What bit rate is the actual CD-Quality?

[powerstone05]

I'm trying to figure out what is considered CD Quality when audio is ripped from an original CD. I think it's 384 Kbps for a compressed audio file but I'm not sure. Does someone know?

[celtic_druid]

Depends on your definition. I guess either lossless, whatever is transparent to you or whatever is transparent to a majority of people.

[cd090580]

True original audio quality is LPCM 44100 Hz 16 bits stereo for a bitrate of 1411 kbps

[powerstone05]

I mean lossless.

[FulciLives]

The audio on a normal CD is 16-bit 44.1Khz Stereo PCM audio. This is often called WAV when it comes to a computer although a WAV audio file can be a number of things (for instance it can be 48Khz instead of 44.1Khz).

MP3 uses a lot of compression but the higher the bitrate then the less the compression. I think the highest MP3 bitrate allowed is 320kbps then 256kbps then 224kbps then 192kbps etc.

In the "old" days when MP3 was new most people felt that 192kbps was CD like quality. Now people have come to realize that even 320kbps ... while sounding much better ... is still not CD like quality ... but people will argue that point as some feel it is "good enough".

I have noticed that some MP3 players (not computer based players but portables etc.) are unable to play back a MP3 that is recorded at 320kbps but seem to be OK if it is at 256kbps or lower.

There is a form of lossess compression called flac but I admit that I really do not know much about it.

- John "FulciLives" Coleman

[Shadarr]

I mean lossless.

cd090580 is right, that's the spec for a pressed AudioCD.

Any higher than that and you are just taking up space, so to speak. You wouldn't 'hear' any more than you would listening to the CD itself.

[powerstone05]

Yes. I know that. Normal MP3s can go up to 320 Kbps, but www.allofmp3.com says that an original sound recording "compressed" is 384 Kbps. I know that WAVs also have best quality but it's uncompressed (They Take up a ton of space, a 10 minute song takes up about 100 MB.)

[FulciLives]

Yes. I know that. Normal MP3s can go up to 320 Kbps, but www.allofmp3.com says that an original sound recording "compressed" is 384 Kbps. I know that WAVs also have best quality but it's uncompressed (They Take up a ton of space, a 10 minute song takes up about 100 MB.)

As I said FLAC is a form of lossless compression and according to the FLAC WEBSITE the compression ratio is close to 50% although in the example given it actually ended up being more like 48% smaller compared to the uncompressed WAV file. So really if the WAV is 100% then the FLAC file was 52% in size. Not exactly 50% compression but close to it.

True that is nowhere near as compressed in size as MP3 but then again it is still a damn good compression ratio for lossless compression.

- John "FulciLives" Coleman

[celtic_druid]

In most cases ~128k VBR is enough for mp3 to be transparent which since transparency means that you can't tell the difference is as I said depending on your definition CD quality, given a CD source. For lossless most formats (flac, wavpack, alac, wma lossless, etc.) are around 50%.

[FulciLives]

In most cases ~128k VBR is enough for mp3 to be transparent which since transparency means that you can't tell the difference is as I said depending on your definition CD quality, given a CD source. For lossless most formats (flac, wavpack, alac, wma lossless, etc.) are around 50%.

I would think that most people would agree that 192kbps is really the low end of being "CD quality" with 128kbps being unacceptable.

- John "FulciLives" Coleman

[MOVIEGEEK]

Transparent(or CD-Quality) is relative to the listener.I find MP3@192kbps to be the best median for sound quality and file size,WMA and AAC sound good at 128kbps.

[celtic_druid]

I am not talking CBR. I was talking about VBR with a bitrate ~128k. CBR is never a good idea. Take the VBR example. Could be better quality than the 192k CBR encode despite the lower average bitrate since VBR means that parts that require it get a higher bitrate. With 192k CBR everything is 192k even if 64k would be enough for some samples or if others require 320.

Try ABX'ing LAME with -V 4, if you can hear the difference, try -V 3, etc.

Have a look over at hydrogenaudio some time.

[MOVIEGEEK]

The problem with VBR is compatibility,some players(ie car stereos) and video encoders(eg TMPGEnc) have a problem with it.

[celtic_druid]

Any compliant decoder has to handle VBR. As for TMPGEnc, if you were planning on re-encoding then avoid mp3 altogether since it will only cause quality loss.