17326 2012-06-05 11:18:29 +0000 (CircularRouting): Undefined behavior for circular graphs 2014-10-28 17:17:56 +0000 1 1 1 Unclassified AudioWG Web Audio API unspecified PC All CLOSED WONTFIX P2 normal TBD 1 philipj crogers matthew.paradis olivier.thereaux padenot public-audio dave.null oldest_to_newest 68635 0 philipj 2012-06-05 11:18:29 +0000 Audio-ISSUE-24 (CircularRouting): Undefined behavior for circular graphs [Web Audio API] http://www.w3.org/2011/audio/track/issues/24 Raised by: Philip Jägenstedt On product: Web Audio API The spec does not define whether or not circular connections are allowed. Whichever is the case, the behavior needs to be defined. 68844 1 olivier.thereaux 2012-06-07 16:07:25 +0000 Proposed changeset, 25 May 2012 https://dvcs.w3.org/hg/audio/rev/74bd0f9f2fb6 Resolution per http://www.w3.org/2012/05/30-audio-minutes.html#item02 «it is OK to have a circular graph so long as there is a delay. The minimum delay should be 128 samples» Discussion thread on the list: http://lists.w3.org/Archives/Public/public-audio/2012AprJun/thread.html#msg461 69735 2 olivier.thereaux 2012-07-09 13:31:03 +0000 The discussion continues on the mailing-list: http://lists.w3.org/Archives/Public/public-audio/2012JulSep/thread.html#msg1 And Robert raised a related issue about the lookahead in the DynamicsCompressorNode: http://lists.w3.org/Archives/Public/public-audio/2012JulSep/0019.html 73753 3 olivier.thereaux 2012-09-13 09:48:49 +0000 This was discussed at the 12th Sept 2012 teleconference. Suggested resolution: circular connections are allowed if there is a delay node present. If the delay is too small, the implementation should clamp it to a minimum, on a per-node basis. There were two suggested resolutions for the minimum delay: * one to specify the minimum as a block of 128 samples (which would make things sound differently on platforms with different sample sizes, but that was deemed acceptable in the same way as graphics look different on platforms with different frame rates and power). * The other was to not specify it and let implementations choose (and, I assume, expose?) their minimum delay. 74023 4 matthew.paradis 2012-09-18 11:07:38 +0000 If circular connections (without delay) are allowed it may be worth considering raising an exception when they are detected. Software such as Pure Data and Max/Msp do this as well as zeroing the output. Without the exception it may make the debugging process longer. 93098 5 padenot 2013-09-06 14:36:25 +0000 Duping against the most recent bug with the latest developments. *** This bug has been marked as a duplicate of bug 23037 *** 113967 6 olivier.thereaux 2014-10-28 17:14:56 +0000 Web Audio API issues have been migrated to Github. See https://github.com/WebAudio/web-audio-api/issues 114117 7 olivier.thereaux 2014-10-28 17:17:56 +0000 Closing. See https://github.com/WebAudio/web-audio-api/issues for up to date list of issues for the Web Audio API.