feat(video): add MIME types for mp4/webm/mov/avi/mkv

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/mime.js

@@ -43,6 +43,11 @@ const OUTPUT_MIME_TYPES = {
   flac: 'audio/flac',
   aac: 'audio/aac',
   m4a: 'audio/x-m4a',
+  mp4: 'video/mp4',
+  webm: 'video/webm',
+  mov: 'video/quicktime',
+  avi: 'video/x-msvideo',
+  mkv: 'video/x-matroska',
 };
 
 export async function detectInputMime(filePath) {

test/mime.test.js

@@ -361,3 +361,90 @@ describe('resolveInputFormat — audio formats', () => {
     await fs.unlink(fixturePath);
   });
 });
+
+describe('outputMimeType — video', () => {
+  it('returns the correct MIME type for each video target format', () => {
+    expect(outputMimeType('mp4')).toBe('video/mp4');
+    expect(outputMimeType('webm')).toBe('video/webm');
+    expect(outputMimeType('mov')).toBe('video/quicktime');
+    expect(outputMimeType('avi')).toBe('video/x-msvideo');
+    expect(outputMimeType('mkv')).toBe('video/x-matroska');
+  });
+});
+
+describe('resolveInputFormat — video magic bytes', () => {
+  it('accepts a minimal mp4 (ftyp box) declared as mp4', async () => {
+    const fixturePath = path.join(import.meta.dirname, 'fixtures', 'sample-video.mp4');
+    await fs.writeFile(
+      fixturePath,
+      Buffer.concat([Buffer.from([0, 0, 0, 0x18]), Buffer.from('ftyp'), Buffer.from('isom')])
+    );
+
+    const result = await resolveInputFormat(fixturePath, 'mp4');
+    expect(result).toEqual({ mime: 'video/mp4', valid: true });
+
+    await fs.unlink(fixturePath);
+  });
+
+  it('accepts a minimal mov (moov atom) declared as mov', async () => {
+    const fixturePath = path.join(import.meta.dirname, 'fixtures', 'sample-video.mov');
+    await fs.writeFile(fixturePath, Buffer.concat([Buffer.from([0, 0, 0, 0x08]), Buffer.from('moov')]));
+
+    const result = await resolveInputFormat(fixturePath, 'mov');
+    expect(result).toEqual({ mime: 'video/quicktime', valid: true });
+
+    await fs.unlink(fixturePath);
+  });
+
+  it('accepts a minimal avi (RIFF/AVI) declared as avi', async () => {
+    const fixturePath = path.join(import.meta.dirname, 'fixtures', 'sample-video.avi');
+    await fs.writeFile(
+      fixturePath,
+      Buffer.concat([Buffer.from('RIFF'), Buffer.from([0, 0, 0, 0]), Buffer.from('AVI ')])
+    );
+
+    const result = await resolveInputFormat(fixturePath, 'avi');
+    expect(result).toEqual({ mime: 'video/vnd.avi', valid: true });
+
+    await fs.unlink(fixturePath);
+  });
+
+  it('accepts a minimal webm (EBML DocType webm) declared as webm', async () => {
+    const fixturePath = path.join(import.meta.dirname, 'fixtures', 'sample-video.webm');
+    await fs.writeFile(
+      fixturePath,
+      Buffer.concat([Buffer.from([0x1a, 0x45, 0xdf, 0xa3, 0x81, 0x42, 0x82, 0x84]), Buffer.from('webm')])
+    );
+
+    const result = await resolveInputFormat(fixturePath, 'webm');
+    expect(result).toEqual({ mime: 'video/webm', valid: true });
+
+    await fs.unlink(fixturePath);
+  });
+
+  it('accepts a minimal mkv (EBML DocType matroska) declared as mkv', async () => {
+    const fixturePath = path.join(import.meta.dirname, 'fixtures', 'sample-video.mkv');
+    await fs.writeFile(
+      fixturePath,
+      Buffer.concat([Buffer.from([0x1a, 0x45, 0xdf, 0xa3, 0x81, 0x42, 0x82, 0x88]), Buffer.from('matroska')])
+    );
+
+    const result = await resolveInputFormat(fixturePath, 'mkv');
+    expect(result).toEqual({ mime: 'video/matroska', valid: true });
+
+    await fs.unlink(fixturePath);
+  });
+
+  it('rejects a webm file declared as mkv', async () => {
+    const fixturePath = path.join(import.meta.dirname, 'fixtures', 'sample-video-mismatch.webm');
+    await fs.writeFile(
+      fixturePath,
+      Buffer.concat([Buffer.from([0x1a, 0x45, 0xdf, 0xa3, 0x81, 0x42, 0x82, 0x84]), Buffer.from('webm')])
+    );
+
+    const result = await resolveInputFormat(fixturePath, 'mkv');
+    expect(result.valid).toBe(false);
+
+    await fs.unlink(fixturePath);
+  });
+});