♻️ refactor

src/decoder.rs

@@ -91,24 +91,19 @@ impl PcmBuffers {
 }
 
 pub struct Decoder {
-	input_ctx: DemuxContext,
+	demuxer: FfmpegDemuxer,
+	
 	decoder: DecodeContext,
 	resampler: ResamplingContext,
 	
-	best_stream_idx: usize,
 	dummy_frame: Option <FfAudioFrame>,
 }
 
 impl Decoder {
 	pub fn new (filename: &str) -> Result <Self> {
-		let input_ctx = ffmpeg_next::format::input (&filename)?;
-		let stream = input_ctx
-		.streams ()
-		.best (ffmpeg_next::media::Type::Audio)
-		.ok_or_else (|| anyhow! ("can't find good audio stream"))?;
-		let best_stream_idx = stream.index ();
+		let (demuxer, codec) = FfmpegDemuxer::new (filename)?;
 		
-		let decoder = stream.codec ().decoder ().audio ()?;
+		let decoder = codec.decoder ().audio ()?;
 		let resampler = decoder.resampler (
 			Sample::F32 (sample::Type::Packed),
 			ChannelLayout::STEREO,
@@ -116,11 +111,10 @@ impl Decoder {
 		)?;
 		
 		Ok (Self {
-			input_ctx,
+			demuxer,
 			decoder,
 			resampler,
 			
-			best_stream_idx,
 			dummy_frame: None,
 		})
 	}
@@ -223,15 +217,14 @@ impl Decoder {
 	}
 	
 	pub fn pump_demuxer (&mut self) -> Result <bool> {
-		while let Some ((stream, packet)) = self.input_ctx.packets ().next () {
-			if stream.index () == self.best_stream_idx {
-				// tracing::trace! ("demuxed packet");
-				self.decoder.send_packet (&packet)?;
-				return Ok (true);
-			}
-		}
+		let packet = self.demuxer.pump ()?;
+		let packet = match packet {
+			Some (x) => x,
+			None => return Ok (false),
+		};
 		
-		Ok (false)
+		self.decoder.send_packet (&packet)?;
+		Ok (true)
 	}
 }
 
@@ -242,11 +235,10 @@ trait Demuxer {
 struct FfmpegDemuxer {
 	input_ctx: DemuxContext,
 	best_stream_idx: usize,
-	decoder: DecodeContext,
 }
 
 impl FfmpegDemuxer {
-	pub fn new (filename: &str) -> Result <Self> {
+	pub fn new (filename: &str) -> Result <(Self, ffmpeg_next::codec::Context)> {
 		let input_ctx = ffmpeg_next::format::input (&filename)?;
 		let stream = input_ctx
 		.streams ()
@@ -254,27 +246,25 @@ impl FfmpegDemuxer {
 		.ok_or_else (|| anyhow! ("can't find good audio stream"))?;
 		let best_stream_idx = stream.index ();
 		
-		let decoder = stream.codec ().decoder ().audio ()?;
+		let codec = stream.codec ();
 		
-		Ok (Self {
+		Ok ((Self {
 			input_ctx,
 			best_stream_idx,
-			decoder,
-		})
+		}, codec))
 	}
 }
 
 impl FfmpegDemuxer {
-	fn pump (&mut self) -> Result <bool> {
+	fn pump (&mut self) -> Result <Option <ffmpeg_next::Packet>> {
 		while let Some ((stream, packet)) = self.input_ctx.packets ().next () {
 			if stream.index () == self.best_stream_idx {
 				// tracing::trace! ("demuxed packet");
-				self.decoder.send_packet (&packet)?;
-				return Ok (true);
+				return Ok (Some (packet));
 			}
 		}
 		
-		Ok (false)
+		Ok (None)
 	}
 }