diff --git a/CHANGELOG b/CHANGELOG
index b98adf7..9e58f49 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,10 @@
+== 8.1.0-beta.4 2025-10-10
+
+Improvements:
+* Added audio sample rate adjustment to built-in presets.
+* Audio sample rates now work similarly to frame rates - when the input has a lower sample rate than the target, the closest standard sample rate is used.
+* Standard audio sample rates supported: 8000, 11025, 16000, 22050, 32000, 44100, 48000, 88200, 96000, 176400, 192000 Hz.
+
 == 8.1.0-beta.3 2025-09-30
 
 Improvements:
diff --git a/lib/ffmpeg/command_args.rb b/lib/ffmpeg/command_args.rb
index cf6dce5..d0b5023 100644
--- a/lib/ffmpeg/command_args.rb
+++ b/lib/ffmpeg/command_args.rb
@@ -16,6 +16,10 @@ module FFMPEG
   #  args.to_s # "-map 0:v:0 -c:v:0 libx264 -r 30"
   class CommandArgs < RawCommandArgs
     STANDARD_FRAME_RATES = [12, 24, 25, 30, 50, 60, 90, 120, 240].freeze
+    STANDARD_AUDIO_SAMPLE_RATES = [
+      8000, 11_025, 16_000, 22_050, 32_000, 44_100,
+      48_000, 88_200, 96_000, 176_400, 192_000
+    ].freeze
 
     class << self
       # Composes a new instance of CommandArgs with the given media.
@@ -95,12 +99,23 @@ def audio_bit_rate(target_value, **kwargs)
       super(adjusted_audio_bit_rate(target_value), **kwargs)
     end
 
+    # Sets the audio sample rate to the minimum of the current audio sample rate and the target value.
+    #
+    # @param target_value [Integer] The target sample rate.
+    # @return [self]
+    def audio_sample_rate(target_value)
+      return self if target_value.nil?
+
+      super(adjusted_audio_sample_rate(target_value))
+    end
+
     # Returns the minimum of the current frame rate and the target value.
     #
     # @param target_value [Integer, Float] The target frame rate.
     # @return [Numeric]
     def adjusted_frame_rate(target_value)
       return target_value if media.frame_rate.nil?
+      return target_value if media.frame_rate <= 0
       return target_value if media.frame_rate > target_value
 
       STANDARD_FRAME_RATES.min_by { (_1 - media.frame_rate).abs }
@@ -126,6 +141,20 @@ def adjusted_audio_bit_rate(target_value)
       min_bit_rate(media.audio_bit_rate, target_value)
     end
 
+    # Returns the minimum of the current audio sample rate and the target value.
+    # Returns the target value if the current sample rate is nil or zero/negative.
+    # If the media sample rate is lower than the target, returns the closest standard sample rate.
+    #
+    # @param target_value [Integer] The target audio sample rate.
+    # @return [Integer]
+    def adjusted_audio_sample_rate(target_value)
+      return target_value if media.audio_sample_rate.nil?
+      return target_value if media.audio_sample_rate <= 0
+      return target_value if media.audio_sample_rate > target_value
+
+      STANDARD_AUDIO_SAMPLE_RATES.min_by { (_1 - media.audio_sample_rate).abs }
+    end
+
     private
 
     def min_bit_rate(*values)
diff --git a/lib/ffmpeg/presets/aac.rb b/lib/ffmpeg/presets/aac.rb
index af7a4fc..db098d5 100644
--- a/lib/ffmpeg/presets/aac.rb
+++ b/lib/ffmpeg/presets/aac.rb
@@ -12,6 +12,7 @@ def aac_128k(
         filename: '%<basename>s.m4a',
         metadata: nil,
         threads: FFMPEG.threads,
+        audio_sample_rate: 48_000,
         &
       )
         AAC.new(
@@ -19,6 +20,7 @@ def aac_128k(
           filename:,
           metadata:,
           threads:,
+          audio_sample_rate:,
           audio_bit_rate: '128k',
           &
         )
@@ -29,6 +31,7 @@ def aac_192k(
         filename: '%<basename>s.m4a',
         metadata: nil,
         threads: FFMPEG.threads,
+        audio_sample_rate: 48_000,
         &
       )
         AAC.new(
@@ -36,6 +39,7 @@ def aac_192k(
           filename:,
           metadata:,
           threads:,
+          audio_sample_rate:,
           audio_bit_rate: '192k',
           &
         )
@@ -46,6 +50,7 @@ def aac_320k(
         filename: '%<basename>s.m4a',
         metadata: nil,
         threads: FFMPEG.threads,
+        audio_sample_rate: 48_000,
         &
       )
         AAC.new(
@@ -53,6 +58,7 @@ def aac_320k(
           filename:,
           metadata:,
           threads:,
+          audio_sample_rate:,
           audio_bit_rate: '320k',
           &
         )
@@ -61,7 +67,7 @@ def aac_320k(
 
