TS-Doctor 2.0 www.cypheros.de

Autor Thema: I-Frame cutting artefact  (Gelesen 4792 mal)

romkazor

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I-Frame cutting artefact
« am: August 10, 2014, 16:40:11 »
Hello, sorry for my English.
When i cut my ts stream(h264) and save, output file has artefact on one frame that connects the parts of the cutting video.
I do cut only on I-frame, but output file dont have two i-frame bpbpbpIIpbpbpb, it have bpbpbpiPibpbpbp
and that P frame is broken. In other programm i have pbpbpbpIIbpbpb
so I tried to change the settings in the Correction Behavior - H264 Special settings and got the same result
and i try cut +- 1from I Frame, but same
Version of tsdoctor 1.2.128
Logo of channel in left up corner i delete
« Letzte Änderung: März 19, 2018, 21:01:51 von Cypheros »

Cypheros

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Re: I-Frame cutting artefact
« Antwort #1 am: August 10, 2014, 20:11:05 »
Do you have the log infos about the cutting?

Should look like this:
Cutting areas (I/P-Frame aligned)
Cut 1 In : 15:04:05.353 (AUD|SPS|PPS|SEI|I-SLICE|)
Cut 1 Out: 16:00:40.733 (AUD|SEI|P-SLICE|)
Cut 1 PCR/PTS/DTS offset: 00:00:00.000

For cut out, TS-Doctor will use P-frames and I-frames.

romkazor

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Re: I-Frame cutting artefact
« Antwort #2 am: August 10, 2014, 23:56:05 »
Yes. And how then correctly cut?
Cutting areas (I/P-Frame aligned)
Cut 1 In : 05:57:45.817 (SPS|PPS|AUD|SEI|SEI|IDR|)
Cut 1 Out: 06:07:29.237 (SPS|PPS|AUD|SEI|I-SLICE|)
Cut 1 PCR/PTS/DTS offset: 00:00:00.000

Cut 2 In : 06:12:05.817 (SPS|PPS|AUD|SEI|SEI|IDR|)
Cut 2 Out: 06:19:01.417 (AUD|SEI|P-SLICE|)
Cut 2 PCR/PTS/DTS offset: -00:04:36.560

Cypheros

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Re: I-Frame cutting artefact
« Antwort #3 am: August 20, 2014, 16:01:27 »
Use new version 1.2.133 and check the new option "I-Frame only cutting" under Settings/Preferences/Correction behavior/H264 special settings. This should avoid the artefacts after cutting.

giusd

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Re: I-Frame cutting artefact
« Antwort #4 am: Oktober 08, 2014, 16:03:32 »
I'm testing the trial version 1.2.134 and I seem to have a similar problem.

I press the cut button exactly on I-Frame, to cut out commercial, but the output video seems to have some artifacts/errors.

Video format: H264 720x576i/AR=16:9/25 fps/Main@3.0
Colorimetry : ColourPrimaries=BT.470-2, TransferCharacteristics=BT.470-2, MatrixCoefficients=BT.470-2
First I-Frame PTS at 25:54:43.320 [00:00:00.920]
First GOP = 52 frames : I184 P185 B180 B181 B178 B179 B182 B183 P192 P193 B188 B189 B186 B187 B190 B191 P200 P201 B196 B197 B194 B195 B198 B199 P208 P209 B204 B205 B202 B203 B206 B207 P212 P213 B210 B211 P216 P217 B214 B215 P220 P221 B218 B219 P224 P225 B222 B223 P228 P229 B226 B227

Scanning for audio details
Audio stream 1: MPEG1 Audio
Audio stream 2: MPEG1 Audio
EIT data found

Transponder time details found
Transponder start time: 2014-07-05 17:33:56
Transponder end time  : 2014-07-05 19:13:34
Transponder time bias : UTC+2:00

Teletext scan: Lines scanned: 46460 / Parity errors: 0

TV Guide (EPG)
Character coding table: ISO 8859-2 (pol)
EPG time bias: UTC+2:00
  2014-07-05 17:30 - 19:00   Niezatapialny Titanic (  film dokumentalny)
  2014-07-05 19:00 - 20:00   Galileo - odc. 266 (  program popularnonaukowy)

  First teletext header at 25:54:42.473 300  1/1   TV4   05.07  17:33 47
  Last teletext header at  01:03:56.756 440  1/1   TV4   05.07  19:13 45
Removing 1 commercials with duration of 13 minutes [15,1%]

