fix: handle missing bitrate in some muxers

fixup

Author: elthariel

lib/ffmpeg/command_args.rb

@@ -130,8 +130,10 @@ def adjusted_audio_bit_rate(target_value)
 
     def min_bit_rate(*values)
       bit_rate =
-        values.compact.map do |value|
-          next value if value.is_a?(Integer)
+        values.filter_map do |value|
+          # Some muxers (webm) might not expose birate under certain conditions
+          next false if value.nil?
+          next (value.positive? ? value : false) if value.is_a?(Integer)
 
           unless value.is_a?(String)
             raise ArgumentError,

spec/ffmpeg/command_args_spec.rb

@@ -96,6 +96,14 @@ module FFMPEG
           expect(args.to_a).to eq(%w[])
         end
       end
+
+      context 'when the reported media bitrate is 0' do
+        it 'returns the requested bitrate' do
+          media = instance_double(Media, video_bit_rate: 0)
+          args = CommandArgs.compose(media) { min_video_bit_rate '2M' }
+          expect(args.to_a).to eq(%w[-minrate 2000k])
+        end
+      end
     end
 
     describe '#max_video_bit_rate' do