I wanted to test the differences in the quality settings of the MythTV DVD import function. So I did a little test importing the same home movie at the different quality settings, comparing each resulting file using the GSPOT codec information tool. Here are the results.

Test Tools

GSPOT v2.52b01 exporting results to files
DVD Home Movie with AC3 6Ch audio, movie runtime 2:16hr
MythDVD import tool configured with default settings of XviD codec

The variances from the Excellent, Good, and Normal were in File Size, Frame Height/Width, Video Bitrate, and Frame Quality. Perfect was encoded with a diffrent codec. Obviously File sizes could be reduced even further if AC3 6Ch audio was not required. Time was NOT recorded although Perfect was about 15minutes, while the other quality settings were 2-3 hours on my XP1800.

Results

Perfect Quality
--- File Information ---
File Name: MY_HOMEMOVIE_perfect.vob
File Name (with full path): Y:\video\MY_HOMEMOVIE_perfect.vob
File Size (in bytes): 7,148,457,984

--- Container Information ---
Base Type (e.g "AVI"): MPEG (.MPG/.MPEG/.VOB)
Subtype (e.g "OpenDML"):
Audio alignment("split across interleaves"):
Total System Bitrate (kbps): 10080
Bytes Missing (if any):
Number of Audio Streams: 4

--- Video Information ---
Video Codec Type(e.g. "DIV3"): MPEG2_Video
Video Codec Name(e.g. "DivX 3, Low-Motion"): MPEG-2
Video Codec Status(e.g. "Codec Is Installed"): Codec(s) are NOT Installed
Duration (hh:mm:ss): 05:21:33
Frame Count: 578203
Frame Width (pixels): 720
Frame Height (pixels): 480
Pixel Aspect Ratio ("SAR"):
Display Aspect Ratio ("DAR"): 1.778
Pics Per Second: 23.976
Frames Per Second: 29.970
Fields Per Second: 59.939
Video Bitrate (kbps): 9800
Frame Quality bit/pixel-frame 0.946
MPEG-4 ("MPEG-4" or ""):
B-VOP ("B-VOP" or ""):
QPel ("QPel" or ""):
GMC ("GMC" or ""):
H264 ("H264" or ""):

MPEG-2 ("MPEG-2" or ""): MPEG-2
Interlaced ("I/L" or ""): I/L
Progressive ("Prog" or ""):
Top Frame First ("TFF" or ""):
Bottom Frame First ("BFF" or ""):
3:2 Pulldown ("3:2" or ""): 3:2
Picture-per-field ("PPF" or ""):

- Aspect Ratio Related:

Broadcast standard: "PAL" (else blank)
Broadcast standard: "NTSC" (else blank) NTSC
src:"VCD", "SVCD", "CVD", or "DVD (else blank): DVD

--- Audio Information ---
MPEG Stream ID (e.g. "0xbd"): 0xbd
MPEG VOB file Substream(e.g. "0x80"): 0x80
Audio Codec (e.g. "AC3"): AC3
Audio Codec Status (e.g. "Codec Is Installed"): Codec(s) are Installed
Audio Sample Rate (Hz): 48000
Audio Bitrate(kbps): 448
Audio Bitrate Type ("CBR" or "VBR"): CBR
Audio Channel Count (e.g. "2" for stereo): 5

Excellent Quality

--- File Information ---
File Name: MY_HOMEMOVIE_excellent.avi
File Name (with full path): Y:\video\MY_HOMEMOVIE_excellent.avi
File Size (in bytes): 2,307,761,324

--- Container Information ---
Base Type (e.g "AVI"): AVI(.AVI)
Subtype (e.g "OpenDML"): OpenDML (AVI v2.0),
Audio alignment("split across interleaves"): Aligned
Total System Bitrate (kbps): 0
Bytes Missing (if any): 0
Number of Audio Streams: 1

--- Video Information ---
Video Codec Type(e.g. "DIV3"): XVID
Video Codec Name(e.g. "DivX 3, Low-Motion"): XviD
Video Codec Status(e.g. "Codec Is Installed"): Codec(s) are Installed
Duration (hh:mm:ss): 02:16:10
Frame Count: 195891
Frame Width (pixels): 720
Frame Height (pixels): 480
Pixel Aspect Ratio ("SAR"):
Display Aspect Ratio ("DAR"): 1.500
Pics Per Second: 23.976
Frames Per Second: 23.976
Fields Per Second:
Video Bitrate (kbps): 1806
Frame Quality bit/pixel-frame 0.218
MPEG-4 ("MPEG-4" or ""): MPEG-4
B-VOP ("B-VOP" or ""): B-VOP
QPel ("QPel" or ""):
GMC ("GMC" or ""):
H264 ("H264" or ""):

MPEG-2 ("MPEG-2" or ""):
Interlaced ("I/L" or ""):
Progressive ("Prog" or ""):
Top Frame First ("TFF" or ""):
Bottom Frame First ("BFF" or ""):
3:2 Pulldown ("3:2" or ""):
Picture-per-field ("PPF" or ""):

- Aspect Ratio Related:

Broadcast standard: "PAL" (else blank)
Broadcast standard: "NTSC" (else blank)
src:"VCD", "SVCD", "CVD", or "DVD (else blank):

