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

88 lines
3.2 KiB
Python

"""
AU audio file parser
Author: Victor Stinner
Creation: 12 july 2006
"""
from hachoir_parser import Parser
from hachoir_core.field import UInt32, Enum, String, RawBytes
from hachoir_core.endian import BIG_ENDIAN
from hachoir_core.text_handler import displayHandler, filesizeHandler
from hachoir_core.tools import createDict, humanFrequency
class AuFile(Parser):
PARSER_TAGS = {
"id": "sun_next_snd",
"category": "audio",
"file_ext": ("au", "snd"),
"mime": (u"audio/basic",),
"min_size": 24*8,
"magic": ((".snd", 0),),
"description": "Sun/NeXT audio"
}
endian = BIG_ENDIAN
CODEC_INFO = {
1: (8, u"8-bit ISDN u-law"),
2: (8, u"8-bit linear PCM"),
3: (16, u"16-bit linear PCM"),
4: (24, u"24-bit linear PCM"),
5: (32, u"32-bit linear PCM"),
6: (32, u"32-bit IEEE floating point"),
7: (64, u"64-bit IEEE floating point"),
8: (None, u"Fragmented sample data"),
9: (None, u"DSP program"),
10: (8, u"8-bit fixed point"),
11: (16, u"16-bit fixed point"),
12: (24, u"24-bit fixed point"),
13: (32, u"32-bit fixed point"),
18: (16, u"16-bit linear with emphasis"),
19: (16, u"16-bit linear compressed"),
20: (16, u"16-bit linear with emphasis and compression"),
21: (None, u"Music kit DSP commands"),
23: (None, u"4-bit ISDN u-law compressed (CCITT G.721 ADPCM)"),
24: (None, u"ITU-T G.722 ADPCM"),
25: (None, u"ITU-T G.723 3-bit ADPCM"),
26: (None, u"ITU-T G.723 5-bit ADPCM"),
27: (8, u"8-bit ISDN A-law"),
}
# Create bit rate and codec name dictionnaries
BITS_PER_SAMPLE = createDict(CODEC_INFO, 0)
CODEC_NAME = createDict(CODEC_INFO, 1)
VALID_NB_CHANNEL = set((1,2)) # FIXME: 4, 5, 7, 8 channels are supported?
def validate(self):
if self.stream.readBytes(0, 4) != ".snd":
return "Wrong file signature"
if self["channels"].value not in self.VALID_NB_CHANNEL:
return "Invalid number of channel"
return True
def getBitsPerSample(self):
"""
Get bit rate (number of bit per sample per channel),
may returns None if you unable to compute it.
"""
return self.BITS_PER_SAMPLE.get(self["codec"].value)
def createFields(self):
yield String(self, "signature", 4, 'Format signature (".snd")', charset="ASCII")
yield UInt32(self, "data_ofs", "Data offset")
yield filesizeHandler(UInt32(self, "data_size", "Data size"))
yield Enum(UInt32(self, "codec", "Audio codec"), self.CODEC_NAME)
yield displayHandler(UInt32(self, "sample_rate", "Number of samples/second"), humanFrequency)
yield UInt32(self, "channels", "Number of interleaved channels")
size = self["data_ofs"].value - self.current_size // 8
if 0 < size:
yield String(self, "info", size, "Information", strip=" \0", charset="ISO-8859-1")
size = min(self["data_size"].value, (self.size - self.current_size) // 8)
yield RawBytes(self, "audio_data", size, "Audio data")
def createContentSize(self):
return (self["data_ofs"].value + self["data_size"].value) * 8