2. TOPICS Why would you want to burn a CD or DVD?
What does it mean to ‘digitize’?
What and why are there various formats?
What hardware do I need?
What media do I need?
What software do I need?
Demonstrations

3. Why would you want to create a CD or DVD disk?
Backup/Archive data onto an (almost) physically indestructible media. It will be read-only.
Copy information to media compatible with some other playback device (such as your car’s audio system.)
Copy to relatively inexpensive media to give to someone where you don’t expect to get it back.

4. Digital data files (documents, etc.)
In this session I intend to describe how to create (“burn”) a CD or DVD containing:
Digital data files (documents, etc.)
Digital audio files from various sources such as CDs, LPs, tapes, microphone, web, etc.
Digital image files from camera, smartphone, scanner, web, etc.
and if time permits, copying digital video files *.
* Creating video disks, rather than copying, will be deferred to a possible future session on making videos.

5. First, let’s describe the CD and DVD media.
It is 120mm in diameter (about 4.75”) and consists of a ‘sandwich’ of two layers of polycarbonate, a strong, clear, brittle plastic. Between these layers the data is represented by spots which represent the 0’s or 1’s which encode the written data.
For commercially mass-produced CDs and DVDs, the data layer is a microscopically thick layer of aluminum foil that has pits mechanically pressed into the foil!
For ‘burned’ CDs and DVDs there is an organic dye that is burned by a laser beam and thus discolored.

6. The data is recorded in concentric and addressable tracks (unlike the spiral groove of a phonograph record.)
The first track is closest to the hub (center) of the disk. This permits the creation of ‘mini-CDs’ which may even be rectangular, the size of a business card. I have a few such mini-CDs, they contained driver software.
The data is on the un-printed UNDERSIDE of the media.
The data is read by sensing reflections of a laser beam, the light emitter and sensor are accurately positioned under the track.

7. A bit of CD history… Phillips invented the audio cassette.
Sony invented the “Walkman” portable cassette player.
Cassettes, while popular, still had problems – jamming, unwinding, breaking, lack of true random addressing capability, lack of dynamic range, hiss, print-through, easily erased accidently, etc.
Sony and Phillips joined forces to create an optical media, the compact disk, known as the “CD”.

8. The Phillips manufacturing plant was set up to make 100mm disks, which could have held 60 minutes of audio. The Sony project leader, inventor of the Walkman, advocated 120mm as that could support 74 minutes – the time needed for a full performance of Beethoven’s 9th Symphony (“Choral”).
Sony marketing prevailed.
Quite fittingly, the first CD made in the United States for commercial release was Bruce Springsteen's 1984 album, "Born in the U.S.A." But it wasn't the first commercially available CD ever. That title belongs to Billy Joel's "52nd Street," which was released on CD in Japan in 1982.

9. We need to take a few minutes to discuss the difference between ANALOG and DIGITAL recording.
Edison’s phonograph (invented 1877, first marketed 1888) used a needle attached to a diaphragm to scratch a groove in a tin-foil coated cylinder. The magnitude (strength) and frequency of the vibration ‘mimicked’ the sound source, and is referred to as being an analog recording.
A similar arrangement of a needle travelling along the groove caused a diaphragm to vibrate, producing sound for playback.
The ‘gramophone’ using flat disks appeared around 1902.

10. COMMON ANALOG DEVICES
There are many analog devices in use today. They all make use of some mechanism which can sense an input and convert it to a recordable form.
Recording Barometer: A pressure sensor produces a voltage which moves pens which write to a slowly rotating paper disk od drum.
Seismometer: Earthquakes produce seismic waves which travel through the earth’s mantle. A seismic wave can produce a measurable ripple in a container of water in a deep well. These wave forms may be used to determine the strength of the quake, and by comparing arrival times at multiple sensors scattered around the world, it is possible to accurately identify the location of the quake by triangulation.

