Audio Frame Rate Converter

This tool provides online audio frame rate conversion by adjusting the sampling rate of input audio files. It accepts common formats (WAV, MP3, AAC) and foregrounds compatibility with production pipelines, broadcast standards, and research datasets. The core objective is to produce an output file whose samples are reindexed to match the target rate while preserving the original timing, pitch, and spectral characteristics as closely as possible. Users supply the source sampling rate, the desired target sampling rate, and the number of channels (1 for mono, 2 for stereo). Optional settings allow dithering and a choice of resampling kernel to influence artifact suppression and frequency response. The process is deterministic and reproducible, enabling consistent results across machines and teams.

This conversion relies on standard digital signal processing techniques. The tool applies a resampling kernel (polyphase sinc as the default, with optional linear or nearest-neighbor modes) to estimate new samples at the target rate. For each output sample index n, the corresponding input index is n * f_in / f_out, and the nearest or interpolated input value is produced. Anti-alias filtering is applied when downsampling to minimize spectral folding, and optional dithering adds tiny noise to reduce quantization artifacts when reducing bit depth. The algorithm ensures duration remains effectively constant: output_duration ≈ input_duration, since N_out = N_in * f_out / f_in and time = N_out / f_out equals N_in / f_in. The tool reports final sample rate, channels, duration, and bit depth in the output metadata.

Who benefits include video editors syncing audio to frame rates (24, 25, 30, 60 fps), game sound designers preparing assets for multiple platforms, researchers preprocessing large datasets, and educators validating experiments. Unique value propositions include batch processing, clear metadata, optional dithering, multiple resampling algorithms, and robust validation against sample-rate drift. Use cases span archiving, broadcasting, and cross-software workflows, where reproducible results and predictable file sizes are essential. The tool is designed for non-expert users while exposing advanced options for power users who require precise control over the resampling process.