5/11/2024

Windows XP Mode on Win7 with VirtualBox

 Windows XP Mode was a freely activated copy of Windows XP from 2001 that ran on Windows 7 Pro and Win 7 Ultimate in the old Connectix Virtual PC. Microsoft acquired Connectix Virtual PC and made it into a a standalone installation package which had to be installed separately from an installer that contained a Windows VHD image of a Windows XP machine called Windows XP Mode.

Windows XP Mode did not need to be activated online, since it relied upon a new version of Activation called OEM BIOS Locking.

The Microsoft Virtual PC software has a form of virtual BIOS which contains the activation key for Windows XP Mode, so after installation was complete within the Virtual PC instance it would autoactivate, or already be activated.

VirtualBox is a slightly more advanced virtual machine kit which comes from Oracle, but also runs on many Windows, Linux and MacOSX and MacOS platforms.

VirtualBox also has a way of loading a BIOS image if dumped from a running systems memory using a tool like SLIC Toolkit. By modifying the dumped image and adjusting the Virtual Machine Settings using the VBoxmanage.exe tool to load it.. the Windows XP Mode image can be loaded into Virtualbox on not only Windows, but Linux, MacOSX and MacOS.. 

The Windows XP Mode VHD must be converted first however using the VBoxmanage tool to clonehd the image and export it as format VDI.

The placement of the BIOS activation string within the modified BIOS dump also moves around slightly from VBox 4.0 to 5.1-5.22 to 6.0 by a single or more bytes. The BIOS is compiled differently for each version of VBox. This technique is known to work on those versions, but the latest version is 7.0 and it is not known if it can still be made to work on that version.

VirtualBox is also know for supporting USB pass thru and offers a more robust long term way of supporting XP SP3 as activated on more varied and modern os platforms in the current year.

3/11/2024

DV 4:1:1 and 320x240 NTSC Video Capture

Sampling 720 x 480 over an actual 320x240 full color picture.

320 x 2 = 640

240 x 2 =480

640 x 480 : 720 x 480 is over fit more than 2:1

Color Alone 160 x 120 : 720 x 480 is over fit more than 4:1

 

(sencore)

320x240 : 160x120 = Luma: Chroma

4:1 from 720 x 480 is a Perfect fit for full color capture

NTSC is field based so has more horizontal than vertical information per unit of time

"mixing" fields to "simulate" Progressive images is incorrect, artifacting is inevitable

DV is frame based storage it "does" compress the interlaced video into progressive frames.

4:1:1 more properly captures 100 percent of the Luma, Chroma and Temporal resolution without distortion

Even if capturing a theoretical 400 or 500 TVL, 720x480 is still over sampling and the increased resolution is in the Luma dimension, not the Chroma, bandwidth allocation is fixed.

 

(sencore)

720 x 480 DV 4:1:1 is still more than enough to capture everything available 

The shape of the pixels captured for an NTSC signal are appropriate for the dimensions of the signal information available and skew more towards the horizontal dimension where there is more information.

The shape of the pixels captured for an ATSC signal are appropriate for the dimensions of the signal information available and skew more towards the vertical dimension to encompass the change in format from interlaced to progressive.

4:1:1 DV is appropriate for 4:3 Aspect and 720x480 digital capture

4:2:0 HDV is appropriate for 16:9 Aspect and 1280 x 720 digital capture

in plain simple language, DV video is appropriate for NTSC 4:3 video capture

in plain simple language HDV video is appropriate for NTSC 16:9 video capture

there is a "Reason" why these standards were developed, they are "overfit" for their purpose


While "live" Broadcast can in theory exceed what can be stored on Video tape in many cases, most of that available on VHS never stored the maximum available and it is already lost.

1/07/2024

Using M4B Audiobook files in Windows 7

Apple basically came up with the MPEG-4 container format MP4 but also came up with the M4B to host audiobooks in AAC format with Artwork and tags of information about the books.

Windows supports M4A format files with basically most of the same functions for storing AAC and Artwork and tags of information, but do not contain the ability to store Chapters or a Bookmark as in an M4B file format.

Within Apple the iTunes program properly handles M4B format and exposes Chapter navigation and stores the last played position as a bookmark.

On Windows the iTunes for Windows program does much the same thing.

However probably the best M4B file format "viewer" or audiobook playback is found with VLC - Video Lan Client 2.2.6 "Umbrella"

In VLC its possible to navigate the chapter marks on the playback timeline as they show up as short vertical grey lines across the bottom of the timeline.

The Playback menu has a complete Chapter menu for jumping specifically to any chapter.

And Custom Bookmarks can be created and written to the M4B file and then referred to so that Playback could jump to a specific Custom Bookmark.



VLC has an xml based Playlist system and a concept for a Media Library that deviates a little from Apple iTunes and Windows Media Player.

First there is the "Media Library" Playlist, disabled by default. It is a special xml playlist stored in the folder with other user interface configuration options; 

Example:

C:\Users\jwillis\AppData\Roaming\vlc\ml.xspf

It gets created by turning on the feature under;

Tools> Preferences >"Show Settings -  [x] All 

Then traveling down to branch [+] Playlist and checking > Use media library

The ml.xspf file gets populated by one of two ways:

1. right clicking with a mouse in the main window and selecting + files or +folders

2. by drag and dropping files or folders on the main window

Then shutting down the VLC client and restarting it will have automatically saved those choices in the ml.xspf file and reload them in the > "Media Library" branch of the [Media Library]

note: VLC will continue to default to loading nothing and focus there on start up, you have to click on the Media Library / Media Library in order to see that it saved your previous media choices.

You can default the Playlist under Media Library / Playlist to refer to a personal xml format .xspf file, but it will not open it.. unless you set the "Default stream" option under:

Tools> Preferences >"Show Settings -  [x] All 

Then traveling down to branch [+] Playlist and filling out "Default stream [ ________ ]

With a specially formatted  "Reverse slash" path prefixed with a file: operator like this -

file:///C:/Users/jwillis/AppData/Roaming/vlc/ml.xspf

And checkboxes that include "Auto start"

But that will also immediately start playing the Playlist.

If you do not it will offer you the choice to open the xspf file to list the choices, but it will not by default display the contents unless clicked upon.

Using the other method with Media Library is frankly closer to what you would expect, you just have to remember to travel to the folder under Playlist to see the most recently saved collection of media.