Package flumotion :: Package component :: Package encoders :: Package vorbis :: Module vorbisutils
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Source Code for Module flumotion.component.encoders.vorbis.vorbisutils

 1  # -*- Mode: Python -*- 
 2  # vi:si:et:sw=4:sts=4:ts=4 
 3   
 4  # Flumotion - a streaming media server 
 5  # Copyright (C) 2004,2005,2006,2007,2008,2009 Fluendo, S.L. 
 6  # Copyright (C) 2010,2011 Flumotion Services, S.A. 
 7  # All rights reserved. 
 8  # 
 9  # This file may be distributed and/or modified under the terms of 
10  # the GNU Lesser General Public License version 2.1 as published by 
11  # the Free Software Foundation. 
12  # This file is distributed without any warranty; without even the implied 
13  # warranty of merchantability or fitness for a particular purpose. 
14  # See "LICENSE.LGPL" in the source distribution for more information. 
15  # 
16  # Headers in this file shall remain intact. 
17   
18  __version__ = "$Rev$" 
19   
20   
21 -def get_preferred_sample_rate(maxrate):
22 """ Get the preferred 'standard' sample rate not exceeded maxrate""" 23 rates = [192000, 96000, 48000, 44100, 32000, 34000, 22050, 16000, 12000, 24 11025, 8000] 25 26 for rate in rates: 27 if rate <= maxrate: 28 return rate 29 30 return 8000
31 32
33 -def get_max_sample_rate(bitrate, channels):
34 # maybe better in a hashtable/associative array? 35 # ZAHEER: these really are "magic" limits that i found by trial and 36 # error used 37 # by libvorbis's encoder to determine what maximum samplerate it 38 # accepts for a bitrate, numchannels combo 39 # THOMAS: strangely enough they don't seem to be easily extractable from 40 # vorbis/lib/modes/setup_*.h 41 # might make sense to figure this out once and for all and verify 42 # GStreamer's behaviour as well 43 if channels == 2: 44 if bitrate >= 45000: 45 retval = 50000 46 elif bitrate >= 40000: 47 retval = 40000 48 elif bitrate >= 30000: 49 retval = 26000 50 elif bitrate >= 24000: 51 retval = 19000 52 elif bitrate >= 16000: 53 retval = 15000 54 elif bitrate >= 12000: 55 retval = 9000 56 else: 57 retval = -1 58 59 elif channels == 1: 60 if bitrate >= 32000: 61 retval = 50000 62 elif bitrate >= 24000: 63 retval = 40000 64 elif bitrate >= 16000: 65 retval = 26000 66 elif bitrate >= 12000: 67 retval = 15000 68 elif bitrate >= 8000: 69 retval = 9000 70 else: 71 retval = -1 72 73 return retval
74