ref: 277998ed89b151c9654c600749021757b4e579c4
dir: /doc/api_simple.html/
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML> <HEAD> <TITLE> Secret Rabbit Code (aka libsamplerate) </TITLE> <META NAME="Author" CONTENT="Erik de Castro Lopo (erikd AT mega-nerd DOT com)"> <META NAME="Version" CONTENT="libsamplerate-0.1.2"> <META NAME="Description" CONTENT="The Secret Rabbit Code Home Page"> <META NAME="Keywords" CONTENT="libsamplerate sound resample audio dsp Linux"> <LINK REL=StyleSheet HREF="SRC.css" TYPE="text/css" MEDIA="all"> </HEAD> <BODY TEXT="#FFFFFF" BGCOLOR="#000000" LINK="#FB1465" VLINK="#FB1465" ALINK="#FB1465"> <!-- pepper --> <CENTER> <IMG SRC="SRC.png" HEIGHT=100 WIDTH=760 ALT="SRC.png"> </CENTER> <!-- pepper --> <BR> <!-- pepper --> <TABLE ALIGN="center" WIDTH="98%"> <TR> <TD VALIGN="top"> <BR> <DIV CLASS="nav"> <BR> <A HREF="index.html">Home</A><BR> <BR> <A HREF="api_simple.html">Simple API</A><BR> <A HREF="api_full.html">Full API</A><BR> <A HREF="api_callback.html">Callback API</A><BR> <A HREF="api_misc.html">Miscellaneous</A><BR> <A HREF="api_misc.html#ErrorReporting">Error Handling</A><BR> <BR> <DIV CLASS="block"> Author :<BR>Erik de Castro Lopo <!-- pepper --> <BR><BR> <!-- pepper --> </DIV> <IMG SRC= "/cgi-bin/Count.cgi?ft=6|frgb=55;55;55|tr=0|md=6|dd=B|st=1|sh=1|df=src_api.dat" HEIGHT=30 WIDTH=100 ALT="counter.gif"> </DIV> </TD> <!-- pepper --> <!-- ######################################################################## --> <!-- pepper --> <TD VALIGN="top"> <DIV CLASS="block"> <H1><B>Simple API</B></H1> <P> The simple API consists of a single function : </P> <PRE> int src_simple (SRC_DATA *data, int converter_type, int channels) ; </PRE> <P> The use of this function rather than the more fully featured API requires the caller to know the total length of the input data before hand and that all input and output data can be held in the system's memory at once. It also assumes that there is a single constant ratio between input and output sample rates. <!-- If these conditions cannot be met, the full featured API should be used instead. In addition, this documentation is complemented by this <A HREF="ex_simple.html">example code</A>. --> </P> <P> Dealing with the easy stuff first, the <B>converter_type</B> parameter should be one of the values defined in <B>samplerate.h</B> and documented <A HREF="api_misc.html#Converters">here</A> while the <b>channels</b> parameter specifies the number of interleaved channels that the sample rate converter is being asked to process (number of input channels and output channels is always equal). There is no hard upper limit on the number of channels; it is limited purely by the amount of memory available. </P> <P> The first parameter to <B>src_simple</B> is a pointer to an <B>SRC_DATA</B> struct (more info <A HREF="api_misc.html#SRC_DATA">here</A>) defined as follows: </P> <PRE> typedef struct { float *data_in, *data_out ; long input_frames, output_frames ; long input_frames_used, output_frames_gen ; int end_of_input ; double src_ratio ; } SRC_DATA ; </PRE> <P> The fields of this struct which must be filled in by the caller are: </P> <PRE> data_in : A pointer to the input data samples. input_frames : The number of frames of data pointed to by data_in. data_out : A pointer to the output data samples. output_frames : Maximum number of frames pointer to by data_out. src_ratio : Equal to output_sample_rate / input_sample_rate. </PRE> <P> When the <B>src_simple</B> function returns <B>output_frames_gen</B> will be set to the number of output frames generated and <B>input_frames_used</B> will be set to the number of input frames used to generate the provided number of output frames. </P> <P> The <B>src_simple</B> function returns a non-zero value when an error occurs. See <A HREF="api_misc.html#ErrorReporting">here</A> for how to convert the error value into a text string. </P> </DIV> </TD></TR> </TABLE> </BODY> </HTML> <!-- Do not edit or modify anything in this comment block. The arch-tag line is a file identity tag for the GNU Arch revision control system. arch-tag: 935c1734-00b4-42fb-998e-36b9136d405b -->