Support easily testing with custom input files and different segment …

…lengths.

README.md

@@ -24,10 +24,14 @@ ffmpeg version 6.0 Copyright (c) 2000-2023 the FFmpeg developers
 
 ## Usage
 
-Split and stitch:
+Split and stitch with the defaults:
 
  ruby run.rb
 
+Test with your own input files and different target segment durations:
+
+ ruby run.rb 0.5 <path-or-url>
+
 You can find all artifacts in the "out" directory:
 
  ls out

calculations.rb

@@ -9,7 +9,7 @@ def get_closest_aligned_time(target_time)
  nearest_frame_index_for_target_time * frame_duration
 end
 
-def generate_command_and_directives_for_segment(index, target_start, target_end, is_last)
+def generate_command_and_directives_for_segment(input_file, index, target_start, target_end, is_last)
  puts "--- segment #{index + 1} ---"
 
  start_time = get_closest_aligned_time(target_start)
@@ -60,7 +60,7 @@ def generate_command_and_directives_for_segment(index, target_start, target_end,
 
  puts "inpoint: #{inpoint}, outpoint: #{outpoint}"
 
- command = "ffmpeg -hide_banner -loglevel error -nostats -y -ss #{start_time_with_padding}us -t #{padded_duration}us -i out/#{SINE_WAVE_FILE_NAME} -c:a libfdk_aac -ar 44100 -f adts out/seg#{index + 1}.aac"
+ command = "ffmpeg -hide_banner -loglevel error -nostats -y -ss #{start_time_with_padding}us -t #{padded_duration}us -i #{input_file} -c:a libfdk_aac -ar 44100 -f adts out/seg#{index + 1}.aac"
  directives = [
  "file 'seg#{index + 1}.aac'",
  "inpoint #{inpoint}us",

run.rb

@@ -1,25 +1,57 @@
 require "fileutils"
+require "uri"
+require "net/http"
 require_relative "./calculations"
 
 # Feel free to change these constants for your own testing.
 SINE_WAVE_DURATION = 10.to_f
 SINE_FREQUENCY = 10.to_f
-TARGET_SEGMENT_DURATION = 1.0.to_f
+DEFAULT_SEGMENT_DURATION = 1.0.to_f
 SINE_WAVE_FILE_NAME = "sine-wave-#{SINE_WAVE_DURATION.to_i}-seconds.wav"
 
 FileUtils.rm_rf "out"
 FileUtils.mkdir_p "out"
 
-# generate the sine wave we'll use as input
-system("ffmpeg -hide_banner -loglevel error -nostats -y -f lavfi -i \"sine=frequency=#{SINE_FREQUENCY}:duration=#{SINE_WAVE_DURATION}\" out/#{SINE_WAVE_FILE_NAME}")
+input_file = nil
+
+if ARGV.count == 1 && ARGV[0] !~ /\A\d+(\.\d+)?\z/
+ input_file = ARGV[0]
+ target_segment_duration = DEFAULT_SEGMENT_DURATION
+else
+ target_segment_duration = (ARGV[0] || DEFAULT_SEGMENT_DURATION).to_f
+end
+
+if ARGV.count == 2
+ input_file = ARGV[1]
+end
+
+if input_file&.start_with?(/^https?:\/\//)
+ uri = URI.parse(input_file)
+ puts "Downloading file from #{uri}..."
+ resp = Net::HTTP.get_response(uri)
+ if resp.code.to_i != 200
+ raise "Failed to download file: #{resp.code.inspect}"
+ end
+ File.write("out/downloaded-file", resp.body)
+ input_file = "out/downloaded-file"
+else
+ # generate the sine wave we'll use as input
+ system("ffmpeg -hide_banner -loglevel error -nostats -y -f lavfi -i \"sine=frequency=#{SINE_FREQUENCY}:duration=#{SINE_WAVE_DURATION}\" out/#{SINE_WAVE_FILE_NAME}")
+ input_file = "out/#{SINE_WAVE_FILE_NAME}"
+end
+
+duration_cmd = "ffprobe -hide_banner -loglevel error -select_streams v:0 -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 #{input_file}"
+puts duration_cmd
+duration = `#{duration_cmd}`.to_f
+puts "Input file duration: #{duration}"
 
 # Generate the commands we'll use to slice the sine wave into segments and the
 # directives we'll use to recombine them later.
-commands_and_directives = (SINE_WAVE_DURATION / TARGET_SEGMENT_DURATION).ceil.to_i.times.map do |i|
- start_time = (i * TARGET_SEGMENT_DURATION * 1000000).round.to_i
- end_time = [((i + 1) * TARGET_SEGMENT_DURATION * 1000000).round, SINE_WAVE_DURATION * 1000000].min.to_i
- is_last = i == (SINE_WAVE_DURATION / TARGET_SEGMENT_DURATION).ceil.to_i - 1
- generate_command_and_directives_for_segment(i, start_time, end_time, is_last)
+commands_and_directives = (duration / target_segment_duration).ceil.to_i.times.map do |i|
+ start_time = (i * target_segment_duration * 1000000).round.to_i
+ end_time = [((i + 1) * target_segment_duration * 1000000).round, duration * 1000000].min.to_i
+ is_last = i == (duration / target_segment_duration).ceil.to_i - 1
+ generate_command_and_directives_for_segment(input_file, i, start_time, end_time, is_last)
 end
 
 all_directives = commands_and_directives.map { |cmd, directives| directives }.join("\n")