--- Audio Information ---
MPEG Stream ID (e.g. "0xbd"):
MPEG VOB file Substream(e.g. "0x80"):
Audio Codec (e.g. "AC3"): 0x2000(AC3, Dolby Laboratories, Inc) AC3
Audio Codec Status (e.g. "Codec Is Installed"): Codec(s) are Installed
Audio Sample Rate (Hz): 48000
Audio Bitrate(kbps): 448
Audio Bitrate Type ("CBR" or "VBR"): CBR
Audio Channel Count (e.g. "2" for stereo): 5

Good Quality

--- File Information ---
File Name: MY_HOMEMOVIE_good.avi
File Name (with full path): Y:\video\MY_HOMEMOVIE_good.avi
File Size (in bytes): 2,080,614,686

--- Container Information ---
Base Type (e.g "AVI"): AVI(.AVI)
Subtype (e.g "OpenDML"): OpenDML (AVI v2.0),
Audio alignment("split across interleaves"): Aligned
Total System Bitrate (kbps): 0
Bytes Missing (if any): 0
Number of Audio Streams: 1

--- Video Information ---
Video Codec Type(e.g. "DIV3"): XVID
Video Codec Name(e.g. "DivX 3, Low-Motion"): XviD
Video Codec Status(e.g. "Codec Is Installed"): Codec(s) are Installed
Duration (hh:mm:ss): 02:16:10
Frame Count: 195891
Frame Width (pixels): 704
Frame Height (pixels): 480
Pixel Aspect Ratio ("SAR"):
Display Aspect Ratio ("DAR"): 1.467
Pics Per Second: 23.976
Frames Per Second: 23.976
Fields Per Second:
Video Bitrate (kbps): 1583
Frame Quality bit/pixel-frame 0.195
MPEG-4 ("MPEG-4" or ""): MPEG-4
B-VOP ("B-VOP" or ""): B-VOP
QPel ("QPel" or ""):
GMC ("GMC" or ""):
H264 ("H264" or ""):

MPEG-2 ("MPEG-2" or ""):
Interlaced ("I/L" or ""):
Progressive ("Prog" or ""):
Top Frame First ("TFF" or ""):
Bottom Frame First ("BFF" or ""):
3:2 Pulldown ("3:2" or ""):
Picture-per-field ("PPF" or ""):

- Aspect Ratio Related:

Broadcast standard: "PAL" (else blank)
Broadcast standard: "NTSC" (else blank)
src:"VCD", "SVCD", "CVD", or "DVD (else blank):

--- Audio Information ---
MPEG Stream ID (e.g. "0xbd"):
MPEG VOB file Substream(e.g. "0x80"):
Audio Codec (e.g. "AC3"): 0x2000(AC3, Dolby Laboratories, Inc) AC3
Audio Codec Status (e.g. "Codec Is Installed"): Codec(s) are Installed
Audio Sample Rate (Hz): 48000
Audio Bitrate(kbps): 448
Audio Bitrate Type ("CBR" or "VBR"): CBR
Audio Channel Count (e.g. "2" for stereo): 5

Normal Quality

--- File Information ---
File Name: MY_HOMEMOVIE_normal.avi
File Name (with full path): Y:\video\MY_HOMEMOVIE_normal.avi
File Size (in bytes): 1,515,929,246

--- Container Information ---
Base Type (e.g "AVI"): AVI(.AVI)
Subtype (e.g "OpenDML"): AVI v1.0,
Audio alignment("split across interleaves"): Aligned
Total System Bitrate (kbps): 0
Bytes Missing (if any): 0
Number of Audio Streams: 1

--- Video Information ---
Video Codec Type(e.g. "DIV3"): XVID
Video Codec Name(e.g. "DivX 3, Low-Motion"): XviD
Video Codec Status(e.g. "Codec Is Installed"): Codec(s) are Installed
Duration (hh:mm:ss): 02:16:10
Frame Count: 195891
Frame Width (pixels): 544
Frame Height (pixels): 320
Pixel Aspect Ratio ("SAR"):
Display Aspect Ratio ("DAR"): 1.700
Pics Per Second: 23.976
Frames Per Second: 23.976
Fields Per Second:
Video Bitrate (kbps): 1030
Frame Quality bit/pixel-frame 0.247
MPEG-4 ("MPEG-4" or ""): MPEG-4
B-VOP ("B-VOP" or ""): B-VOP
QPel ("QPel" or ""):
GMC ("GMC" or ""):
H264 ("H264" or ""):

MPEG-2 ("MPEG-2" or ""):
Interlaced ("I/L" or ""):
Progressive ("Prog" or ""):
Top Frame First ("TFF" or ""):
Bottom Frame First ("BFF" or ""):
3:2 Pulldown ("3:2" or ""):
Picture-per-field ("PPF" or ""):

- Aspect Ratio Related:

Broadcast standard: "PAL" (else blank)
Broadcast standard: "NTSC" (else blank)
src:"VCD", "SVCD", "CVD", or "DVD (else blank):

--- Audio Information ---
MPEG Stream ID (e.g. "0xbd"):
MPEG VOB file Substream(e.g. "0x80"):
Audio Codec (e.g. "AC3"): 0x2000(AC3, Dolby Laboratories, Inc) AC3
Audio Codec Status (e.g. "Codec Is Installed"): Codec(s) are Installed
Audio Sample Rate (Hz): 48000
Audio Bitrate(kbps): 448
Audio Bitrate Type ("CBR" or "VBR"): CBR
Audio Channel Count (e.g. "2" for stereo): 5