<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/> <title>GNU Radio 3.3.0 C++ API: gr_framer_sink_1.h Source File</title> <link href="tabs.css" rel="stylesheet" type="text/css"/> <link href="doxygen.css" rel="stylesheet" type="text/css"/> </head> <body> <!-- Generated by Doxygen 1.6.3 --> <h1>gr_framer_sink_1.h</h1><a href="gr__framer__sink__1_8h.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/* -*- c++ -*- */</span> <a name="l00002"></a>00002 <span class="comment">/*</span> <a name="l00003"></a>00003 <span class="comment"> * Copyright 2005,2006 Free Software Foundation, Inc.</span> <a name="l00004"></a>00004 <span class="comment"> * </span> <a name="l00005"></a>00005 <span class="comment"> * This file is part of GNU Radio</span> <a name="l00006"></a>00006 <span class="comment"> * </span> <a name="l00007"></a>00007 <span class="comment"> * GNU Radio is free software; you can redistribute it and/or modify</span> <a name="l00008"></a>00008 <span class="comment"> * it under the terms of the GNU General Public License as published by</span> <a name="l00009"></a>00009 <span class="comment"> * the Free Software Foundation; either version 3, or (at your option)</span> <a name="l00010"></a>00010 <span class="comment"> * any later version.</span> <a name="l00011"></a>00011 <span class="comment"> * </span> <a name="l00012"></a>00012 <span class="comment"> * GNU Radio is distributed in the hope that it will be useful,</span> <a name="l00013"></a>00013 <span class="comment"> * but WITHOUT ANY WARRANTY; without even the implied warranty of</span> <a name="l00014"></a>00014 <span class="comment"> * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the</span> <a name="l00015"></a>00015 <span class="comment"> * GNU General Public License for more details.</span> <a name="l00016"></a>00016 <span class="comment"> * </span> <a name="l00017"></a>00017 <span class="comment"> * You should have received a copy of the GNU General Public License</span> <a name="l00018"></a>00018 <span class="comment"> * along with GNU Radio; see the file COPYING. If not, write to</span> <a name="l00019"></a>00019 <span class="comment"> * the Free Software Foundation, Inc., 51 Franklin Street,</span> <a name="l00020"></a>00020 <span class="comment"> * Boston, MA 02110-1301, USA.</span> <a name="l00021"></a>00021 <span class="comment"> */</span> <a name="l00022"></a>00022 <a name="l00023"></a>00023 <span class="preprocessor">#ifndef INCLUDED_GR_FRAMER_SINK_1_H</span> <a name="l00024"></a>00024 <span class="preprocessor"></span><span class="preprocessor">#define INCLUDED_GR_FRAMER_SINK_1_H</span> <a name="l00025"></a>00025 <span class="preprocessor"></span> <a name="l00026"></a>00026 <span class="preprocessor">#include <<a class="code" href="gr__sync__block_8h.html">gr_sync_block.h</a>></span> <a name="l00027"></a>00027 <span class="preprocessor">#include <<a class="code" href="gr__msg__queue_8h.html">gr_msg_queue.h</a>></span> <a name="l00028"></a>00028 <a name="l00029"></a>00029 <span class="keyword">class </span><a class="code" href="classgr__framer__sink__1.html" title="Given a stream of bits and access_code flags, assemble packets.input: stream of bytes...">gr_framer_sink_1</a>; <a name="l00030"></a>00030 <span class="keyword">typedef</span> <a class="code" href="classboost_1_1shared__ptr.html" title="shared_ptr documentation stub">boost::shared_ptr<gr_framer_sink_1></a> <a class="code" href="classboost_1_1shared__ptr.html" title="shared_ptr documentation stub">gr_framer_sink_1_sptr</a>; <a name="l00031"></a>00031 <a name="l00032"></a>00032 <a class="code" href="classboost_1_1shared__ptr.html" title="shared_ptr documentation stub">gr_framer_sink_1_sptr</a> <a name="l00033"></a>00033 <a class="code" href="gr__framer__sink__1_8h.html#a4fb6b2ccea5f7c7f4fe9a04e005b09e2">gr_make_framer_sink_1</a> (<a class="code" href="classboost_1_1shared__ptr.html" title="shared_ptr documentation stub">gr_msg_queue_sptr</a> target_queue); <a name="l00034"></a>00034 <span class="comment"></span> <a name="l00035"></a>00035 <span class="comment">/*!