Can frames from .m2ts file from Blu-ray discs be cut out w/o quality loss?

[c627627]

Frames from standard DVDs can be cut out without any loss in quality when compared to the original DVD.

If I extract a giant 30GB .m2ts file from a Blu-ray disc, can I remove a few frames out of it and save it w/o quality loss just like I can standard DVD files?


The 30 GB .m2ts file does import into Sony Vegas, but I am guessing if it is Rendered As an edited .m2ts file that there will be some quality loss?

[poisondeathray]

That's not exactly true... for dvd mpeg2, if you make a cut within a GOP, that entire GOP has to be re-encoded = generation loss within that GOP . This is called "smart rendering" . The rest of the segments get passed through untouched. Only when the cut is at the end of a GOP, preceding th next I-frame , is the cutting completely lossless


There are 3 different compression schemes found on blu-ray. Vegas can't do it for blu-ray of any type

If the blu-ray is MPEG2, then videoredo (normal version) can do it

If the blu-ray is AVC/h.264 then videoredo (beta 4) can do it (but it's sometimes buggy)

If the blu-ray is VC-1, then nothing can do it



If you want to cut at GOP boundaries (not frame accurate), then you can do it with tssniper, or tsmuxer (cut by timecode)

[c627627]

Thank you for your advice.

I have imported the 30 GB .m2ts file into GSpot v2.70a and it says that it is of
File Type: MPEG-2 Transport Stream
Mime Type: video/mp2t


I understand I can use videoredo according to your post. I will try it.
I assume it will let me cut out parts of that .m2ts file, but I am guessing that I will not be able to insert anything inside that .m2ts file just like you can't really insert anything into MPEG-2 DVD files but you can (sometimes as you noted) edit parts out of them w/o any quality loss.

[poisondeathray]

use mediainfo to determine the compression

gspot isn't very good for this

every blu-ray is wrapped in a mpeg2 transport stream (.m2ts) , but this says nothing about the compression used

[c627627]

Very well, mediainfo displays it as:

Container and general information
BDAV: 29.7 GiB, -10s 709ms Maximum Overall bit rate: 48.0 Mbps
1 video stream: AVC
11 audio streams: DTS / AC-3 / DTS / DTS / AC-3 / DTS / AC-3 / DTS / DTS / AC-3 / AC-3
6 text streams: PGS / PGS / PGS / PGS / PGS / PGS

First video stream
1920*1080 (16:9), at 23.976 fps, AVC (High@L4.1) (CABAC / 4 Ref Frames)


I opened the .m2ts file in VideReDo, cut one small part out of it and tried to Save it but got this error:

[poisondeathray]

is that the beta version? the compression is avc, so the normal videoredo won't work (it's not 100% working anyway, that's why it's still in beta)

if you cut at I-frames you can use tssniper, h264_ts cutter, or tsmuxer . GOP length is usually 1 second for hollywood blu-ray (so every 24 frames), so cuts won't be perfect (within 1 second), but there will be no quality loss

[c627627]

Yes, I simply downloaded the latest VideReDo, should I have installed the latest stable release?


Yes, I know cuts won't be perfect - that is what I meant for standard DVD, how things can be edited out (within a second or so) but they can be easily and quickly edited out w/o any loss so that the final product is identical in quality to the original. I will try the three you mentioned tssniper, h264_ts cutter, and tsmuxer to see which one is the easiest to use.

Once again, I assume I cannot insert a frame (a picture) into the .m2ts file w/o decreasing the final output quality of the Blu-ray, correct?

[c627627]

Unrelated questions, would you happen to know the answer to these two please:

https://forum.videohelp.com/threads/327986-How-to-Stop-Blu-ray-Menu-Theme-Song-Looping
https://forum.videohelp.com/threads/330231-Is-there-a-program-to-edit-HDDVD-like-Clown_...n-edit-Blu-ray

[poisondeathray]

Videoredo beta is still buggy and only works some of the time for AVC . You can try getting rid of some of the streams with tsmuxer and try again -it might be all the audio tracks giving videoredo grief (i.e. remux into a new .m2ts with only video and main audio)

Once again, I assume I cannot insert a frame (a picture) into the .m2ts file w/o decreasing the final output quality of the Blu-ray, correct?

No you can't just insert a frame; at least not very easily.

blu-ray requires specific encoding and buffer values. At minimum, you would need to re-encode the affected GOP and join the segments. The software isn't mature enough as DVD software

[c627627]

H264TS_Cutter errors and TSSniper errors are attached, however I think tsMuxeR may work.

