If you can produce a simple minimal repro that exhibits this issue on some procedural signal (sine wave, etc) I'd love to look into it some more - I'm maintaining a hardened version of the Speex Resampler and would be very concerned if this bug made it into production. - Sherief -----Original Message----- From: speex-dev-bounces at xiph.org [mailto:speex-dev-bounces at xiph.org] On Behalf Of Colin Guthrie Sent: Saturday, December 04, 2010 9:33 AM To: speex-dev at xiph.org Subject: Re: [Speex-dev] Problems with Speex Resamplers Hi John 'Twas brillig, and John Ridges at 03/12/10 20:21 did gyre and gimble:> If you're using stereo audio with the resampler, there is a bug that can > occur under certain situations (and maybe that's what's been happening > to you). Check out: > > http://lists.xiph.org/pipermail/speex-dev/2009-August/007406.htmlI tried making those changes to my build but sadly it didn't help :( Thanks for the suggestion. Col -- Colin Guthrie gmane(at)colin.guthr.ie http://colin.guthr.ie/ Day Job: Tribalogic Limited [http://www.tribalogic.net/] Open Source: Mageia Contributor [http://www.mageia.org/] PulseAudio Hacker [http://www.pulseaudio.org/] Trac Hacker [http://trac.edgewall.org/] _______________________________________________ Speex-dev mailing list Speex-dev at xiph.org http://lists.xiph.org/mailman/listinfo/speex-dev
'Twas brillig, and Sherief N. Farouk at 06/12/10 14:29 did gyre and gimble:> If you can produce a simple minimal repro that exhibits this issue on some > procedural signal (sine wave, etc) I'd love to look into it some more - I'm > maintaining a hardened version of the Speex Resampler and would be very > concerned if this bug made it into production.Well at present, I'm not sure it is a bug at all. I suspect that it is in some capacity related to PulseAudio's rewinding that causes this. e.g. a new sounds starts that triggers a rewind, and the resampler is reset and some other rewind happens and the latency of the resampler during this reset phase is somehow longer than we need it to be or something along those lines. After the rewind is dealt with, then the latency of the resampler is not a problem any more... (and not resetting and doing other such things also prevents overhead). I'm not sure about the above hand-wavey, vague explanation but I suspect it's something in that general area that's causing the problems rather than a bug in speex per se. Col. -- Colin Guthrie gmane(at)colin.guthr.ie http://colin.guthr.ie/ Day Job: Tribalogic Limited [http://www.tribalogic.net/] Open Source: Mageia Contributor [http://www.mageia.org/] PulseAudio Hacker [http://www.pulseaudio.org/] Trac Hacker [http://trac.edgewall.org/]
How much latency are we talking about? It seems that this issue cannot be easily pinpointed, but if it turns out to be related to the Speex Resampler let me know and I will put it on my task list. - Sherief -----Original Message----- From: speex-dev-bounces at xiph.org [mailto:speex-dev-bounces at xiph.org] On Behalf Of Colin Guthrie Sent: Monday, December 06, 2010 9:47 AM To: speex-dev at xiph.org Subject: Re: [Speex-dev] Problems with Speex Resamplers 'Twas brillig, and Sherief N. Farouk at 06/12/10 14:29 did gyre and gimble:> If you can produce a simple minimal repro that exhibits this issue on some > procedural signal (sine wave, etc) I'd love to look into it some more -I'm> maintaining a hardened version of the Speex Resampler and would be very > concerned if this bug made it into production.Well at present, I'm not sure it is a bug at all. I suspect that it is in some capacity related to PulseAudio's rewinding that causes this. e.g. a new sounds starts that triggers a rewind, and the resampler is reset and some other rewind happens and the latency of the resampler during this reset phase is somehow longer than we need it to be or something along those lines. After the rewind is dealt with, then the latency of the resampler is not a problem any more... (and not resetting and doing other such things also prevents overhead). I'm not sure about the above hand-wavey, vague explanation but I suspect it's something in that general area that's causing the problems rather than a bug in speex per se. Col. -- Colin Guthrie gmane(at)colin.guthr.ie http://colin.guthr.ie/ Day Job: Tribalogic Limited [http://www.tribalogic.net/] Open Source: Mageia Contributor [http://www.mageia.org/] PulseAudio Hacker [http://www.pulseaudio.org/] Trac Hacker [http://trac.edgewall.org/] _______________________________________________ Speex-dev mailing list Speex-dev at xiph.org http://lists.xiph.org/mailman/listinfo/speex-dev