--- title: Something isn't right... | daily.dev description: A live-coding stream follows an attempt to build a virtual piano by parsing WAV files and playing audio through PipeWire in Zig. The host writes a RIFF/WAV... canonical: https://daily.dev/posts/something-isn-t-right--g30o2x7is twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Something isn't right... | daily.dev og:description: A live-coding stream follows an attempt to build a virtual piano by parsing WAV files and playing audio through PipeWire in Zig. The host writes a RIFF/WAV... og:url: https://daily.dev/posts/something-isn-t-right--g30o2x7is og:image: https://api.daily.dev/og/posts/g30O2X7iS.png og:image:alt: Something isn't right... og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Something isn't right... **[sphaerophoria](https://daily.dev/sources/sphaerophoria)** · 95 min read · 0 upvotes · 0 comments ## Summary A live-coding stream follows an attempt to build a virtual piano by parsing WAV files and playing audio through PipeWire in Zig. The host writes a RIFF/WAV chunk parser from scratch, reads format and data chunks, then hits a maddening, intermittent circular-buffer corruption bug when trying to play back sampled audio. After extensive debugging with logging, thread-ID checks, and backtraces, the root cause turns out to be PipeWire's real-time thread flag being set unnecessarily (copy-pasted from a tutorial), causing callbacks to fire from a different thread than expected. Once removed, playback works correctly, and the stream ends with a plan to tackle Fourier transforms and visualization in a future session. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### Why would audio playback via a PipeWire stream crackle or corrupt a circular buffer intermittently? Intermittent circular buffer corruption during PipeWire playback can be caused by unnecessarily setting the real-time thread flag (RT_PROCESS) when connecting a stream, which causes PipeWire's process callback to run on a different thread than the one calling the service/iterate loop. Removing that flag, so the loop runs entirely on one thread, eliminates the thread-safety violation and fixes both the crackling and the crashes. _Developers chasing elusive PipeWire threading bugs can find similar war stories and fixes curated on daily.dev._ ### What is the basic structure of a WAV (RIFF) file that I need to parse to read audio samples? A WAV file starts with a 4-byte 'RIFF' identifier, followed by a 4-byte file size field and a 4-byte 'WAVE' format identifier, after which a series of chunks follow, each with a 4-byte chunk ID and 4-byte chunk size. The 'fmt ' chunk holds audio format, channel count, sample rate, byte rate, block align, and bits per sample; the 'data' chunk holds the raw little-endian PCM samples themselves. _Anyone writing a binary file parser from scratch can track practical format breakdowns like this on daily.dev._ ## Similar posts on daily.dev - [A Live Chiptune Synthesizer in Erlang](https://daily.dev/posts/a-live-chiptune-synthesizer-in-erlang-ymojxunnn) · Erlang Solutions · 0 upvotes · 0 comments --- Tags: [#linux](https://daily.dev/tags/linux), [#zig](https://daily.dev/tags/zig) [View this post on daily.dev](https://daily.dev/posts/something-isn-t-right--g30o2x7is) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Something isn't right...","url":"https://daily.dev/posts/something-isn-t-right--g30o2x7is","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/something-isn-t-right--g30o2x7is"},"datePublished":"2026-10-03T22:25:40.084Z","dateModified":"2026-10-03T22:26:09.428Z","description":"A live-coding stream follows an attempt to build a virtual piano by parsing WAV files and playing audio through PipeWire in Zig. 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