From 53af3d325fd8f623dc6625539182fcaf7ac9e0f8 Mon Sep 17 00:00:00 2001
From: Muaz Ahmad <mahmad2000@protonmail.com>
Date: Fri, 8 Sep 2023 14:56:21 +0500
Subject: [PATCH] Moved transcoder command creation to separate package
 entirely

---
 rtmp/flv/writer.go       | 26 ++------------------------
 transcoder/transcoder.go | 40 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 24 deletions(-)
 create mode 100644 transcoder/transcoder.go

diff --git a/rtmp/flv/writer.go b/rtmp/flv/writer.go
index cfe5beb..341bf3f 100644
--- a/rtmp/flv/writer.go
+++ b/rtmp/flv/writer.go
@@ -2,9 +2,8 @@ package flv
 
 import (
 	"io"
-	"os/exec"
 	"encoding/binary"
-	"os"
+	"stream_server/transcoder"
 )
 
 type FLVWriter struct {
@@ -12,29 +11,8 @@ type FLVWriter struct {
 }
 
 func NewFLVWriter(stream_key string) (*FLVWriter, error) {
-	base_dir, _ := os.UserHomeDir()
 	writer := new(FLVWriter)
-	// spawn ffmpeg as a transcoder + hls segmenter
-	// most are generic commands, added a prefix to each segment url to make serving it over http easier
-	transcoder := exec.Command(
-		"ffmpeg",
-		"-probesize", "500",
-		"-i", "pipe:0",
-		"-c:a", "aac",
-		"-c:v", "h264",
-		"-b:v", "1M",
-		"-g", "30",
-		"-hls_time", "6",
-		"-hls_list_size", "4",
-		"-hls_base_url", "/vid/" + stream_key + "/",
-		"-hls_segment_type", "fmp4",
-		"-hls_flags", "delete_segments",
-		"-hls_flags", "+program_date_time",
-		"stream.m3u8",
-	)
-	transcoder.Dir = base_dir + "/live/" + stream_key + "/" // shift to the appropriate dir for the given stream key
-	flvpipe, err := transcoder.StdinPipe() // give control over the ffmpeg input as a stdin pipe (will push in flv packets as they come)
-	transcoder.Start() // spawn ffmpeg
+	flvpipe, err := transcoder.NewTranscoder(stream_key) // give control over the ffmpeg input as a stdin pipe (will push in flv packets as they come)
 	if err != nil {
 		return nil, err
 	}
diff --git a/transcoder/transcoder.go b/transcoder/transcoder.go
new file mode 100644
index 0000000..1ec1051
--- /dev/null
+++ b/transcoder/transcoder.go
@@ -0,0 +1,40 @@
+package transcoder
+
+import (
+	"os/exec"
+	"os"
+	"io"
+)
+
+func NewTranscoder(stream_key string) (io.WriteCloser, error) {
+	base_dir, _ := os.UserHomeDir()
+	command := "ffmpeg"
+	command_args := []string{
+		"-probesize", "500",
+		"-i", "pipe:0",
+		"-c:a", "libopus",
+		"-c:v", "vp9", 
+			"-quality", "realtime", 
+			"-speed", "7", 
+			"-tile-columns", "4", 
+			"-frame-parallel", "1", 
+			"-threads", "8",
+		"-b:v", "1M",
+		"-g", "30",
+		"-hls_time", "6",
+		"-hls_list_size", "4",
+		"-hls_base_url", "/vid/" + stream_key + "/",
+		"-hls_segment_type", "fmp4",
+		"-hls_flags", "delete_segments",
+		"-hls_flags", "+program_date_time",
+		"stream.m3u8",
+	}
+	transcoder := exec.Command(command, command_args...)
+	transcoder.Dir = base_dir + "/live/" + stream_key + "/"
+	data_in, err := transcoder.StdinPipe()
+	if err != nil {
+		return nil, err
+	}
+	transcoder.Start()
+	return data_in, nil
+}