Esegui 
Ho registrato per due volte dal digitale terrestre uno stesso film trasmesso prima da Italia1 e tempo dopo da Iris.
Entrambi i video sono identici cambia solo la grandezza, il primo 2,40Gb (video 2,23Gb-audio 119Mb), il secondo 1,82Gb (video 1,70Gb-audio 79,4Mb).
Messi a confronto questi due video in riproduzione sembrano qualitativamente identici, anche con il ferma immagine (stesso frame).
Ma allora perché hanno diversa grandezza, dove sta la differenza, eppure tolta la differenza audio ci sono quasi 600Mb di differenza video.
Per maggiori chiarimenti allego i files di Mediainfo relativi ai due video.
General
Complete name : D:\ITALIA1.mpg
Format : MPEG-PS
File size : 2.40 GiB
Duration : 1h 26mn
Overall bit rate mode : Variable
Overall bit rate : 3 955 Kbps
Video
ID : 224 (0xE0)
Format : MPEG Video
Format version : Version 2
Format profile : Main@Main
Format settings, BVOP : Yes
Format settings, Matrix : Custom
Format settings, GOP : Variable
Duration : 1h 26mn
Bit rate mode : Variable
Bit rate : 3 684 Kbps
Maximum bit rate : 15.0 Mbps
Width : 704 pixels
Height : 576 pixels
Display aspect ratio : 16:9
Frame rate : 25.000 fps
Standard : PAL
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.363
Stream size : 2.23 GiB (93%)
Audio
ID : 192 (0xC0)
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 2
Duration : 1h 26mn
Bit rate mode : Constant
Bit rate : 192 Kbps
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Compression mode : Lossy
Stream size : 119 MiB (5%)
General
Complete name : D:\IRIS.mpg
Format : MPEG-PS
File size : 1.82 GiB
Duration : 1h 26mn
Overall bit rate mode : Variable
Overall bit rate : 3 001 Kbps
Video
ID : 224 (0xE0)
Format : MPEG Video
Format version : Version 2
Format profile : Main@Main
Format settings, BVOP : Yes
Format settings, Matrix : Custom
Format settings, GOP : Variable
Duration : 1h 26mn
Bit rate mode : Variable
Bit rate : 2 813 Kbps
Maximum bit rate : 15.0 Mbps
Width : 704 pixels
Height : 576 pixels
Display aspect ratio : 16:9
Frame rate : 25.000 fps
Standard : PAL
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.277
Stream size : 1.70 GiB (94%)
Audio
ID : 192 (0xC0)
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 2
Duration : 1h 26mn
Bit rate mode : Constant
Bit rate : 128 Kbps
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Compression mode : Lossy
Stream size : 79.4 MiB (4%)