     # Preset to encode AAC audio files.
     class AAC < Preset
-      attr_reader :threads, :audio_bit_rate
+      attr_reader :threads, :audio_bit_rate, :audio_sample_rate
 
       # @param name [String] The name of the preset.
       # @param filename [String] The filename format of the output.
@@ -74,10 +80,12 @@ def initialize(
         metadata: nil,
         threads: FFMPEG.threads,
         audio_bit_rate: '128k',
+        audio_sample_rate: 48_000,
         &
       )
         @threads = threads
         @audio_bit_rate = audio_bit_rate
+        @audio_sample_rate = audio_sample_rate
         preset = self
 
         super(name:, filename:, metadata:) do
@@ -92,6 +100,7 @@ def initialize(
 
           map media.audio_mapping_id do
             audio_bit_rate preset.audio_bit_rate
+            audio_sample_rate preset.audio_sample_rate
           end
         end
       end
diff --git a/lib/ffmpeg/presets/dash/aac.rb b/lib/ffmpeg/presets/dash/aac.rb
index 13546bc..67dfa5b 100644
--- a/lib/ffmpeg/presets/dash/aac.rb
+++ b/lib/ffmpeg/presets/dash/aac.rb
@@ -14,6 +14,7 @@ def aac_128k(
           metadata: nil,
           threads: FFMPEG.threads,
           segment_duration: 4,
+          audio_sample_rate: 48_000,
           &
         )
           AAC.new(
@@ -22,6 +23,7 @@ def aac_128k(
             metadata:,
             threads:,
             segment_duration:,
+            audio_sample_rate:,
             audio_bit_rate: '128k',
             &
           )
@@ -33,6 +35,7 @@ def aac_192k(
           metadata: nil,
           threads: FFMPEG.threads,
           segment_duration: 4,
+          audio_sample_rate: 48_000,
           &
         )
           AAC.new(
@@ -41,6 +44,7 @@ def aac_192k(
             metadata:,
             threads:,
             segment_duration:,
+            audio_sample_rate:,
             audio_bit_rate: '192k',
             &
           )
@@ -52,6 +56,7 @@ def aac_320k(
           metadata: nil,
           threads: FFMPEG.threads,
           segment_duration: 4,
+          audio_sample_rate: 48_000,
           &
         )
           AAC.new(
@@ -60,6 +65,7 @@ def aac_320k(
             metadata:,
             threads:,
             segment_duration:,
+            audio_sample_rate:,
             audio_bit_rate: '320k',
             &
           )
@@ -68,7 +74,7 @@ def aac_320k(
 
       # Preset to encode DASH AAC audio files.
       class AAC < DASH
-        attr_reader :audio_bit_rate
+        attr_reader :audio_bit_rate, :audio_sample_rate
 
