I’m glad to announce that TrustedAudio.com opens its doors for beta-testing.
TrustedAudio (TA) is a professional web-based tool that provides an easy and reliable way to share, deliver, and distribute audio files securely by means of watermarking and digital signing.
At this stage, public registration is closed, but you can ask for invite by leaving your request via the Contacts form on the TA website or just sending mail with request to mailbox /at/ trustedaudio /dot/ com.
AWT2 0.11.0 is a major technology update.
– (decoder) redesigned and rewritten watermark detection engine; watermark search in non-watermarked audio is now 7-10 times faster, without compromising the reliability of watermark extraction.
– (decoder, CLI) -stop_on_found command line parameter has been modified, it now allows specifying -stop_on_found=N to stop after N slices with found watermarks.
– (decoder) -fast_scan mode is now more reliable
– various speed improvements and optimizations
AWT1 1.2.7 features several bug-fixes.
AudioWatermarking.info announces release of AWT4 – an audio triggering, signalling and watermarking solution providing time-precise “digital stamping” with high data rate. The technology allows placing/extracting capacious digital codes in audio streams at precise time places to trigger time- and data-specific events with high timing accuracy (~30ms).
AWT2 0.10.03 is a major technology upgrade. AWT2 now natively supports Dual-Layer watermarking. Two independent watermarks can be embedded into the same audio stream at different stages of audio content distribution. Dual-layer watermarking is available in both AWT2 CLI tools and AWT2 SDK.
I published an open paper that describes a little crazy (but seems to be novel) idea of combining digital sound and QR codes together. The paper briefly describes a new approach that brings quite effective and easy data hiding and watermarking technique to general public through the use of QR codes (or similar bar-codes).
Read the paper: Alex Radzishevsky, Visual Domain Audio Watermarking (VDAW) and Spectral Barcode Audio Watermarking (SBAW), February 2014.
New AWT2 SDK (0.10.00) is a complete rework of the core encoding engine. It now supports real-time live audio streams encoding with low latency.
– Fully rewritten encoder code, backwards/forwards compatible with older decoders
– faster encoding, dramatically reduced encoder memory consumption
– completely new cross-platform SDK with real-time, low latency live audio stream encoding functionality
– fully thread safe SDK
– improved signal limiter with configurable attack/release times
The new SDK is available now.
… digitally!
World’s first limited edition 808 kick drum by HeavyListening.com has been digitally signed by AWT2. You can visit the project web-page for more details…
New in AWT2 0.09.04 version:
– bugfix in the encoder: noise generation feature (“-noise_level” command line parameter) was ignoring “-skip_first” and “-skip_last” settings; fixed.
– improvement in the encoder: “-skip_last” value can be negative, in this case the parameter specifies duration of audio to be watermarked (all the rest is skipped and not watermarked)
Full changes log is available here.
AWT2 free evaluation package is available here.
Sometimes you may need to be able analyzing live audio stream using AWT2 watermark decoder. Here is an efficient recipe on establishing live analysis of audio stream from sound card (mic or line-in) using all freeware tools on Microsoft Windows machine.
Tools involved:
Create a folder, extract SoX and Blat packages into it. Put AWT2 decoder into it. You should have approximately the following files structure:
blat.dll pthreadgc2.dll zlib1.dll awt2_dec.exe blat.exe sox.exe
Create a batch-file, call it ‘AWT2Monitor-runme.bat’ (without quotes). This batch continuously monitors (listens to) audio stream by invoking sound recording and watermark detection every N seconds. The contents of the batch:
@REM === Audio stream monitoring definitions @SET slicelen= 16 @SET slicestep= 8 @REM === Entering infinite loop @echo start > result.txt @SET /a waitsec= 1 + slicestep :Start @REM Get current timestamp in a form: @REM DD-MM-YYYY-HH-MM-SS-ms (e.g. 10-02-2013-21-04-46-48) @set SAVESTAMP=%DATE:/=-%-%TIME::=-% @set SAVESTAMP=%SAVESTAMP: =% @set SAVESTAMP=%SAVESTAMP:,=-% @set SAVESTAMP=%SAVESTAMP:.=-% @REM Start recording audio slice from the 'default' sound @REM device and analyze it using AWT2 decoder @start /SEPARATE /MIN call _rec_and_analyze.bat %SAVESTAMP%.wav %slicelen% @REM Wait 8 seconds before the next slice @PING 127.0.0.1 -n %waitsec% -w 1000 > nul @more result.txt @goto Start
The batch file runs continuously in the infinite loop. You will need to close its window to stop the listening process.
You can change time delay (step) between recorded audio slices by changing the value of ‘slicestep’ variable (in the example above the recording is performed every 8 seconds). You can change the length of the recorded audio stream slice y changing the value of ‘slicelen’ variable (in the example above the slice length is set to 16 seconds). With these recording settings, the recorded slices overlap, that provides reliable monitoring of the audio stream.
