SickGear/lib/hachoir_parser/audio/midi.py
2015-08-20 16:48:28 +01:00

246 lines
9 KiB
Python

"""
Musical Instrument Digital Interface (MIDI) audio file parser.
Documentation:
- Standard MIDI File Format, Dustin Caldwell (downloaded on wotsit.org)
Author: Victor Stinner
Creation: 27 december 2006
"""
from hachoir_parser import Parser
from hachoir_core.field import (FieldSet, Bits, ParserError,
String, UInt32, UInt24, UInt16, UInt8, Enum, RawBits, RawBytes)
from hachoir_core.endian import BIG_ENDIAN
from hachoir_core.text_handler import textHandler, hexadecimal
from hachoir_core.tools import createDict, humanDurationNanosec
from hachoir_parser.common.tracker import NOTE_NAME
MAX_FILESIZE = 10 * 1024 * 1024
class Integer(Bits):
def __init__(self, parent, name, description=None):
Bits.__init__(self, parent, name, 8, description)
stream = parent.stream
addr = self.absolute_address
value = 0
while True:
bits = stream.readBits(addr, 8, parent.endian)
value = (value << 7) + (bits & 127)
if not(bits & 128):
break
addr += 8
self._size += 8
if 32 < self._size:
raise ParserError("Integer size is bigger than 32-bit")
self.createValue = lambda: value
def parseNote(parser):
yield Enum(UInt8(parser, "note", "Note number"), NOTE_NAME)
yield UInt8(parser, "velocity")
def parseControl(parser):
yield UInt8(parser, "control", "Controller number")
yield UInt8(parser, "value", "New value")
def parsePatch(parser):
yield UInt8(parser, "program", "New program number")
def parseChannel(parser, size=1):
yield UInt8(parser, "channel", "Channel number")
def parsePitch(parser):
yield UInt8(parser, "bottom", "(least sig) 7 bits of value")
yield UInt8(parser, "top", "(most sig) 7 bits of value")
def parseText(parser, size):
yield String(parser, "text", size)
def parseSMPTEOffset(parser, size):
yield RawBits(parser, "padding", 1)
yield Enum(Bits(parser, "frame_rate", 2),
{0:"24 fps", 1:"25 fps", 2:"30 fps (drop frame)", 3:"30 fps"})
yield Bits(parser, "hour", 5)
yield UInt8(parser, "minute")
yield UInt8(parser, "second")
yield UInt8(parser, "frame")
yield UInt8(parser, "subframe", "100 subframes per frame")
def formatTempo(field):
return humanDurationNanosec(field.value*1000)
def parseTempo(parser, size):
yield textHandler(UInt24(parser, "microsec_quarter", "Microseconds per quarter note"), formatTempo)
def parseTimeSignature(parser, size):
yield UInt8(parser, "numerator", "Numerator of time signature")
yield UInt8(parser, "denominator", "denominator of time signature 2=quarter 3=eighth, etc.")
yield UInt8(parser, "nb_tick", "Number of ticks in metronome click")
yield UInt8(parser, "nb_32nd_note", "Number of 32nd notes to the quarter note")
class Command(FieldSet):
COMMAND = {}
for channel in xrange(16):
COMMAND[0x80+channel] = ("Note off (channel %u)" % channel, parseNote)
COMMAND[0x90+channel] = ("Note on (channel %u)" % channel, parseNote)
COMMAND[0xA0+channel] = ("Key after-touch (channel %u)" % channel, parseNote)
COMMAND[0xB0+channel] = ("Control change (channel %u)" % channel, parseControl)
COMMAND[0xC0+channel] = ("Program (patch) change (channel %u)" % channel, parsePatch)
COMMAND[0xD0+channel] = ("Channel after-touch (channel %u)" % channel, parseChannel)
COMMAND[0xE0+channel] = ("Pitch wheel change (channel %u)" % channel, parsePitch)
COMMAND_DESC = createDict(COMMAND, 0)
COMMAND_PARSER = createDict(COMMAND, 1)
META_COMMAND_TEXT = 1
META_COMMAND_NAME = 3
META_COMMAND = {
0x00: ("Sets the track's sequence number", None),
0x01: ("Text event", parseText),
0x02: ("Copyright info", parseText),
0x03: ("Sequence or Track name", parseText),
0x04: ("Track instrument name", parseText),
0x05: ("Lyric", parseText),
0x06: ("Marker", parseText),
0x07: ("Cue point", parseText),
0x20: ("MIDI Channel Prefix", parseChannel),
0x2F: ("End of the track", None),
0x51: ("Set tempo", parseTempo),
0x54: ("SMPTE offset", parseSMPTEOffset),
0x58: ("Time Signature", parseTimeSignature),
0x59: ("Key signature", None),
0x7F: ("Sequencer specific information", None),
}
META_COMMAND_DESC = createDict(META_COMMAND, 0)
META_COMMAND_PARSER = createDict(META_COMMAND, 1)
def __init__(self, *args, **kwargs):
if 'prev_command' in kwargs:
self.prev_command = kwargs['prev_command']
del kwargs['prev_command']
else:
self.prev_command = None
self.command = None
FieldSet.__init__(self, *args, **kwargs)
def createFields(self):
yield Integer(self, "time", "Delta time in ticks")
next = self.stream.readBits(self.absolute_address+self.current_size, 8, self.root.endian)
if next & 0x80 == 0:
# "Running Status" command
if self.prev_command is None:
raise ParserError("Running Status command not preceded by another command.")