Cutting areas (I-Frame aligned)
Cut 1 In : 25:54:43.320 (AUD|SPS|PPS|SEI|SEI|SEI|I-SLICE|FILL|)
Cut 1 Out: 26:23:31.100 (AUD|SPS|PPS|SEI|SEI|SEI|I-SLICE|FILL|)
Cut 1 PCR/PTS/DTS offset: 00:00:00.000

Cut 2 In : 26:36:35.640 (AUD|SPS|PPS|SEI|SEI|SEI|I-SLICE|FILL|)
Cut 2 Out: 27:21:09.420 (AUD|SPS|PPS|SEI|SEI|SEI|I-SLICE|FILL|)
Cut 2 PCR/PTS/DTS offset: -00:13:04.520


Intersections
Intersection 1 at 00:28:47.800

Deleting PMT entry: PID 0131 type 6 = ITU-T Rec. H.222.0 | ISO/IEC 13818-1 PES packets containing private data (Teletext)
Deleting PMT entry: PID 0134 type 4 = ISO/IEC 13818-3 Audio

I made a cut at 28 minutes, 47 sec. But the transition between cut-in and cut-out is not correct.

I noticed, that i must step through around 4 I-Frames during commercial start, and around 3 I-Frames before commercial ends.
So, even when i try to cut on the FIRST I-Frame during commercial start, and LAST I-Frame of the commercial - i can't - because of artifacts during playback.

1. Is it possibile to cut on I-Frame right after commercial starts and right before it ends?

--------------------------------------------------------------------------------------------

Another thing that bothers me is that TS-Doctor is cutting off the very begining of the video.
I dont't like it. I want the video to start from 00:00:00 and not from 00:00:02 or sth like that.

It only happens when i try to cut something out.

If i only "fix" the video, TS-Doctor does not chop off the begining - That's what i like!
But since i want to cut out commercials, ts doctor will automatically chop off the begining - That's not what i like.

------------------------------------------------------------------------------------

Another thing that i noticed is that the output video is not identicall with the source.
With or without filler data, the video is different. It's not bit-by-bit identical.
I'm not saying it's a big difference, but it is there.

If i take a snapshot form input video and output video, there are pixel differences.
Even the filesizes of the screenshots confirm this.


Is there some kind of a colorspace conversion, or what? What could cause this difference.


here are my settings
« Letzte Änderung: Oktober 08, 2014, 23:41:35 von giusd »

Mam

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Re: I-Frame cutting artefact
« Antwort #5 am: Oktober 08, 2014, 22:03:07 »
In general, the pixel issues when cutting BBC films are known already. In the current state, TS Doc does not work very good on cutting BBC movies.
There is nothing you can do about it, we already wait over a year for a fix  :'(
Lächle! Du kannst sie nicht alle töten!

Derrick

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Re: I-Frame cutting artefact
« Antwort #6 am: Oktober 08, 2014, 22:19:49 »
In general, the pixel issues when cutting BBC films are known already. In the current state, TS Doc does not work very good on cutting BBC movies.
There is nothing you can do about it, we already wait over a year for a fix  :'(
Wrong answer, there are no commercials on BBC ;)

Zitat
I press the cut button exactly on I-Frame, to cut out commercial, but the output video seems to have some artifacts/errors.

btw. I can't complain about trimming BBC HD recordings :)

giusd

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Re: I-Frame cutting artefact
« Antwort #7 am: Oktober 08, 2014, 22:23:48 »
In general, the pixel issues when cutting BBC films are known already. In the current state, TS Doc does not work very good on cutting BBC movies.
There is nothing you can do about it, we already wait over a year for a fix  :'(
But it happens with every video processed by TS-Doctor.
here is another example from different tv station, and from completelly different tv-show



EDIT:
In general, the pixel issues when cutting BBC films are known already. In the current state, TS Doc does not work very good on cutting BBC movies.
There is nothing you can do about it, we already wait over a year for a fix  :'(
Wrong answer, there are no commercials on BBC ;)

Zitat
I press the cut button exactly on I-Frame, to cut out commercial, but the output video seems to have some artifacts/errors.

btw. I can't complain about trimming BBC HD recordings :)

Let me rephrase what i said.
The pixel differences are not related with/to cutting.
It's just that if i only try to "fix" (run the recording, without even cutting) through TS-Doctor, the output video is not pixel identical.
It looks to me like some sort of color space conversion, but i don't know much about it. That's why i ask, the developer of TS-Doctor should know what is happening behind the scenes.
« Letzte Änderung: Oktober 08, 2014, 22:36:02 von giusd »

