[asterisk-bugs] [Asterisk 0014491]: [patch] DTMF blips at end of recordings in __ast_play_and_record()

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=14491 
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Reported By:                asbestoshead
Assigned To:                jpeeler
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Project:                    Asterisk
Issue ID:                   14491
Category:                   Applications/General
Reproducibility:            always
Severity:                   tweak
Priority:                   normal
Status:                     assigned
Target Version:             1.6.0.x Pending Blocker
Asterisk Version:           Older 1.6.0 
Regression:                 No 
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
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Date Submitted:             2009-02-17 10:39 CST
Last Modified:              2009-07-28 18:21 CDT
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Summary:                    [patch] DTMF blips at end of recordings in
__ast_play_and_record()
Description: 
When using a channel with real in-band DTMF (e.g. Dahdi), voicemail
greetings and other recordings have remnants of the DTMF tone left at the
end. Usually it's about 5-15ms of DTMF before the Dahdi DTMF detector
kicked in, and sometimes there's an additional 5ms at the end of the tone.

The attached patch stops recording on button DOWN, not button UP; it also
trims the last 400ms from the recording in the case where it was terminated
by DTMF. I'm not 100% happy with this, but it seems to completely get rid
of noisy blips at the end of recordings a little over 50% (*) of the time,
and I haven't heard complaints about it truncating too much. I'm sort of
looking for feedback more than anything.

The patch is against 1.6.0-beta9, but it applies cleanly to 1.6.0.5.

(*) 24 out of 43 users who changed their greetings since I applied the
patch. Some of them might have retried if they heard the blip, but most
probably wouldn't notice. I didn't notice, until it was pointed out to me
-- and since then it's all I can hear :)
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 (0108333) jpeeler (administrator) - 2009-07-28 18:21
 https://issues.asterisk.org/view.php?id=14491#c108333 
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I've been looking at this and haven't found a good solution yet. We can't
just trim 400 ms of audio (or really any uncalculated amount). I don't see
how timing the duration between DTMF_END and DTMF_BEGIN events is going to
help because the dtmf frames are not written to the file. The file duration
must be calculated as the comment reports using the file length and not
some form of timing. The only thing I can think of so far is to mute more
fragments previous to detection. 

Issue History 
Date Modified    Username       Field                    Change               
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2009-07-28 18:21 jpeeler        Note Added: 0108333                          
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