Parser of FastTrackerII Extended Module (XM) version 1.4

- Modplug source code (file modplug/soundlib/Load_mod.cpp)
- Dumb source code (files include/dumb.h and src/it/readmod.c
- Documents on "MOD" format on Wotsit

Compressed formats (i.e. starting with "PP20" or having "PACK" as type
are not handled. Also NoiseTracker's NST modules aren't handled, although
it might be possible: no file format and 15 samples

Author: Christophe GISQUET <christophe.gisquet@free.fr>
Creation: 18th February 2007

from math import log10
from hachoir_parser import Parser
from hachoir_core.field import (FieldSet,
    Bits, UInt16, UInt8,
    RawBytes, String, GenericVector)
from hachoir_core.endian import BIG_ENDIAN
from hachoir_core.text_handler import textHandler

# Old NoiseTracker 15-samples modules can have anything here.
    "M.K.": ("Noise/Pro-Tracker", 4),
    "M!K!": ("Noise/Pro-Tracker", 4),
    "M&K&": ("Noise/Pro-Tracker", 4),
    "RASP": ("StarTrekker", 4),
    "FLT4": ("StarTrekker", 4),
    "FLT8": ("StarTrekker", 8),
    "6CHN": ("FastTracker", 6),
    "8CHN": ("FastTracker", 8),
    "CD81": ("Octalyser", 8),
    "OCTA": ("Octalyser", 8),
    "FA04": ("Digital Tracker", 4),
    "FA06": ("Digital Tracker", 6),
    "FA08": ("Digital Tracker", 8),

def getFineTune(val):
    return ("0", "1", "2", "3", "4", "5", "6", "7", "8",
            "-8", "-7", "-6", "-5", "-4", "-3", "-2", "-1")[val.value]

def getVolume(val):
    return "%.1f dB" % (20.0*log10(val.value/64.0))

class SampleInfo(FieldSet):
    static_size = 30*8
    def createFields(self):
        yield String(self, "name", 22, strip='\0')
        yield UInt16(self, "sample_count")
        yield textHandler(UInt8(self, "fine_tune"), getFineTune)
        yield textHandler(UInt8(self, "volume"), getVolume)
        yield UInt16(self, "loop_start", "Loop start offset in samples")
        yield UInt16(self, "loop_len", "Loop length in samples")

    def createValue(self):
        return self["name"].value

class Header(FieldSet):
    static_size = 1084*8

    def createFields(self):
        yield String(self, "name", 20, strip='\0')
        yield GenericVector(self, "samples", 31, SampleInfo, "info")
        yield UInt8(self, "length")
        yield UInt8(self, "played_patterns_count")
        yield GenericVector(self, "patterns", 128, UInt8, "position")
        yield String(self, "type", 4)

    def getNumChannels(self):
        return MODULE_TYPE[self["type"].value][1]

class Note(FieldSet):
    static_size = 8*4
    def createFields(self):
        yield Bits(self, 4, "note_hi_nibble")
        yield Bits(self, 12, "period")
        yield Bits(self, 4, "note_low_nibble")
        yield Bits(self, 4, "effect")
        yield UInt8(self, "parameter")

class Row(FieldSet):
    def __init__(self, parent, name, channels, desc=None):
        FieldSet.__init__(self, parent, name, description=desc)
        self.channels = channels
        self._size = 8*self.channels*4

    def createFields(self):
        for index in xrange(self.channels):
            yield Note(self, "note[]")

class Pattern(FieldSet):
    def __init__(self, parent, name, channels, desc=None):
        FieldSet.__init__(self, parent, name, description=desc)
        self.channels = channels
        self._size = 64*8*self.channels*4

    def createFields(self):
        for index in xrange(64):
            yield Row(self, "row[]", self.channels)

class AmigaModule(Parser):
        "id": "mod",
        "category": "audio",
        "file_ext": ("mod", "nst", "wow", "oct", "sd0" ),
        "mime": (u'audio/mod', u'audio/x-mod', u'audio/mod', u'audio/x-mod'),
        "min_size": 1084*8,
        "description": "Uncompressed amiga module"
    endian = BIG_ENDIAN

    def validate(self):
        t = self.stream.readBytes(1080*8, 4)
        if t not in MODULE_TYPE:
            return "Invalid module type '%s'" % t
        self.createValue = lambda t: "%s module, %u channels" % MODULE_TYPE[t]
        return True

    def createFields(self):
        header = Header(self, "header")
        yield header
        channels = header.getNumChannels()

        # Number of patterns
        patterns = 0
        for index in xrange(128):
            patterns = max(patterns,
                           header["patterns/position[%u]" % index].value)
        patterns += 1

        # Yield patterns
        for index in xrange(patterns):
            yield Pattern(self, "pattern[]", channels)

        # Yield samples
        for index in xrange(31):
            count = header["samples/info[%u]/sample_count" % index].value
            if count:
                self.info("Yielding sample %u: %u samples" % (index, count))
                yield RawBytes(self, "sample_data[]", 2*count, \
                               "Sample %u" % index)
hachoir-parser documentation built on Sept. 20, 2017, 5:30 p.m.