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Author Topic: Field that contains gapless playback info?  (Read 4504 times)

cncb

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Field that contains gapless playback info?
« on: July 22, 2009, 09:01:17 pm »

Is there a field that can be accessed from the SDK that contains the gapless playback info ("start" and "end" shown in the detailed format window)?  I tried "Audio Analysys Info" but it seems to be empty.
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-Craig    MO 4Media remote and player:  Android/TV/Auto | iOS | Windows 10/UWP

cncb

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Re: Field that contains gapless playback info?
« Reply #1 on: July 27, 2009, 04:13:13 pm »

Is there any way to access this info via automation?
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-Craig    MO 4Media remote and player:  Android/TV/Auto | iOS | Windows 10/UWP

Matt

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Re: Field that contains gapless playback info?
« Reply #2 on: July 27, 2009, 04:25:23 pm »

It's not databased, but instead read at playback time.

We could still make it accessible from the TagInfo(...) expression but it would have to load and parse the file so would be a little slow.

Would that work?
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Matt Ashland, JRiver Media Center

cncb

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Re: Field that contains gapless playback info?
« Reply #3 on: July 27, 2009, 07:25:50 pm »

Yes, that would be great.  Thanks.
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-Craig    MO 4Media remote and player:  Android/TV/Auto | iOS | Windows 10/UWP

cncb

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Re: Field that contains gapless playback info?
« Reply #4 on: August 05, 2009, 04:25:46 pm »

I know this is low priority but is there any chance this could make a build soon?  Thanks.
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-Craig    MO 4Media remote and player:  Android/TV/Auto | iOS | Windows 10/UWP

cncb

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Re: Field that contains gapless playback info?
« Reply #5 on: August 13, 2009, 07:43:25 am »

bump?
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-Craig    MO 4Media remote and player:  Android/TV/Auto | iOS | Windows 10/UWP

Matt

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Re: Field that contains gapless playback info?
« Reply #6 on: August 13, 2009, 10:22:55 am »

We'll add this to 14.0.50 and later.

Tag(Gapless Header)
Tag(Gapless Footer)

Note that tag fields are case sensitive.

The context could be file-type specific.  In the case of MP3, the return value will be blocks (or samples depending on your lingo).

Also, remember that Tag(...) expressions must open the file and parse the tag so are 1000's of times slower than database fields.  Use them accordingly.
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Matt Ashland, JRiver Media Center

cncb

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Re: Field that contains gapless playback info?
« Reply #7 on: August 13, 2009, 04:11:38 pm »

Thanks very much.  Can you tell me which audio file types where the return value would not be samples?
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-Craig    MO 4Media remote and player:  Android/TV/Auto | iOS | Windows 10/UWP

cncb

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Re: Field that contains gapless playback info?
« Reply #8 on: August 15, 2009, 09:26:49 am »

Most of my gapless footers are in the range of 1000-2000 samples.  It must be more complicated than this but to convert this to seconds I divide by the sample rate (44100) to get ~45 ms?  This doesn't seem right.  It almost seems feasible that these values could be ms instead of samples?  Am I missing something in the calculation?  Thanks.
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-Craig    MO 4Media remote and player:  Android/TV/Auto | iOS | Windows 10/UWP

Matt

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Re: Field that contains gapless playback info?
« Reply #9 on: August 17, 2009, 02:03:28 pm »

Quote
Thanks very much.  Can you tell me which audio file types where the return value would not be samples?

Only MP3 supports the field for now.  I'm just trying to future-proof.

Most of my gapless footers are in the range of 1000-2000 samples.  It must be more complicated than this but to convert this to seconds I divide by the sample rate (44100) to get ~45 ms?  This doesn't seem right.  It almost seems feasible that these values could be ms instead of samples?  Am I missing something in the calculation?  Thanks.

You've got it right.  The gap is just a portion of a second.
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Matt Ashland, JRiver Media Center

cncb

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Re: Field that contains gapless playback info?
« Reply #10 on: August 17, 2009, 03:02:52 pm »

Thanks, Matt, but something doesn't seem right.  The gapless header for all ~4700 tracks in my library seems to be 576 - I have a hard time believing that they will all be exactly the same.  I'm reading the "Gapless" values from the "file format" tag window which seems to be the same as what the Tag() function returns.  I also have a sample track which has over a second of silence at the end when I play it in WMP but MC reports the gapless footer as only 1554 samples (35 ms)?  May I send you this small sample file?
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-Craig    MO 4Media remote and player:  Android/TV/Auto | iOS | Windows 10/UWP

Matt

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Re: Field that contains gapless playback info?
« Reply #11 on: August 17, 2009, 03:23:49 pm »

Thanks, Matt, but something doesn't seem right.  The gapless header for all ~4700 tracks in my library seems to be 576 - I have a hard time believing that they will all be exactly the same.  I'm reading the "Gapless" values from the "file format" tag window which seems to be the same as what the Tag() function returns.  I also have a sample track which has over a second of silence at the end when I play it in WMP but MC reports the gapless footer as only 1554 samples (35 ms)?  May I send you this small sample file?

The gapless information is unrelated to silence at the head or tail.  It's an encoder thing telling a decoder how to eat the small amount of extra it encodes into the file.

There is an independent option in Media Center to not play silence, but this is not related to gapless headers / footers.
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Matt Ashland, JRiver Media Center

cncb

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Re: Field that contains gapless playback info?
« Reply #12 on: August 17, 2009, 03:33:38 pm »

Sorry, I guess I asked for the wrong thing :-[.  So, you could have "gapless" playback selected in MC and still have silence between tracks?  Is there a way to get the amount of "silence" at the beginning and end of the files?
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-Craig    MO 4Media remote and player:  Android/TV/Auto | iOS | Windows 10/UWP

Matt

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Re: Field that contains gapless playback info?
« Reply #13 on: August 17, 2009, 03:36:46 pm »

So, you could have "gapless" playback selected in MC and still have silence between tracks?

Yes, if the originals had silence.

Quote
Is there a way to get the amount of "silence" at the beginning and end of the files?

Short of decoding the files and analyzing them, no.  We've toyed with moving the 'skip silence' option into an audio analyzer field so that CD burning could better leverage it without decoding before a burn, but it's a big change for something that isn't widely desired.
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Matt Ashland, JRiver Media Center

cncb

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Re: Field that contains gapless playback info?
« Reply #14 on: August 17, 2009, 04:28:58 pm »

So, I take it you determine the silence during playback?  I apologize for asking for the wrong thing and having you waste time adding it.
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-Craig    MO 4Media remote and player:  Android/TV/Auto | iOS | Windows 10/UWP

Matt

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Re: Field that contains gapless playback info?
« Reply #15 on: August 17, 2009, 04:43:25 pm »

So, I take it you determine the silence during playback?

Yes.  It's a DSP of sorts.


Quote
I apologize for asking for the wrong thing and having you waste time adding it.

No biggie.  It might turn out to be useful for some other reason.
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Matt Ashland, JRiver Media Center
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