fix: correctly detect old-style MOV files (no ftyp box)

Author: bajankristof

lib/ffmpeg/media.rb

@@ -83,11 +83,11 @@ def initialize(message, output)
       when /\basf_o\b/     then '.asf'
       when /\b(mov|mp4)\b/
         case major_brand
-        when /\Aqt\b/i  then '.mov'
-        when /\Am4a\b/i then '.m4a'
-        when /\Am4v\b/i then '.m4v'
-        when /\Am4s\b/i then '.m4s'
-        else                 '.mp4'
+        when nil, /\Aqt\b/i then '.mov'
+        when /\Am4a\b/i     then '.m4a'
+        when /\Am4v\b/i     then '.m4v'
+        when /\Am4s\b/i     then '.m4s'
+        else                     '.mp4'
         end
       when /\bmatroska\b/
         if streams

spec/ffmpeg/media_spec.rb

@@ -609,6 +609,16 @@ module FFMPEG
         end
       end
 
+      context 'when the media is an old-style QuickTime MOV without an ftyp box' do
+        let(:path) { fixture_media_file('rotated@0.mov') }
+
+        before { allow(subject).to receive(:major_brand).and_return(nil) }
+
+        it 'returns .mov' do
+          expect(subject.extname).to eq('.mov')
+        end
+      end
+
       context 'when the media is a WAV' do
         let(:path) { fixture_media_file('hello.wav') }