Bolette Jurik (SB)
This test used only one of the 5 servers in the SB Test Platform, see EVAL-LSDR6-1.
Informally the workflow is as follows. Migration from Mp3 to Wav is done using FFmpeg which is one of the SCAPE Action Services recommended tools. The QA is split into a number of steps. The first step is validation that the migrated file is a correct file in the wanted format. This is done using JHOVE2.The second step compares the header information properties of the original and the migrated files to see if they are ‘close enough’. This is done using Ffprobe to extract header information and Taverna Beanshells to compare the extracted properties. Another step could be to extract more properties by ‘playing’ the two files.
The third step uses an analysis tool comparing the sound waves. To do this we have to ‘play’ or interpret the mp3 file, just as a human needs to ‘play’ or interpret the file to hear the sound. The player used in this workflow is MPG321. Note that MPG321 is an independent implementation of an mp3-decoder – thus independent from FFmpeg, which is used to actually migrate the file. The result of playing the file is a WAV file. The migrated file is already a WAV file, and we can compare the two files using the analysis tool xcorrSound waveform-compare (earlier migrationQA).