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 Fluendo, S.L. (www.fluendo.com). 
 6  # All rights reserved. 
 7   
 8  # This file may be distributed and/or modified under the terms of 
 9  # the GNU General Public License version 2 as published by 
10  # the Free Software Foundation. 
11  # This file is distributed without any warranty; without even the implied 
12  # warranty of merchantability or fitness for a particular purpose. 
13  # See "LICENSE.GPL" in the source distribution for more information. 
14   
15  # Licensees having purchased or holding a valid Flumotion Advanced 
16  # Streaming Server license may use this file in accordance with the 
17  # Flumotion Advanced Streaming Server Commercial License Agreement. 
18  # See "LICENSE.Flumotion" in the source distribution for more information. 
19   
20  # Headers in this file shall remain intact. 
21   
22 -def get_preferred_sample_rate (maxrate):
23 """ Get the preferred 'standard' sample rate not exceeded maxrate""" 24 rates = [192000, 96000, 48000, 44100, 32000, 34000, 22050, 16000, 12000, 25 11025, 8000] 26 27 for rate in rates: 28 if rate <= maxrate: 29 return rate 30 31 return 8000
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
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