Reduced video size after muxing with mkvmerge

[sazolis]

Hi!

I used mkvmerge to delete an audio track from an mkv file. However, the video size was also reduced from 58.2 GiB to 53.1 GiB. The audio track was 2.41 GiB. The total file size was reduced from 73.6 to 66 GiB. So clearly there is a bitrate loss.

The compression in the Extra Options tab was set to ''none''. Does anybody have any idea why is this happening? Mkvmerge should not encode the video...

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings, CABAC : Yes
Format settings, ReFrames : 2 frames
Format settings, GOP : M=1, N=10
Codec ID : V_MPEG4/ISO/AVC
Duration : 3h 48mn
Bit rate mode : Variable
Bit rate : 36.5 Mbps -> 33.3 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.670
Stream size : 58.2 GiB -> 53.1 GiB (80%)
Title : Video (29853 kbps)
Language : English
Default : Yes
Forced : No

[Baldrick]

Can you play the entire video without problems?

[sazolis]

Yes, the video can be played without problems. And because of the high bitrate I can not really distinguish between the quality of the two streams. So it is strange...

[Baldrick]

mkvmerge can not convert so you can't lose any video quality. But mkvmerge might have stripped/cutted a part of the video. Or it's just a big mkv overhead.

How did you make the original mkv? With makemkv or something else?

[sazolis]

Yes, the video was made with makemkv.

Actually, I will have to check indeed if there is any part that has been cut. So far I just jumped to various locations in the mkv. Is there any tool that compares two videos?

[Selur]

1. wouldn't it be easier to simply to a detailed mediainfo analysis on both files,...
2. don't trust the audio/video bitrates MediaInfo posts
my bet would be that there's not something fishy going on, but you either left something else out when remuxing or your audio was larger

[sazolis]

Thanks for the tips. I will try to remux and take out only a subtitle. Then the file size should be almost the same...

[jdking3i]

I am having a similar issue. When adding a subtitle stream to a MKV generated by MakeMKV, the file size reduces from 34.6Gb to 33.7Gb. I'm concerned because I've added information to the container, and the file size is diminishing.

[ndjamena]

I am having a similar issue. When adding a subtitle stream to a MKV generated by MakeMKV, the file size reduces from 34.6Gb to 33.7Gb. I'm concerned because I've added information to the container, and the file size is diminishing.

Well, for one thing Subtitles aren't all that big.

For another, I always remux the files I create using MakeMKV with MKVMerge afterwards, because MKVMerge is a better Matroska muxer that better uses the Matroska feature-set and therefore the files come out smaller in the end.

And then there's the fact that some people turn OFF a lot of MKVMerge's features when they mux a file, for compatibility reasons. Not all players support the full Matroska feature-set, so using them will just leave the files unplayable. But that of course makes the files larger, and remuxing them again without those features having been turned off will lead to a smaller file.

And finally, PGS and VobSub subtitles can be compressed using zlib when muxed into a Matroska file, some programs don't do that, or don't do it by default, so remuxing a PGS or VobSub subtitle with zlib enabled will lead to a much smaller file. MakeMKV is one of those programs that doesn't use zlib by default, you need to enable it in the profile to get it working. MKVMerge of course ALWAYS uses zlib unless specifically told not to, so simply remuxing a default MakeMKV file containing subtitles using MKVMerge at default settings will make the file smaller.

[DTS-HD-MA]

First of all sorry for replying here but i dont know how to create a new post .
Now if you wish to help here is my problem.
I have a Mkv movie with dts sound 1080p.
When i convert to ts(extracting core only for sound) and playback the ts file to my tv the video after adn every fey frames does a small frame lag and do that every 2 or 1 second it is like ever last frame the video keeps lagging its small bug but its annoying.i tried lots of different choises on the tsmuxerGui but nothing helped me.I dont know whats the problem.I do that muxing cause when i play back movies to my tv with the mkv format and dts sound the video lag and freeze all the time but with ts doesnt do that only the small lag because of the muxing i dont know.

[ndjamena]

Point MediaInfo at the MKV.

[DTS-HD-MA]

If you are refering to my problem then the settings are:
Video: X264 9288Kbps
Frame Rate: 23.976
Resolution: 1920x1040
Audio: DTS 1509Kbps 6ch
If you need more details please let me know.