| 1 | The functions afSetVirtualSampleFormat, afSetVirtualByteOrder, |
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| 2 | afSetVirtualChannels, afSetVirtualPCMMapping set the virtual data |
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| 3 | format for a particular track of an audio file. |
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| 4 | |
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| 5 | SYNOPSIS |
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| 6 | |
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| 7 | #include <audiofile.h> |
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| 8 | |
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| 9 | int afSetVirtualSampleFormat (AFfilehandle file, int track, |
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| 10 | int sampleFormat, int sampleWidth); |
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| 11 | |
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| 12 | int afSetVirtualByteOrder (AFfilehandle file, int track, |
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| 13 | int byteOrder); |
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| 14 | |
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| 15 | int afSetVirtualChannels (AFfilehandle file, int track, int channels); |
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| 16 | |
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| 17 | int afSetVirtualRate (AFfilehandle file, int track, double rate); |
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| 18 | |
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| 19 | int afSetVirtualPCMMapping (AFfilehandle file, int track, |
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| 20 | double slope, double intercept, double minclip, double maxclip); |
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| 21 | |
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| 22 | PARAMETERS |
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| 23 | |
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| 24 | * file is an AFfilehandle which refers to an open audio file and is |
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| 25 | usually created by afOpenFile. |
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| 26 | |
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| 27 | * track is an integer which identifies a particular track in an open |
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| 28 | audio file. The only valid track is AF_DEFAULT_TRACK for all |
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| 29 | currently supported file formats. |
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| 30 | |
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| 31 | * sampleFormat is an integer which denotes a virtual sample format. |
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| 32 | Valid values are AF_SAMPFMT_TWOSCOMP, AF_SAMPFMT_UNSIGNED, |
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| 33 | AF_SAMPFMT_FLOAT, and AF_SAMPFMT_DOUBLE. Note that this |
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| 34 | implementation of the Audio File Library only supports the two's |
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| 35 | complement sample format at present. |
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| 36 | |
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| 37 | * sampleWidth is a positive integer which specifies the number of bits in a |
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| 38 | virtual sample. |
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| 39 | |
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| 40 | * channels is a positive integer which specifies the number of |
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| 41 | interleaved audio channels in the given audio track. |
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| 42 | |
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| 43 | * byteOrder is an integer which specifies the virtual byte order of |
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| 44 | samples in the given audio track. byteOrder can be either |
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| 45 | AF_BYTEORDER_BIGENDIAN or AF_BYTEORDER_LITTLEENDIAN. |
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| 46 | |
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| 47 | * slope and intercept are double-precision floating point values which |
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| 48 | indicate the audio data sample slope and zero-crossing value, |
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| 49 | respectively, for the given sample format. |
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| 50 | |
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| 51 | * minclip and maxclip are double-precision floating point values |
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| 52 | which indicates the minimum or maximum sample values to be returned. |
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| 53 | Any values less than minclip will be set to minclip, and any values |
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| 54 | greater than maxclip will be set to maxclip. |
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| 55 | |
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| 56 | RETURN VALUE |
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| 57 | |
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| 58 | These functions return 0 for success and -1 for failure. |
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| 59 | |
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| 60 | BUGS |
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| 61 | |
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| 62 | At present, afSetVirtualRate is not implemented. |
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