File size limitations

What's the maximum duration of a dictation?

The maximum size of an audio file depends on several limitations.

File system limitations

Maximum file size

Hard drives (or hard-drive partitions) are formatted using one of several file system types. The maximum size of a file depends on which file system is in use.

The file system of a drive can be found in Windows by right-clicking on the drive in Windows Explorer and selecting Properties. Please consider the file system of this software's working folder, as well as the file systems of any network shared folders that are being used.

Audio file size

This software stores audio internally using 16-bit uncompressed PCM WAV files. The number of bytes per second needed to store one of these audio recordings depends on the sample rate (also known as frequency) and the number of channels.

Maximum audio duration

To calculate the longest amount of audio that honours the maximum file size:

Maximum file size in bytes / (Bytes per second per channel * Number of channels) = Maximum number of seconds

Examples

2,147,483,648 / (88,200 * 2) = 12,173
The longest stereo 44KHz recording that will fit on a FAT16 file system is approximately 12,173 seconds (~3.3 hours).

4,294,967,296 / (44,100 * 4) = 24,347
The longest 4 channel 22KHz recording that will fit on a FAT32 file system is approximately 24,347 seconds (~6.7 hours).

Software limitations

This software is limited to a maximum of 2,147,483,647 samples per audio file. At a sample rate of 44KHz, that gives approximately 13.5 hours of audio.

Other considerations

Meta-data (such as dictation notes) and attachments that are stored in the same file as the audio, as is the case with the DCT file format, will increase the total size of a file.

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