Video Format

[biferi]

I have a lot of Movie VOB Files on My Hard Drive that I Watch.

I was going to put them on My SD Card and Watch them on My Projector.

I Looked on Google and everything I See Says the most Supported Format is mkv For Devices.

So I Convert all My VOB Files to mkv and I Set everything to Original.

My File Size for all the mkv Files is 243 GB but if I use the same Setting and Convert My VOB Files to MPEG 2. all the Files are 217 GB in Size.

Why is MPEG 2. a Smaller File Size?
MPEG 2. should be a Better Quality so the File Size would be Larger.

What am I not Understanding?

[davexnet]

File size = bitrate x running time. It's as simple as that

[DB83]

Slightly more complex answer.

Both vob and mkv are container formats so could contain multiple audio streams etc. Mpeg2 is a file format so, typically, would have just one video and audio stream.


You have been here long enough to know that you can use mediainfo to inspect all the various files to see what they contain.


And, as stated, even if the vob has just one video and audio stream the bitrate could be different hence the different file size,


What are you using to convert the vob to mkv or mpeg2 for that matter ? If you use makemkv to create the mkv the file file will, practically, be the same size (slight variation for the file header and that is all) as the original vob

[Cornucopia]

FYI, MPEG2 is a container format (actually 2 - Program Stream or PS, of which VOB is a superset, and Transport Stream or TS), as well as video and audio encoding stream formats ("codecs").

I agree w/ DB83, review what you've got properly (both before & after). And use a better tool to REMUX from VOB to MKV, instead of re-encoding. That way you will keep the quality, and the filesize will be comparable.

However, even if you succeed in getting MPG2+AC3 within the MKV, how do you know that your projector will accept that. Just because it says MKV could mean MANY or FEW codecs are actually accepted. My educated guess is that it wants something like h264/AVC video and AAC audio within the MKV. If that is true, you'd have to re-encode to THAT format.

Scott

[biferi]

I am using Any Video Converter Free.

And I keep all the Settings Set to Original so when it Converts My VOB Files it uses the Same BitRate and the same Frame Rate and the same Frame Size and the same Audio.

And after it Converts all My VOB Files to MPEG 2. it all comes to 217 GB and this is great.

But I just did not Understand why if I do the same thing but Convert them to mkv the File Size is a lot Larger?

MPEG 2. should be a Better Quality than mkv if I am Right?

MPEG 2. is more for Movies and Videos so I Thought it would be Better Quality than mkv Format?

And if anything is Better Quality the File Size should be Larger because it is keeping more of the Data.

Am I not Right?

[Cornucopia]

If you start with VOB (a superset of MPEG2 PS) and go to MPEG2 PS, you do not (and probably ARE NOT, certainly should not) need to re-encode, but just remux.

If you start with VOB and go to MKV, you COULD simply remux, but more than likely it will expect to re-encode (unless you use something like makemkv). Then, you cannot set to "original" because it is not keeping the orignal. The closest it can get is to re-encode at a bitrate close to the original, which ends up always varying a bit, depending on other factors.

A clip that is 1 generation earlier than another will always be better (or at worst equal) quality than the later generation clip. However, depending on the re-encoding parameters, and on possible noise reduction implemented, that later generation clip may look worse, the same, or possibly better.

No format is "more for movies and videos" than any other format.

No you are NOT right, quality is dependent upon multiple things: original source, resolution, compression efficiency, bitrate, compression settings....

In this way, you could take an uncompressed camera original file (1st gen), encode it to MPEG2 (for use with a DVD for example) at 8Mbps and get a decent, but slightly softer quality 2nd gen file and occasionally encountering macroblock artifacts.
Then you go back and take the same uncompressed cam orignal, this time encode it to AVC (h264) at 4Mbps, and get a 2nd gen file that is 1/2 the size of the mpeg2 but is better quality, with less noticeable artifacts.
BECAUSE AVC/h264 is a more efficient codec.
The only downside is that AVC/h264 requires a better processor and has a bit more overal delay in processing than does MPEG2. But that was probably only an issue in the mid-2000s, and most computers and devices since then can easily handle both.
If however, you took the 2nd gen MPEG2 and made a 3rd gen AVC/h246 from it, even if you re-encoded to 8Mbps, your AVC/h264 file will be WORSE quality (though probably close) than the MPEG2, because as far as it is concerned, the MPEG2 (with its accompanying quality) IS the source for it. It would include the MPEG2's artifacts plus its own artifacts.


Scott

[DB83]

Doing a file size comparison of ALL the files is not going to tell you anything. You must compare one vob >> mpeg2 >> mkv.

And just how many files are there ? Vobs are typically .99 gb. So you could have in excess of 200 files there. A rough calculaton states the individual file size difference is 120 kb which is not much at all.


And the actual quality is NOT the same since even with these selections you are re-encoding a lossy format which loses actual quality. Makemkv from vob to mkv retains ALL the quality since no re-encoding is done.