encode/decode audio memes with ffmpeg to improve storage

2 files changed, 59 insertions, 15 deletions

diff --git a/src/audio/play_queue.rs b/src/audio/play_queue.rs
index 119b8c5..fcbb4f9 100644
--- a/src/audio/play_queue.rs
+++ b/src/audio/play_queue.rs
@@ -1,13 +1,13 @@
 use std::{
     collections::VecDeque,
-    io::Cursor,
+    io::{self, BufRead, BufReader, Cursor},
+    process,
     sync::{Arc, RwLock},
     thread,
     time::Duration,
 };
 
 use either::{Left, Right};
-use flate2::bufread::DeflateDecoder;
 use serenity::{
     prelude::*,
     voice,
@@ -94,9 +94,9 @@ impl PlayQueue {
                 }
 
                 let mut queue = queue_lck.write().unwrap();
-                let item = queue.queue.pop_front().unwrap();
+                let mut item = queue.queue.pop_front().unwrap();
 
-                let src = match item.data {
+                let src = match &mut item.data {
                     Left(ref url) => {
                         match ytdl(url, item.start, item.end) {
                             Ok(src) => src,
@@ -108,7 +108,52 @@ impl PlayQueue {
                         }
                     },
                     Right(ref vec) => {
-                        voice::pcm(true, DeflateDecoder::new(Cursor::new(vec.clone())))
+                        let mut transcoder = process::Command::new("ffmpeg")
+                            .args(&[
+                                "-format", "opus",
+                                "-i", "pipe:0",
+                                "-acodec", "pcm_s16le",
+                                "-f", "s16le",
+                                "-"
+                            ])
+                            .stdin(process::Stdio::piped())
+                            .stdout(process::Stdio::piped())
+                            .stderr(process::Stdio::piped())
+                            .spawn()
+                            .expect("unable to call ffmpeg");
+
+                        let process::Child {
+                            stdin,
+                            stderr,
+                            stdout,
+                            ..
+                        } = transcoder;
+
+                        thread::spawn(move || {
+                            let stderr = BufReader::new(stderr.unwrap());
+
+                            for line in stderr.lines() {
+                                let line = line.unwrap();
+
+                                trace!("{}", line);
+                            }
+                        });
+
+                        let v = vec.clone();
+                        thread::spawn(move || {
+                            if let Err(e) = io::copy(&mut Cursor::new(v), &mut stdin.unwrap()) {
+                                use std::io::ErrorKind;
+                                if e.kind() == ErrorKind::BrokenPipe {
+                                    debug!("ffmpeg closed unexpectedly");
+                                } else {
+                                    error!("copying audio to ffmpeg {}", e);
+                                }
+                            }
+                        });
+
+                        let result = voice::pcm(true, stdout.unwrap());
+
+                        result
                     }
                 };
 
diff --git a/src/audio/ytdl.rs b/src/audio/ytdl.rs
index e88d8f8..8239683 100644
--- a/src/audio/ytdl.rs
+++ b/src/audio/ytdl.rs
@@ -45,6 +45,8 @@ pub(crate) trait CodecInfo {
 }
 
 pub(crate) struct Pcm {}
+
+#[allow(dead_code)]
 pub(crate) struct Opus {}
 
 impl CodecInfo for Pcm {
@@ -66,12 +68,9 @@ impl CodecInfo for Opus {
     fn ffmpeg_opts() -> &'static[&'static str] {
         lazy_static! {
             static ref OPTS: Vec<&'static str> = vec! [
-//                "-f", "s16le",
+                "-f", "opus",
                 "-acodec", "libopus",
-                "-sample_fmt", "s16",
-                "-vbr", "off",
-//                "-b:a 96k",
-//                "-vn",
+                "-b:a 96k",
             ];
         }
 
@@ -129,6 +128,11 @@ pub(crate) fn ffmpeg_dl<T: CodecInfo>(uri: &str, start: Option<Duration>, end: O
         .map(|s| s.to_owned())
         .collect::<Vec<_>>();
 
+    if let Some(e) = end {
+        opts.push("-to".to_owned());
+        opts.push(format!("{:02}:{:02}:{:02}", e.num_hours(), e.num_minutes() % 60, e.num_seconds() % 60));
+    }
+
     let codec_opts = T::ffmpeg_opts().into_iter().map(|&s| s.to_owned()).collect::<Vec<_>>();
     opts.extend(codec_opts);
 
@@ -137,11 +141,6 @@ pub(crate) fn ffmpeg_dl<T: CodecInfo>(uri: &str, start: Option<Duration>, end: O
         opts.push(format!("{}", limit));
     }
 
-    if let Some(e) = end {
-        opts.push("-to".to_owned());
-        opts.push(format!("{:02}:{:02}:{:02}", e.num_hours(), e.num_minutes() % 60, e.num_seconds() % 60));
-    }
-
     opts.push("-".to_owned());
 
     debug!("ffmpeg -i \"{}\" {}", uri, opts.join(" "));