Using the Beagle USB 480 Protocol Analyzer, Data Center Software, and a third party digital audio editor, developers can capture and decode USB audio protocol to measure audio signal quality. This can be accomplished by exporting USB audio data files from the Data Center trace between USB devices like a USB type headset/earphone and an audio player such as a mobile phone. By converting the .tdc file into to a .wav file using third party software, users can essentially extract audio files from this trace. Below are steps to achieve this:
Step 1: Capture the USB audio data via the Data Center Software. In the example image, audio was played on the headset from a PC, so OUT transactions are audio raw data.
Step 2: Uncheck SOFs/Keep-Alives in the LiveFilter pane to keep only OUT transactions and filter out all other transactions.
Step 3: Clip out the before and after indices of OUT transactions by right clicking on the top most/bottom most OUT transaction→ Quick Filters→ Exclude Indices Before/Exclude Indices After respectively.
Step 4: Right click on the top-most row, deselect all columns except "DATA" column.
After all steps applied, the trace should look like the example below:
Step 5: To export the data, select File → Export and choose .bin as the file type.
Step 6: The .bin file can be imported as RAW file in Audacity to convert to .wav file. In Audacity, import the .bin file (File→ Import→ Raw Audio). Please make sure to use the correct encoding scheme, bitrate, endian-ness, mono/stereo as the original audio to regenerate the audio correctly.
Step 7. Play the RAW audio to verify. If the desired audio is not heard, adjust the parameters in the Import Raw Audio window and try again. If the desired audio is obtained, select File→Export→ Export as WAV and save.