A collection of freeware open-source audio codecs is a part of VC Freeware components.
The following audio codecs are implmentated in native Delphi source code and are ready to use.
Most of them are based on original C/C++ soucre codec from different sources.
| G.711 |
11/88 |
Logarithmic, 8 kHz, 64 kbit/s, CBR codec used mostly in telephony since 1972. Has two slightly different versions: μ-law (North America and Japan) and A-law (most other countries). |
unaG711.pas |
ITU G.711 |
RFC 3551 |
| G.722.1 |
05/05 |
Transform-based codec, 16 kHz, 24/48 kbit/s, CBR codec providing high quality with moderate bitrate optimized for both speech and music. |
unaG7221.pas |
ITU G.722.1 |
RFC 5577 |
| GSM-FR |
6.10 |
RPE-LTP speech codec, 8 kHz, 13 kbit/s, moderate quality, low bitrate and complexity. WAV49 modification by Microsoft ACM implementation has a different bit order and is also supported. |
unaGSM.pas |
ETSI EN 300 961,
ref C-code |
RFC 3551 |
| IMA ADPCM/DVI4/VDVI |
6.10 |
ADPCM codec, 8 kHz, 32 kbit/s, low quality, very low complexity. |
unaADPCM.pas |
IMA ADPCM specification |
RFC 3551 |
Download all codec sources as a part of VC Freeware components.
