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<div id="projectname">Jack2
 <span id="projectnumber">1.9.9</span>
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<a href="#func-members">Functions</a> </div>
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<div class="title">Reading and writing MIDI data</div> </div>
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<tr class="heading"><td colspan="2"><h2><a name="func-members"></a>
Functions</h2></td></tr>
<tr class="memitem:ga0b293148ef9a30db48474e3c611e8514"><td class="memItemLeft" align="right" valign="top">uint32_t </td><td class="memItemRight" valign="bottom"><a class="el" href="group__MIDIAPI.html#ga0b293148ef9a30db48474e3c611e8514">jack_midi_get_event_count</a> (void *port_buffer) JACK_OPTIONAL_WEAK_EXPORT</td></tr>
<tr class="memitem:ga838c794bd1451bfd47edde1c7cd1ff4f"><td class="memItemLeft" align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="group__MIDIAPI.html#ga838c794bd1451bfd47edde1c7cd1ff4f">jack_midi_event_get</a> (<a class="el" href="struct__jack__midi__event.html">jack_midi_event_t</a> *event, void *port_buffer, uint32_t event_index) JACK_OPTIONAL_WEAK_EXPORT</td></tr>
<tr class="memitem:ga7635c6e0a4eb2314a5fb5a058c278078"><td class="memItemLeft" align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="group__MIDIAPI.html#ga7635c6e0a4eb2314a5fb5a058c278078">jack_midi_clear_buffer</a> (void *port_buffer) JACK_OPTIONAL_WEAK_EXPORT</td></tr>
<tr class="memitem:gab69743a191f150757fa3708eae8fdb81"><td class="memItemLeft" align="right" valign="top">size_t </td><td class="memItemRight" valign="bottom"><a class="el" href="group__MIDIAPI.html#gab69743a191f150757fa3708eae8fdb81">jack_midi_max_event_size</a> (void *port_buffer) JACK_OPTIONAL_WEAK_EXPORT</td></tr>
<tr class="memitem:ga150dcdc37583e1ecbe0a6f16b6ac48a9"><td class="memItemLeft" align="right" valign="top">jack_midi_data_t * </td><td class="memItemRight" valign="bottom"><a class="el" href="group__MIDIAPI.html#ga150dcdc37583e1ecbe0a6f16b6ac48a9">jack_midi_event_reserve</a> (void *port_buffer, jack_nframes_t time, size_t data_size) JACK_OPTIONAL_WEAK_EXPORT</td></tr>
<tr class="memitem:gaa25503c07ac3c2ed62d79be9c25d42ed"><td class="memItemLeft" align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="group__MIDIAPI.html#gaa25503c07ac3c2ed62d79be9c25d42ed">jack_midi_event_write</a> (void *port_buffer, jack_nframes_t time, const jack_midi_data_t *data, size_t data_size) JACK_OPTIONAL_WEAK_EXPORT</td></tr>
<tr class="memitem:ga0f5af3d054e218a5b90fd4c636425e45"><td class="memItemLeft" align="right" valign="top">uint32_t </td><td class="memItemRight" valign="bottom"><a class="el" href="group__MIDIAPI.html#ga0f5af3d054e218a5b90fd4c636425e45">jack_midi_get_lost_event_count</a> (void *port_buffer) JACK_OPTIONAL_WEAK_EXPORT</td></tr>
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<hr/><a name="details" id="details"></a><h2>Detailed Description</h2>
<hr/><h2>Function Documentation</h2>
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<td class="memname">uint32_t jack_midi_get_event_count </td>
<td>(</td>
<td class="paramtype">void * </td>
<td class="paramname"><em>port_buffer</em></td><td>)</td>
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<p>Get number of events in a port buffer.</p>
<dl class="params"><dt>Parameters:</dt><dd>
<table class="params">
<tr><td class="paramname">port_buffer</td><td>Port buffer from which to retrieve event. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns:</dt><dd>number of events inside <em>port_buffer</em> </dd></dl>
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<td class="memname">int jack_midi_event_get </td>
<td>(</td>
<td class="paramtype"><a class="el" href="struct__jack__midi__event.html">jack_midi_event_t</a> * </td>
<td class="paramname"><em>event</em>, </td>
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<td class="paramtype">void * </td>
<td class="paramname"><em>port_buffer</em>, </td>
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<td class="paramtype">uint32_t </td>
<td class="paramname"><em>event_index</em> </td>
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<td>)</td>
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<p>Get a MIDI event from an event port buffer.</p>
<p>Jack MIDI is normalised, the MIDI event returned by this function is guaranteed to be a complete MIDI event (the status byte will always be present, and no realtime events will interspered with the event).</p>
<dl class="params"><dt>Parameters:</dt><dd>
<table class="params">
<tr><td class="paramname">event</td><td>Event structure to store retrieved event in. </td></tr>
<tr><td class="paramname">port_buffer</td><td>Port buffer from which to retrieve event. </td></tr>
<tr><td class="paramname">event_index</td><td>Index of event to retrieve. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns:</dt><dd>0 on success, ENODATA if buffer is empty. </dd></dl>
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<td class="memname">void jack_midi_clear_buffer </td>
<td>(</td>
<td class="paramtype">void * </td>
<td class="paramname"><em>port_buffer</em></td><td>)</td>
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<p>Clear an event buffer.</p>
<p>This should be called at the beginning of each process cycle before calling <a class="el" href="group__MIDIAPI.html#ga150dcdc37583e1ecbe0a6f16b6ac48a9">jack_midi_event_reserve</a> or <a class="el" href="group__MIDIAPI.html#gaa25503c07ac3c2ed62d79be9c25d42ed">jack_midi_event_write</a>. This function may not be called on an input port's buffer.</p>
