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Author Topic: Any official word on MC supporting new gapless playback on iPods?  (Read 2391 times)

lalittle

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Any official word on MC supporting new gapless playback on iPods?
« on: September 20, 2006, 06:15:45 pm »

Is there any official word from JR yet regarding the new "gapless playback" support in the new Apple iPod firmware?  Apparently, iTunes now does some extra processing where it "indexes" the files on the iPod.  At this time, it appears that the only way to achieve gapless support on the iPod using the native Apple firmware (i.e. not Rockbox) is to let iTunes do it's "indexing" on the files AFTER MC has synched the unit.  Unfortunately, this is a long process and early reports suggest that making any changes to the sync via MC results in the entire process having to be redone.

Is there any word on whether or not this is something that MC will be adding to it's iPod support (eliminating the need for "indexing" the files in iTunes) and, if so, when this might be implemented?

Thanks for any information on this,

Larry
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bob

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Re: Any official word on MC supporting new gapless playback on iPods?
« Reply #1 on: September 21, 2006, 10:02:30 am »

I read the following from seth on the pjb100-mp3 user group on yahoo (the pjb has been able to do gapless playback of mp3's using cue sheets for years). It came from a discussion of switching to the iPod now that it has gapless playback.

Quote
I purchased an 8GB iPod nano (the new one with the aluminum shell) and installed iTunes 7.  The short answer is that gapless play works in iTunes 7 and on the new iPod nano with my existing MP3 files.

More specifically, I have quite a library of MP3 files that I encoded using LAME VBR.  These files will play gapless using the Foobar2000 player in Windows.  (LAME includes information in the VBR header as to how much silence to trim from the start and end of the file to account for the coding delay and frame padding.  An enabled MP3 player that reads this section of the VBR header will play the files gapless.)

Until iTunes 7 and the most recent iPods (gen 5 video iPod and gen 2 nano) there were playback glitches at the track boundaries regardless of if you used LAME encoded files or files encoded natively within iTunes.  I have no idea how Apple accomplished the gapless playback but the new iPods apparently have a faster ARM CPU and a much larger SDRAM buffer (256MB vs 64MB) so I wouldn't hold your breath on firmware updates to make this work with older iPod models.

As anyone who has installed iTunes 7 knows, the new version of iTunes will scan through your music library to enable the gapless playback.
I have read that the MP3 files themselves are not touched.  What iTunes is likely doing is adding information to its internal database such that it is aware of the amount of silence at the start/end of each file in your music library.  This information is then transferred to the iPod such that the iPod knows the same.  The obvious advantage to this method is that it can be made to work with any type of audio (MP3, AAC, etc.) regardless of if there is a place within the file to store the gap info.

So it would appear if one could determine where and how in the itunesdb the information is stored it could be done. Of course it would require that your ripped mp3's already used a version of lame new enough to support the exact header info required for gapless playback. I know most all of mine are too old and would have to be re-ripped. Of course you would only have to re-rip the CD's that actually lack gaps and there aren't TOO many of them, right??
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hit_ny

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Re: Any official word on MC supporting new gapless playback on iPods?
« Reply #2 on: September 21, 2006, 11:57:53 am »

I read the following from seth on the pjb100-mp3 user group on yahoo (the pjb has been able to do gapless playback of mp3's using cue sheets for years).
How well does the pjb-100 play with MC ?

Do they still make them anymore, looks like the pjb-100 might be the only portable CUE player for a long time to come.
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lalittle

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Re: Any official word on MC supporting new gapless playback on iPods?
« Reply #3 on: September 21, 2006, 03:17:07 pm »

Of course it would require that your ripped mp3's already used a version of lame new enough to support the exact header info required for gapless playback. I know most all of mine are too old and would have to be re-ripped.

Bob -- Thanks for posting that information.

Don't be too sure that your files are "too old."  The LAME encoder has been including this information for quite some time now (a few years) so you may find that your files already have the gapless info in them.  I know that MC9 was already using a version of LAME that included this information, and this version is somewhere around three years old.

This aside, I'm unclear if the Apple method of achieving gapless playback requires this information in the file or not.  I honestly don't know if iTunes used an encoder that did this -- I didn't "think" that they used the LAME encoder.

Thanks again,

Larry
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Alex B

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Re: Any official word on MC supporting new gapless playback on iPods?
« Reply #4 on: September 21, 2006, 05:01:34 pm »

Quote
I know that MC9 was already using a version of LAME that included this information, and this version is somewhere around three years old.

By default LAME has written a LAME header with delay information since the v. 3.90.

MJ8 already used (and still uses) LAME 3.92 and wrote a LAME header unless a specific custom command line was used for disabling it.

These threads at HA have some information about Apple's new gapless system:

http://www.hydrogenaudio.org/forums/index.php?showtopic=48231
http://www.hydrogenaudio.org/forums/index.php?showtopic=48253
http://www.hydrogenaudio.org/forums/index.php?showtopic=48593
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hit_ny

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Re: Any official word on MC supporting new gapless playback on iPods?
« Reply #5 on: September 22, 2006, 11:38:26 am »

MJ8 already used (and still uses) LAME 3.92 and wrote a LAME header unless a specific custom command line was used for disabling it.
Yeah, but MC only started to care about those fields from 11.1 onwards, as in being able to gaplessly parse tracks with them. I'm still unsure whether iTunes or the iPod actually use these headers.

From what i can tell about iTunes/iPods new gapless, is that it is no better than the regular gapless play MC has always had.
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SwellGuy

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Re: Any official word on MC supporting new gapless playback on iPods?
« Reply #6 on: September 22, 2006, 11:55:37 am »

Gapless playback will be in the next build of MC 12.
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glynor

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Re: Any official word on MC supporting new gapless playback on iPods?
« Reply #7 on: September 22, 2006, 11:59:27 am »

* glynor shakes his head...

You guys are amazing sometimes.  Apple touts it as a fancy new feature, which (by implication) took months of hard work by dedicated code warriors chained to their desks.

JRiver responds in, what... A week?  Two?   8)
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lalittle

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Re: Any official word on MC supporting new gapless playback on iPods?
« Reply #8 on: September 22, 2006, 02:19:15 pm »

Gapless playback will be in the next build of MC 12.

Fantastic.

Thanks,

Larry
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bob

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Re: Any official word on MC supporting new gapless playback on iPods?
« Reply #9 on: September 22, 2006, 02:58:41 pm »

How well does the pjb-100 play with MC ?

Do they still make them anymore, looks like the pjb-100 might be the only portable CUE player for a long time to come.

Ummmh, not at all with current versions unforch.. I think MJ8 was the last version that worked. They're no longer being made. Nice piece of hardware though. The insides are very elegant and the battery life is fantastic given the size of the battery. Up to 15 hrs. Hackers have put up to 100 g drives on them and the interface is really nice, all one level, easy to understand. Quite slow USB 1 interface. It literally takes a day to load one with 20 gigs.
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