Command Line Reference

Full documentation for IISC's powerful command line interface — automate any text-to-speech or audio conversion task.

▶ Usage
iisc <command> <infile/text> [outfile] [options] <> = Required [] = Optional
⭐ Recommended Examples
# Read text aloud directly iisc /tts "The text you want to listen to" iisc /tts input.txt # Convert text to WAV file iisc /ttw "The text you want to convert into wav file" output.wav iisc /ttw input.txt output.wav # Convert text to MP3 file iisc /ttm "The text you want to convert into mp3 file" output.mp3 iisc /ttm input.txt output.mp3 # Convert between audio formats iisc /wtm input.wav output.mp3 iisc /mtw input.mp3 output.wav
📄 Commands
/? Display command line help
/e List all speech engines (voices) with their index numbers
/tts Text to Speech — Read text or a file directly through the speakers
/ttw Text to WAV — Convert text or a file into a WAV audio file
/ttm Text to MP3 — Convert text or a file into an MP3 audio file
/wtm WAV to MP3 — Convert an existing WAV file into MP3
/mtw MP3 to WAV — Convert an existing MP3 file into WAV
⚙️ Options
-e <v>
Select speech engine by index.
<v> = 0 … N  (default: 0)
Use iisc /e to list all available engines, or iisc /e -e <v> for details on a specific engine.
-s <v>
Adjust speech speed.
<v> = 50 … 500  (default: engine-dependent)
-p <v>
Adjust speech pitch.
<v> = 50 … 400  (default: engine-dependent)
-w <v>
Write-to-file speed multiplier.
<v> = 1 … 128+  (default: 8)
Maximum value depends on your CPU speed.
-r <v>
Output sampling frequency (kHz).
<v> = 8, 11.025, 12, 16, 22.05, 24, 32, 44.1, 48  (default: automatic)
-b <v>
Output bitrate (kbps).
<v> depends on the -r value — see table below  (default: 128)
-m <v>
Stereo mode.
s = stereo   j = joint stereo   f = force ms_stereo on all frames   m = mono   a = auto
Default: s or j depending on bitrate.
-q <v>
MP3 quality level.
<v> = 0 (highest quality, very slow) … 9 (poor quality, fast)
Recommended: 2 (slow, good quality)   7 (fast, ok quality)
Default: 5
📊 Sample Frequency ↔ Bitrate Reference
MPEG Standard Sample Frequencies (kHz) Valid Bitrates (kbps)
MPEG-1 Layer III 32   48   44.1 32  40  48  56  64  80  96  112  128  160  192  224  256  320
MPEG-2 Layer III 16   24   22.05 8  16  24  32  40  48  56  64  80  96  112  128  144  160
MPEG-2.5 Layer III 8   12   11.025 8  16  24  32  40  48  56  64  80  96  112  128  144  160
💡
Tip for smallest file size: Use -r 24 -b 8 (24 kHz sampling, 8 kbps bitrate). Useful when file size matters more than audio quality.