| 1 | .TH "roar_vs_position" "3" "June 2011" "RoarAudio" "RoarAudio Programmer's Manual" |
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| 2 | |
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| 3 | .SH NAME |
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| 4 | roar_vs_position, roar_vs_latency \- Get stream position information |
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| 5 | |
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| 6 | .SH SYNOPSIS |
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| 7 | |
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| 8 | #include <roaraudio.h> |
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| 9 | |
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| 10 | ssize_t roar_vs_position(roar_vs_t * vss, int backend, int * error); |
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| 11 | |
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| 12 | roar_mus_t roar_vs_latency(roar_vs_t * vss, int backend, int * error); |
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| 13 | |
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| 14 | .SH "DESCRIPTION" |
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| 15 | \fBroar_vs_position()\fR returns the current server site position of the stream plus |
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| 16 | the current offset for the selected backend. |
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| 17 | |
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| 18 | \fBroar_vs_latency()\fR returns the latency between the client site stream position and the server |
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| 19 | site position plus the latency by the backend. |
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| 20 | |
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| 21 | Use of roar_vs_latency() is not recommended as it requires the codec to use a true constant bit rate. |
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| 22 | |
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| 23 | Calling these functions too often will result in bad performance and incorrect data |
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| 24 | (pool interval smaller than server response time). Polling up to 20 times per second shoudn't be a problem. |
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| 25 | |
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| 26 | .SH "PARAMETERS" |
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| 27 | .TP |
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| 28 | \fBvss\fR |
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| 29 | The VS object to be used. |
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| 30 | |
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| 31 | .TP |
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| 32 | \fBbackend\fR |
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| 33 | The backend used for correction. This can be a stream ID of the stream to use as backend or one of the special values |
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| 34 | defined by the constants ROAR_VS_BACKEND_*. |
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| 35 | ROAR_VS_BACKEND_NONE is used to ask for no correction. |
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| 36 | ROAR_VS_BACKEND_DEFAULT is used to ask for the default correction. This should be used in all common cases. |
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| 37 | ROAR_VS_BACKEND_FIRST is used to ask for correction based on the first primary stream on the same mixer. |
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| 38 | |
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| 39 | .TP |
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| 40 | \fBerror\fR |
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| 41 | This is a pointer to a integer used to store the error value in case of error. |
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| 42 | This can be NULL if not used but it is very recommended to use this error value to report |
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| 43 | good error messages to the user. |
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| 44 | |
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| 45 | .SH "RETURN VALUE" |
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| 46 | roar_vs_position() returns the stream position on success and \-1 on error. |
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| 47 | Stream position is the current position of the stream in units of samples (not frames!). |
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| 48 | |
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| 49 | roar_vs_latency() returns the stream latency on success and zero on error. However zero is a valid |
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| 50 | value. In case of error \fBerror\fR is set to the error. In case of no error but zero latency |
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| 51 | \fBerror\fR is cleared (set to ROAR_ERROR_NONE). |
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| 52 | Latency is retruned in mu-seconds (1/10^-6s). |
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| 53 | |
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| 54 | .SH "EXAMPLES" |
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| 55 | FIXME |
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| 56 | |
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| 57 | .SH "SEE ALSO" |
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| 58 | \fBroarvs\fR(7), |
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| 59 | \fBlibroar\fR(7), |
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| 60 | \fBRoarAudio\fR(7). |
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| 61 | |
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| 62 | .\" ll |
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