<dl class="params"><dt>Parameters:</dt><dd>
<table class="params">
<tr><td class="paramname">port_buffer</td><td>Port buffer to clear (must be an output port buffer). </td></tr>
</table>
</dd>
</dl>
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<td class="memname">size_t jack_midi_max_event_size </td>
<td>(</td>
<td class="paramtype">void * </td>
<td class="paramname"><em>port_buffer</em></td><td>)</td>
<td></td>
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<p>Get the size of the largest event that can be stored by the port.</p>
<p>This function returns the current space available, taking into account events already stored in the port.</p>
<dl class="params"><dt>Parameters:</dt><dd>
<table class="params">
<tr><td class="paramname">port_buffer</td><td>Port buffer to check size of. </td></tr>
</table>
</dd>
</dl>
</div>
</div>
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<td class="memname">jack_midi_data_t* jack_midi_event_reserve </td>
<td>(</td>
<td class="paramtype">void * </td>
<td class="paramname"><em>port_buffer</em>, </td>
</tr>
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<td class="paramkey"></td>
<td></td>
<td class="paramtype">jack_nframes_t </td>
<td class="paramname"><em>time</em>, </td>
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<td class="paramkey"></td>
<td></td>
<td class="paramtype">size_t </td>
<td class="paramname"><em>data_size</em> </td>
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<td>)</td>
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<p>Allocate space for an event to be written to an event port buffer.</p>
<p>Clients are to write the actual event data to be written starting at the pointer returned by this function. Clients must not write more than <em>data_size</em> bytes into this buffer. Clients must write normalised MIDI data to the port - no running status and no (1-byte) realtime messages interspersed with other messages (realtime messages are fine when they occur on their own, like other messages).</p>
<p>Events must be written in order, sorted by their sample offsets. JACK will not sort the events for you, and will refuse to store out-of-order events.</p>
<dl class="params"><dt>Parameters:</dt><dd>
<table class="params">
<tr><td class="paramname">port_buffer</td><td>Buffer to write event to. </td></tr>
<tr><td class="paramname">time</td><td>Sample offset of event. </td></tr>
<tr><td class="paramname">data_size</td><td>Length of event's raw data in bytes. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns:</dt><dd>Pointer to the beginning of the reserved event's data buffer, or NULL on error (ie not enough space). </dd></dl>
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<td class="memname">int jack_midi_event_write </td>
<td>(</td>
<td class="paramtype">void * </td>
<td class="paramname"><em>port_buffer</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">jack_nframes_t </td>
<td class="paramname"><em>time</em>, </td>
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<td class="paramkey"></td>
<td></td>
<td class="paramtype">const jack_midi_data_t * </td>
<td class="paramname"><em>data</em>, </td>
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<td></td>
<td class="paramtype">size_t </td>
<td class="paramname"><em>data_size</em> </td>
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<p>Write an event into an event port buffer.</p>
<p>This function is simply a wrapper for <a class="el" href="group__MIDIAPI.html#ga150dcdc37583e1ecbe0a6f16b6ac48a9">jack_midi_event_reserve</a> which writes the event data into the space reserved in the buffer.</p>
<p>Clients must not write more than <em>data_size</em> bytes into this buffer. Clients must write normalised MIDI data to the port - no running status and no (1-byte) realtime messages interspersed with other messages (realtime messages are fine when they occur on their own, like other messages).</p>
<p>Events must be written in order, sorted by their sample offsets. JACK will not sort the events for you, and will refuse to store out-of-order events.</p>
<dl class="params"><dt>Parameters:</dt><dd>
<table class="params">
<tr><td class="paramname">port_buffer</td><td>Buffer to write event to. </td></tr>
<tr><td class="paramname">time</td><td>Sample offset of event. </td></tr>
<tr><td class="paramname">data</td><td>Message data to be written. </td></tr>
<tr><td class="paramname">data_size</td><td>Length of <em>data</em> in bytes. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns:</dt><dd>0 on success, ENOBUFS if there's not enough space in buffer for event. </dd></dl>
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<td class="memname">uint32_t jack_midi_get_lost_event_count </td>
<td>(</td>
<td class="paramtype">void * </td>
<td class="paramname"><em>port_buffer</em></td><td>)</td>
<td></td>
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<p>Get the number of events that could not be written to <em>port_buffer</em>.</p>
<p>This function returning a non-zero value implies <em>port_buffer</em> is full. Currently the only way this can happen is if events are lost on port mixdown.</p>
<dl class="params"><dt>Parameters:</dt><dd>
<table class="params">
<tr><td class="paramname">port_buffer</td><td>Port to receive count for. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns:</dt><dd>Number of events that could not be written to <em>port_buffer</em>. </dd></dl>
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