From e954df3f896bd18494cd27d77b26bbb2005de8a7 Mon Sep 17 00:00:00 2001
From: JSDurand <mmemmew@gmail.com>
Date: Wed, 24 Aug 2022 23:54:13 +0800
Subject: First commit

Now the project is in a somewhat complete state, ready for future
enhancements.
---
 src/output/mod.rs | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 src/output/mod.rs

(limited to 'src/output/mod.rs')

diff --git a/src/output/mod.rs b/src/output/mod.rs
new file mode 100644
index 0000000..520a500
--- /dev/null
+++ b/src/output/mod.rs
@@ -0,0 +1,68 @@
+//! This file implements the interface to save waves into a file.
+
+use std::{
+    error::Error,
+    fmt::{self, Display, Formatter},
+    io::{self, Write},
+};
+
+use super::*;
+
+#[derive(Debug)]
+pub enum OutputError {
+    Io(std::io::Error),
+    FFMpeg(String),
+    EmptyWaves,
+}
+
+impl Display for OutputError {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Io(e) => write!(f, "io: {e}"),
+            Self::EmptyWaves => write!(f, "empty waves"),
+            OutputError::FFMpeg(s) => write!(f, "FFMPEG error: {s}"),
+        }
+    }
+}
+
+impl Error for OutputError {}
+
+impl From<io::Error> for OutputError {
+    fn from(io: io::Error) -> Self {
+        Self::Io(io)
+    }
+}
+
+/// A type that implements this trait implements a generic function
+/// for saving waves into files.
+pub trait Output {
+    /// Save waves DATA with RATE samples per second into a file with
+    /// NAME.
+    fn save(&self, data: Wave, rate: Samples, name: &str) -> Result<(), OutputError>;
+}
+
+/// A dummy struct to hold a generic function for saving waves.
+#[derive(Default)]
+pub struct PlainOutput {}
+
+impl Output for PlainOutput {
+    fn save(&self, data: Wave, _rate: Samples, name: &str) -> Result<(), OutputError> {
+        if data.is_empty() {
+            return Err(OutputError::EmptyWaves);
+        }
+
+        let bytes: Vec<u8> = data.iter().flat_map(|pulse| pulse.to_le_bytes()).collect();
+
+        let mut file = std::fs::OpenOptions::new()
+            .create(true)
+            .write(true)
+            .open(name)?;
+
+        file.write_all(&bytes)?;
+
+        Ok(())
+    }
+}
+
+#[cfg(feature = "ffmpeg")]
+pub mod ffmpeg_output;
-- 
cgit v1.2.3-18-g5258