Class: FilesHunter::Decoders::RIFF

Inherits:

Object
FilesHunter::Decoder
BeginPatternDecoder
FilesHunter::Decoders::RIFF

show all

Defined in:: lib/fileshunter/Decoders/RIFF.rb

Overview

WAV files can contain MP3 files

Constant Summary collapse

BEGIN_PATTERN_RIFF = Reference: www.sno.phy.queensu.ca/~phil/exiftool/TagNames/RIFF.html Reference: msdn.microsoft.com/en-us/library/windows/desktop/dd318189%28v=vs.85%29.aspx Reference: www.the-labs.com/Video/odmlff2-avidef.pdf

'RIFF'

BEGIN_PATTERN_RIFX =

'RIFX'

BEGIN_PATTERN_JUNK =

'JUNK'

BEGIN_PATTERN_FILE =

Regexp.new("RIF(F|X)", nil, 'n')

INFO_ELEMENTS_ID = INFO elements

{
  'AGES' => :Rated,
  'CMNT' => :Comment,
  'CODE' => :EncodedBy,
  'COMM' => :Comments,
  'DIRC' => :Directory,
  'DISP' => :SoundSchemeTitle,
  'DTIM' => :DateTimeOriginal,
  'GENR' => :Genre,
  'IARL' => :ArchivalLocation,
  'IART' => :Artist,
  'IAS1' => :FirstLanguage,
  'IAS2' => :SecondLanguage,
  'IAS3' => :ThirdLanguage,
  'IAS4' => :FourthLanguage,
  'IAS5' => :FifthLanguage,
  'IAS6' => :SixthLanguage,
  'IAS7' => :SeventhLanguage,
  'IAS8' => :EighthLanguage,
  'IAS9' => :NinthLanguage,
  'IBSU' => :BaseURL,
  'ICAS' => :DefaultAudioStream,
  'ICDS' => :CostumeDesigner,
  'ICMS' => :Commissioned,
  'ICMT' => :Comment,
  'ICNM' => :Cinematographer,
  'ICNT' => :Country,
  'ICOP' => :Copyright,
  'ICRD' => :DateCreated,
  'ICRP' => :Cropped,
  'IDIM' => :Dimensions,
  'IDPI' => :DotsPerInch,
  'IDST' => :DistributedBy,
  'IEDT' => :EditedBy,
  'IENC' => :EncodedBy,
  'IENG' => :Engineer,
  'IGNR' => :Genre,
  'IKEY' => :Keywords,
  'ILGT' => :Lightness,
  'ILGU' => :LogoURL,
  'ILIU' => :LogoIconURL,
  'ILNG' => :Language,
  'IMBI' => :MoreInfoBannerImage,
  'IMBU' => :MoreInfoBannerURL,
  'IMED' => :Medium,
  'IMIT' => :MoreInfoText,
  'IMIU' => :MoreInfoURL,
  'IMUS' => :MusicBy,
  'INAM' => :Title,
  'IPDS' => :ProductionDesigner,
  'IPLT' => :NumColors,
  'IPRD' => :Product,
  'IPRO' => :ProducedBy,
  'IRIP' => :RippedBy,
  'IRTD' => :Rating,
  'ISBJ' => :Subject,
  'ISFT' => :Software,
  'ISGN' => :SecondaryGenre,
  'ISHP' => :Sharpness,
  'ISRC' => :Source,
  'ISRF' => :SourceForm,
  'ISTD' => :ProductionStudio,
  'ISTR' => :Starring,
  'ITCH' => :Technician,
  'IWMU' => :WatermarkURL,
  'IWRI' => :WrittenBy,
  'LANG' => :Language,
  'LOCA' => :Location,
  'PRT1' => :Part,
  'PRT2' => :NumberOfParts,
  'RATE' => :Rate,
  'STAR' => :Starring,
  'STAT' => :Statistics,
  'TAPE' => :TapeName,
  'TCDO' => :EndTimecode,
  'TCOD' => :StartTimecode,
  'TITL' => :Title,
  'TLEN' => :Length,
  'TORG' => :Organization,
  'TRCK' => :TrackNumber,
  'TURL' => :URL,
  'TVER' => :Version,
  'VMAJ' => :VegasVersionMajor,
  'VMIN' => :VegasVersionMinor,
  'YEAR' => :Year,
  # Exif tags
  'ecor' => :Make,
  'emdl' => :Model,
  'emnt' => :MakerNotes,
  'erel' => :RelatedImageFile,
  'etim' => :TimeCreated,
  'eucm' => :UserComment,
  'ever' => :ExifVersion
}

