Audio Converter Plus

AudioConverter converts audio files to popular formats: MP3, AAC, FLAC, ALAC, WAV, AIFF, Opus, Ogg Vorbis. The app preserves tags, understands CUE sheets, finds artwork, pulls the soundtrack out of video files, and shows what is actually inside a recording before you convert it. Simple or Pro The settings have two modes. Simple keeps four things on screen: format, quality level, destination folder and the plan for the batch. Pro opens every setting there is, and a Pro setting that still changes the result stays visible in Simple mode, where one tap resets it. Presets set everything at once for a job: iPhone, car audio, FLAC archive, audiobook, podcast, or your own. Quality settings You can choose bitrate (CBR, VBR or ABR for MP3; the HE-AAC and HE-AAC v2 profiles for AAC), sample rate, and bit depth. FLAC is encoded by libFLAC: 16 or 24 bits as you ask, compression level 0 to 8, sample rates up to 384 kHz. Resampling has a choice of filter quality, and dithering switches on by itself when the bit depth actually drops. Matching source and destination formats are copied without re-encoding. Sound processing A twelve-band equalizer, 20 Hz to 20 kHz, with ready-made curves and your own presets: you hear it while listening, it is applied to the result, and the headroom for boosted bands is calculated for you. Loudness normalization to EBU R128 / ReplayGain, per track or per album, either written as tags or applied to the samples with clipping protection. Manual gain in dB, fade in and fade out, silence trimming at both ends, mono downmix and single-channel pick. Before you convert The app predicts the size of the result and warns about pointless settings, such as a bitrate above the source or lossy to lossless. The plan for the batch shows whether there is room for the result, which files already exist and what will happen to them, and which names clash. A loudness card reads out integrated LUFS, loudness range, true peak and DR. A spectrogram with zoom, an FFT window choice and PNG export tells you whether a "lossless" file was in fact transcoded from a lossy one, and there is a live spectrum during playback. SHA-256 and MD5 checksums confirm the source file is the one you think it is. Tags and artwork Edit tags and artwork for one file or many at once; edits go into the results, and into the originals only on request. Keep all tags, basic ones or none. Artwork comes from the file, its folder, an online search or your own image. CUE sheets The app can split a disc image (one large FLAC or WAV + CUE) into individual tracks. Names and tags are taken from the CUE sheet, whose text encoding is detected automatically and can also be set by hand. Batch processing Add folders with nested files. You can preserve the folder structure, put everything into a single folder, or organize into "Artist" / "Album" folders. Output names follow the original or a template built from tags, and a name conflict can skip, overwrite or rename. The number of files processed at once is settable from 1 to 6, and a batch can be paused and resumed. In the background Leave the app and the batch keeps converting, while iOS shows how far it has got. You can listen to a track before converting it: it keeps playing with the screen locked, the controls are on the Lock Screen and in Control Center, and playback pauses when you unplug your headphones. Adding files From the Files app, or from another app with "Open in…". On iPad you can also drag files in from Files or any other app. The interface is available in 15 languages. Supported formats: Input: any audio iOS and iPadOS can play, plus WavPack, APE, Musepack, TTA, Speex, Shorten, AC3, DSD (DSF and DFF, DSD64 to DSD1024), tracker music (MOD, XM, IT, S3M) and the audio tracks of video files. Output: AAC (.m4a), ALAC (.m4a), MP3, FLAC (16/24-bit, up to 384 kHz), WAV (16/24-bit, 32-bit float), AIFF, Opus, Ogg Vorbis.