         # @param name [String] The name of the preset.
         # @param filename [String] The filename format of the output.
@@ -82,9 +88,11 @@ def initialize(
           threads: FFMPEG.threads,
           segment_duration: 4,
           audio_bit_rate: '128k',
+          audio_sample_rate: 48_000,
           &
         )
           @audio_bit_rate = audio_bit_rate
+          @audio_sample_rate = audio_sample_rate
           preset = self
 
           super(
@@ -102,6 +110,7 @@ def initialize(
 
             map media.audio_mapping_id do
               audio_bit_rate preset.audio_bit_rate
+              audio_sample_rate preset.audio_sample_rate
             end
           end
         end
diff --git a/lib/ffmpeg/presets/dash/h264.rb b/lib/ffmpeg/presets/dash/h264.rb
index 7c7089b..7330d5b 100644
--- a/lib/ffmpeg/presets/dash/h264.rb
+++ b/lib/ffmpeg/presets/dash/h264.rb
@@ -20,6 +20,7 @@ def h264_360p(
           segment_duration: 4,
           keyframe_interval: 2,
           audio_bit_rate: '128k',
+          audio_sample_rate: 48_000,
           frame_rate: 30,
           ld_frame_rate: 24,
           &
@@ -32,11 +33,11 @@ def h264_360p(
             segment_duration:,
             keyframe_interval:,
             h264_presets: [
-              Presets.h264_360p(audio_bit_rate:, frame_rate:)
+              Presets.h264_360p(audio_bit_rate:, audio_sample_rate:, frame_rate:)
             ],
             ld_h264_presets: [
-              Presets.h264_240p(audio_bit_rate:, frame_rate: ld_frame_rate),
-              Presets.h264_144p(audio_bit_rate:, frame_rate: ld_frame_rate)
+              Presets.h264_240p(audio_bit_rate:, audio_sample_rate:, frame_rate: ld_frame_rate),
+              Presets.h264_144p(audio_bit_rate:, audio_sample_rate:, frame_rate: ld_frame_rate)
             ],
             &
           )
@@ -50,6 +51,7 @@ def h264_480p(
           segment_duration: 4,
           keyframe_interval: 2,
           audio_bit_rate: '128k',
+          audio_sample_rate: 48_000,
           frame_rate: 30,
           ld_frame_rate: 24,
           &
@@ -62,12 +64,12 @@ def h264_480p(
             segment_duration:,
             keyframe_interval:,
             h264_presets: [
-              Presets.h264_480p(audio_bit_rate:, frame_rate:),
-              Presets.h264_360p(audio_bit_rate:, frame_rate:)
+              Presets.h264_480p(audio_bit_rate:, audio_sample_rate:, frame_rate:),
+              Presets.h264_360p(audio_bit_rate:, audio_sample_rate:, frame_rate:)
             ],
             ld_h264_presets: [
-              Presets.h264_240p(audio_bit_rate:, frame_rate: ld_frame_rate),
-              Presets.h264_144p(audio_bit_rate:, frame_rate: ld_frame_rate)
+              Presets.h264_240p(audio_bit_rate:, audio_sample_rate:, frame_rate: ld_frame_rate),
+              Presets.h264_144p(audio_bit_rate:, audio_sample_rate:, frame_rate: ld_frame_rate)
             ],
             &
           )
@@ -81,6 +83,7 @@ def h264_720p(
           segment_duration: 4,
           keyframe_interval: 2,
           audio_bit_rate: '128k',
+          audio_sample_rate: 48_000,
           ld_frame_rate: 24,
           sd_frame_rate: 30,
           hd_frame_rate: 30,
@@ -94,13 +97,13 @@ def h264_720p(
             keyframe_interval:,
             segment_duration:,
             h264_presets: [
-              Presets.h264_720p(audio_bit_rate:, frame_rate: hd_frame_rate),
-              Presets.h264_480p(audio_bit_rate:, frame_rate: sd_frame_rate),
-              Presets.h264_360p(audio_bit_rate:, frame_rate: sd_frame_rate)
+              Presets.h264_720p(audio_bit_rate:, audio_sample_rate:, frame_rate: hd_frame_rate),
+              Presets.h264_480p(audio_bit_rate:, audio_sample_rate:, frame_rate: sd_frame_rate),
+              Presets.h264_360p(audio_bit_rate:, audio_sample_rate:, frame_rate: sd_frame_rate)
             ],
             ld_h264_presets: [
-              Presets.h264_240p(audio_bit_rate:, frame_rate: ld_frame_rate),
-              Presets.h264_144p(audio_bit_rate:, frame_rate: ld_frame_rate)
+              Presets.h264_240p(audio_bit_rate:, audio_sample_rate:, frame_rate: ld_frame_rate),
+              Presets.h264_144p(audio_bit_rate:, audio_sample_rate:, frame_rate: ld_frame_rate)
             ],
             &
           )
@@ -114,6 +117,7 @@ def h264_1080p(
           segment_duration: 4,
           keyframe_interval: 2,
           audio_bit_rate: '128k',
+          audio_sample_rate: 48_000,
           ld_frame_rate: 24,
           sd_frame_rate: 30,
           hd_frame_rate: 30,
