feat: video2ascii player

Author: Mark24Code

lib/convert2ascii/terminal-player.rb

@@ -0,0 +1,179 @@
+require "rainbow"
+require_relative "./terminal"
+
+module Convert2Ascii
+  class TerminalPlayer
+
+    SAFE_SLOW_DELTA = 0.9 # seconds
+    SAFE_FAST_DELTA = 0.2 # seconds
+
+    attr_accessor :play_loop, :step_duration, :debug
+    def initialize(**args)
+      @debug = false
+      @audio = args[:audio]
+      @frames = args[:frames]
+      @play_loop = args[:play_loop]
+      @step_duration = args[:step_duration]
+
+      @first_frame = true
+      @backspace_adjust = "\033[A" * (@frames.length + 1)
+
+      regist_hook
+    end
+
+    def play
+      begin
+        init_screen
+        render
+      rescue => error
+        raise error
+      ensure
+        clean_up
+      end
+    end
+
+    private
+
+    def regist_hook
+      trap("INT") {
+        clean_up
+        exit 0
+      }
+
+      # TODO  ??? 改变会消失
+      # # 窗口变化事件
+      # trap("SIGWINCH") {
+      #   resize
+      # }
+    end
+
+    def resize
+      clear_screen
+    end
+
+    def clear_screen
+      Terminal.clear_buffer
+    end
+
+    def init_screen
+      clear_screen
+      setup
+    end
+
+    def setup
+      Terminal.open_buffer
+      Terminal.hide_cursor
+      Terminal.clear_screen
+    end
+
+    def clean_up
+      if !@debug
+        Terminal.close_buffer
+        Terminal.clear_screen
+        Terminal.show_cursor
+      end
+    end
+
+    def debug_log(var_name)
+      puts Rainbow('-- debug ----').yellow
+      puts "class:"
+      p var_name.class
+      puts "value:"
+      p var_name
+    end
+
+    def full_screen(content)
+
+      if !content
+        return content
+      end
+      # 补齐高度，没内容也要追加 \n 刷新，因为会拖拽 窗体尺寸会变化
+      rows, _ = Terminal.winsize
+      # content: pure text with "\n"
+      content = content.split("\n")
+
+      rows_fill = []
+      delta = rows - content.length
+
+      if delta > 0
+        delta.times do
+          rows_fill << "\n"
+        end
+      elsif delta < 0
+        content = content[0..(rows - 1)]
+      end
+
+      content.join("\n")
+    end
+
+    def self_adaption_frame_play
+      # 当偏移在-90ms（音频滞后于视频）到+20ms（音频超前视频）之间时，人感觉不到视听质量的变化，这个区域可以认为是同步区域
+      # https://github.com/0voice/audio_video_streaming/blob/main/article/029-%E9%9F%B3%E8%A7%86%E9%A2%91%E5%90%8C%E6%AD%A5%E7%AE%97%E6%B3%95.md
+
+      start_time = Time.now
+      if @audio
+        Thread.new do
+          start_time = Time.now # 以音频为准
+          system("afplay #{@audio}")
+          if @debug
+            puts Rainbow("[info] audio time: #{Time.now - start_time} s").green
+          end
+
+          # TODO control audio play
+          # Open3.popen3("afplay #{@audio}") do |stdin, stdout, stderr, wait_thr|
+          #   # 可以在这里处理输出或错误信息
+          # end
+        end
+      end
+      frame_index = 0
+      loop do
+        if frame_index <= @frames.length
+          content = @frames[frame_index]
+          if !@first_frame
+            $stdout.print @backspace_adjust
+          end
+          clear_screen
+          $stdout.print(full_screen(content))
+          @first_frame = false
+          sleep(@step_duration)
+        end
+
+        actual_time = Time.now - start_time
+        video_play_time = frame_index * @step_duration
+
+        offset_time = actual_time - video_play_time
+        if offset_time > SAFE_SLOW_DELTA
+          offset = (offset_time / @step_duration).floor
+          if @debug
+            puts Rainbow("[+] #{offset}").green
+          end
+        elsif offset_time < -1 * SAFE_FAST_DELTA
+          offset = 0
+        else
+          offset = 1
+        end
+
+        frame_index += offset
+
+        if @debug
+          puts ""
+          real_time = Time.now - start_time
+          frame_time = (frame_index + 1) * @step_duration
+          puts Rainbow("RealTime: #{real_time} s").green
+          puts Rainbow("FrameTime: #{frame_time} s").green
+          puts Rainbow("Real - Frame: #{real_time - frame_time} s").green
+          puts Rainbow("[+] #{offset}").green
+          puts Rainbow("@step_duration #{@step_duration}").green
+        end
+
+        if !@play_loop && frame_index > @frames.length
+          break
+        end
+      end
+    end
+
+    def render
+      self_adaption_frame_play
+    end
+  end
+end