Rockbox Technical Forums

Rockbox General => Rockbox General Discussion => Topic started by: thefrazzle on June 10, 2006, 02:19:25 AM

Title: how do I get gapless playback on self-made ripped CD comps?
Post by: thefrazzle on June 10, 2006, 02:19:25 AM
installed rockbox as instructed - seems to be working OK (I'm assuming I don't have to 'activate a gapless playback feature'). have many self-made audio CD comps burned on Nero and ripped to X5 using dMC audio CD input. CDs play seamlessly (lots of crossfading) on DVD player but still gaps on X5.
will I have to reburn my comps using different software to enable gapless playback on X5?
Title: Re: how do I get gapless playback on self-made ripped CD comps?
Post by: Febs on June 10, 2006, 07:18:27 AM
Have you tried using Rockbox's crossfade feature?

What format are these files on your player?  If they're in MP3, they will only be gapless if encoded with LAME 3.90.1 or later. 
Title: Re: how do I get gapless playback on self-made ripped CD comps?
Post by: thefrazzle on June 10, 2006, 10:58:31 PM
They are MP3s burned to audio CD (as an audio CD not MP3 disc) then ripped as MP3s (keeping same track order as audio CD) to the X5. dBpower AMP is release 11 which uses Lame 3.96.1 encoder to rip CDs to MP3 format.
Title: Re: how do I get gapless playback on self-made ripped CD comps?
Post by: Xpander on June 11, 2006, 01:50:28 AM
Well there you go.  MP3s are not designed to be gapless.  OGG Vorbis, on the other hand, is.

Try playing around with crossfade before you go re-converting everything.
Title: Re: how do I get gapless playback on self-made ripped CD comps?
Post by: Febs on June 11, 2006, 04:59:22 AM
While this is true, MP3s ripped with LAME 3.96.1 should play back gaplessly (or very, very close to gaplessly) in Rockbox. 

I agree with the previous poster though.  Why go through the hassle of burning the MP3s to CD and then re-ripping (which degrades the quality of the MP3) when you can achieve the same result using the crossfade feature and a playlist?
Title: Re: how do I get gapless playback on self-made ripped CD comps?
Post by: saratoga on June 11, 2006, 03:57:26 PM
Well there you go.  MP3s are not designed to be gapless.  OGG Vorbis, on the other hand, is.


Who cares what its designed for when LAME is in fact gapless?

OP:  Try playing the songs in foobar or other gapless mp3 player.  Do they have gaps?
Title: Re: how do I get gapless playback on self-made ripped CD comps?
Post by: Xpander on June 12, 2006, 09:13:45 PM

Who cares what its designed for when LAME is in fact gapless?

OP:  Try playing the songs in foobar or other gapless mp3 player.  Do they have gaps?

Um, no.  LAME is not in fact gapless.  LAME CAN be gapless.  But not, for instance, if the info tag isn't written.

Which might explain your issue, Frazzle.  Check out this thread.

http://forum.dbpoweramp.com/showthread.php?t=5863

The gap issue was inherent in DMC r11 for both ripped MP3s and burned mp3 CDs (if you used Nero to burn your CDs, that might explain why you've never run into the problem in the past).  Later releases of DMC corrects the mp3 CD but the info tag writing problem wasn't mention in the version changes.

I think you might be able to "fix" your MP3s using a foobar plugin.  This info might be on Hydrogenaudio somewhere; I'll go check later if I have some time.
Title: Re: how do I get gapless playback on self-made ripped CD comps?
Post by: saratoga on June 12, 2006, 10:27:19 PM

Um, no.  LAME is not in fact gapless. 

Trivially easy to disprove.  I'm listening to a gapless LAME file right now.

Quote
LAME CAN be gapless. 

You just said its not.  Either it is, or it isn't.

Quote
But not, for instance, if the info tag isn't written.

And vorbis isn't gapless if I insert gaps.  Why are you posting this?  To show that you know about LAME? 
Title: Re: how do I get gapless playback on self-made ripped CD comps?
Post by: Xpander on June 13, 2006, 12:46:24 AM
And vorbis isn't gapless if I insert gaps.  Why are you posting this?  To show that you know about LAME? 

Oh I'm sorry, it's not necesessarily gapless.  Why are you posting this, to show that you know how to nitpick over semantics?  ::)

Yes, I'm showing off my wealth of knowledge of technology.  OR, I could have been looking around for a possible solution for the OP while you've successfully done jack.  Way to demonstrate how to not pick a fight over the internet.  What are you, 12?

