<body bgcolor="#ffffff" background="https://img.web.de/v/p.gif" class="bgRepeatYes" style="background-repeat: repeat; background-color: rgb(255, 255, 255); color: rgb(0, 0, 0); font-size: 9pt; padding-left: 0px;" ><p>Hi Jean-Marc,</p>
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<p>yes, I tested with floating point. It is only a fixed point problem, floating point works fine. Even a fixed point decoder is o.k. -- problem is inside encoder.</p>
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<p>I had the idea of an "above unity" pitch gain, too, but I did not manage to modifiy the encoder in a way to fix it. Because the encoder's pitch handling is some kind of "feedback system" (i.e. a change in output parameters of frame N will influence input parameters in frame N+1), it's not so easy for me to reduce gain to test for stability. All modifications I tried made the situation worse, so I need some adivce how to proceed...</p>
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<p>The complexity parameter has some influence, too: For a sine input of 2200 Hz, the instability is present only for complexity values up to 3, but for the 2000 Hz input, instability can be observed even for the highest complexity values.</p>
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<p>As already written, I observed that the pitch and pitch gain values computed with the fixed point encoder seem quite odd and are absolutely different from the ones computed with floating point. This seems to stabilize for higher complexity values, so I'm not sure if this is the cause of the problem or only a side effect.</p>
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<p>best regards,</p>
<p>Frank</p>
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<p><span style="font-size: 9pt;"><span style="font-family: verdana,geneva;"><span style="background-color: transparent;"><span style="color: #000000;"><span style="color: #000000;"> </span></span></span></span></span><br />Jean-Marc Valin <jean-marc.valin@usherbrooke.ca> hat am 13. Januar 2010 um 12:48 geschrieben:<br /><br />> Hi Frank,<br />> <br />> Sorry, I *do* care about the problem and just happen to be overworked at <br />> the moment. What I suspect is that the pitch gain gets close enough to <br />> unity that the loss makes it bust. Did you test with the floating-point <br />> code?<br />> <br />> Jean-Marc<br />> <br />> On 2010-01-13 03:45, Frank Lorenz wrote:<br />> > Hi,<br />> ><br />> > is no one willing to spent some effort on this topic? At least it would<br />> > be good<br />> > to know if anybody can reproduce this problem.<br />> ><br />> > I did further investigation on the topic and found out that the encoder<br />> > in fixed<br />> > point mode produces absolutely different pitch and pitch gain parameters<br />> > than in<br />> > floating point mode (for a 2000 Hz input signal). The codec breaks on<br />> > frame loss<br />> > if the encoder is in fixed point mode, decoder doesn't matter, so I<br />> > assume the<br />> > pitch parameters are "bad".<br />> > Maybe its caused by accuracy/rounding problems for this periodic signal?<br />> ><br />> > Because I do not know much about the internals of Speex, it's hard for me to<br />> > analyse the pitch / pitch gain computation. Some help would be really<br />> > nice...<br />> ><br />> > best regards,<br />> > Frank<br />> ><br />> ><br />> ><br />> > ---------- Ursprüngliche Nachricht ----------<br />> > Von: Frank Lorenz <Frank_wtal@web.de><br />> > An: speex-dev@xiph.org<br />> > Datum: 4. Januar 2010 um 09:57<br />> > Betreff: Re: [Speex-dev] Fixed Point on wideband-mode: Single Frame loss<br />> > on 2000<br />> > Hz sine causes "freak off"<br />> ><br />> ><br />> > Hi Jean-Marc, all,<br />> ><br />> > I didn't get any response to my issue up to now and would like to now if<br />> > anyone<br />> > can reproduce this behaviour and if there is some idea what happens. I am<br />> > willing to fix this issue, but because I do not know the internals of<br />> > speex, I<br />> > need some advice on how to proceed...