Extracting Audio Data from a Data Center Software USB Trace


Using the Beagle USB 480 Protocol Analyzer, Data Center software, and a third-party digital audio editor, developers can capture and decode the USB audio protocol to measure audio signal quality. This can be accomplished by exporting USB audio data files from Data Center Trace between USB devices such as a USB headphone/earphone and an audio player such as a cell phone. By converting the .tdc file to a .wav file using third-party software, users can essentially extract audio files from this recording. Below are the steps to achieve this:

Step 1: Capture the USB audio via the Data Center software. In the example image, audio was played from a PC via the headset, so the OUT transactions are raw audio data.







Step 2: Disable SOFs/Keep Alives in the LiveFilter window to keep only OUT transactions and filter out all other transactions.







Step 3: Cut out the before and after indices of OUT transactions by right-clicking the top/bottom OUT transaction→ Quick Filter→ Exclude Before Indices/Exclude After Indices.








Step 4: Right-click on the top row, deselect all columns except the "DATA" column.







After all the steps have been applied, the curve should look like the following example:







Step 5: To export the data, choose File → Export and select .bin as the file type.






Step 6: The .bin file can be imported into Audacity as a RAW file to convert it to a .wav file. In Audacity, import the .bin file (File→ Import→ Raw Audio). Be sure to use the correct encoding scheme, bit rate, endianity, and mono/stereo as the original audio to regenerate the audio correctly.






Step 7. Play the RAW audio to check it. If the desired audio is not heard, adjust the parameters in the Import Raw Audio window and try again. When the desired audio is obtained, choose File→Export→ Export as WAV and save.



USB 480 Protocol Analyzer
The Beagle USB 480 Protocol Analyzer is a high-speed, distortion-free bus monitor. Developers can monitor the data traffic on the USB bus, this in real time with a packet-level time resolution of 16.67 ns.