Seeking, buffer size and error handing improvements

- Set ideal sample buffer size after decoding first full packet
- Prevent audio glitches after seeking
- Reset decoder when the format reader requires it

Credits: @pdeljanov
This commit is contained in:
Roderick van Domburg 2022-01-04 21:23:53 +01:00
parent a49bcb70a7
commit eabdd79275
No known key found for this signature in database
GPG key ID: A9EF5222A26F0451

View file

@ -1,7 +1,7 @@
use std::io;
use symphonia::core::{
audio::{SampleBuffer, SignalSpec},
audio::SampleBuffer,
codecs::{Decoder, DecoderOptions},
errors::Error,
formats::{FormatReader, SeekMode, SeekTo},
@ -16,13 +16,13 @@ use super::{AudioDecoder, AudioPacket, DecoderError, DecoderResult};
use crate::{
metadata::audio::{AudioFileFormat, AudioFiles},
player::NormalisationData,
PAGES_PER_MS,
NUM_CHANNELS, PAGES_PER_MS, SAMPLE_RATE,
};
pub struct SymphoniaDecoder {
decoder: Box<dyn Decoder>,
format: Box<dyn FormatReader>,
sample_buffer: SampleBuffer<f64>,
sample_buffer: Option<SampleBuffer<f64>>,
}
impl SymphoniaDecoder {
@ -48,15 +48,6 @@ impl SymphoniaDecoder {
hint.mime_type("audio/flac");
}
let max_format_size = if AudioFiles::is_ogg_vorbis(format) {
8192
} else if AudioFiles::is_mp3(format) {
2304
} else {
// like FLAC
65535
};
let format_opts = Default::default();
let metadata_opts: MetadataOptions = Default::default();
let decoder_opts: DecoderOptions = Default::default();
@ -79,30 +70,27 @@ impl SymphoniaDecoder {
DecoderError::SymphoniaDecoder("Could not retrieve channel configuration".into())
})?;
if rate != crate::SAMPLE_RATE {
if rate != SAMPLE_RATE {
return Err(DecoderError::SymphoniaDecoder(format!(
"Unsupported sample rate: {}",
rate
)));
}
if channels.count() != crate::NUM_CHANNELS as usize {
if channels.count() != NUM_CHANNELS as usize {
return Err(DecoderError::SymphoniaDecoder(format!(
"Unsupported number of channels: {}",
channels
)));
}
let max_frames = decoder
.codec_params()
.max_frames_per_packet
.unwrap_or(max_format_size);
let sample_buffer = SampleBuffer::new(max_frames, SignalSpec { rate, channels });
Ok(Self {
decoder,
format,
sample_buffer,
// We set the sample buffer when decoding the first full packet,
// whose duration is also the ideal sample buffer size.
sample_buffer: None,
})
}
@ -171,6 +159,10 @@ impl AudioDecoder for SymphoniaDecoder {
},
)?;
// Seeking is a `FormatReader` operation, so the decoder cannot reliably
// know when a seek took place. Reset it to avoid audio glitches.
self.decoder.reset();
Ok(self.ts_to_ms(seeked_to_ts.actual_ts))
}
@ -184,23 +176,33 @@ impl AudioDecoder for SymphoniaDecoder {
return Err(DecoderError::SymphoniaDecoder(err.to_string()));
}
}
Err(Error::ResetRequired) => {
self.decoder.reset();
return self.next_packet();
}
Err(err) => {
return Err(err.into());
}
};
let position_ms = self.ts_to_ms(packet.pts());
match self.decoder.decode(&packet) {
Ok(audio_buf) => {
self.sample_buffer.copy_interleaved_ref(audio_buf);
let position_ms = self.ts_to_ms(packet.pts());
let samples = AudioPacket::Samples(self.sample_buffer.samples().to_vec());
Ok(decoded) => {
if self.sample_buffer.is_none() {
let spec = *decoded.spec();
let duration = decoded.capacity() as u64;
self.sample_buffer
.replace(SampleBuffer::new(duration, spec));
}
let sample_buffer = self.sample_buffer.as_mut().unwrap(); // guaranteed above
sample_buffer.copy_interleaved_ref(decoded);
let samples = AudioPacket::Samples(sample_buffer.samples().to_vec());
Ok(Some((position_ms, samples)))
}
Err(Error::ResetRequired) => {
// This may happen after a seek.
self.decoder.reset();
self.next_packet()
}
// Also propagate `ResetRequired` errors from the decoder to the player,
// so that it will skip to the next track and reload the entire Symphonia decoder.
Err(err) => Err(err.into()),
}
}