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Merged
bajankristof merged 1 commit into from
Oct 14, 2025
Merged

feat: add audio sample rate adjustment to built-in presets #33

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7 changes: 7 additions & 0 deletions CHANGELOG
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Original file line number Diff line number Diff line change
@@ -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:
Expand Down
29 changes: 29 additions & 0 deletions lib/ffmpeg/command_args.rb
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Original file line number Diff line number Diff line change
Expand Up @@ -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.
Expand Down Expand Up @@ -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 }
Expand All @@ -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)
Expand Down
11 changes: 10 additions & 1 deletion lib/ffmpeg/presets/aac.rb
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Original file line number Diff line number Diff line change
Expand Up @@ -12,13 +12,15 @@ def aac_128k(
filename: '%<basename>s.m4a',
metadata: nil,
threads: FFMPEG.threads,
audio_sample_rate: 48_000,
&
)
AAC.new(
name:,
filename:,
metadata:,
threads:,
audio_sample_rate:,
audio_bit_rate: '128k',
&
)
Expand All @@ -29,13 +31,15 @@ def aac_192k(
filename: '%<basename>s.m4a',
metadata: nil,
threads: FFMPEG.threads,
audio_sample_rate: 48_000,
&
)
AAC.new(
name:,
filename:,
metadata:,
threads:,
audio_sample_rate:,
audio_bit_rate: '192k',
&
)
Expand All @@ -46,13 +50,15 @@ def aac_320k(
filename: '%<basename>s.m4a',
metadata: nil,
threads: FFMPEG.threads,
audio_sample_rate: 48_000,
&
)
AAC.new(
name:,
filename:,
metadata:,
threads:,
audio_sample_rate:,
audio_bit_rate: '320k',
&
)
Expand All @@ -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.
Expand All @@ -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
Expand All @@ -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
Expand Down
11 changes: 10 additions & 1 deletion lib/ffmpeg/presets/dash/aac.rb
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Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,7 @@ def aac_128k(
metadata: nil,
threads: FFMPEG.threads,
segment_duration: 4,
audio_sample_rate: 48_000,
&
)
AAC.new(
Expand All @@ -22,6 +23,7 @@ def aac_128k(
metadata:,
threads:,
segment_duration:,
audio_sample_rate:,
audio_bit_rate: '128k',
&
)
Expand All @@ -33,6 +35,7 @@ def aac_192k(
metadata: nil,
threads: FFMPEG.threads,
segment_duration: 4,
audio_sample_rate: 48_000,
&
)
AAC.new(
Expand All @@ -41,6 +44,7 @@ def aac_192k(
metadata:,
threads:,
segment_duration:,
audio_sample_rate:,
audio_bit_rate: '192k',
&
)
Expand All @@ -52,6 +56,7 @@ def aac_320k(
metadata: nil,
threads: FFMPEG.threads,
segment_duration: 4,
audio_sample_rate: 48_000,
&
)
AAC.new(
Expand All @@ -60,6 +65,7 @@ def aac_320k(
metadata:,
threads:,
segment_duration:,
audio_sample_rate:,
audio_bit_rate: '320k',
&
)
Expand All @@ -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.
Expand All @@ -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(
Expand All @@ -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
Expand Down
73 changes: 40 additions & 33 deletions lib/ffmpeg/presets/dash/h264.rb
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Original file line number Diff line number Diff line change
Expand Up @@ -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,
&
Expand All @@ -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)
],
&
)
Expand All @@ -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,
&
Expand All @@ -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)
],
&
)
Expand All @@ -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,
Expand All @@ -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)
],
&
)
Expand All @@ -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,
Expand All @@ -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)
],
&
)
Expand All @@ -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,
Expand All @@ -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)
],
&
)
Expand All @@ -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,
Expand All @@ -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)
],
&
)
Expand Down Expand Up @@ -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
Expand Down
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