to 1 if you want Beyond TV chapter cutlist output
output_projectx=0            ; set to 1 if you want ProjectX cutlist output (Xcl)
output_avisynth=0
output_vdr=0                ; set to 1 if you want XBMC to skipping commercials
output_demux=0                ; set to 1 if you want comskip to demux the mpeg file while scanning
sage_framenumber_bug=0
sage_minute_bug=0
live_tv=1                    ; set to 1 if you use parallelprocessing and need the output while recording
live_tv_retries=4            ; change to 16 when using live_tv in BTV, used for mpeg PS and TS
dvrms_live_tv_retries=300            ; only used for dvr_ms
standoff=0                    ; change to 8000000 when using live_tv in BTV
cuttermaran_options="cut=\"true\" unattended=\"true\" muxResult=\"false\" snapToCutPoints=\"true\" closeApp=\"true\""
mpeg2schnitt_options="mpeg2schnitt.exe /S /E /R25  /Z %2 %1"
avisynth_options="LoadPlugin(\"MPEG2Dec3.dll\") \nMPEG2Source(\"%s\")\n"
dvrcut_options="dvrcut \"%s.dvr-ms\" \"%s_clean.dvr-ms\" "
windowtitle="Comskip - %s"