11. Polygraph: Measures heart, respiration, blood pressure, skin conductivity etc. A trained analyst can correlate these involuntary reactions to the stress level of the person being examined – the ‘lie detector’.
Anemometer: Measures wind speed.
Speedometer: Indicates speed of a vehicle.
Volt/Ohm Meter: Measures electric voltage, resistance, amperage
Thermometer: Indicates thermal activity.
Dashboard Fuel Gauge: Indicates the level of fuel in your tank. (Not known for accuracy!)

12. Some “back of the envelope” calculations…
33-1/3 RPM for 20 minutes/side -> 667 revolutions.
6 inch radius outer groove, 2 inch radius inner groove.
4” recording space/667 = 0.006” between adjacent grooves of the spiral.
At the outer groove the distance the stylus travels in one revolution is 2 pi R or 37.7”.
That works out to about 2.25”/second at the outer rim.
Here is a wave form for a pure tone.
If ‘A above middle C’, there would be 440 of these cycles per second.
(2.25 inch/second) / (440 cycles/second) = inch/cycle.

13. DIGITIZING
No matter what we are putting on the CD (or DVD) it must ultimately be a digital format – just 0’s and 1’s.
The trick is to get our material into digital format.
Since the first CDs were audio, I will start there.

14. Voltage
Here is a 10-second lesson from Physics 101 – Electricity and Magnetism.
If you move a magnetic field relative to a coil of wire, an electric current or voltage will be generated proportional to the strength of the field and the rate of movement.
So here we have a device which converts mechanical motion – the ‘stylus’ riding over bumps - producing an electric current. This is the principle behind the cartridge in a phonograph record. Of course in practice the movement is side-to-side, but that’s hard to illustrate.

15. MONOPHONIC STEREOPHONIC
In a monophonic cartridge the coil is constrained so it can only move side-to-side. The current is proportional to how far the coil moves.
In a stereo cartridge there are two coils, each is perpendicular to its corresponding ‘wall’ of the groove. Thus two separate output signals are generated – the left and right channels of a stereo signal.

16. +3.0 volts
65,535
For audio, the millivolts generated by the cartridge are processed by a pre-amp circuit to a range of +/- 3 volts. It is then converted to a number – digitized – in the range of 0 to 65,535.
0.0 volts
-3.0 volts
Remember our A above middle-C tone, where one cycle took seconds? When sound waves are digitized they are sampled 44,000 times per second. So there should be 100 samples (vertical bars) in my diagram. To make it visible I had to reduce it to about 70. The number of samples is sufficient to allow for accurate reconstruction of the analog wave form for playback.

17. Here is a screen shot of an excellent, cross-platform (Windows/Mac/Linux) open-source (i.e. free) digital recording program – AUDACITY.
The spectrograph displays the wave form for about 1 second of recording.
65,534 (very loud)
32,767 (mid-point - silent)
0 (equally very loud)
Click to hear it.

18. On the previous slide Audacity displayed about 48,000 samples – all scrunched together. Here I have enlarged a 0.06 second section of the clip, and it shows the waveform created by about 2,680 samples.
The sound card sensed the voltage generated by the microphone, amplified it, and then Audacity sampled the chip’s output voltages, converted them to a stream of digital values and ultimately saved it to disk.
It doesn’t matter if the source is an LP, a tape, an audio stream, a microphone, or another CD – ultimately the sound is recorded as a stream of digital values.

19. TEXT FILE H e l l o e v e r y o n e .
Other types of data
TEXT FILE
I created a little text file with “Hello everyone.” in it. The file extension is .TXT so by convention a program that knows how text is represented should be used. The most common encoding in western countries is ASCII. I then used a programmer’s utility to display the contents of the file as numeric values. It uses the HEX (base 16) notation. Instead of the digits 0 to 9, it uses 0 to 9 plus A through F for values 10 through 15.
H e l l o e v e r y o n e .
c 6c 6f f e

20. IMAGE FILE
I created a 16 pixel by 16 pixel image and filled it with pure RED.
Its format is BMP - ‘bit map pixels’ the simplest image format.
Here it is, enlarged:
Again, using a programmer’s HEX editor I then displayed the contents as numbers. After a few bytes that specify the dimensions (16 x 16 pixels) it repeats 256 instances of the triplet FF, 0, 0.
FF is ‘hex’ for 255 in decimal, and means ‘maximum RED’. The zero values are how much GREEN and BLUE light should be mixed in, i.e. NONE. By using 3 8-bit bytes for RGB, we can differentiate between 32,000+ distinct colors.

