§ ØŽ’jkã ó2—dZddlZ d dededed efd „ZdS) z.Audio utilities shared across model providers.éNéÀ]ééÚ sample_rateÚchannelsÚbits_per_sampleÚreturnc óø—||z|zdz}||zdz}dtjdd¦«zdzdztjdd¦«ztjdd |||||¦«zd ztjdd¦«zS) a\Build a 44-byte WAV/RIFF header for streaming PCM. The RIFF and ``data`` chunk sizes are set to ``0xFFFFFFFF`` since the total length isn't known yet. Decoders that only need sample-rate, channel count and bit depth (e.g. the web ``WavStreamPlayer``) treat everything after the ``data`` chunk header as PCM, so this is sufficient for live decoding of an open-ended stream. Both DashScope omni and OpenAI streaming deliver raw PCM upstream; prefixing the first chunk with this header lets the frontend start playback immediately without buffering the whole response. ésRIFFzrsfðà4Ð4Ø € € € ðØØð$ð$Øð$àð$ðð$ð ð $ð$ð$ð$ð$ð$r