Audio File Parser

Instructions:

• Write a ruby script that accepts a directory as an input. Eg. ruby audio_parser.rb <input_dir>

  • This script will extract metadata information from Wav files.
  • Any non Wav files will be ignored by the script.
  • The script should be able to generate applicable output(s) even if some files are ignored.

• Extract the following metadata information from the Wav files.

  • IMPORTANT! You must not use any existing third party executable to extract the data like mediainfo or ffprobe.
  • You are allowed to use any ruby library to help you read and interpret the bytes from the input files.

Attribute	Type	Sample Value	Mediainfo equivalend field name
Format	String	1 = "PCM",	Audio format
		any other value = "Compressed"
Channel Count	Integer	2	Channel(s)
Sampling Rate	Integer	88200 or 88.2 kHz	Sampling Rate
Byte Rate	Integer	150000	None
Bit Depth	Integer	32	Bit depth
Bit Rate	Integer	2822400	Bit rate

Notes:

• Bit Rate is calculated using the formula: Sampling Rate _ Channel Count _ Bit Depth
• Format is either 1 or other integer number but for this exercise, we will map it to "PCM" if you detected 1 or "Compressed" for other integer values.

Output

• Generate an output folder and the current timestamp to store your output files.
  • Eg. output/1708976890/sample-file-3.xml
• Write the output in an xml file using the provided wav.xsd file as your guide.
  • Each valid file should have a corresponding xml using the same file name. E.g. sample-file-3.xml
  • You are allowed to use any existing ruby xml libraries to make xml building faster.
• We will run your code over the given input_files and check the generated output xmls.

Bonus Points

• Handling Errors
• Unit Test

Hint

• You would have to do a quick research on the structure of a Wav file. (Easily found information)
• You can also check Resource Interchange File Format (RIFF).
• You don't need to parse the whole file. You just need to parse where the metadata info is stored.
• You can use mediainfo to validate your output manually.

Enjoy this Music Related Exercise :)

## Solution

Requirements;

Ruby 3.0.0 is required to run this program.

User Documentation:

To use the audio parser, run the ruby file and pass in the input_files directory as an argument.

ruby audio_parser.rb ./input_files