GSM to CDDA Converter

Decode GSM speech into raw CD-quality CDDA audio online

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CD-Ready Audio

Bring GSM telephony recordings up to the CDDA standard — 44.1 kHz, 16-bit stereo audio ready for disc burning and mastering.

Red Book Compliant

The CDDA output follows the standard Compact Disc specification, ensuring compatibility with CD authoring and burning tools.

Secure Processing

GSM uploads are deleted right after conversion. CDDA files are automatically purged from our servers within 24 hours.

How to convert GSM to CDDA

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose cdda or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your cdda file right afterwards

About formats

GSM 06.10 (Full Rate) is the foundational speech codec of the Global System for Mobile Communications standard, ratified by ETSI in 1991 and deployed across hundreds of cellular networks worldwide. Operating at a fixed 13 kbit/s, the algorithm applies Regular Pulse Excitation with Long-Term Prediction (RPE-LTP) to compress 20 ms frames of 8 kHz mono speech into just 33 bytes each. This approach models the vocal tract as a linear predictive filter, encodes the excitation signal, and leverages pitch periodicity for further reduction — tuned to deliver intelligible voice under the bandwidth constraints of early digital mobile channels. The codec powers not only GSM telephony but also many VoIP applications, voicemail systems, and IVR platforms that benefit from its low bitrate. Three concrete advantages stand out. First, extraordinary compression: one minute of speech fits in roughly 100 KB, enabling efficient storage and transmission. Second, universal tooling — libraries such as libgsm and SoX handle encoding and decoding on every major platform. Third, a royalty-free patent landscape that has encouraged adoption across open-source telephony projects like Asterisk and FreeSWITCH.
Initial release: 1991
CDDA (Compact Disc Digital Audio), known as the Red Book standard, defines audio stored on music CDs. Jointly developed by Sony and Philips and published in 1980, it established parameters that shaped digital audio for decades: 16-bit linear PCM at 44.1 kHz stereo, yielding 1,411.2 kbps uncompressed. Each disc holds up to 80 minutes organized into tracks with index points, sub-channel data for text display, and error correction codes (CIRC) ensuring reliable playback despite minor scratches. When audio is ripped from a CD, the resulting stream is often saved with the .cdda extension as raw PCM before conversion. The most obvious advantage is uncompressed, lossless nature — what reaches your ears is mathematically identical to the studio master at the specified resolution. Robust error correction provides excellent resilience, maintaining audio integrity even when disc surfaces suffer moderate wear. Having sold billions of units since the first commercial release in 1982, CDDA established baseline quality expectations for digital music and remains the reference against which compressed codecs are measured.
Developer: Sony / Philips
Initial release: October 1980

Frequently Asked Questions

Why convert GSM to CDDA?

CDDA is raw CD audio at 44.1 kHz, 16-bit stereo — the format needed for burning audio CDs or feeding CD mastering software.

Does converting improve the GSM audio quality?

No. The conversion upsamples and reformats the narrow-band GSM signal to CD specifications, but missing frequency data cannot be recovered.

Can I burn the CDDA output to a disc?

Yes. The CDDA format matches the Red Book CD standard, so it can be fed directly into CD burning software for audio disc creation.

What is the CDDA sample rate?

CDDA uses 44,100 Hz sample rate with 16-bit depth and two channels — the universal Compact Disc Digital Audio specification.

Are my files handled privately?

Uploaded GSM recordings are erased after conversion. CDDA results are removed from servers within 24 hours.