Thawing Potion

New corpora

• CMU Arctic (#225)
• L2 Arctic (#227, #251)
• VCTK (#228, #253, #254)
• CallHome English (#278)
• CallHome Egyptian (#208)
• Multilingual Librispeech (#282 -- can be quite slow but we plan on improving the speed in further releases)

Features

PyTorch Dataset API

• Lhotse's samplers are now fully deterministic, have len() that returns the number of batches, and return a consistent number of batches in all distributed workers. (#213, #222, #223, #224, #255, #267, thanks @janvainer)
• On-the-fly feature extraction in PyTorch datasets (#229)
• visualisations of ASR batches with multiple transforms applied (#234)

Features and transforms

• Add LIbrosaFbank consistent with various TTS applications (#252, thanks @janvainer)
• SpecAugment (#246)
• option to pad cuts from left/right/both directions (#216)
• Randomized smoothing augmentation (#272, #273, #274)
• Randomized extra padding (#281)

I/O and serialization

• [experimental] Downloading audio from HTTP/S3/GCP/Azure URLs upon request (#233)
• Use HDF5 as the default storage backend for features (#237)
• Add JSONL support (#262)
• Support for auto-magically determined serializers (CLI + Python API) (#264)

Removed features

• Removed WavAugment support (use torchaudio.sox_effects instead) (#232)

General improvements

• Add tolerance to validate_recordings_and_supervisions (#208, thanks @janvainer )
• Fix incorrect truncation in cut mixing for data augmentation (#214)
• Return lengths from feature and token collations (#211, thanks @janvainer)
• Refactor Standardize to GlobalMVN (#230, thanks @janvainer)
• Fix rare error in randomized Recording's resampling test (#239)
• Fix concatenate cuts omitting the longest cut when duration_factor > 1 (#240)
• Fix CutMix not adding enough noise in long cuts (#241)
• Add max_cuts keyword to global stats computation in GlobalMVN (#245)
• Improved error message for mixing audio (#248)
• Add a check for matching sampling rates when mixing cuts (#247)
• Fix - make VCTK CLI discoverable (#250)
• Fix trim_to_supervisions and CLI (#249)
• Fix find segments float rounding issues (#265)
• Update the examples of libirispeech (full) and ami (#268, thanks @jimbozhang)
• Fix test for sphere files (#269, thanks @csukuangfj)
• More informative error message for incorrect channels in load_audio() (#270)