</span> <a name="l00036"></a>00036 <span class="comment"> * \brief Given a stream of bits and access_code flags, assemble packets.</span> <a name="l00037"></a>00037 <span class="comment"> * \ingroup sink_blk</span> <a name="l00038"></a>00038 <span class="comment"> *</span> <a name="l00039"></a>00039 <span class="comment"> * input: stream of bytes from gr_correlate_access_code_bb</span> <a name="l00040"></a>00040 <span class="comment"> * output: none. Pushes assembled packet into target queue</span> <a name="l00041"></a>00041 <span class="comment"> *</span> <a name="l00042"></a>00042 <span class="comment"> * The framer expects a fixed length header of 2 16-bit shorts</span> <a name="l00043"></a>00043 <span class="comment"> * containing the payload length, followed by the payload. If the </span> <a name="l00044"></a>00044 <span class="comment"> * 2 16-bit shorts are not identical, this packet is ignored. Better</span> <a name="l00045"></a>00045 <span class="comment"> * algs are welcome.</span> <a name="l00046"></a>00046 <span class="comment"> *</span> <a name="l00047"></a>00047 <span class="comment"> * The input data consists of bytes that have two bits used.</span> <a name="l00048"></a>00048 <span class="comment"> * Bit 0, the LSB, contains the data bit.</span> <a name="l00049"></a>00049 <span class="comment"> * Bit 1 if set, indicates that the corresponding bit is the</span> <a name="l00050"></a>00050 <span class="comment"> * the first bit of the packet. That is, this bit is the first</span> <a name="l00051"></a>00051 <span class="comment"> * one after the access code.</span> <a name="l00052"></a>00052 <span class="comment"> */</span> <a name="l00053"></a><a class="code" href="classgr__framer__sink__1.html">00053</a> <span class="keyword">class </span><a class="code" href="classgr__framer__sink__1.html" title="Given a stream of bits and access_code flags, assemble packets.input: stream of bytes...">gr_framer_sink_1</a> : <span class="keyword">public</span> <a class="code" href="classgr__sync__block.html" title="synchronous 1:1 input to output with historyOverride work to provide the signal processing...">gr_sync_block</a> <a name="l00054"></a>00054 { <a name="l00055"></a>00055 <span class="keyword">friend</span> <a class="code" href="classboost_1_1shared__ptr.html" title="shared_ptr documentation stub">gr_framer_sink_1_sptr</a> <a name="l00056"></a>00056 <a class="code" href="classgr__framer__sink__1.html#a4fb6b2ccea5f7c7f4fe9a04e005b09e2">gr_make_framer_sink_1</a> (<a class="code" href="classboost_1_1shared__ptr.html">gr_msg_queue_sptr</a> target_queue); <a name="l00057"></a>00057 <a name="l00058"></a>00058 <span class="keyword">private</span>: <a name="l00059"></a>00059 <span class="keyword">enum</span> state_t {STATE_SYNC_SEARCH, STATE_HAVE_SYNC, STATE_HAVE_HEADER}; <a name="l00060"></a>00060 <a name="l00061"></a>00061 <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">int</span> MAX_PKT_LEN = 4096; <a name="l00062"></a>00062 <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">int</span> HEADERBITLEN = 32; <a name="l00063"></a>00063 <a name="l00064"></a>00064 <a class="code" href="classboost_1_1shared__ptr.html">gr_msg_queue_sptr</a> d_target_queue; <span class="comment">// where to send the packet when received</span> <a name="l00065"></a>00065 state_t d_state; <a name="l00066"></a>00066 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> d_header; <span class="comment">// header bits</span> <a name="l00067"></a>00067 <span class="keywordtype">int</span> d_headerbitlen_cnt; <span class="comment">// how many so far</span> <a name="l00068"></a>00068 <a name="l00069"></a>00069 <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> d_packet[MAX_PKT_LEN]; <span class="comment">// assembled payload</span> <a name="l00070"></a>00070 <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> d_packet_byte; <span class="comment">// byte being assembled</span> <a name="l00071"></a>00071 <span class="keywordtype">int</span> d_packet_byte_index; <span class="comment">// which bit of d_packet_byte we're working on</span> <a