self.command = self.prev_command.command
else:
yield Enum(textHandler(UInt8(self, "command"), hexadecimal), self.COMMAND_DESC)
self.command = self["command"].value
if self.command == 0xFF:
yield Enum(textHandler(UInt8(self, "meta_command"), hexadecimal), self.META_COMMAND_DESC)
yield UInt8(self, "data_len")
size = self["data_len"].value
if size:
command = self["meta_command"].value
if command in self.META_COMMAND_PARSER:
parser = self.META_COMMAND_PARSER[command]
else:
parser = None
if parser:
for field in parser(self, size):
yield field
else:
yield RawBytes(self, "data", size)
else:
if self.command not in self.COMMAND_PARSER:
raise ParserError("Unknown command: %s" % self["command"].display)
parser = self.COMMAND_PARSER[self.command]
for field in parser(self):
yield field
def createDescription(self):
if "meta_command" in self:
return self["meta_command"].display
else:
return self.COMMAND_DESC[self.command]
class Track(FieldSet):
def __init__(self, *args):
FieldSet.__init__(self, *args)
self._size = (8 + self["size"].value) * 8
def createFields(self):
yield String(self, "marker", 4, "Track marker (MTrk)", charset="ASCII")
yield UInt32(self, "size")
cur = None
if True:
while not self.eof:
cur = Command(self, "command[]", prev_command=cur)
yield cur
else:
size = self["size"].value
if size:
yield RawBytes(self, "raw", size)
def createDescription(self):
command = self["command[0]"]
if "meta_command" in command \
and command["meta_command"].value in (Command.META_COMMAND_TEXT, Command.META_COMMAND_NAME) \
and "text" in command:
return command["text"].value.strip("\r\n")
else:
return ""
class Header(FieldSet):
static_size = 10*8
FILE_FORMAT = {
0: "Single track",
1: "Multiple tracks, synchronous",
2: "Multiple tracks, asynchronous",
}
def createFields(self):
yield UInt32(self, "size")
yield Enum(UInt16(self, "file_format"), self.FILE_FORMAT)
yield UInt16(self, "nb_track")
yield UInt16(self, "delta_time", "Delta-time ticks per quarter note")
def createDescription(self):
return "%s; %s tracks" % (
self["file_format"].display, self["nb_track"].value)
class MidiFile(Parser):
MAGIC = "MThd"
PARSER_TAGS = {
"id": "midi",
"category": "audio",
"file_ext": ["mid", "midi"],
"mime": (u"audio/mime", ),
"magic": ((MAGIC, 0),),
"min_size": 64,
"description": "MIDI audio"
}
endian = BIG_ENDIAN
def validate(self):
if self.stream.readBytes(0, 4) != self.MAGIC:
return "Invalid signature"
if self["header/size"].value != 6:
return "Invalid header size"
return True
def createFields(self):
yield String(self, "signature", 4, r"MIDI signature (MThd)", charset="ASCII")
yield Header(self, "header")
while not self.eof:
yield Track(self, "track[]")
def createDescription(self):
return "MIDI audio: %s" % self["header"].description
def createContentSize(self):
count = self["/header/nb_track"].value - 1
start = self["track[%u]" % count].absolute_address
# Search "End of track" of last track
end = self.stream.searchBytes("\xff\x2f\x00", start, MAX_FILESIZE*8)
if end is not None:
return end + 3*8
return None