Audio Watermarking Tools 1 (AWT1) is another product that is now offered at AudioWatermarking.info. AWT1 is a watermarking solution realizing so called “strict watermarking” approach in the sense that the source (not watermarked) audio data is required in order to find and decode watermark in the watermarked recording. In other words, watermark extraction is performed by “comparing” source and watermarked streams.
Both AWT1 and AWT2 are based on the same very basic patented approach, but use it in two different ways. While AWT1 requires the source audio file to decode watermark from the watermarked recording, AWT2 does not need the source. As a result, AWT1 watermarks are somewhat more robust to destructive audio transformations and the encoding speed is very high, while AWT2 is of course more practical, resistant to time-stretching, allows automated decoding (since non-watermarked sources are not needed) and provides higher watermarking data rate.
Check them out.
Details on AWT2
Details on AWT1