audio format for playing audio cd

Audacity Help Forum Windows
1

I have been given conflicting info on what formats will play on an audio CD player.

I’m a non-technical volunteer broadcaster on community radio. I was using mp3 on flash drives to play music on my radio shows, using the flash outlets on the audio CD players. I learned about how much quality loss there was in conversions by the time my audio got on the air, so I started putting music files into WAV in Audacity. But WAV files cannot be played from flash dirves by the CD players, so I was advised to burn the files to CDs so they will play . Now someone else has told me WAV will not play on audio CD. Is this so? What would be the best workable lossless format to use for my purposes?

Another problem has been that files burned to CD will not read out the titles, even though I title the tracks that I burn. It only numbers the tracks. Is there any way around this?

If I can’t use WAV, I won’t have time to start over before my next show tomorrow. So if I need to go back to mp3 for the time being, is there more loss if I convert my present WAV files to mp3 (which were converted directly from the original mp3 to WAV), rather than get the original mp3 files again?

2

An audio CD is an audio CD. An audio CD player plays audio CD’s, not WAV or anything else, even though the format of the CD stream is similar to WAV.

Burn WAV files to the audio CD, not MP3.

If you have a flash drive, look at its manual for supported formats.

Use CD-Text if you want to see the song titles in the CD player: http://en.wikipedia.org/wiki/CD-Text . This only works if the CD burning software and the CD drive support it.


Gale

3

Thank you. If I were at all astute, I wouldn’t need to ask. But are you saying that if I burn the WAV files to a CD on the audio setting, the music should play on a regular CD player? Does the CD burner automatically convert the file from WAV to something else, and to what?

Just for my understanding, which results in more loss: converting an mp3 to WAV and back to mp3, or editing and saving the original mp3?

Another case of conflicting advise: Does saving an mp3 file at a higher kbps rate than the original cause distortion?

I need to ask because I mostly need to start from mp3s, so I’m trying to understand what happens with various conversions.

4

Your radio station should have an engineer or technician to help you with this stuff…

What kind of recording system does the station normally use to play pre-recorded “spots” or PSA’s?


Thank you. If I were at all astute, I wouldn’t need to ask. But are you saying that if I burn the WAV files to a CD on the audio setting, the music should play on a regular CD player? Does the CD burner automatically convert the file from WAV to something else, and to what?

An audio CD has the same basic underlying PCM format as WAV. A 16-bit, 44.1klHz, stereo WAV file can be copied losslessly back-and-forth between audio CD and WAV.

Just for my understanding, which results in more loss: converting an mp3 to WAV and back to mp3, or editing and saving the original mp3?

When you edit an MP3 in Audacity (or any regular audio editor) it has to be decompressed. If you re-save as MP3, you are going through a 2nd lossy compression step. (There are special-purpose MP3 editors such as mp3directCut that can do some limited editing without decompressing.)

Another case of conflicting advise: Does saving an mp3 file at a higher kbps rate than the original cause distortion?

No. It’s probably “safest” to use a higher bitrate. There is (theoretical) damage done every time you compress. It’s not quite this simple, but basically at higher bitrates you have bigger files because less data is being “thrown” away. (BTW - AAC was designed to have minimal damage from re-compression.)

I have been given conflicting info on what formats will play on an audio CD player.

As Gale says, CD is a very specific format. However, some CD players in cars can play MP3 or WMA etc., and most DVD players can play various formats in addition to regular CDs and DVDs (most DVD players can play MP3). A USB port for a flash drive on a CD player is something special and you have to check the owner’s manual.

I’m a non-technical volunteer broadcaster on community radio. I was using mp3 on flash drives to play music on my radio shows, using the flash outlets on the audio CD players. I learned about how much quality loss there was in conversions by the time my audio got on the air

High quality (high bitrate) MP3 can sound identical to the uncompressed original, although “best practice” is to use a lossless source. For Internet radio the audio is likely to go through further lossy-compression, and it’s best to minimize the number of times the audio is lossy-compressed.

There are lossless compression formats such as FLAC & ALAC that can easily be tagged (with artist/album/title/artwork), but these formats are not as widely supported as WAV/MP3/AAC, and you’d need a format your radio station can easily play.

But WAV files cannot be played from flash dirves by the CD players, so I was advised to burn the files to CDs so they will play.

If the CD player can play MP3s, from a flash drive, I’m surprised it can’t play WAV. But, you’ll have to check the owner’s manual.

Another problem has been that files burned to CD will not read out the titles

If you play a CD on a computer, the player software usually takes a “fingerprint” of the CD and goes online to find the album/artist/title/artwork. Of course, if you have a homemade CD it will not be in the CDDB or Gracenote databases. (CD-TEXT is not universal.)

5

Are you suggesting someone on this Forum is giving you incorrect advice?

If you burn as a “music CD” or an “audio CD” then the CD should play on a regular CD player or on a computer.

If you burn as a “data CD” then the CD will only play on a computer.

Consult the help of your CD burning software if you are not sure of the setting needed to burn an audio CD.

The audio on a CD is not a file, but a stream of lossless 16-bit 44100 Hz stereo PCM data. See: http://en.wikipedia.org/wiki/Compact_Disc_Digital_Audio .

Both are the same loss - one extra MP3 encoding (assuming you encode the MP3 at the same bit rate or quality).