ELEMENT_ID_WAVE = Wave elements

'WAVE'

ELEMENT_ID_FORMAT =

'fmt '

ELEMENT_ID_DATA =

'data'

ELEMENT_ID_FACT =

'fact'

ELEMENT_ID_AVI = AVI elements

'AVI '

ELEMENT_ID_STRH =

'strh'

ELEMENT_ID_STRF =

'strf'

ELEMENT_ID_MOVI =

'movi'

ELEMENT_ID_IDX1 =

'idx1'

ELEMENT_ID_DMLH =

'dmlh'

ELEMENT_ID_IDIT =

'IDIT'

HDLR_ELEMENTS =

{
  ELEMENT_ID_IDIT => nil,
  'ISMP' => nil,
  'avih' => nil
}

STREAM_ELEMENTS =

{
  'strd' => nil,
  'strf' => nil,
  'strh' => nil,
  'strn' => nil,
  'indx' => nil
}

ODML_IDX_ELEMENTS =

{}

ELEMENT_ID_ANI = ANI elements

'ACON'

ELEMENT_ID_ANIH =

'anih'

ELEMENT_ID_ICON =

'icon'

ELEMENT_ID_SEQ =

'seq '

ELEMENT_ID_RATE =

'rate'

RIFF_INFO_ELEMENTS =

{}

ELEMENT_ID_LIST =

'LIST'

RIFF_GENERIC_ELEMENTS =

{
  BEGIN_PATTERN_JUNK => nil,
  ELEMENT_ID_LIST => {
    'INFO' => RIFF_INFO_ELEMENTS,
    # AVI elements
    'hdrl' => HDLR_ELEMENTS,
    'strl' => STREAM_ELEMENTS,
    ELEMENT_ID_MOVI => nil,
    'ncdt' => { :element_info => { :ignore_unknown_elements => true } },
    'odml' => {
      ELEMENT_ID_DMLH => nil
    },
    # ANI elements
    'fram' => {
      ELEMENT_ID_ICON => nil
    }
  }.merge(ODML_IDX_ELEMENTS)
}

RIFF_ROOT_ELEMENTS =

{
  # Wave elements
  ELEMENT_ID_WAVE => {
    ELEMENT_ID_FORMAT => nil,
    ELEMENT_ID_DATA => nil,
    ELEMENT_ID_FACT => nil
  },
  # AVI elements
  ELEMENT_ID_AVI => nil,
  ELEMENT_ID_IDX1 => nil,
  # ANI elements
  ELEMENT_ID_ANI => {
    ELEMENT_ID_ANIH => nil,
    ELEMENT_ID_SEQ => nil,
    ELEMENT_ID_RATE => nil
  }
}

RIFF_ELEMENTS =

{
  BEGIN_PATTERN_RIFF => RIFF_ROOT_ELEMENTS,
  BEGIN_PATTERN_RIFX => RIFF_ROOT_ELEMENTS
}

RIFF_ELEMENTS_WITH_SIZE =

[
BEGIN_PATTERN_RIFF,
BEGIN_PATTERN_RIFX,
BEGIN_PATTERN_JUNK,
ELEMENT_ID_LIST,
# WAVE elements
ELEMENT_ID_FORMAT,
ELEMENT_ID_DATA,
ELEMENT_ID_FACT,
# AVI elements
ELEMENT_ID_IDX1,
ELEMENT_ID_DMLH,
# ANI elements
ELEMENT_ID_ANIH,
ELEMENT_ID_ICON,
ELEMENT_ID_SEQ,
ELEMENT_ID_RATE
      ] +
RIFF_INFO_ELEMENTS.keys +
HDLR_ELEMENTS.keys +
STREAM_ELEMENTS.keys +
ODML_IDX_ELEMENTS.keys

AVI_STREAM_TYPES =

[ 'db', 'dc', 'pc', 'wb' ]

TRAILING_00_REGEXP =

Regexp.new("\x00*$".force_encoding(Encoding::ASCII_8BIT), nil, 'n')

