👕 refactor: removed the memcpy by moving it to a place where I had to memcpy anyway

src/decoder.rs

@@ -1,15 +1,11 @@
-use std::{
-	io::Cursor,
-};
-
 use anyhow::{
 	anyhow,
 	Result,
 };
 
 use byteorder::{
+	ByteOrder,
 	LittleEndian,
-	ReadBytesExt,
 };
 
 // This crate flitters between being very convenient and being a type labyrinth.
@@ -24,15 +20,42 @@ use ffmpeg_next::{
 			self,
 			Sample,
 		},
-		frame::Audio as AudioFrame,
+		frame::Audio as FfAudioFrame,
 	},
 };
 
 pub const SAMPLE_RATE: u32 = 48000;
 
+pub struct AudioFrame {
+	frame: FfAudioFrame,
+}
+
+impl AudioFrame {
+	pub fn data (&self) -> &[u8] {
+		// Hard-coded because I'm only support f32 interleaved stereo
+		&self.frame.data (0) [0..self.frame.samples () * 4 * 2]
+	}
+	
+	pub fn rate (&self) -> u32 {
+		self.frame.rate ()
+	}
+	
+	pub fn samples (&self) -> usize {
+		self.frame.samples ()
+	}
+}
+
+impl From <FfAudioFrame> for AudioFrame {
+	fn from (frame: FfAudioFrame) -> Self {
+		Self {
+			frame,
+		}
+	}
+}
+
 #[derive (Default)]
 pub struct PcmBuffers {
-	buffers: Vec <Vec <f32>>,
+	buffers: Vec <Vec <u8>>,
 	
 	// Always points into the first buffer, if any
 	consumer_cursor: usize,
@@ -40,7 +63,7 @@ pub struct PcmBuffers {
 
 impl PcmBuffers {
 	pub fn samples_available (&self) -> usize {
-		self.buffers.iter ().map (|b| b.len ()).sum::<usize> () - self.consumer_cursor
+		(self.buffers.iter ().map (|b| b.len ()).sum::<usize> () - self.consumer_cursor) / 8
 	}
 	
 	#[warn(unused_must_use)]
@@ -55,31 +78,16 @@ impl PcmBuffers {
 				self.consumer_cursor = 0;
 			}
 			
-			*x = self.buffers [0][self.consumer_cursor];
-			self.consumer_cursor += 1;
+			*x = LittleEndian::read_f32 (&self.buffers [0][self.consumer_cursor..]);
+			self.consumer_cursor += 4;
 		}
 		
 		true
 	}
 	
-	pub fn produce (&mut self, new_buffer: Vec <f32>) {
+	pub fn produce_bytes (&mut self, new_buffer: Vec <u8>) {
 		self.buffers.push (new_buffer);
 	}
-	
-	pub fn produce_bytes (&mut self, new_buffer: &[u8]) {
-		let mut b = vec! [0.0f32; new_buffer.len () / 4];
-		let mut rdr = Cursor::new (new_buffer);
-		
-		rdr.read_f32_into::<LittleEndian> (&mut b).unwrap ();
-		
-		self.produce (b);
-	}
-}
-
-#[derive (Default)]
-pub struct SharedState {
-	pub pcm_buffers: PcmBuffers,
-	pub quit: bool,
 }
 
 pub struct Decoder {
@@ -88,7 +96,7 @@ pub struct Decoder {
 	pub resampler: ResamplingContext,
 	
 	best_stream_idx: usize,
-	dummy_frame: Option <AudioFrame>,
+	dummy_frame: Option <FfAudioFrame>,
 }
 
 impl Decoder {
@@ -117,8 +125,8 @@ impl Decoder {
 		})
 	}
 	
-	fn new_frame () -> AudioFrame {
-		let mut x = AudioFrame::empty ();
+	fn new_frame () -> FfAudioFrame {
+		let mut x = FfAudioFrame::empty ();
 		x.set_channel_layout (ChannelLayout::STEREO);
 		x.set_format (Sample::F32 (sample::Type::Packed));
 		x
@@ -129,18 +137,6 @@ impl Decoder {
 			assert_eq! (frame.rate (), 48000);
 			assert! (frame.samples () > 0);
 			
