ggml-org/llama.cpp b7651

on GitHub

mtmd: mtmd_audio_streaming_istft (#18645)

Change is decoupled from #18641.

LFM2.5-Audio-1.5B
needs streaming istft for generating output audio.

• add streaming ISTFT class (mtmd_audio_streaming_istft) with overlap-add for audio reconstruction
• replace global audio cache with per-instance cache, the model requires
  two independent caches, for preprocessing (audio input) and for istft
  (audio output).
• unified templated FFT/IFFT implementation supporting both forward and inverse transforms