From 2533d2f4697e678a5d34898e72603256c16de739 Mon Sep 17 00:00:00 2001
From: Alex Gleason <alex@alexgleason.me>
Date: Fri, 28 Feb 2025 20:52:11 -0600
Subject: [PATCH] Support readable in extractVideoFrame

---
 packages/transcode/ffmpeg.ts     | 8 +++++++-
 packages/transcode/frame.test.ts | 5 +++--
 packages/transcode/frame.ts      | 7 +++++--
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/packages/transcode/ffmpeg.ts b/packages/transcode/ffmpeg.ts
index d52b0c9d..4a53f760 100644
--- a/packages/transcode/ffmpeg.ts
+++ b/packages/transcode/ffmpeg.ts
@@ -38,7 +38,13 @@ export function ffmpeg(input: URL | ReadableStream<Uint8Array>, flags: FFmpegFla
 
   // Pipe the input stream into FFmpeg stdin and ensure completion
   if (input instanceof ReadableStream) {
-    input.pipeTo(child.stdin);
+    input.pipeTo(child.stdin).catch((e: unknown) => {
+      if (e instanceof Error && e.name === 'BrokenPipe') {
+        // Ignore. ffprobe closes the pipe once it has read the metadata.
+      } else {
+        throw e;
+      }
+    });
   }
 
   // Return the FFmpeg stdout stream
diff --git a/packages/transcode/frame.test.ts b/packages/transcode/frame.test.ts
index 93894df2..8fba6e94 100644
--- a/packages/transcode/frame.test.ts
+++ b/packages/transcode/frame.test.ts
@@ -1,8 +1,9 @@
 import { extractVideoFrame } from './frame.ts';
 
 Deno.test('extractVideoFrame', async () => {
-  const uri = new URL('./buckbunny.mp4', import.meta.url);
-  const result = await extractVideoFrame(uri);
+  await using file = await Deno.open(new URL('./buckbunny.mp4', import.meta.url));
+
+  const result = await extractVideoFrame(file.readable);
 
   await Deno.mkdir(new URL('./tmp', import.meta.url), { recursive: true });
   await Deno.writeFile(new URL('./tmp/buckbunny-poster.jpg', import.meta.url), result);
diff --git a/packages/transcode/frame.ts b/packages/transcode/frame.ts
index 68e30e5e..689677ff 100644
--- a/packages/transcode/frame.ts
+++ b/packages/transcode/frame.ts
@@ -1,7 +1,10 @@
 import { ffmpeg } from './ffmpeg.ts';
 
-export function extractVideoFrame(file: URL, ss: string = '00:00:01'): Promise<Uint8Array> {
-  const output = ffmpeg(file, {
+export function extractVideoFrame(
+  input: URL | ReadableStream<Uint8Array>,
+  ss: string = '00:00:01',
+): Promise<Uint8Array> {
+  const output = ffmpeg(input, {
     'ss': ss, // Seek to timestamp
     'frames:v': '1', // Extract only 1 frame
     'q:v': '2', // High-quality JPEG (lower = better quality)