name="l00072"></a>00072 <span class="keywordtype">int</span> d_packetlen; <span class="comment">// length of packet</span> <a name="l00073"></a>00073 <span class="keywordtype">int</span> d_packet_whitener_offset; <span class="comment">// offset into whitener string to use</span> <a name="l00074"></a>00074 <span class="keywordtype">int</span> d_packetlen_cnt; <span class="comment">// how many so far</span> <a name="l00075"></a>00075 <a name="l00076"></a>00076 <span class="keyword">protected</span>: <a name="l00077"></a>00077 <a class="code" href="classgr__framer__sink__1.html#a8462ea2bad2d49086220c2b5eb894805">gr_framer_sink_1</a>(<a class="code" href="classboost_1_1shared__ptr.html">gr_msg_queue_sptr</a> target_queue); <a name="l00078"></a>00078 <a name="l00079"></a>00079 <span class="keywordtype">void</span> <a class="code" href="classgr__framer__sink__1.html#ae6506c6d757bfee229e2caf7eeaef1dc">enter_search</a>(); <a name="l00080"></a>00080 <span class="keywordtype">void</span> <a class="code" href="classgr__framer__sink__1.html#ae4c482a3ab679642356620f0c216465b">enter_have_sync</a>(); <a name="l00081"></a>00081 <span class="keywordtype">void</span> <a class="code" href="classgr__framer__sink__1.html#ad4215dba4e9dcff8b7ed24615b334875">enter_have_header</a>(<span class="keywordtype">int</span> payload_len, <span class="keywordtype">int</span> whitener_offset); <a name="l00082"></a>00082 <a name="l00083"></a><a class="code" href="classgr__framer__sink__1.html#a25b0dab75810602a2f50e734aa2da66b">00083</a> <span class="keywordtype">bool</span> <a class="code" href="classgr__framer__sink__1.html#a25b0dab75810602a2f50e734aa2da66b">header_ok</a>() <a name="l00084"></a>00084 { <a name="l00085"></a>00085 <span class="comment">// confirm that two copies of header info are identical</span> <a name="l00086"></a>00086 <span class="keywordflow">return</span> ((d_header >> 16) ^ (d_header & 0xffff)) == 0; <a name="l00087"></a>00087 } <a name="l00088"></a>00088 <a name="l00089"></a><a class="code" href="classgr__framer__sink__1.html#a797381f43858bf0745cc268442ef39b4">00089</a> <span class="keywordtype">void</span> <a class="code" href="classgr__framer__sink__1.html#a797381f43858bf0745cc268442ef39b4">header_payload</a>(<span class="keywordtype">int</span> *len, <span class="keywordtype">int</span> *offset) <a name="l00090"></a>00090 { <a name="l00091"></a>00091 <span class="comment">// header consists of two 16-bit shorts in network byte order</span> <a name="l00092"></a>00092 <span class="comment">// payload length is lower 12 bits</span> <a name="l00093"></a>00093 <span class="comment">// whitener offset is upper 4 bits</span> <a name="l00094"></a>00094 *len = (d_header >> 16) & 0x0fff; <a name="l00095"></a>00095 *offset = (d_header >> 28) & 0x000f; <a name="l00096"></a>00096 } <a name="l00097"></a>00097 <a name="l00098"></a>00098 <span class="keyword">public</span>: <a name="l00099"></a>00099 <a class="code" href="classgr__framer__sink__1.html#a0be4776f164eaf5a7593b2fc773d7991">~gr_framer_sink_1</a>(); <a name="l00100"></a>00100 <a name="l00101"></a>00101 <span class="keywordtype">int</span> <a class="code" href="classgr__framer__sink__1.html#aec0600ab0fbe296c5dc83f9ad39a4344" title="just like gr_block::general_work, only this arranges to call consume_each for you...">work</a>(<span class="keywordtype">int</span> noutput_items, <a name="l00102"></a>00102 <a class="code" href="classstd_1_1vector.html">gr_vector_const_void_star</a> &input_items, <a name="l00103"></a>00103 <a class="code" href="classstd_1_1vector.html">gr_vector_void_star</a> &output_items); <a name="l00104"></a>00104 }; <a name="l00105"></a>00105 <a name="l00106"></a>00106 <span class="preprocessor">#endif </span><span class="comment">/* INCLUDED_GR_FRAMER_SINK_1_H */</span> </pre></div></div> <hr class="footer"/><address style="text-align: right;"><small>Generated on Wed Dec 29 19:51:00 2010 for GNU Radio 3.3.0 C++ API by <a href="http://www.doxygen.org/index.html"> <img class="footer" src="doxygen.png" alt="doxygen"/></a> 1.6.3 </small></address> </body> </html>