lib/aviglitch/frames.rb in aviglitch-0.1.3 vs lib/aviglitch/frames.rb in aviglitch-0.1.4

@@ -16,12 +16,14 @@
   # of AviGlitch::Frame object.
   #
   class Frames
     include Enumerable
 
-    SAFE_FRAMES_COUNT = 150000              #:nodoc:
-    @@warn_if_frames_are_too_large = true   #:nodoc:
+    # :stopdoc:
+    SAFE_FRAMES_COUNT = 150000
+    @@warn_if_frames_are_too_large = true
+    # :startdoc:
 
     attr_reader :meta
 
     ##
     # Creates a new AviGlitch::Frames object.
@@ -54,23 +56,37 @@
       @io = io
     end
 
     ##
     # Enumerates the frames.
+    # It returns Enumerator if a block is not given.
     def each
-      temp = Tempfile.new 'frames'
-      frames_data_as_io(temp, Proc.new)
-      overwrite temp
-      temp.close!
+      if block_given?
+        temp = Tempfile.new 'frames'
+        frames_data_as_io(temp, Proc.new)
+        overwrite temp
+        temp.close!
+      else
+        self.enum_for :each
+      end
     end
 
     ##
     # Returns the number of frames.
     def size
       @meta.size
     end
 
+    ##
+    # Returns the number of the specific +frame_type+.
+    def size_of frame_type
+      detection = "is_#{frame_type.to_s.sub(/frames$/, 'frame')}?"
+      @meta.select { |m|
+        Frame.new(nil, m[:id], m[:flag]).send detection
+      }.size
+    end
+
     def frames_data_as_io io = nil, block = nil  #:nodoc:
       io = Tempfile.new('tmep') if io.nil?
       @meta = @meta.select do |m|
         @io.pos = @pos_of_movi + m[:offset] + 8   # 8 for id and size
         frame = Frame.new(@io.read(m[:size]), m[:id], m[:flag])
@@ -97,24 +113,23 @@
       unless safe_frames_count? @meta.size
         @io.close!
         exit
       end
       # Overwrite the file
-      data.seek 0, IO::SEEK_END
       @io.pos = @pos_of_movi - 4  # 4 for size
       @io.print [data.pos + 4].pack('V')  # 4 for 'movi'
       @io.print 'movi'
       data.rewind
-      while d = data.read(1024) do
+      while d = data.read(BUFFER_SIZE) do
         @io.print d
       end
       @io.print 'idx1'
       @io.print [@meta.size * 16].pack('V')
-      @meta.each do |m|
-        @io.print m[:id]
-        @io.print [m[:flag], m[:offset], m[:size]].pack('V3')
-      end
+      idx = @meta.collect { |m|
+        m[:id] + [m[:flag], m[:offset], m[:size]].pack('V3')
+      }.join
+      @io.print idx
       eof = @io.pos
       @io.truncate eof
 
       # Fix info
       ## file size
@@ -150,11 +165,11 @@
       other_data = Tempfile.new 'other'
       other_frames.frames_data_as_io other_data
       this_data.seek 0, IO::SEEK_END
       this_size = this_data.pos
       other_data.rewind
-      while d = other_data.read(1024) do
+      while d = other_data.read(BUFFER_SIZE) do
         this_data.print d
       end
       other_data.close!
       # meta
       other_meta = other_frames.meta.collect do |m|
@@ -322,11 +337,11 @@
     def delete_at n
       self.slice! n
     end
 
     ##
-    # Modify keyframes to deltaframes at given range, or all.
-    def clear_keyframes! range = nil
+    # Mutates keyframes into deltaframes at given range, or all.
+    def mutate_keyframes_into_deltaframes! range = nil
       range = 0..self.size if range.nil?
       self.each_with_index do |frame, i|
         if range.include? i
           frame.flag = 0 if frame.is_keyframe?
         end