Compression

[mh505]

Could someone explain to me how it is possible to deliver the same quality in compressing a file to 2.9GB or 7,9GB.

On my 24" monitor at 1920x1080 I can see no difference whatever between the 2 versions (see below). What is the secret? What SW delivers this kind of quality and at what configuration?

Appreciate your thoughts



Version I: 2.84GB; MP4 Container

VIDEO:
Bitrate : 3,848 Kbps
Codec ID : MPEG-4/H.264/AVC
Resolution : 1920 x 1040
Aspect Ratio : 16:9 (DAR)
Frame Rate : 23.976 fps
Quality Frame : 0.069

Audio:
Codec ID : mp4a/AAC-LC
Bitrate : 448 kbps CBR,90 kbps CBR
Channel(s) : 5.1 Channel Surround,2 Channel Stereo
Sample Rate : 48.0 KHZ

~~~~~~~~~~

Version II: 7.94GB; MKV Container
VIDEO:
Bitrate : 2,470 Kbps
Codec ID : H.264/AVC
Resolution : 1920 x 1040
Aspect Ratio : 16:9 (DAR)
Frame Rate : 23.976 fps
Quality Frame : NA

Audio:
Codec ID : DTS
Bitrate : 1,536 kbps CBR
Channel(s) : 5.1 Channel Surround,2 Channel Stereo
Sample Rate : 48.0 KHZ

[Atak_Snajpera]

video bitrate is higher in first file

[QBhd]

The Second has DTS audio

[amtm]

But the dts track does not take up 5gigs at 1536kbps. Even if the movie was three hours long the difference in the size of the two audio tracks would only be ~1.5 gigs. That doesn't explain the 5gig less size.

[kypec]

I doubt those details belong to two versions of same source material length. Why is there nowhere duration of video clips mentioned? I'm pretty sure OP will eventually find out that smaller file contain 45 minutes of video whereas bigger file contain 120 minutes of video.

[amtm]

At those bitrates the smaller file would be ~94 mins while the second would have to be ~275 mins. There is clearly something wrong.

[Asmodian]

It looks like there must be a duration difference in this example based on the bitrate but if a video is already transparent more bits won't change perceived quality. I usually cannot tell the difference between a crf 16 and crf 10 encode but crf 10 is much larger.

[LoRd_MuldeR]

Could someone explain to me how it is possible to deliver the same quality in compressing a file to 2.9GB or 7,9GB.

On my 24" monitor at 1920x1080 I can see no difference whatever between the 2 versions (see below). What is the secret? What SW delivers this kind of quality and at what configuration?

Appreciate your thoughts

(1) A more efficient/sophisticated encoder will be able to retain the same level of quality at a much lower (average) bitrate, compared to a poor encoder.

(2) If some encoder can retain "transparent" quality at a certain bitrate, then cranking up the bitrate even further won't improve the subjective quality - but increase the file size!

(3) How did you obtain/create the two versions? You should know the 'software & configuration' that was used to create those files. Or ask the creator...

[Groucho2004]

What SW delivers this kind of quality and at what configuration?

Why don't you ask the person who encoded the file?

Edit: Mulder beat me to it. :D

[amtm]

(1) A more efficient/sophisticated encoder will be able to retain the same level of quality at a much lower (average) bitrate, compared to a poor encoder.

(2) If some encoder can retain "transparent" quality at a certain bitrate, then cranking up the bitrate even further won't improve the subjective quality - but increase the file size.

These would be true but he then goes on to claim that the smaller one has a higher bitrate. So it's either a typo or second movie is 3 times as long in duration.

[LoRd_MuldeR]

Well, higher average bitrate and smaller file size at the same duration, of course, is impossible. Higher peak bitrate still is possible at a smaller file size though.

(Also the program that was used to "calculate" the bitrate from the encoded file may simply be wrong)

[mh505]

Thanks much for your interest and rapid response. Here are some answers:

Length
Both files have the same length: 93:59 min

Creator
I don't know who created those files

There are no typos as far as I can tell.

Let me restate the question then. Is there a consensus as to what is the best encoding / compression SW out there. I don't care if it's open source or 3rd party and will be happy to spend the money should I come across a SW that can deliver this kind of quality at less than half the file-size

[Atak_Snajpera]

x264.

[Groucho2004]

I don't know who created those files
Is there a consensus as to what is the best encoding / compression SW out there.
You might want to check out the forum rules #6 and #12.

[LoRd_MuldeR]

Creator
I don't know who created those files

~closed for rule #6~