Cypheros

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Re: I-Frame cutting artefact
« Antwort #8 am: Oktober 09, 2014, 00:39:02 »
TS-Doctor just copy the video stream from a start picture (iframe) to an end frame (iframe oder pframe). There is no transcoding or someting that changes the image quality.
In rare cases TV stations not respecting the standards and using the wrong color space. TS-Doctor detects this and you get a dialog with the hint, that the color space is wrong and need to be changed. If you say "Yes" TS-Doctor will change the color space to TV standards. That's the only way to get a different image. If you don't get that dialog, there is no change of the general image quality.

By the way the two images look quite similar. I would say the color spaces are identical. Different color spaces producing more differences in the black and white areas.
Please keep in mind, that alot of video decoder like LAVFilters and others are using random dithering to make HD pictures looks better. If you are comparing such images, you will not never get the same result, even for the same frame of the same file.

giusd

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Re: I-Frame cutting artefact
« Antwort #9 am: Oktober 09, 2014, 01:58:01 »
TS-Doctor just copy the video stream from a start picture (iframe) to an end frame (iframe oder pframe). There is no transcoding or someting that changes the image quality.
In rare cases TV stations not respecting the standards and using the wrong color space. TS-Doctor detects this and you get a dialog with the hint, that the color space is wrong and need to be changed. If you say "Yes" TS-Doctor will change the color space to TV standards. That's the only way to get a different image. If you don't get that dialog, there is no change of the general image quality.

By the way the two images look quite similar. I would say the color spaces are identical. Different color spaces producing more differences in the black and white areas.
Please keep in mind, that alot of video decoder like LAVFilters and others are using random dithering to make HD pictures looks better. If you are comparing such images, you will not never get the same result, even for the same frame of the same file.
There was no message about color space change.
The comparison is valid.
I'm quite obsessed with quality, i do a lot of comparisons for myself.

I did a test just now in VirtualDub with video from my camera. I cut out half of the video from the original input video, and i used Direct Stream Copy option.
After comparison images look the same, and have the same filesize.

That's not the case with TS-Doctor.
Unfortunatelly i can't test the TV recording with virtualldub, becasue it doesnt accept such files.

PS.
Can you say something about those 2 other problems that bothers me.
They are listed in previous posts
« Letzte Änderung: Oktober 09, 2014, 02:00:27 von giusd »

giusd

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Re: I-Frame cutting artefact
« Antwort #10 am: Oktober 09, 2014, 03:14:19 »
Ok, i tested this thoroughly.
It's because of interlacing >:( That damned interlacing!
I pretty much always use MPC-HC with pretty much always progresive videos.
I just forgot that our broadcaster use interlacing.

You were partly right.
The screenshots taken with MPC-HC from interlaced videos are different even when using the same video. Deinterlacing was turned on.
With progresive videos everything is the same. Deinterlacing was turned off.

I took some snapshots with VLC with deinterlacing turned off, and screenshots were the same.

I'm glad it's because of postprocessing, and not some sort of compression.

Damn, that interlacing caught me off guard >:( :P

glazooh

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Re: I-Frame cutting artefact
« Antwort #11 am: August 18, 2016, 17:10:33 »
This thread is nearly two years old now but appears to still be the situation with cutting artefacts, I couldn't find another thread.
I thought 'yay' when I saw the post about setting the I-Frame only cutting, but of course it made no difference if it is in fact being caused by the file being interlaced.
Did anybody find a way round this problem ?
The only thing I could think of was to convert the TS Doctor edited file to huffyuv, creating a huge file, and then edit it painstakingly in VirtualDub to delete the corrupted frames, then convert that to the required format.
Extremely long-winded and not really feasible for large recordings of long sports events.

Cypheros

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Re: I-Frame cutting artefact
« Antwort #12 am: August 23, 2016, 00:42:39 »
Do you have a log file for the file?

glazooh

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Re: I-Frame cutting artefact
« Antwort #13 am: August 23, 2016, 13:03:44 »
Sure - log attached along with screen grab of corrupted frame from the edit.
Thanks for looking.

Cypheros

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Re: I-Frame cutting artefact
« Antwort #14 am: August 23, 2016, 22:47:45 »
I can't see the GOP size. I guess there is problem with the iframes on itv4. I'll check that and do a test recording.

 


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