[WT-support] Fwd: Why Extract and Save QSO shifts time?

[Bob Wilson, N6TV]

First, please note that Win-Test has no idea when a QSO "starts"; it only
knows when a QSO "ends":  the moment you press Enter or Plus to log the
QSO.  So, all the time offsets are relative to that timestamp, minus some
estimate of how long it takes to make a QSO, which seems to be about 15 to
20 seconds.

So, if you select "start 1 second before," it apparently calculates the
time 16 to 21 seconds before the end of the QSO, and starts the extract
there.  Why AltGr-Enter works differently is unknown.

I don't think the recording and playback computer matters, however, if
recordings were made on multiple computers that did not use time
synchronization (by setting one Win-Test computer as "time master"), that
might cause playback or extract problems.

FYI, a free program called Audacity can be used to trim MP3 recordings
quite precisely.  I suggest using Audacity to trim the MP3 extract files
produced by Win-Test.  The Audacity "Export" feature lets you manually add
info to the MP3 file, such as the date, time, frequency and callsign. Too
bad Win-Test does not do this for us automatically.

73,
Bob, N6TV
On Apr 3, 2015 12:04 AM, "Tonno Vahk" <tonno.vahk at gmail.com> wrote:

> Thanks Bob,
>
>
>
> The recording computer was with XP and used:
>
>
>
> fraunhofer IIS MPEG Layer-3 Codec (advanced)
>
> mono
>
> 8000hz
>
> 8 kbit/s
>
>
>
> I am listening to the files on my other W7 computer. I ran the batch file
> on that one but it as expected makes no difference.
>
>
>
> When I send the Time Before… to 1 sec then then recording in reality
> starts ca 21 second before the moment when the QSO starts playing when
> activated with AltGr+Enter. Should they be starting at the same time in
> reality when set to 1 sec?
>
>
>
> Should I try to listen on the same XP computer that recorded QSOs? Should
> I perhaps try to set higher bit rate or sth?
>
>
>
> 73
>
> tonno
>
>
>
> *From:* support-bounces at f5mzn.org [mailto:support-bounces at f5mzn.org] *On
> Behalf Of *Bob Wilson, N6TV
> *Sent:* Thursday, April 02, 2015 12:15 AM
> *To:* Win-Test Reflector
> *Subject:* Re: [WT-support] Why Extract and Save QSO shifts time?
>
>
>
> I have not been able to exactly reproduce this problem on WT 4.16, but I
> am using the Fraunhofer CODEC instead of LAME.  There's a note in the
> Release notes about this:
>
>
>
>
>
> - MP3 setup : Only the CBR codecs are now displayed in the setup
>
>   dialogs. The usage of the ABR codecs (most of the LAME ACM ones) is
>
>   too erratic to be trusted in.
>
>
>
> (CBR = Constant Bit Rate, ABR = Average Bit Rate)
>
>
>
> Win-Test uses interpolation to locate the correct offset within the MP3
> file.  It records the timestamp of every QSO precisely, when it is logged,
> but then it must use interpolation to *approximate* the offset to the
> audio clip within the MP3 file.  Maybe that has something to do with it.
>
>
>
> Tip:  to enable the fixed bit rate Fraunhofer CODEC on Windows 7 and
> later, 32-bit or 64-bit, and run the batch file referenced here:
>
>
>
> http://www.komeil.com/blog/enable-fraunhofer-mp3-l3codecp-acm-windows
>
> http://www.komeil.com/download/264  (click the small blue download
> button, nothing else, then run the batch file, as administrator)
>
>
>
> It's a little scary to run this batch file because it updates the Windows
> Registry (be sure to download, right click on file, and select "Run as
> Administrator"), but it has worked very well for me on multiple computers
> with no apparent side effects.
>
>
>
> In WT 4.16, you can set the "Time Before QSO was Logged" to a minimum of
> 1s, but not 0s.  However, it still seems to start the recording about 15
> seconds before the QSO was logged, not 1 second, so it does work rather
> mysteriously.  But I am using an 8000 Hz sample rate and a 24 kBit/s bit
> rate.  Perhaps when other rates are used, the QSO offset isn't calculated
> precisely.  Or there could be a subtle bug in the Contest Recorder offset
> calculations at certain bit rates.
>
>
>
> Please tell us exactly which CODEC, Sample Rate, and Bit Rate you have
> selected so we can try to replicate the problem.
>
>
> 73,
>
> Bob, N6TV
>
>
>
> On Wed, Apr 1, 2015 at 1:28 PM, Tonno Vahk <tonno.vahk at gmail.com> wrote:
>
> A small thing. When you play a QSO recording from the log with AltGr+Enter
> everything is fine and recording starts at correct time. But when you
> Extract and Save QSO the recording starts considerably earlier even if you
> set Time Before QSO Was Logged to zero. That means in order to get normal
> 30
> sec to 1 minute audio clip one has to actually extract the next or one
> after
> next QSO!
>
> Any ideas why this happens? It is pretty inconvinient especially if there
> is
> no immidiate next QSO. I remember that way back it worked fine but this
> issue has developed at some point of time..
>
> 73
> Tonno
> Es5tv
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.win-test.com/pipermail/support/attachments/20150403/72e03c06/attachment.htm>