From 25d5db8db6f63d5a5263de5c9ee0d5323bc9b533 Mon Sep 17 00:00:00 2001
From: Alex Gleason <alex@alexgleason.me>
Date: Thu, 27 Feb 2025 20:06:23 -0600
Subject: [PATCH] transcode: use a structured object for ffmpeg options

---
 packages/ditto/utils/transcode.ts | 37 +++++++++++++------------------
 1 file changed, 15 insertions(+), 22 deletions(-)

diff --git a/packages/ditto/utils/transcode.ts b/packages/ditto/utils/transcode.ts
index 8062f85a..3d8d8162 100644
--- a/packages/ditto/utils/transcode.ts
+++ b/packages/ditto/utils/transcode.ts
@@ -1,26 +1,19 @@
-export async function transcodeVideoStream(
-  inputStream: ReadableStream<Uint8Array>,
-): Promise<ReadableStream<Uint8Array>> {
+export async function transcodeVideoStream(input: ReadableStream<Uint8Array>): Promise<ReadableStream<Uint8Array>> {
+  const opts = {
+    'i': 'pipe:0', // Read input from stdin
+    'c:v': 'libx264', // Convert to H.264
+    'preset': 'veryfast', // Encoding speed
+    'loglevel': 'fatal', // Suppress logs
+    'crf': '23', // Compression level (lower = better quality)
+    'c:a': 'aac', // Convert to AAC audio
+    'b:a': '128k', // Audio bitrate
+    'movflags': 'frag_keyframe+empty_moov', // Ensures MP4 streaming compatibility
+    'f': 'mp4', // Force MP4 format
+  };
+
   const command = new Deno.Command('ffmpeg', {
     args: [
-      '-i',
-      'pipe:0', // Read input from stdin
-      '-c:v',
-      'libx264', // Convert to H.264
-      '-preset',
-      'veryfast', // Encoding speed
-      '-loglevel',
-      'fatal', // Suppress logs
-      '-crf',
-      '23', // Compression level (lower = better quality)
-      '-c:a',
-      'aac', // Convert to AAC audio
-      '-b:a',
-      '128k', // Audio bitrate
-      '-movflags',
-      'frag_keyframe+empty_moov', // Ensures MP4 streaming compatibility
-      '-f',
-      'mp4', // Force MP4 format
+      ...Object.entries(opts).flatMap(([k, v]) => [`-${k}`, v]),
       'pipe:1', // Output to stdout
     ],
     stdin: 'piped',
@@ -38,7 +31,7 @@ export async function transcodeVideoStream(
 
   // Pipe the input stream into FFmpeg stdin and ensure completion
   const writer = process.stdin.getWriter();
-  const reader = inputStream.getReader();
+  const reader = input.getReader();
 
   async function pumpInput() {
     try {