Which alternative produces a better picture quality?

MKV playback, recompression, remuxing, codec packs, players, howtos, etc.
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nidany
Posts: 3
Joined: Thu Jun 14, 2018 9:45 pm

Which alternative produces a better picture quality?

Post by nidany »

I've tried 2 approaches in getting mkv file from a single source: A bdmv file sent to me of an old Japanese movie.
MakeMkv: I got a 26 gb mkv file, 1920x1080, with very high specs (media info).
DvdFab: I got a much smaller mkv file, 15 gb, 1920x820 with much lower specs.
The DvdFab produced the movie ONLY without the black horizontal frames which appear when I play it on a large 65" OLED screen.
I fully understand that the screen shows these 2 black frames because of the different ratio. (1:2.32 vs 1:1.78)
Assuming that I don't care about those black lines, I'd like to know whether there is REALLY a difference in picture quality or the mediainfo specs just reflect the difference in ratio?
Following are the mediainfo specs:
_____________________________
Video
ID : 1
ID in the original source medium : 4113 (0x1011)
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings : CABAC / 4 Ref Frames
Format settings, CABAC : Yes
Format settings, RefFrames : 4 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 1 h 35 min
Bit rate mode : Variable
Bit rate : 35.0 Mb/s
Maximum bit rate : 37.0 Mb/s
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 23.976 (24000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.703
Stream size : 23.4 GiB (96%)
Language : English
Default : No
Forced : No
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Original source medium : Blu-ray
______________________________________
Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings : CABAC / 2 Ref Frames
Format settings, CABAC : Yes
Format settings, RefFrames : 2 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 1 h 35 min
Nominal bit rate : 18.9 Mb/s
Width : 1 920 pixels
Height : 820 pixels
Display aspect ratio : 2.35:1
Frame rate mode : Constant
Frame rate : 23.976 (24000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.500
Writing library : x264 core 142
Default : Yes
Forced : No
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Original source medium : Blu-ray
Woodstock
Posts: 10381
Joined: Sun Jul 24, 2011 11:21 pm

Re: Which alternative produces a better picture quality?

Post by Woodstock »

MakeMKV is going to produce a file with the original video. It is just changing the container that holds the data.

If a program is producing a SMALLER file, especially by doing things like removing the letterboxing, then it is re-encoding the video, and that will cause a degradation of quality.

It may not be noticeable to you. I always run my ripped video through handbrake to reduce its size.
nidany
Posts: 3
Joined: Thu Jun 14, 2018 9:45 pm

Re: Which alternative produces a better picture quality?

Post by nidany »

Woodstock wrote:MakeMKV is going to produce a file with the original video. It is just changing the container that holds the data.

If a program is producing a SMALLER file, especially by doing things like removing the letterboxing, then it is re-encoding the video, and that will cause a degradation of quality.

It may not be noticeable to you. I always run my ripped video through handbrake to reduce its size.
Thank you.
Does the use of handbrake degrade the video?
Does it re-encode?
Woodstock
Posts: 10381
Joined: Sun Jul 24, 2011 11:21 pm

Re: Which alternative produces a better picture quality?

Post by Woodstock »

Any system that reduces the size in a lossy manner is going to reduce the video quality. And a lossless encoder is going to make a larger file than a lossy encoder.

The starting point is a lossy encode.

Encoders start by unpacking the source, applying filters on the resulting picture (like removing the letterbox), then encoding the picture, repeating as necessary to do every frame. There is some inter-frame things done to reduce the bit rate even further.

The bits that were lost when the original video was encoded to put it on the BD or DVD are lost for good. If you look closely enough, you'll see compression artifacts in the raw BD video. The hope is that you won't look THAT closely. :)
nidany
Posts: 3
Joined: Thu Jun 14, 2018 9:45 pm

Re: Which alternative produces a better picture quality?

Post by nidany »

Thanks, again, Woodstock, for sharing your knowledge.
It really made a difference for me
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