@@ -127,14 +131,14 @@ def h264_1080p(
             keyframe_interval:,
             segment_duration:,
             h264_presets: [
-              Presets.h264_1080p(audio_bit_rate:, frame_rate: hd_frame_rate),
-              Presets.h264_720p(audio_bit_rate:, frame_rate: hd_frame_rate),
-              Presets.h264_480p(audio_bit_rate:, frame_rate: sd_frame_rate),
-              Presets.h264_360p(audio_bit_rate:, frame_rate: sd_frame_rate)
+              Presets.h264_1080p(audio_bit_rate:, audio_sample_rate:, frame_rate: hd_frame_rate),
+              Presets.h264_720p(audio_bit_rate:, audio_sample_rate:, frame_rate: hd_frame_rate),
+              Presets.h264_480p(audio_bit_rate:, audio_sample_rate:, frame_rate: sd_frame_rate),
+              Presets.h264_360p(audio_bit_rate:, audio_sample_rate:, frame_rate: sd_frame_rate)
             ],
             ld_h264_presets: [
-              Presets.h264_240p(audio_bit_rate:, frame_rate: ld_frame_rate),
-              Presets.h264_144p(audio_bit_rate:, frame_rate: ld_frame_rate)
+              Presets.h264_240p(audio_bit_rate:, audio_sample_rate:, frame_rate: ld_frame_rate),
+              Presets.h264_144p(audio_bit_rate:, audio_sample_rate:, frame_rate: ld_frame_rate)
             ],
             &
           )
@@ -148,6 +152,7 @@ def h264_1440p(
           segment_duration: 4,
           keyframe_interval: 2,
           audio_bit_rate: '128k',
+          audio_sample_rate: 48_000,
           ld_frame_rate: 24,
           sd_frame_rate: 30,
           hd_frame_rate: 30,
@@ -161,15 +166,15 @@ def h264_1440p(
             keyframe_interval:,
             segment_duration:,
             h264_presets: [
-              Presets.h264_1440p(audio_bit_rate:, frame_rate: hd_frame_rate),
-              Presets.h264_1080p(audio_bit_rate:, frame_rate: hd_frame_rate),
-              Presets.h264_720p(audio_bit_rate:, frame_rate: hd_frame_rate),
-              Presets.h264_480p(audio_bit_rate:, frame_rate: sd_frame_rate),
-              Presets.h264_360p(audio_bit_rate:, frame_rate: sd_frame_rate)
+              Presets.h264_1440p(audio_bit_rate:, audio_sample_rate:, frame_rate: hd_frame_rate),
+              Presets.h264_1080p(audio_bit_rate:, audio_sample_rate:, frame_rate: hd_frame_rate),
+              Presets.h264_720p(audio_bit_rate:, audio_sample_rate:, frame_rate: hd_frame_rate),
+              Presets.h264_480p(audio_bit_rate:, audio_sample_rate:, frame_rate: sd_frame_rate),
+              Presets.h264_360p(audio_bit_rate:, audio_sample_rate:, frame_rate: sd_frame_rate)
             ],
             ld_h264_presets: [
-              Presets.h264_240p(audio_bit_rate:, frame_rate: ld_frame_rate),
-              Presets.h264_144p(audio_bit_rate:, frame_rate: ld_frame_rate)
+              Presets.h264_240p(audio_bit_rate:, audio_sample_rate:, frame_rate: ld_frame_rate),
+              Presets.h264_144p(audio_bit_rate:, audio_sample_rate:, frame_rate: ld_frame_rate)
             ],
             &
           )
@@ -183,6 +188,7 @@ def h264_4k(
           segment_duration: 4,
           keyframe_interval: 2,
           audio_bit_rate: '128k',
+          audio_sample_rate: 48_000,
           ld_frame_rate: 24,
           sd_frame_rate: 30,
           hd_frame_rate: 60,
@@ -197,16 +203,16 @@ def h264_4k(
             segment_duration:,
             keyframe_interval:,
             h264_presets: [
-              Presets.h264_4k(audio_bit_rate:, frame_rate: uhd_frame_rate),
-              Presets.h264_1440p(audio_bit_rate:, frame_rate: hd_frame_rate),
-              Presets.h264_1080p(audio_bit_rate:, frame_rate: hd_frame_rate),
-              Presets.h264_720p(audio_bit_rate:, frame_rate: hd_frame_rate),
-              Presets.h264_480p(audio_bit_rate:, frame_rate: sd_frame_rate),
-              Presets.h264_360p(audio_bit_rate:, frame_rate: sd_frame_rate)
+              Presets.h264_4k(audio_bit_rate:, audio_sample_rate:, frame_rate: uhd_frame_rate),
+              Presets.h264_1440p(audio_bit_rate:, audio_sample_rate:, frame_rate: hd_frame_rate),
+              Presets.h264_1080p(audio_bit_rate:, audio_sample_rate:, frame_rate: hd_frame_rate),
+              Presets.h264_720p(audio_bit_rate:, audio_sample_rate:, frame_rate: hd_frame_rate),
+              Presets.h264_480p(audio_bit_rate:, audio_sample_rate:, frame_rate: sd_frame_rate),
+              Presets.h264_360p(audio_bit_rate:, audio_sample_rate:, frame_rate: sd_frame_rate)
             ],
             ld_h264_presets: [
-              Presets.h264_240p(audio_bit_rate:, frame_rate: ld_frame_rate),
