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1636
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1 function saveaudio (name, X, ext, bit) |
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2 |
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3 # usage: saveaudio (name, X, [, ext [, bit]]) |
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4 # |
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5 # Saves a vector X of audio data in the file "name.ext". |
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6 # The format of the audio file is determined by ext which has to be |
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7 # written without an inital "."; default value for ext is "lin". |
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8 # |
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9 # Currently, the following audio formats are supported: |
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10 # *) mu-law files with extension "mu", "au" or "snd" |
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11 # *) linearly encoded files with extension "lin" or "raw" |
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12 # If the data is saved linearly, the bit argument decides whether an |
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13 # 8-bit (default) or a 16-bit format is used. |
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14 |
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15 # Written by AW (Andreas.Weingessel@ci.tuwien.ac.at) on Sep 5, 1994 |
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16 # Last modified by AW on Oct 29, 1994 |
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17 # Copyright Dept of Probability Theory and Statistics TU Wien |
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18 |
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19 if (nargin < 2 || nargin > 4) |
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20 usage ("saveaudio (X, name [, ext [, bit]])"); |
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21 endif |
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22 |
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23 if (nargin == 2) |
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24 ext = "lin"; |
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25 endif |
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26 |
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27 if (nargin < 4) |
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28 bit = 8; |
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29 elseif (bit != 8 && bit != 16) |
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30 error ("saveaudio: bit must be either 8 or 16"); |
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31 endif |
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32 |
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33 [nr, nc] = size (X); |
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34 if (nc != 1) |
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35 if (nr == 1) |
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36 X = X'; |
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37 nr = nc; |
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38 else |
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39 error ("saveaudio: X must be a vector."); |
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40 endif |
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41 endif |
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42 |
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43 num = fopen ([name, ".", ext], "w"); |
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44 |
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45 if (strcmp (ext, "lin") || strcmp (ext, "raw")) |
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46 if (bit == 8) |
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47 ld = max (abs (X)); |
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48 if (ld > 127) # convert 16 to 8 bit |
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49 if (ld < 16384) |
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50 sc = 64 / ld; |
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51 else |
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52 sc = 1 / 256; |
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53 endif |
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54 X = fix (X * sc); |
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55 endif |
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56 X = X + 127; |
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57 c = fwrite (num, X, "uchar"); |
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58 else |
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59 c = fwrite (num, X, "short"); |
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60 endif |
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61 elseif (strcmp (ext, "mu") || strcmp (ext, "au") || strcmp (ext, "snd")) |
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62 Y = lin2mu (X); |
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63 c = fwrite (num, Y, "uchar"); |
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64 else |
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65 fclose (num); |
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66 error ("saveaudio does not support given extension"); |
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67 endif |
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68 |
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69 fclose (num); |
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70 |
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71 endfunction |
