...
WAV files will be converted, by freac (Free Audio Converter) a tool yet undeterminedmentioned on the flac project's page, into .flac files before they're uploaded. It has multi-platform support so can be used for most operating systems.
Question: Do we want to merge the oral history audio files into a single file? Some of the sections are very short (1-3 minutes) while in other cases the sections can be quite long leading to a file that's hours long. My suggestion is we take a page from the Oral History division (into sections like 1-1, 1-2) when they do interviews over multiple times. Each session (1-1 though 1-X) is combined into a single file, where 2-1 would be in a second file. This may make downloading or playing them tricky. Perhaps the same technique we use for the books to provide a zipped file with all of the sections would be best when someone wants to download an interview consisting of multiple sessions.
Response from Lee Berry, Curator of Oral Histories (via Nicole J. email 3/6/19): "I’m disinclined to merge the audio files, since they’re usually indicated in the transcript and it can be helpful to know which audio file you’re listening to as you navigate the PDF." Based on her response, let's move ahead with a zipped folder containing all the sections within a single interview.
flac assurance: To make sure what our flac file is a proper copy, even though we are not promising preservation, we need to be sure that the flac can be transferred back to the wav file with no changes in data. This is done by taking a checksum of the original wav and then after the flac is made generating a new wav from the flac and comparing its checksum to the original file. The tool used for the conversion is freac (to make the flac) and the flac command line tool to rebuild a new wav. In all cases the flac command line tool is considered to be the gold standard for conversion in or out of the flac format, not ffmpeg. Other tools, Audacity, were tested but did not generate the same checksum between the new and old wav files, making any future programmatic comparisons difficult.
Content not covered:
- We will not be working at all with WMA files yet due to issues in handling the audio codec and questions about the best option for conversion. As there are very few of these files this should not be a problem.
- We will not transfer or preserve any tags on the audio files themselves. Currently (3/2019) it does not seem like any Oral Histories use tags on the audio file itself.
- We are serving as a method of access for the Oral Histories, not as a preservation system. We will preserve the files we have to the same standards other digital collections files are preserved but Oral Histories is handling the preservation of their files themselves according to their practices.
...