-              Presets.h264_144p(audio_bit_rate:, frame_rate: ld_frame_rate)
+              Presets.h264_240p(audio_bit_rate:, audio_sample_rate:, frame_rate: ld_frame_rate),
+              Presets.h264_144p(audio_bit_rate:, audio_sample_rate:, frame_rate: ld_frame_rate)
             ],
             &
           )
@@ -305,6 +311,7 @@ def initialize(
               # Reset the audio stream's timestamps to start from 0.
               filter Filter.new(:audio, 'asetpts', expr: 'PTS-STARTPTS')
               audio_bit_rate h264_presets.first.audio_bit_rate
+              audio_sample_rate h264_presets.first.audio_sample_rate
             end
           end
         end
diff --git a/lib/ffmpeg/presets/h264.rb b/lib/ffmpeg/presets/h264.rb
index 3a7a087..1b41145 100644
--- a/lib/ffmpeg/presets/h264.rb
+++ b/lib/ffmpeg/presets/h264.rb
@@ -14,6 +14,7 @@ def h264_144p(
         metadata: nil,
         threads: FFMPEG.threads,
         audio_bit_rate: '128k',
+        audio_sample_rate: 48_000,
         video_preset: 'ultrafast',
         video_profile: 'baseline',
         frame_rate: 30,
@@ -27,6 +28,7 @@ def h264_144p(
           metadata:,
           threads:,
           audio_bit_rate:,
+          audio_sample_rate:,
           video_preset:,
           video_profile:,
           frame_rate:,
@@ -44,6 +46,7 @@ def h264_240p(
         metadata: nil,
         threads: FFMPEG.threads,
         audio_bit_rate: '128k',
+        audio_sample_rate: 48_000,
         video_preset: 'ultrafast',
         video_profile: 'baseline',
         frame_rate: 30,
@@ -57,6 +60,7 @@ def h264_240p(
           metadata:,
           threads:,
           audio_bit_rate:,
+          audio_sample_rate:,
           video_preset:,
           video_profile:,
           frame_rate:,
@@ -74,6 +78,7 @@ def h264_360p(
         metadata: nil,
         threads: FFMPEG.threads,
         audio_bit_rate: '128k',
+        audio_sample_rate: 48_000,
         video_preset: 'ultrafast',
         video_profile: 'baseline',
         frame_rate: 30,
@@ -87,6 +92,7 @@ def h264_360p(
           metadata:,
           threads:,
           audio_bit_rate:,
+          audio_sample_rate:,
           video_preset:,
           video_profile:,
           frame_rate:,
@@ -104,6 +110,7 @@ def h264_480p(
         metadata: nil,
         threads: FFMPEG.threads,
         audio_bit_rate: '128k',
+        audio_sample_rate: 48_000,
         video_preset: 'fast',
         video_profile: 'main',
         frame_rate: 30,
@@ -117,6 +124,7 @@ def h264_480p(
           metadata:,
           threads:,
           audio_bit_rate:,
+          audio_sample_rate:,
           video_preset:,
           video_profile:,
           frame_rate:,
@@ -134,6 +142,7 @@ def h264_720p(
         metadata: nil,
         threads: FFMPEG.threads,
         audio_bit_rate: '128k',
+        audio_sample_rate: 48_000,
         video_preset: 'fast',
         video_profile: 'high',
         frame_rate: 60,
@@ -147,6 +156,7 @@ def h264_720p(
           metadata:,
           threads:,
           audio_bit_rate:,
+          audio_sample_rate:,
           video_preset:,
           video_profile:,
           frame_rate:,
@@ -164,6 +174,7 @@ def h264_1080p(
         metadata: nil,
         threads: FFMPEG.threads,
         audio_bit_rate: '128k',
+        audio_sample_rate: 48_000,
         video_preset: 'fast',
         video_profile: 'high',
         frame_rate: 60,
@@ -177,6 +188,7 @@ def h264_1080p(
           metadata:,
           threads:,
           audio_bit_rate:,
+          audio_sample_rate:,
           video_preset:,
           video_profile:,
           frame_rate:,
@@ -194,6 +206,7 @@ def h264_1440p(
         metadata: nil,
         threads: FFMPEG.threads,
         audio_bit_rate: '128k',
+        audio_sample_rate: 48_000,
         video_preset: 'fast',
         video_profile: 'high',
         frame_rate: 60,
@@ -207,6 +220,7 @@ def h264_1440p(
           metadata:,
           threads:,
           audio_bit_rate:,
+          audio_sample_rate:,
           video_preset:,
           video_profile:,
           frame_rate:,
@@ -224,6 +238,7 @@ def h264_4k(
         metadata: nil,
         threads: FFMPEG.threads,
         audio_bit_rate: '128k',
+        audio_sample_rate: 48_000,
         video_preset: 'fast',
         video_profile: 'high',
         frame_rate: 60,
@@ -237,6 +252,7 @@ def h264_4k(
           metadata:,
           threads:,
           audio_bit_rate:,
+          audio_sample_rate:,
           video_preset:,
           video_profile:,
           frame_rate:,
@@ -251,7 +267,7 @@ def h264_4k(
 
