No lossy codec is perfectly gapless, Here is the killer sample |
No lossy codec is perfectly gapless, Here is the killer sample |
Feb 1 2004, 20:42
Post
#1
|
|
|
Moderator Group: Super Moderator Posts: 3934 Joined: 29-September 01 Member No.: 73 |
I found a problem sample for gapless encoding. Whatever I do, there is an audible click between the tracks. I've analyzed its cause, and found that it comes from edge effects. The termination of the waveform far from zero causes ringing, that manifests itself as an audible click, even when the files are played gapless.
I saw the problem with MP3 and MusePack. MP3 : Lame 3.90.3 --alt-preset standard ; Foobar2000 disc writer MPC : Mppenc 1.14 --xlevel ; Mppdec You can get the file here : http://www.hydrogenaudio.org/forums/index....35&t=18207&st=0 Look at the attached picture to see the problem in the waveform. |
|
|
|
![]() |
Feb 2 2004, 13:32
Post
#2
|
|
|
Group: Members Posts: 60 Joined: 28-February 03 Member No.: 5236 |
I'll be very interested to see what you can come up with Pio. With the step file you've certainly devised what must be the severest test of mp3 encoding.
The screen shot of a perfect 'cut and shut' (glitch.jpg) that I posted clearly shows the artefacts, and is audible because of the unvarying background. In a normal music file this will still be present (as shown be looking at the delta file) but will be masked out by the music itself. This is distinct from the louder artefact that will be generated by imperfect silence detection and shown in the attatched 'imperfect.jpg'. Note the difference in scale ! UJ |
|
|
|
Pio2001 No lossy codec is perfectly gapless Feb 1 2004, 20:42
Case Amazingly Ogg Vorbis at -q5 seems to handle this j... Feb 1 2004, 21:05
AtaqueEG How do I decode?
Edit: Nevermind, I found foobar2... Feb 1 2004, 21:10
guruboolez I confirm: vorbis is OK. DualStream is perfectly g... Feb 1 2004, 21:15
guruboolez I've tried with WMA9 :
-standard encoder isn... Feb 1 2004, 21:34
Seed The click is evident with mppenc 1.14/1.15r until ... Feb 1 2004, 22:26
guruboolez Good point. --insane is working flawlessly on my s... Feb 1 2004, 22:38
Seed Since the problem exists with FAAC all the way unt... Feb 1 2004, 22:58
Seed One last observation: mppenc 1.95z67 fails at up t... Feb 1 2004, 23:46
Pio2001 Isn't the problem similar to encoding a ... Feb 2 2004, 00:48
hujay Added the following files to the uploads
silent1.... Feb 2 2004, 04:45
Shockwave Not to go off subject here Pio, but what proggy di... Feb 2 2004, 06:25
Pio2001 Thank you for the samples, Hujay, I'll check t... Feb 2 2004, 12:23
Pio2001 I didn't manage to process the samples like I ... Feb 2 2004, 19:48![]() ![]() |
|
Lo-Fi Version | Time is now: 26th May 2013 - 07:58 |