<br />> ><br />> > best regards,<br />> > Frank<br />> ><br />> ><br />> ><br />> > Frank Lorenz <Frank_wtal@web.de> hat am 21. Dezember 2009 um 10:49<br />> > geschrieben:<br />> ><br />> > > An update:<br />> > ><br />> > > I found that the "ADD32: output is not int:" messages are caused by the<br />> > > enhancer. When I turn the enhancer off, the messages vanish, but the<br />> > "freak<br />> > > out" of the codec is still there - so the problem seems not to be<br />> > related to<br />> > > the overflow messages.<br />> > ><br />> > > best regards,<br />> > > Frank<br />> > ><br />> > ><br />> > > ---------- Ursprüngliche Nachricht ----------<br />> > > Von: Frank Lorenz <Frank_wtal@web.de><br />> > > An: speex-dev@xiph.org<br />> > > Datum: 18. Dezember 2009 um 13:36<br />> > > Betreff: [Speex-dev] Fixed Point on wideband-mode: Single Frame loss<br />> > on 2000<br />> > > Hz sine causes "freak off"<br />> > ><br />> > > Hi,<br />> > ><br />> > > I'm quite sure we found a bug inside the codec (1.2rc1, wideband<br />> > mode). It<br />> > > only<br />> > > occurs when speex is compiled with the FIXED_POINT flag.<br />> > ><br />> > > I feed in a 2000 Hz sine wave (-15 dBFS). When I simulate a single<br />> > frame loss<br />> > > (i.e. pass a null pointer to speex_decode_int as second parameter for<br />> > just one<br />> > > frame), the decoder<br />> > > starts to freak out a second later: It produces horrible noise with 0<br />> > dBFS.<br />> > > This<br />> > > horrible noise will not vanish until you turn off the input signal.<br />> > ><br />> > > I did some investigation on this with FIXED_DEBUG. The error messages are<br />> > > (lots<br />> > > of this):<br />> > > ADD32: output is not int: 1702286034 in ltp.c: line 68<br />> > > ADD32: output is not int: 1455757562 in ltp.c: line 69<br />> > ><br />> > > Call stack for this (only set the break point once, may be there are<br />> > other<br />> > > call<br />> > > stacks on error, too):<br />> > ><br />> > > sb_decode ( ) at sb_celp.c:898<br />> > > nb_decode ( ) at nb_celp.c:1471<br />> > > multicomb ( ) at filter.c:709<br />> > > interp_pitch ( ) at filter.c:603<br />> > > inner_prod ( ) at ltp.c:68<br />> > ><br />> > > Can you help please?<br />> > ><br />> > > best regards,<br />> > > Frank<br />> > > ______________________________________________________<br />> > > GRATIS für alle WEB.DE-Nutzer: Die maxdome Movie-FLAT!<br />> > > Jetzt freischalten unter http://movieflat.web.de<br />> > <http://movieflat.web.de/><br />> > ><br />> > > _______________________________________________<br />> > > Speex-dev mailing list<br />> > > Speex-dev@xiph.org<br />> > > http://lists.xiph.org/mailman/listinfo/speex-dev<br />> > ______________________________________________________<br />> > GRATIS für alle WEB.DE-Nutzer: Die maxdome Movie-FLAT!<br />> > Jetzt freischalten unter http://movieflat.web.de <http://movieflat.web.de/><br />> ><br />> > _______________________________________________<br />> > Speex-dev mailing list<br />> > Speex-dev@xiph.org<br />> > http://lists.xiph.org/mailman/listinfo/speex-dev<br />> ><br />> > Web Bug from https://img.web.de/p.gif<br />> > WEB.DE MillionenKlick: Kostenlos tippen, täglich 1 Million gewinnen!<br />> > http://produkte.web.de/go/07/<br />> ><br />> ><br />> ><br />> > _______________________________________________<br />> > Speex-dev mailing list<br />> > Speex-dev@xiph.org<br />> > http://lists.xiph.org/mailman/listinfo/speex-dev<br />></p> <br><br><table cellpadding="0" cellspacing="0" border="0"><tr><td bgcolor="#000000"><img src="https://img.web.de/p.gif" width="1" height="1" border="0" alt="" /></td></tr><tr><td style="font-family:verdana; font-size:12px; line-height:17px;">GRATIS für alle WEB.DE-Nutzer: Die maxdome Movie-FLAT! <br>Jetzt freischalten unter http://movieflat.web.de</td></tr></table></body>