     # Preset to encode H.264 video files.
     class H264 < Preset
-      attr_reader :threads, :audio_bit_rate, :video_preset, :video_profile,
+      attr_reader :threads, :audio_bit_rate, :audio_sample_rate, :video_preset, :video_profile,
                   :frame_rate, :constant_rate_factor, :pixel_format,
                   :max_width, :max_height
 
@@ -273,6 +289,7 @@ def initialize(
         metadata: nil,
         threads: FFMPEG.threads,
         audio_bit_rate: '128k',
+        audio_sample_rate: 48_000,
         video_preset: 'fast',
         video_profile: 'high',
         frame_rate: 30,
@@ -292,6 +309,7 @@ def initialize(
 
         @threads = threads
         @audio_bit_rate = audio_bit_rate
+        @audio_sample_rate = audio_sample_rate
         @video_preset = video_preset
         @video_profile = video_profile
         @frame_rate = frame_rate
@@ -321,6 +339,7 @@ def initialize(
 
           map media.audio_mapping_id do
             audio_bit_rate preset.audio_bit_rate
+            audio_sample_rate preset.audio_sample_rate
           end
         end
       end
diff --git a/lib/ffmpeg/version.rb b/lib/ffmpeg/version.rb
index 12e60fa..1fb60af 100644
--- a/lib/ffmpeg/version.rb
+++ b/lib/ffmpeg/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module FFMPEG
-  VERSION = '8.1.0-beta.3'
+  VERSION = '8.1.0-beta.4'
 end
diff --git a/spec/ffmpeg/command_args_spec.rb b/spec/ffmpeg/command_args_spec.rb
index 2eac701..a079f5a 100644
--- a/spec/ffmpeg/command_args_spec.rb
+++ b/spec/ffmpeg/command_args_spec.rb
@@ -21,6 +21,22 @@ module FFMPEG
         end
       end
 