21. So now we have a stream of numbers that represent our music, or, as I just hinted, a document or still image. Trust me, a video is ultimately converted to digits as well.
How can we play/view it? It all depends upon the capabilities of the playback/viewing device. So let’s examine some.

22. AUDIO playback
There are two categories of playback devices. The simplest only understand wave files where there is a digital value for each sample. These devices are “dumb” in that no processing takes place other than converting the digital value to an analog wave form to be sent to the speakers. Each sample is represented, and the CD typically has no more than 74 minutes of content.
Examples of such devices are:
Tape-based: Cassette player, Walkman, 8-track player, boombox, etc.
Optical CD/DVD: Early players that can only handle commercial recordings or home-burned CDs that use the .CDA format. Example would be a boombox, or a car system that just has the simplest controls (i.e. no LCD screen)

23. Audio playback
“Smart” Devices: If a device has more than a basic processor, it can decode a compressed audio file. The most common compression format for audio is .MP3.
A CD which has compressed audio files will not play in a ‘dumb’ device.
If a device has an on-screen menu capability there is a good chance that it can handle an optical disk containing MP3 encoded audio.
MP3 files are typically used in computers, tablets, smartphones, MP3 players (such as iPod) etc. They are also popular for streaming, such as internet radio, YouTube, Spotify etc..
A CD that has MP3 files put on it can typically hold 10 times the number of minutes compared to a standard audio CD.

24. So what is .MP3? It is an encoding mechanism that is able to greatly reduce the amount of data that is stored on the media. There are many different types of encoders, each of which has a ‘Codec’ – software to COde or DECode the data.
The easiest example of compression is one commonly used for image files, so I am going to very briefly return to IMAGE files to illustrate compression.
So here is JPEG (Joint Photo Experts Group) – also known as .JPG.

25. A typical smartphone or tablet has at least a 6 mega-pixel camera – 6 million pixels. Each pixel requires 3 bytes (values 0 to 255) to record how much RED, GREEN, and BLUE is needed to define the color of that pixel. There are 32,767 possible combinations. (There’s that number again!) So a 6MP camera needs to have 18MB of internal space to hold the image as it comes out of the sensor. A processor chip in the camera will then do some compression as it saves the image to the memory card. If your camera supports “RAW mode” you may elect to store the data exactly as seen by the sensor.
The next slide illustrates one of the compression mechanisms used for digital images.

27. VIDEO COMPRESSION
Video files make use of “MPEG” (Motion Picture Experts Group.) At a varying frequency depending upon how active the image is, a “base image” of the entire screen is stored. Then about 30 times per second (frame rate) the software detects what has changed from the previous frame. It calculates a box around the change and saves the location, dimension, and contents of the change. Some things, such as a change of view or panning, force a complete replacement of the base frame.
For example, at a football game the camera may be at the 50-yard line and looking at a play near the end zone. During a one second interval, it need not re-draw most of the field, the fans in the stands, etc. It just needs to recognize the movement of the players. It must also ‘re-paint’ portions of the base image to replace the vacated area. In the pre-MPG4 days this sometimes would result in a ‘comet tail’ for a thrown football.

28. What Hardware do I need?
The original CD (Compact Disk) standard was developed in 1980 and became relatively common in computers about A CD can hold about 640 MB of data. The original drives were rated as to how fast they could read data into memory, or write (burn) data from memory to the media. “1X” is the speed needed to stream .WAV/.CDA audio without pauses. The original drives for computers were rated 4X for reading, and 1X for burning. The media was similarly rated. Current drives are in the neighborhood of 52X for reading and perhaps 12X for writing.
The original CD drives in computers were usually read-only, consumer burner drives came later.

