4 replies to this topic

[Sir Bors]

Hi to all I am back with a second question.  Actually I have wondered this for awhile and since
I was here I thought I would ask it.

Tried to do a search on this but could not come up with anything.

Why is a CD rewrite limited to 70 mins if you have less than 700 MB or data?  I recorded a speech and
it comes in at a lot less than 700 MB but is longer than 70 mins.  Even if I compress it down to a lower
quality why am I still limited by the time?

I am sure there is a reasonable answer to this.

Sincerely,
Sir Bors

[ogdens]

Sir Bors, on Sep 8 2006, 01:47 PM, said:

Hi to all I am back with a second question. Actually I have wondered this for awhile and since
I was here I thought I would ask it.

Tried to do a search on this but could not come up with anything.

Why is a CD rewrite limited to 70 mins if you have less than 700 MB or data? I recorded a speech and
it comes in at a lot less than 700 MB but is longer than 70 mins. Even if I compress it down to a lower
quality why am I still limited by the time?

I am sure there is a reasonable answer to this.

Sincerely,
Sir Bors

Try this, (third one down on Google)  

http://en.wikipedia....s_and_diameters

[Sir Bors]

Dear Digital Guru,

Thank-you for you reply.

I read the article you suggested.  Let me see if I understand it.

A CD player scans the CD at a rate of 1.2 to 1.4 m/s or constant linear velocity.  So that I am listening to the music, or in this case the speaker, as the CD is turning.  A basic stand alone CD player would not have the ability to store music.

So if it was not a audio file, but less say text files, I could then get up to 700 MB of storage.  But since I am putting audio files on it then the 80 min limit is used.

Am I correct?

Sincerely,
Sir Bors

[ogdens]

Sir Bors, on Sep 8 2006, 05:36 PM, said:

Dear Digital Guru,

Thank-you for you reply.

I read the article you suggested. Let me see if I understand it.

A CD player scans the CD at a rate of 1.2 to 1.4 m/s or constant linear velocity. So that I am listening to the music, or in this case the speaker, as the CD is turning. A basic stand alone CD player would not have the ability to store music.

So if it was not a audio file, but less say text files, I could then get up to 700 MB of storage. But since I am putting audio files on it then the 80 min limit is used.

Am I correct?

Sincerely,
Sir Bors

I don't have the time or the patience to answer, maybe another fellow user will jump in here (or not).

[james_hardin]

Sir Bors, on Sep 8 2006, 05:36 PM, said:

Dear Digital Guru,

Thank-you for you reply.

I read the article you suggested.  Let me see if I understand it.

A CD player scans the CD at a rate of 1.2 to 1.4 m/s or constant linear velocity.  So that I am listening to the music, or in this case the speaker, as the CD is turning.  A basic stand alone CD player would not have the ability to store music.

So if it was not a audio file, but less say text files, I could then get up to 700 MB of storage.  But since I am putting audio files on it then the 80 min limit is used.

Am I correct?

Sincerely,
Sir Bors

Mostly, Yes!

An Audio CD is written to Red Book standards and under those standards it is only going to hold a certain amount of time , 80 minutes on a 700mb CD.

Data is written (and read) with a different standard so 700mb is the available space.

An mp3 CD, is in reality a Data CD so you can save hours of audio on one provided the total capacity (700mb) is not exceeded. However it can only be played on a device that is capable of reading a Data CD. Most CD players don't have this capability.

In the end it is not the 'type' of files you put on it but the 'type' of project – Data or Audio.