Create another batch file, call it ‘_rec_and_analyze.bat’ (without quotes). Here are the contents of this batch:
@REM Running SoX tool to record N sec long slice from the 'default' sound card @sox.exe --channels 1 --rate 44100 --bits 16 -d "%1" trim 0 %2 @REM Running AWT2 decoder to analyze the recorded slice @awt2_dec.exe "%1" 4 -silent >"%1".txt @IF NOT EXIST "%1" goto panic @REM storing result as text to show in the main listener loop @SET /p res= < "%1".txt @echo %1 - %res% > result.txt @REM Check whether a watemark was found more "%1".txt | find /i "No watermark" @IF ERRORLEVEL 1 goto watermark @IF NOT ERRORLEVEL 1 goto nowatermark :watermark @ECHO !Watermark detected! @mkdir Watermarked @copy "%1" Watermarked\ @copy "%1".txt Watermarked\ @REM Send e-mail with attached WAVE file and watermark in the subject blat -SaveSettings -f mymail@mail.com -server mail.com -port 26 -u user -pw pswrd blat "%1".txt -attach "%1" -to to@mail.com -i "AWT2_Analyzer" -subject "watermark found" @goto ext :nowatermark @ECHO !No watermark! @goto ext :ext @del "%1" @del "%1".txt @exit :panic @ECHO Could not record audio! Panic! @echo Could not record audio > result.txt @exit
This batch performs recording from the sound card input into a wave file (audio slice) and then performs watermark detection in the recorded wave using AWT2 decoder. If a watermark is detected, the recorded wave file is sent by e-mail in the attachment together with the information about detected watermark in the message body. You need to put appropriate information into mail addresses and mail server parameters in the Blat tool calling string. All watermarked waves are stored in ‘watermarked’ sub-folder. In case of no watermark, the recorded audio slice is deleted.
You should have the following files structure:
_rec_and_analyze.bat AWT2Monitor-runme.bat blat.dll pthreadgc2.dll zlib1.dll awt2_dec.exe blat.exe sox.exe
Before running this simple monitoring system, make the desired sound card input to be the default recording audio source in your Windows OS (in Windows 7, go to “Recording devices” tab, right-click with your mouse on the desired sound card input and chose “Set as Default Device”). In the audio device properties (or in the volume mixer) set appropriate recording level to avoid audio signal clipping.
Run ‘AWT2Monitor-runme.bat’ to start live audio stream listening and analysis.
The new AWT2 0.09.00 is a major AWT2 release. Here is what’s new:
– AWT2 encoder uses new, redesigned encoding algorithm (backward compatible with the older one). The new algorithm features new “-modulation_gain” parameter that triggers an additional modulation mechanism of the encoder aimed to increase watermark robustness. With default setting (0 dB) the modulation of the signal is not performed. Lower values (e.g. -6 dB) enable special modulation of sub-band signals that helps the watermarks to withstand audio transformations and corruptions. In addition, the use of the modulation improves watermarking reliability of monotonous signals. “Safe” (imperceptible) modulation gain values are from 0 to -12 dB. The setting is available in the command-line encoder tool only (not in the GUI front-end).
– new “-noise_level” parameter in the encoder which defines a level of artificially generated noise mixed into the processed audio signal. This feature resolves a problem with watermarking of speech recordings. Typical speech recordings usually contain many regions of silence (pauses between words and phrases). Due to the lack of any audible information in these regions, the watermarks cannot be added into them, that reduces overall watermark robustness in the output signal. To overcome this problem, artificially generated low-level “comfort noise” can be mixed into the source audio signal to fill the silent gaps and allow carrying watermarks even in originally silent regions. It is recommended to use this feature to watermark speech recordings. Recommended noise level setting is around -50 dB (optimal setting can vary depending on input signal level and content). The setting is available in the command-line encoder tool only (not in the GUI front-end).
– new “-output_gain” parameter in the encoder that defines attenuation level of the output (watermarked) signal. As a result of encoder’s signal processing, the output signal amplitude can become higher than the input. To prevent possible saturation/clipping of the output signal, limiter is applied on the very last stage of the processing. However, in some cases use of the limiter may be not desirable. The user can specify a desired output attenuation gain to avoid automatic limitation of the output signal. The setting is available in the command-line encoder tool only (not in the GUI front-end).
– increased encoder and decoder execution speed (various memory and code optimizations made)
– fixed bug in SDK (“high capacity” mode was set incorrectly)
– fixed minor problem with encoding of tailing 200ms of audio
– fixed potential encoder crash in case of wrong -skip_first / -skip_last values
– updated AWT2 User Guide and AWT2 SDK.
AWT2 free evaluation package is available here.
