test_mpeg.m

来自「音频的水印加入算法」· M 代码 · 共 97 行

function Test_MPEG(wavePath)
%
% Main script - fs = 44100; bitrate = 128;
%   
%   Author: Michael Arnold ([e-mail])
%           Fraunhofer Institute for Computer Graphics (IGD)     
%----------------------------------------------------------------------------
%
% Test_MPEG(wavePath) computes the minimum masking threshold LTMin.
%
% -- INPUT --
% wavePath: Path to the WAVE files for calculating LTmin.
% -----------  

%
% Load tables and global constants
global FFT_SIZE MIN_POWER NOT_EXAMINED IRRELEVANT TONAL NON_TONAL 
global TH INDEX BARK ATH SPL Map CB LTq 
load('Common_Const.mat');
load('Tables_fs_44100.mat');

% Input Wave file muss ein MONO File sein !!!
UseGuiForInput = 1; 

% Specify NumberOfBands
NumberOfBands = 32;

% Draw
DRAW = 1;

% Fetch name of input file and prepare name of output file
if UseGuiForInput  
  
  % Set path to the wave files for testing.
  if isempty(wavePath),
	if isunix 
	  wavePath = '~/';
	else
	  wavePath = 'C:\';
	end
  end
  
  % Get Filename and Path for Input-AudioFile
  [fname, pname] = uigetfile( strcat(wavePath,'*.wav') ,...
							  'WAVE file to analyze'); 
  
  % Exit if user presses the cancel button
  if fname == 0 | pname == 0,
	return;
  end
  
  WavFile    = strcat(pname, fname);  
else 
  WavFile = wavePath;
end

% Loading the Wavfile, which should be MONO.
[properties Fs bits] = wavread(WavFile, 'size'); 
samples = properties(1);
channels = properties(2);  

if  channels ~= 1  
  error('This test is only for MONO files!'); 
end 

% Loop over blocks of size FFT_SIZE 
for OFFSET = 1:FFT_SIZE:samples;

  Input = wavread(WavFile, [OFFSET OFFSET+511])';

  % Psychoacoustic analysis 
  %-------------------------  
  [LTMin, Delta] = PsychoAcousticModel(Input, NumberOfBands);
  
  if (DRAW)
	plot(LTMin); title('Minimum masking threshold');
	xlabel('Subband number'); ylabel('dB'); 
  end
  
  keyInput = input('Press return to analyze block OR q to quit ...','s');
  
  if ~isempty(keyInput) & keyInput == 'q',
	% Close figure
	close
	return;
  end
  
end