High bit rate MP3’s are close enough to lossless that the average listener cannot tell the difference. But if you repeatedly re-encode an MP3 even at high bit rate or quality, the audio will suffer. This is because exporting MP3 is always lossy, whatever the bit rate or quality.

It causes quality loss, but less loss than if you chose a lower bit rate.

Export the MP3 from Audacity as WAV, then burn to audio CD. Then there is only the loss in the original MP3.


Gale

6

Thank you for these detailed answers, they clear up a lot for me. To answer questions and remarks:

“Are you suggesting someone on this Forum is giving you incorrect advice?” No. I was told various things by other people.

“Your radio station should have an engineer or technician to help you with this stuff…” We are a very low budget community station, some staff is part time, and we volunteers commonly go in only once a week, or even once a month. The operations director is on vacation. The engineer is rarely around, I’ve never met him.

“What kind of recording system does the station normally use to play pre-recorded “spots” or PSA’s?” They are programmed on the station computer to be run at given times by the on-air operators who push a button on the board.

"If the CD player can play MP3s, from a flash drive, I’m surprised it can’t play WAV. " From a flash drive, the player won’t even read the existence of any content in WAV.

7

I don’t think anybody actually hit this yet.

You use an CD Authoring Program such as iTunes or Windows Media to convert a WAV file onto an Audio CD with zero loss or damage (unless you drop it afterwards or the dog gets to it). This is the Audio CD which will play in your mum’s Buick and almost anywhere else — certainly any stand-alone music CD player. It’s the one that has a maximum length of about 78 minutes and doesn’t naturally carry song titles. It’s the one Garth Brooks puts his music on.

If you don’t use a CD Authoring Program or you select the wrong CD type when you burn, then you could end up with a Data CD that has a WAV file burned on it. That is not a standard Audio CD and will not play in your mum’s Buick. An Audio CD is a specific thing.

A Data CD is the way to burn an MP3 or anything else onto the disk. A Data CD is a flat, shiny hard drive. You could put Photoshop files on there if you want.

You can tell a CD Authoring Program to burn an Audio CD from an MP3 rather than a WAV file, but that gives you a very high quality Audio CD with MP3 damaged music on it.

The solution to needing an MP3 show on a thumb drive is to create the MP3 at the highest possible quality. I think that’s Stereo 320 in Audacity. MP3 sound damage should be very slightly higher than the original MP3 music. The damage never goes away. If you go this recommended route, you should try a short, off-air test show to make sure the station can play it.

Next down the convenience rabbit hole is a series of Audio CDs that you made from an Audacity WAV Export. The quality is slightly higher, but the convenience kind of sucks. I got a nice 100 count CD stack from Costco. I used to use plastic cases, but I “graduated” to paper.

Down at the bottom of the stack is convincing management to let you deliver in a high quality, convenient format, and then find out what that format is.

Koz

8

Thanks. Yes, I see it is a balancing act, benefit, convenience, etc. I will see how the CDs go.

Is there a particular program you’d recommend for putting a text listing on a CD?

9

Is there a particular program you’d recommend for putting a text listing on a CD?

Your player (or player software if you are using a computer) has to support it to…

[u]This guide[/u] says you can do it with [u]ImgBurn[/u]. (I use ImgBurn to burn CDs, but I’ve never made a CD with CD text.)

10

Is there a particular program you’d recommend for putting a text listing on a CD?

You left out a word. In addition to the music or in place of the music? Any Data CD will carry a text file. Again, they’re little shiny hard drives.

Strict, compatible Audio CDs will not carry song titles or anything but the music.

Use CD-Text if you want to see the song titles in the CD player: > http://en.wikipedia.org/wiki/CD-Text > . This only works if the CD burning software and the CD drive support it.

iTunes has an option for CD Text. The attached is a screen capture showing that option in the burn dialog as well as the other options. You can get iTunes for Windows.

It’s Very Highly Recommended that you try one of these disks on the equipment you plan to use before you commit a show to it.

Koz
Screen Shot 2014-05-05 at 7.55.19 PM.png

11

“Strict, compatible Audio CDs will not carry song titles or anything but the music.”

I don’t understand this point. How is it that commercial CDs have track lists that normally read out on the player’s screen? What do they use?

12

It depends on the CD and the player.
A few years ago Sony had thousands of CDs sent back because they would not play in car CD players. They were non-standard CDs. Not all commercial CDs keep to the “Red book standard”.

Commercial CDs all carry an id. Some computer CD players use that to look up the track details in a database.

Some CDs may contain CD Text, but that is not Red book standard: http://en.wikipedia.org/wiki/Compact_Disc_Digital_Audio#Standard

13

Of course you could drag the MP3 tracks you want to play on to an Ipad or HD Fire and play via the headphone socket into the Radio Desk. Instant start being available via the Pause / Play on tablet.

14

Of course you could drag the MP3 tracks you want to play on to an Ipad or HD Fire and play via the headphone socket into the Radio Desk. Instant start being available via the Pause / Play on tablet.

All true, but the station doesn’t typically bring out connections like that. They’re hidden behind the mixing desk and a good way to not have a show any more is to get caught messing with cables back there.

Management has instructed that the only two ways to get into the desk are a “real” Audio CD via a broadcast CD player and the thumb drive socket associated with it. The thumb drive socket will not accept WAV.

That and the show started out MP3 music at the beginning of production. Making a new MP3 for delivery will double the compression distortion and the goal is to avoid that distortion.

Koz