Instance Method Summary collapse

Methods inherited from BeginPatternDecoder

#find_segments

Methods inherited from FilesHunter::Decoder

#segments_found, #setup

Instance Method Details

#decode(offset) ⇒ `Object`

# File 'lib/fileshunter/Decoders/RIFF.rb', line 231

def decode(offset)
  ending_offset = nil

  # Check endianness
  name = @data[offset..offset+3]
  @bindata_16 = BinData::Uint16le
  @bindata_32 = BinData::Uint32le
  if (name == BEGIN_PATTERN_RIFX)
    @bindata_16 = BinData::Uint16be
    @bindata_32 = BinData::Uint32be
  end

  # Parse RIFF
  found_RIFF = false
  found_WAVE_data = false
  found_AVI_data = false
  extension = nil
  cursor, nbr_elements = parse_riff_element(offset, RIFF_ELEMENTS) do |element_hierarchy, element_cursor, size, container_end_offset|
    element_name = element_hierarchy[-1]
    if ((element_name == BEGIN_PATTERN_RIFF) or
        (element_name == BEGIN_PATTERN_RIFX))
      # Check we are not getting on a second RIFF file
      if found_RIFF
        ending_offset = element_cursor - 8
        next nil
      end
      found_RIFF = true
    elsif (INFO_ELEMENTS_ID[element_name] != nil)
      # Standard info
      metadata( INFO_ELEMENTS_ID[element_name] => read_ascii(element_cursor, size) )
    else
      # Special cases
      case element_name

      # Wave elements
      when ELEMENT_ID_WAVE
        extension = :wav
        found_relevant_data(extension)
      when ELEMENT_ID_FORMAT
        invalid_data("@#{cursor} - Wave file having an invalid fmt size: #{size}") if (size < 16)
        # Decode header
        audio_format = @bindata_16.read(@data[element_cursor..element_cursor+1])
        num_channels = @bindata_16.read(@data[element_cursor+2..element_cursor+3])
        sample_rate = @bindata_32.read(@data[element_cursor+4..element_cursor+7])
        byte_rate = @bindata_32.read(@data[element_cursor+8..element_cursor+11])
        block_align = @bindata_16.read(@data[element_cursor+12..element_cursor+13])
        bits_per_sample = @bindata_16.read(@data[element_cursor+14..element_cursor+15])
        metadata(
          :audio_format => audio_format,
          :num_channels => num_channels,
          :sample_rate => sample_rate,
          :byte_rate => byte_rate,
          :block_align => block_align,
          :bits_per_sample => bits_per_sample
        )
      when ELEMENT_ID_DATA
        found_WAVE_data = true

      # AVI elements
      when ELEMENT_ID_AVI
        extension = :avi
        found_relevant_data(:avi)
      when ELEMENT_ID_MOVI
        # Parse the following RIFF tags manually
        cursor = element_cursor
        stream_id = @data[cursor..cursor+1]
        stream_type = @data[cursor+2..cursor+3]
        while ((cursor < container_end_offset) and
               (stream_id.match(/^\d\d$/) != nil) and
               (AVI_STREAM_TYPES.include?(stream_type)))
          # Read size
          stream_size = @bindata_32.read(@data[cursor+4..cursor+7])
          stream_size += 1 if stream_size.odd?
          log_debug "@#{cursor} - Found AVI stream #{stream_id}#{stream_type} of size #{stream_size}"
          cursor += 8 + stream_size
          stream_id = @data[cursor..cursor+1]
          stream_type = @data[cursor+2..cursor+3]
        end
        found_AVI_data = true
        next cursor
      when ELEMENT_ID_IDIT
        metadata( :date_time_original => read_ascii(element_cursor, size) )

      # ANI elements
      when ELEMENT_ID_ANI
        extension = :ani
        found_relevant_data(:ani)

      end

    end

    # By default: no data
    next element_cursor
  end
  metadata( :nbr_elements => nbr_elements )
  invalid_data("@#{cursor} - Missing WAVE data.") if ((extension == :wav) and (!found_WAVE_data))
  invalid_data("@#{cursor} - Missing AVI data.") if ((extension == :avi) and (!found_AVI_data))
  ending_offset = cursor if (ending_offset == nil)

  return ending_offset
end

#get_begin_pattern ⇒ `Object`



227
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# File 'lib/fileshunter/Decoders/RIFF.rb', line 227

def get_begin_pattern
  return BEGIN_PATTERN_FILE, { :offset_inc => 4, :max_regexp_size => 4 }
end