The thing is, on the attached tsMuxeR picture, I wish to cut out the part I chose, but tsMuxer keeps that part and cuts everything else. How do I do the reverse, keep everything except for the part b/w 19 and 43 seconds of the .m2ts file?

[poisondeathray]

for tssniper and h264ts_cutter you need your directshow subsystem working properly. Install haali media splitter and ffdshow. On win7 you also need to use preferred filter tweaker


for tsmuxer you can try cutting the beginning and end , then join them (use "join" button)

[c627627]

Oh, I see, thanks for that. I feel that tsMuxeR is the easiest to use as it requires nothing additional to be installed.

1. If I start tsMuxeR, and simply do what you said (cut twice, join once) - will the final file be identical to the original except for the cut 24 seconds, in other words, do I need to go into any other setting of tsMuxeR to make sure it doesn't change or insert anything else, so that it just takes the .m2ts file as pictured above and cuts out one part w/o making any other changes whatsoever, then joins the two cut parts back together?


2. What do you use to determine or preview which hour/minute/second of the file is cut out with tsMuxeR?

3. Can you just put the end at 100000 min so you don't have to figure out the exact length of the .m2ts file if you wish the end to be the actual end of the file?

[c627627]

It just occurred to me. In this specific scenario where I am cutting out 24 seconds from a two hour file and since the cut out is being made form the 19th to the 43rd second of the 2 hour file....

maybe I can open the first 19 seconds as cut by tsMuxeR in Sony Vegas. Then insert additional frames then Render As an .m2ts file then join with the larger almost two hour chunk.


That way only the first 19 seconds will be in somewhat lower quality but from the 19th second onward, it would be the original unchanged file, so under these circumstances, maybe you can edit and add additional frames w/o an overall loss to quality of the two hour file?

Adding and changing the first cut out m2ts file would not change and affect anything other than the quality of those first 19 seconds or is there more to it?

[poisondeathray]

It gets "dicey" when you do these manipulations, because you risk buffer underruns. Blu-ray requires a special buffer model and you can't just cut & paste things.

You can try it , but it's not always going to work properly in all players (there might be stutter at the join site)

2. What do you use to determine or preview which hour/minute/second of the file is cut out with tsMuxeR?

You can use a media player, or avisynth script

Can you just put the end at 100000 min so you don't have to figure out the exact length of the .m2ts file if you wish the end to be the actual end of the file?

not sure... give it a shot

maybe I can open the first 19 seconds as cut by tsMuxeR in Sony Vegas. Then insert additional frames then Render As an .m2ts file then join with the larger almost two hour chunk.

This gets really problematic. The reason is there are many different types of AVC encoding and profiles , settings etc.... , and they don't all join nicely. You almost need to use the same encoder and settings. The encoder in vegas isn't blu-ray compliant, so chances of success are low

[c627627]

Thank you. Am I only looking at a possible jitter at the joining point? Or are there other theoretical downsides other than the obvious loss in quality of the edited part?

[poisondeathray]

There won't be obvious loss in quality if you encode it properly

The potential problems are getting it join (if at all) , and possible glitches at the "joints"


Just to concatenate it properly: you need identical audio, fps, sample rate, dozens of matching encoding settings... it's a lot more difficult than you think to add sections...because you probably don't have access to the same studio encoder

[c627627]

First of all, per your instructions, the tsMuxeR cut twice/join once operation worked perfectly. I will from now use that simple method to edit out whichever .m2ts file tsMuxeR can open...


As for the other topic, I was only going to overlay a single picture over the existing video and audio inside Sony Vegas.

It would cover only parts of the existing video for 24 seconds. I was hoping that would make things easier?


By the way I wish to overlay the equivalent of this standard DVD picture over the other, that's what this is about:

[c627627]

...and I spoke too soon. Although the cut/joined .m2ts file played perfectly when opened in Media Player Classic, the re-assembled Blu-ray did not play well in either PowerDVD or Total Media Theatre.


Back to the drawing board, I will try installing the items you suggested over the weekend and give it another shot using those other programs you suggested.

Thank you for helping me.

[c627627]

I have tested all the mentioned programs and found all of them to be buggy enough to prevent cutting out portions of Blu-ray video. I am trying to use TMPGEnc Video Mastering Works 5 but I am stuck at a screen which asks me which format to encode it to. I obviously am making the wrong choices since it starts the 2 hour + encoding process.

EDIT: Never mind, I just found out that this program is not capable of smart rendering