Kindly stop addressing me, thanks.
Title: Re: how do I get gapless playback on self-made ripped CD comps?
Post by: Febs on June 13, 2006, 06:00:26 AM
And vorbis isn't gapless if I insert gaps.  Why are you posting this?  To show that you know about LAME?
Vorbis is inherently gapless.  MP3 is NOT inherently gapless.  MP3s cannot play gaplessly unless (1) you use the LAME encoder to encode them, and (2) you have a player that knows how to read the header information that LAME inserts, which allows the player to skip the gaps that are inherent in the MP3 format.
Title: Re: how do I get gapless playback on self-made ripped CD comps?
Post by: MU4L on June 13, 2006, 07:53:18 AM
And vorbis isn't gapless if I insert gaps.  Why are you posting this?  To show that you know about LAME?
Vorbis is inherently gapless.  MP3 is NOT inherently gapless.  MP3s cannot play gaplessly unless (1) you use the LAME encoder to encode them, and (2) you have a player that knows how to read the header information that LAME inserts, which allows the player to skip the gaps that are inherent in the MP3 format.

And the winner is ... Febs!


 :P



EDIT: What bitrate were the MP3's that were burned to the CD in the first place?
Title: Re: how do I get gapless playback on self-made ripped CD comps?
Post by: thefrazzle on June 14, 2006, 07:56:41 PM
Thanks for all the advice;

Why go through the hassle of burning the MP3s to CD and then re-ripping (which degrades the quality of the MP3) when you can achieve the same result using the crossfade feature and a playlist?

Burning with Nero, say, allows me to edit, fade-in / out as well as crossfade.
Also, how will the quality be degraded?
Title: Re: how do I get gapless playback on self-made ripped CD comps?
Post by: markun on June 17, 2006, 04:59:22 AM
Also, how will the quality be degraded?

Read the part about lossy compression.

http://en.wikipedia.org/wiki/Generation_loss#Techniques_that_bring_back_generation_loss_in_digital_systems

Title: Re: how do I get gapless playback on self-made ripped CD comps?
Post by: Chronon on June 30, 2006, 05:37:24 PM
I'm going to hazzard a guess here.  It seems to me that the gaps come in when the mp3s are converted to AudioCD.  All of the header information is probably lost then.  If it only plays well through your DVD player with crossfade on then it sounds like gaps have been introduced.

Now when you take this CD and re-rip it with LAME you may not get any extra gaps but you 'might' have gaps that were picked up by the first conversion... plus, as someone said, the quality will be degraded from the original mp3.

I'm no expert in this.  Does anyone know what happens when you do this:
LAME mp3 --> AudioCD (WAV?) --> LAME mp3 ?
Title: Re: how do I get gapless playback on self-made ripped CD comps?
Post by: Febs on June 30, 2006, 06:15:12 PM
I'm no expert in this.  Does anyone know what happens when you do this:
LAME mp3 --> AudioCD (WAV?) --> LAME mp3 ?
You get an MP3 that is of lower quality than the first generation MP3.
Title: Re: how do I get gapless playback on self-made ripped CD comps?
Post by: Chronon on July 03, 2006, 08:40:44 PM
Yeah, I know that.   ::)

I guess I should have been more clear.  I was guessing that the LAME header for the mp3 would not be translated over to WAV and 'might' lead to gaps. . . But I suppose it depends on what mp3 decoder you use and whether it sends a gapless un-compressed bitstream to the CD burner (which should probably be the case most of the time).  I was just trying to think through whether this process would preserve gaplessness.
Title: Re: how do I get gapless playback on self-made ripped CD comps?
Post by: jhMikeS on July 06, 2006, 10:56:24 PM
There are problems with the LAME gapless and do not know if it extends to all platforms. Even though I use LAME 3.96.1 with the --nogap switch to encode a full CD from WAV, there are often still audible clicks (very short and quiet) between tracks which if everything were working correctly shouldn't be there. The WAVs play correctly without clicks, can be stitched together without the clicks, and the length in samples of each mod 588 is zero.

One album where this is quite noticeable is Steve Miller / Fly Like an Eagle since the audio volume is uniform across the track boundaries. OGG doesn't have that problem either but I feel everything should work as it should.

I can't currently place this in the bug reports of course.  >:(