29. DVD
The Digital Versatile Disk (DVD) was developed in 1995 and has made CDs somewhat obsolete. Current DVD drives are fully compatible with CDs for all operations. So if you have a CD drive already and are good with 640MB, fine. Otherwise get a DVD writer.
The standard capacity is 4.7GB, more than 7 times that of a CD. Originally DVD drives were read-only. Within a few years DVD R/W drives became available and were fully compatible with CD media in all modes, thus making CD-only drive hardware obsolete.
USB “flash drives” have replaced optical drives (CD and DVD) usage in many cases. If your computer does not have an optical drive it is not hard to add a drive to a desktop machine’s empty bay. Alternatively, or for a notebook machine, an external DVD drive with a USB interface may be found, typically for under $30. The club has such a drive which you may ‘sign-out’ for short-term loan. See Hugh Ward.

30. CD-R standard recordable, now 700MB capacity
Optical Media Types
CD-R standard recordable, now 700MB capacity
Staples brand pack $14.29
Staples 50 pack $ pack $35.99
DVD-R standard recordable, 4.7GB capacity
Staples brand 50 pack $21.09
Staples 50 pack $ pack $24.99
MicroCenter pack $18.99
Older DVD players differentiated between DVD+R and DVD-R recordings. I have not seen any such devices for years, so I don’t care which type of media I purchase.
In the pre-Windows XP days there were CD-R/W (re-writable) drives and media. Multi-Session capability has obsoleted the need for CD-R/W.

31. SESSION
Originally, when a CD was created (“burned”) it was required that it all be done in one continuous operation. The last task in creating the CD was to “CLOSE” it, writing the directory information. From then on the contents could not be modified – no add, change, or delete. Thus closing the CD defined the end of a ‘session’ and a single session was the only thing that a ‘dumb’ player could work with.
Commercial audio CDs are by definition single-session CDs.

32. MULTI-SESSION
Microsoft included support for the creation of of multi-session CDs in Windows XP but did not reveal it to the end users. A multi-session CD creates the equivalent of a volume for each collection of files written, each with its own directory. When read by a player, the newest directory is processed first, thus a newer copy is found and used, making the older copy unreachable. Thus files may be added, and if a file is changed only the newest is retrieved. The space consumed by the older copy is not reclaimable. An entry for a deleted file is created with a flag, making the deleted file unavailable.
Typical Windows burning programs still do not support multi-session. However it did show up in Windows 7 but was hard to use. Windows 10 now makes it easy to use.

33. MULTI-SESSION SUPPORT
Windows 10 – built into File Manager – I will demonstrate it.
Mac OS-X – became available in How to do it is explained in
several user forums.
Linux – the free, open-source utility program BRASERO supports multi-session.
Multi-session support made the need for the more costly CD RW (Re-writable) media unnecessary.

34. BOOTABLE
When a computer powers up it examines the devices for partitions that have the “ACTIVE” bit turned ON. The sequence is controlled by the computer’s ROM BIOS Setup utility on a motherboard chip. The typical search sequence is floppy drive, USB device (flash drive, external hard disk, etc.), optical drive and hard drive. Most burning software does not support creating a partition and marking it as active.
Microsoft now distributes a free utility – Media Creation Tool – which will download an image of Windows 10 and then create a bootable DVD, or a bootable USB flash drive, or an .ISO file which may then be used to create the bootable DVD or flash drive at a later time. This is now Microsoft’s standard method for distributing the baseline operating system.

35. .ISO FILE
An .ISO file is an ‘image’ file, it contains the entire contents of a CD or DVD, including the partition table and boot tracks if they exist. Think of an .ISO file as being a container. Application programs cannot read or modify the contents of an .ISO file. However there are specialized programs that know how to either create the image from component files, or given the image, how to use it to ‘burn’ a CD or DVD including the partition table and boot tracks.
The most common usage of an .ISO file is to deliver a copy of a CD or DVD via the internet. This was and is the standard mechanism for distributing software products. It is used by Linux and now Windows. It is probably also used by Apple for distributing OS-X.

36. DEMONSTRATIONS
The rest of the lecture will be to describe and/or demonstrate the various techniques used for creating an optical disk. The process is called ‘burning’ because a laser beam is used to burn a layer of an organic dye within the disk media.

