Revision as of 20:50, 23 March 2006

This article is a stub. You can help the Hydrogenaudio Knowledgebase by expanding it.

This is a list of Frequently Asked Questions. The questions are grouped according to their categories, then sorted alphabetically.

Please note that this FAQ provides very short answers; explore the links to get deeper information.

General Audio Compression

Can I increase quality by converting a lossy compressed file to a higher-bitrate lossy compressed file?: Short Answer: This is called Transcoding, and the answer is no.

Does encoding preserves surround info?

Short Answer: MP3 destroys surround sound information.

In addition, check the following links:

Experience of a HA Member with Rear Channel on the HA Forums

What is the best audio format?: Short Answer: Depends on your needs.; For a detailed explanation, see Audio format guide.

Why do encoded files get clipped when the original WAVs are not clipped?

Short answer:

Quantization errors may cause the signal to clip, and
Gibbs phenomenon through the limitation of bandwidth may cause the signal to clip.

Check the following links for more details:

Explanation on ff123's site

What is an ABX blind test?

Go see ABX

In addition, check the following links:

Blind Listening Test Explanation on the HA Forums

What is "transparency"?: Go see transparency

Why not use graphs / frequency analysis to compare codecs?

Nothing can be said about quality or audible difference by looking at pictures, because a lossy encoder works by removing as much inaudible sounds as possible. A lack of frequencies can well mean that some audible parts are missing (bad work, or too low setting), or that the encoder managed a very good compression, removing a lot of useless things.

In addition, check the following links:

Lossy encoding
Lossless encoding
frequency analysis
Confusion on CBR & VBR thread on the HA Forums
... and this thread for a more sarcastic discussion.

MP3-related

Why is joint stereo better than pure stereo ?: You better start here (thread on the HA Forums)

Quality

Simple

What do I need to get started?
What is ABX?
Why is ABX needed?

Advanced

What are good test procedures?

This article is a stub. You can help the Hydrogenaudio Knowledgebase by expanding it.

@@ Line 1: / Line 1: @@
 {{stub}}
-This is a list of ''Frequently Asked Questions''. The questions are grouped according to their categories.
+This is a list of ''Frequently Asked Questions''. The questions are grouped according to their categories, then sorted alphabetically.
 Please note that this FAQ provides very short answers; explore the links to get deeper information.
@@ Line 7: / Line 7: @@
 =General Audio Compression=
+;Can I increase quality by converting a lossy compressed file to a higher-bitrate lossy compressed file?
+:'''Short Answer:''' This is called [[Transcoding]], and the answer is '''no'''.
@@ Line 13: / Line 17: @@
 :In addition, check the following links:
 :* [http://www.hydrogenaudio.org/forums/index.php?act=ST&f=15&t=4639 Experience of a HA Member with Rear Channel] on the HA Forums
+;What is the best audio format?
+:'''Short Answer:''' Depends on your needs.
+:For a detailed explanation, see [[Audio format guide]].
+;Why do encoded files get clipped when the original WAVs are not clipped?
+:'''Short answer:'''
+:#Quantization errors may cause the signal to clip, and
+:#Gibbs phenomenon through the limitation of bandwidth may cause the signal to clip.
+:Check the following links for more details:
+:* [http://ff123.net/norm.html Explanation on ff123's site]
@@ Line 21: / Line 38: @@
-;Why not use graphs to compare codecs?
+;What is "transparency"?
+:Go see [[transparency]]
+;Why not use graphs / frequency analysis to compare codecs?
 :Nothing can be said about quality or audible difference by looking at pictures, because a [[lossy]] encoder works by removing as much inaudible sounds as possible. A lack of frequencies can well mean that some audible parts are missing (bad work, or too low setting), or that the encoder managed a very good compression, removing a lot of useless things.
 :In addition, check the following links:
 :* [[lossy|Lossy]] encoding
 :* [[lossless|Lossless]] encoding
+:* [[frequency analysis]]
 :* [http://www.hydrogenaudio.org/forums/index.php?showtopic=7834&st=0&p=77265&#entry77265 Confusion on CBR & VBR thread] on the HA Forums
+:* ... and [http://www.hydrogenaudio.org/forums/index.php?showtopic=42646&hl= this thread] for a more sarcastic discussion.
@@ Line 41: / Line 64: @@
 * What do I need to get started?
-* What is transparency/cd-quality?
-* What are the best formats?
-* How do you tell what is the best format?
-: See [[Audio format guide]]
 * What is [[ABX]]?
 * Why is [[ABX]] needed?
-* [[Transcoding]] - Can I increase quality by converting X lossy compressed file to Y lossy compressed file?
 ==Advanced==
-* Can I use [[frequency analysis]] or other tools to judge quality?
 * What are good test procedures?
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