Large size difference in mov and mpg, no apparent loss of quality.

[prioryjim]

Hello
I have a High Def ( Cheap ) camcorder

It produces files .MOV
I have a file about 60 seconds long which is 162 Meg
Vlc codec info for the MOV shows
Resolution 1440x1080
Frame Rate 29.9

Now I convert to mpg using "SUPER"
And the size drops to 14.8 Meg
Vlc codec info for the mpg shows
Resolution 1440x1080
Frame Rate 29.9

Any I don't think I can tell the difference in quality !
Why the large difference in file sizes ?
Does the mpg actually lose and quality ?
Thanks Jim

[guns1inger]

Use MediaInfo to look at the original bitrate and the new bitrate to see the difference. Yes, there will be a quality hit with a reduction of that size. How noticeable it will be depends on the content of the video, the screen you are viewing it on, the player you are using, and the state of your eyes.

[prioryjim]

Details below, how would I get a convention where the quality is the same ?

General
Complete name : C:\Users\jiml\Pictures\AmblesideDec2009\jim.MPG
Format : MPEG-PS
File size : 14.5 MiB
Duration : 1mn 19s
Overall bit rate : 1 527 Kbps

Video
ID : 224 (0xE0)
Format : MPEG Video
Format version : Version 2
Format profile : Main@High 1440
Format settings, BVOP : No
Format settings, Matrix : Default
Duration : 1mn 19s
Bit rate mode : Variable
Bit rate : 1 242 Kbps
Width : 1 440 pixels
Height : 1 080 pixels
Display aspect ratio : 4:3
Frame rate : 29.970 fps
Resolution : 8 bits
Colorimetry : 4:2:0
Scan type : Progressive
Bits/(Pixel*Frame) : 0.027
Stream size : 11.8 MiB (81%)

Audio
ID : 192 (0xC0)
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 2
Duration : 1mn 19s
Bit rate mode : Constant
Bit rate : 224 Kbps
Channel(s) : 2 channels
Sampling rate : 44.1 KHz
Stream size : 2.12 MiB (15%)

Menu


General
Complete name : C:\Users\jiml\Pictures\AmblesideDec2009\FILE0029.M OV
Format : MPEG-4
Format profile : QuickTime
Codec ID : qt
File size : 158 MiB
Duration : 1mn 19s
Overall bit rate : 16.7 Mbps
Encoded date : UTC 2009-12-11 13:39:09
Tagged date : UTC 2009-12-11 13:39:09
AMBA :



Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 1mn 19s
Bit rate mode : Variable
Bit rate : 0
Maximum bit rate : 0
Width : 1 440 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 29.970 fps
Stream size : 157 MiB (99%)
Title : Ambarella AVC / Ambarella AVC
Language : English
Encoded date : UTC 2009-12-11 13:39:09
Tagged date : UTC 2009-12-11 13:39:09

Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format version : Version 4
Format profile : LC
Format settings, SBR : No
Codec ID : 40
Duration : 1mn 19s
Bit rate mode : Constant
Bit rate : 128 Kbps
Channel(s) : 2 channels
Channel positions : L R
Sampling rate : 48.0 KHz
Resolution : 16 bits
Stream size : 1.21 MiB (1%)
Title : Ambarella AAC / Ambarella AAC
Language : English
Encoded date : UTC 2009-12-11 13:39:09
Tagged date : UTC 2009-12-11 13:39:09

[jagabo]

Why the large difference in file sizes ?

Different codecs have different compression abilities.

Does the mpg actually lose and quality ?

Each compression with lossy codecs reduces quality. The losses may not be very visible if you use sufficient bitrate (ie, don't over compress).