Problem gapless play after m4a to flag conversion

[jo-wie]

I've buyed a complete CD in iTunes (plus format DRM free) and I'm able to play it gapless in iTunes, I can copy the m4a files to my Squeezecenter library on my Linux box and they stream gapless transcoded on the fly by faad, I can use foobar2000 on my Win XP machine and play the m4a files gapless. My Squeezebox and foobar are able to stream other flac files gapless.

Now do I convert the m4a files with dMC to flac (compression 5, Release 12 - 1.2.1) and the files do not fit together (slight difference in position and volume) when I play them gapless on foobar2000 or Squeezebox. Do dbpoweramp have a problem with the conversion or did I miss some settings?

As a work around did I burn a CD from iTunes and ripped it with dbPowerampi to flag - gapless play do work.

Why do I convert them to flag? Because I cannot ff or rw the transcoded stream on the Squeezebox and MusicIP is running headless on my Linux Squeezecenter box and Linux MIP cannot analyse ACC.

[jo-wie]

Re: Problem gapless play after m4a to flag conversion

Ups, just found that I can update flac to version 13. Will do and try again.

[jo-wie]

Re: Problem gapless play after m4a to flag conversion

Same problem with flac version 13.

[Spoon]

Re: Problem gapless play after m4a to flag conversion

You m4a are Apple Lossless or aac?

[jo-wie]

Re: Problem gapless play after m4a to flag conversion

Files are AAC. Is it possible to buy loseless in the iTunes shop?

[Spoon]

Re: Problem gapless play after m4a to flag conversion

No it is not possible. AAC will add a very slight delay (200 to 2000 samples maximum) so should not really be audible. What is the length of a m4a file shown in foobar? and the length of the FLAC file (converted by dbpoweramp) again shown in foobar.

[jo-wie]

Re: Problem gapless play after m4a to flag conversion

Two examples from

The Alan Parsons Project
Tales of Mystery and Imagination - Edgar Allan Poe

The Fall of the House of Usher: Prelude
flac 7:02.534 (18633728 samples)
aac 7:02.493 (18631956 samples)

The Fall of the House of Usher: Arrival
flac 2:39.684 (7042048 samples)
aac 2:39.640 (7040124 samples)

The differerence is noticeable.

Thank you Spoon for your support, it's not critical for me but others could have more files to convert and should know that gapless play can be an issue. I thought that it would be better with iTunes when DRM is not a matter anymore - I'm wrong. :(

[Spoon]

Re: Problem gapless play after m4a to flag conversion

Our reading of m4a aac is not gapless, hence the extra 1800 samples.

[moley6knipe]

Re: Problem gapless play after m4a to flag conversion

Paranoia alert! The Apple Lossless m4a side of things is gapless, yes?

I do hope so, the end of my ripping is in sight! Have to say I haven't noticed any audible gaps.

[Spoon]

Re: Problem gapless play after m4a to flag conversion

Every single lossless code is gapless, if it was not, it would not be gapless.

[jo-wie]

Re: Problem gapless play after m4a to flag conversion

Paranoia alert! The Apple Lossless m4a side of things is gapless, yes?

I do hope so, the end of my ripping is in sight! Have to say I haven't noticed any audible gaps.

In my case we're talking about lossy acc NOT about Apple lossless m4a files.

[jo-wie]

Re: Problem gapless play after m4a to flag conversion

... I can copy the m4a files to my Squeezecenter library on my Linux box and they stream gapless transcoded on the fly by faad, ...

Gapless transcoded to flac by faad? I've to hear it in this way again because it's confusing.

[moley6knipe]

Re: Problem gapless play after m4a to flag conversion

In my case we're talking about lossy acc NOT about Apple lossless m4a files.

For sure jo-wie, s'just me being paranoid and double checking! Thanks for the reassurance Spoon.

Jo-wie, bit of a clunky workaround, but how about trying this: convert your aac files to Apple Lossless in iTunes, and then convert those Apple Lossless files to FLAC using dB. I'd be surprised if iTunes doesn't read it's own aac files gaplessly!

[jo-wie]

Re: Problem gapless play after m4a to flag conversion

For sure jo-wie, s'just me being paranoid and double checking! Thanks for the reassurance Spoon.

Jo-wie, bit of a clunky workaround, but how about trying this: convert your aac files to Apple Lossless in iTunes, and then convert those Apple Lossless files to FLAC using dB. I'd be surprised if iTunes doesn't read it's own aac files gaplessly!

Good idea, I will try.

Thanks,

jo-wie

[moley6knipe]

Re: Problem gapless play after m4a to flag conversion

post back and let us know how it goes!