Hi guys, I'm running Asterisk 1.2.13 on a Debian Linux system (that was just the version that was packaged for it). I've been using monitor() to record calls, with fairly satisfactory results - at least until the last few months. I've been recording VoIP calls, and using monitor() with no arguments, so I'm getting separate wav files for each leg (both use ALAW, BTW), and combining them with soxmix, which apparently does support ALAW (if I'm right in presuming the wav files would be in this format - I'm no expert on such things). I'm then using mplayer to listen to them. However, I'm finding that the two legs of the call often get quite badly out of sync, so much so that I've often heard the answer to a question come before the question itself in a recording, when it certainly didn't happen like that at the time! In one such instance, the in-file and out-file also differed in length by some 30 seconds, while being nearly an hour long each; they were perfectly in sync right at the beginning of the call, but already quite badly out by only 6 minutes in. I'm pretty stumped here; I can only imagine that, for some reason, not all silence is being recorded in the sound files, so that, when there's silence on one leg and voice on the other, they become uncoordinated. I'm puzzled as to why this wasn't a problem previously, though; I suspect it was before I was using SIP for VoIP, so, in that case, in the previous (working) case, one leg was IAX while the other was SIP, while now, both are SIP. Canreinvite is set to no, however, so I didn't think this would be an issue. It is possible, however, that it was a problem before, but that I failed to notice it, or perhaps it triggered less often for some other reason. any thoughts appreciated! BTW, I'm blind, which partly limits my choice of applications (I've been using console based ones, as I haven't worked out how to use X). Best wishes, Nikhil.
On 21 May 2009, at 22:02, Nikhil Nair wrote:> I'm pretty stumped here; I can only imagine that, for some reason, > not all > silence is being recorded in the sound files.Silence suppression might be enabled somewhere? Asterisk doesn't like that generally, so might screw recordings too.. Steve
(monitor legs are out of sync) On Thu, 21 May 2009, Nikhil Nair wrote:> I'm running Asterisk 1.2.13...A more modern version wouldn't hurt.> I've been using monitor() to record calls, with fairly satisfactory > results - at least until the last few months.If you don't need the legs separate, mixmonitor() may give different results.> I've been recording VoIP calls, and using monitor() with no arguments, > so I'm getting separate wav files for each leg (both use ALAW, BTW)...If you load both legs into something like Audacity, do the files play in sync? Thanks in advance, ------------------------------------------------------------------------ Steve Edwards sedwards at sedwards.com Voice: +1-760-468-3867 PST Newline Fax: +1-760-731-3000
Hi Nikhil, Several of these "out of sync" issues have been resolves in many recent versions of Asterisk. I'm not sure if many of the out of sync issues were reported against 1.2 when it was receiving bug updates, so you may need to move to Asterisk 1.4 in order to get these updates. Additionally, I'm not sure which version is better for your reading software, but there is a web based version of the Asterisk book at http://astbook.asteriskdocs.org or you can grab the PDF fro http://www.asteriskdocs.org (if you need help compiling a newer version of Asterisk). Hope that helps! Leif. Nikhil Nair wrote:> However, I'm finding that the two legs of the call often get quite badly > out of sync, so much so that I've often heard the answer to a question > come before the question itself in a recording, when it certainly didn't > happen like that at the time! In one such instance, the in-file and > out-file also differed in length by some 30 seconds, while being nearly an > hour long each; they were perfectly in sync right at the beginning of the > call, but already quite badly out by only 6 minutes in.-- Leif Madsen. http://www.leifmadsen.com http://www.oreilly.com/catalog/asterisk