Improve player (#823)

* Improve error handling
* Harmonize `Seek`: Make the decoders and player use the same math for converting between samples and milliseconds
* Reduce duplicate calls: Make decoder seek in PCM, not ms
* Simplify decoder errors with `thiserror`

playback/src/audio_backend/portaudio.rs

@@ -148,7 +148,10 @@ impl<'a> Sink for PortAudioSink<'a> {
             };
         }
 
-        let samples = packet.samples();
+        let samples = packet
+            .samples()
+            .map_err(|e| io::Error::new(io::ErrorKind::Other, e.to_string()))?;
+
         let result = match self {
             Self::F32(stream, _parameters) => {
                 let samples_f32: &[f32] = &converter.f64_to_f32(samples);