+      context 'when the media frame rate is zero' do
+        it 'sets the frame rate to the target value' do
+          media = instance_double(Media, frame_rate: 0)
+          args = CommandArgs.compose(media) { frame_rate 60 }
+          expect(args.to_a).to eq(%w[-r 60])
+        end
+      end
+
+      context 'when the media frame rate is negative' do
+        it 'sets the frame rate to the target value' do
+          media = instance_double(Media, frame_rate: -1)
+          args = CommandArgs.compose(media) { frame_rate 60 }
+          expect(args.to_a).to eq(%w[-r 60])
+        end
+      end
+
       context 'when the media frame rate is higher than the target value' do
         it 'sets the frame rate to the target value' do
           media = instance_double(Media, frame_rate: 60)
@@ -32,7 +48,6 @@ module FFMPEG
       context 'when the media frame rate is lower than the target value' do
         it 'sets the frame rate to the closest standard value' do
           {
-            0 => 12,
             21 => 24,
             26 => 25,
             29.94 => 30,
@@ -157,5 +172,67 @@ module FFMPEG
         end
       end
     end
+
+    describe '#audio_sample_rate' do
+      context 'when the target value is nil' do
+        it 'does not set the audio sample rate' do
+          media = instance_double(Media, audio_sample_rate: 48_000)
+          args = CommandArgs.compose(media) { audio_sample_rate nil }
+          expect(args.to_a).to eq(%w[])
+        end
+      end
+
+      context 'when the media audio sample rate is nil' do
+        it 'sets the audio sample rate to the target value' do
+          media = instance_double(Media, audio_sample_rate: nil)
+          args = CommandArgs.compose(media) { audio_sample_rate 48_000 }
+          expect(args.to_a).to eq(%w[-ar 48000])
+        end
+      end
+
+      context 'when the media audio sample rate is zero' do
+        it 'sets the audio sample rate to the target value' do
+          media = instance_double(Media, audio_sample_rate: 0)
+          args = CommandArgs.compose(media) { audio_sample_rate 48_000 }
+          expect(args.to_a).to eq(%w[-ar 48000])
+        end
+      end
+
+      context 'when the media audio sample rate is negative' do
+        it 'sets the audio sample rate to the target value' do
+          media = instance_double(Media, audio_sample_rate: -1)
+          args = CommandArgs.compose(media) { audio_sample_rate 48_000 }
+          expect(args.to_a).to eq(%w[-ar 48000])
+        end
+      end
+
+      context 'when the media audio sample rate is higher than the target value' do
+        it 'sets the audio sample rate to the target value' do
+          media = instance_double(Media, audio_sample_rate: 96_000)
+          args = CommandArgs.compose(media) { audio_sample_rate 48_000 }
+          expect(args.to_a).to eq(%w[-ar 48000])
+        end
+      end
+
+      context 'when the media audio sample rate is lower than the target value' do
+        it 'sets the audio sample rate to the closest standard value' do
+          {
+            8000 => 8000,
+            10_000 => 11_025,
+            12_000 => 11_025,
+            20_000 => 22_050,
+            44_100 => 44_100,
+            45_000 => 44_100,
+            47_000 => 48_000,
+            90_000 => 88_200,
+            100_000 => 96_000
+          }.each do |media_sample_rate, expected_value|
+            media = instance_double(Media, audio_sample_rate: media_sample_rate)
+            args = CommandArgs.compose(media) { audio_sample_rate 192_000 }
+            expect(args.to_a).to eq(%W[-ar #{expected_value}])
+          end
+        end
+      end
+    end
   end
 end