-			let actual_bytes = frame.data (0).len ();
-			let expected_bytes = frame.samples () * 4 * 2;
-			
-			assert! (actual_bytes >= expected_bytes);
-			
-			if actual_bytes > expected_bytes {
-				let extra_bytes = actual_bytes - expected_bytes;
-				let extra_samples = extra_bytes / 4 / 2;
-				// tracing::debug! ("Extra bytes: {}", extra_bytes);
-				// tracing::debug! ("Extra samples: {}", extra_samples);
-			}
-			
 			Some (frame)
 		}
 		else {
@@ -191,7 +187,7 @@ impl Decoder {
 		
 		Ok (if frame_resampled.samples () > 0 {
 			// tracing::trace! ("Pulled from resampler FIFO");
-			Some (frame_resampled)
+			Some (frame_resampled.into ())
 		}
 		else {
 			None
@@ -199,13 +195,13 @@ impl Decoder {
 	}
 	
 	pub fn pump_decoder (&mut self) -> Result <Option <AudioFrame>> {
-		let mut frame_src = AudioFrame::empty ();
+		let mut frame_src = FfAudioFrame::empty ();
 		if let Err (_) = self.decoder.receive_frame (&mut frame_src) {
 			return Ok (None);
 		};
 		
 		if self.dummy_frame.is_none () {
-			let mut dummy_frame = AudioFrame::new (
+			let mut dummy_frame = FfAudioFrame::new (
 				frame_src.format (),
 				0,
 				frame_src.channel_layout (),
@@ -216,14 +212,14 @@ impl Decoder {
 		
 		let nb_output_samples = frame_src.samples ();
 		
-		let mut frame_resampled = AudioFrame::new (
+		let mut frame_resampled = FfAudioFrame::new (
 			Sample::F32 (sample::Type::Packed),
 			nb_output_samples,
 			ChannelLayout::STEREO
 		);
 		
 		self.resampler.run (&frame_src, &mut frame_resampled)?;
-		Ok (Some (frame_resampled))
+		Ok (Some (frame_resampled.into ()))
 	}
 	
 	pub fn pump_demuxer (&mut self) -> Result <bool> {

src/main.rs

@@ -52,8 +52,7 @@ fn cmd_debug_dump (args: &[String]) -> Result <()> {
 	let mut f = File::create ("pcm-dump.data")?;
 	
 	while let Some (frame) = decoder.next ()? {
-		f.write_all (&frame.data (0) [0..frame.samples () * 4 * 2])?;
-		// f.write_all (frame.data (0))?;
+		f.write_all (frame.data ())?;
 	}
 	
 	Ok (())
@@ -78,6 +77,12 @@ fn cmd_debug_pipe (args: &[String]) -> Result <()> {
 	
 	Ok (())
 }
+
+#[derive (Default)]
+pub struct SharedState {
+	pub pcm_buffers: decoder::PcmBuffers,
+	pub quit: bool,
+}
 	
 fn cmd_play (args: &[String]) -> Result <()> {
 	tracing_subscriber::fmt::init ();
@@ -87,7 +92,7 @@ fn cmd_play (args: &[String]) -> Result <()> {
 	.map (|s| s.to_string ())
 	.collect ();
 	
-	let pair = Arc::new ((Mutex::new (decoder::SharedState::default ()), Condvar::new ()));
+	let pair = Arc::new ((Mutex::new (SharedState::default ()), Condvar::new ()));
 	let pair2 = Arc::clone (&pair);
 	let pair3 = Arc::clone (&pair);
 	
@@ -116,7 +121,7 @@ fn cmd_play (args: &[String]) -> Result <()> {
 				while pcm_buffers.samples_available () < 12_000 {
 					// tracing::trace! ("Decoder is trying to work...");
 					match decoder.next ()? {
-						Some (frame) => pcm_buffers.produce_bytes (&frame.data (0) [0..frame.samples () * 4 * 2]),
+						Some (frame) => pcm_buffers.produce_bytes (frame.data ().into ()),
 						None => {
 							tracing::info! ("Finished decoding file");
 							break 'one_file;