Duration seems to be reported too long

[bpeperkamp]

Reproducer

Thanks for creating Lofty!

I do have a question though. It seems that the duration from properties is off, or i am doing something wrong. It happens with all file types. An example (also happens with other formats):

let mut file_content = File::open(entry.path())?;
let wav_file = WavFile::read_from(&mut file_content, ParseOptions::new())?;
println!("WAV: {}", wav_file.properties().duration().as_secs());

In all found files the duration is reported longer than it actually is. An example file will report 208 secs (3:48 mins). While sox/vlc/ffmpeg will report it as: 3:28 mins. The amount of samples is 9211020 and the sample rate is 44100 Hz.

9211020/44100 = 208.866666667 (which explains the duration)

Am i missing something here?

Summary

The file duration seems to report higher values

Expected behavior

It should report the duration correctly

Assets

No response

[bpeperkamp]

I'll try to figure it out, will make a pull request/comment if i do :)

[Serial-ATA]

Am i missing something here?

Nope! Lofty tries not to read too much into the actual audio data, only what's absolutely needed (which can sometimes be wrong). Some difference from FFmpeg is acceptable, for example see the AAC properties test:

lofty-rs/lofty/src/properties/tests.rs

Lines 30 to 32 in 59184c0

	duration: Duration::from_millis(1474), /* TODO: This is ~100ms greater than FFmpeg's report, can we do better? */
	overall_bitrate: 117, // 9 less than FFmpeg reports
	audio_bitrate: 117, // 9 less than FFmpeg reports

But a 20sec difference is pretty bad.

Feel free to email a file to serial AT [domain on my profile], I can look into it when I have time.