37. Burn an AUDIO CD for a ‘dumb’ player using Windows 10’s Media Player
Since it is unlikely that any of you will need to do this, I will just describe it.
There are two ways to launch Windows Media Player
Click “Start” menu and find Windows Media Player, or
Type WMP in “Search for Files/Folders” adjacent to the “Start” button.
Insert a blank CD into your computer.
Switch to media list and click “Burn” on the tab.
Add the songs you want to copy by dragging them into the burn list. Repeat as needed.
Click the “Burn option” and choose Audio CD.
If your audio files are MP3 format, WMP will convert them to CDA on the CD.

38. Create a MULTI-SESSION CD or DVD
This method uses the FILE MANAGER that is part of WINDOWS 10
Launch FILE MANAGER (previously EXPLORER.)
Navigate to the optical drive. On many machines it is D: or E:. If you don’t know, expand “This PC” and look at the device list. If you know the drive letter, just type it into the “Quick Access” bar, including the colon character.
You will be prompted to insert a blank CD or DVD into the drive tray.
Once the media is in the drive, you will see this dialog box.
Select “Like a USB flash drive” and click NEXT.
It will take a few seconds for the CD or DVD to be initialized.

39. At this point, Windows File Manager will have one FILE MANAGER window open.
Navigate to where some of the files that you want to place on the CD/DVD reside.
Click FILE then OPEN NEW WINDOW
You will now have two windows open to the same location.
Resize and move them so that they are next to each other and each take up about half of the screen.
Select one of them and type the drive letter and colon in the Quick Access bar. (I did this in the left window on next slide.)
Your screen should now look much like the next slide.

40. Drag and Drop files/folders here to put copies on the CD/DVD.

41. As soon as you ‘drop’ a group of files or folders into the CD/DVD’s folder your optical drive will spin and write them to the disk.
You will get a progress bar (as on the right) as the files are copied.
You may create a folder structure on the CD/DVD and drop files into the folder(s) if you want.
Point to any location on the computer or network using the other copy of Windows File Manager and copy them to the CD/DVD folder.

42. When you have finished, find the optical drive in the left window pane of the window associated with the CD/DVD.
Right-click on the drive and select CLOSE SESSION.
When that completes, right-click again and select EJECT.
You may now remove the CD/DVD.
Mark the media, indicating that it is multi-session enabled.
If you want to add to it, just repeat the process but use this CD/DVD instead of a blank.

43. MULTI-SESSION SUPPORT
WINDOWS – As mentioned, it has been in Windows since XP, but was not generally visible until Windows 7. Many commercial and freeware burning programs ignore it, including my favorite ImgBurn (next slides.)
MAC OS-X - A search using Google shows forum posts describing how to do it in release I don’t have a Mac, so I won’t attempt to provide instructions here.
LINUX – The free/open-source utility BRASERO supports multi-session. There may be others, but BRASERO is the one mentioned most often in the user support forums. I have used it in the Ubuntu distribution of Linux.

44. ImgBurn
ImgBurn is a popular freeware program for creating .ISO files, burning them to optical disk, copying disks (non-copy protected) and burning regular CDs/DVDs from regular files. As noted, it does NOT support multi-session.
Write an image file (.ISO) to disc.
Write Files/Folders to disc.
Create an image file(.ISO) from disc.
Create image file (.ISO) from Files/Folders.
Verify disc.
Discover hardware and capabilities.

45. Obtaining ImgBurn
ImgBurn is one of the most popular free downloads out there. That’s good news and bad news. The good news is that it is powerful. The bad news is that it is commonly distributed in ‘packages’ which may include parasites. The packages often are disguised as ‘Downloaders” or “Installers” and said to include a ‘scanner’ or ‘tune-up’ component.
Some anti-virus packages alert on ImgBurn – because someone installed using a package and think the problem is ImgBurn, not the ‘crapware’ that was packaged with it.
If you do want ImgBurn then here is how to get it safely.

46. Go to the publisher’s site: https://imgburn. com/index. php/
Then click on the link to his file server and download the setup program.

47. Demonstrations of ImgBurn