<?xml version="1.0" encoding="ANSI_X3.4-1968" standalone="no"?> <!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/html; charset=ANSI_X3.4-1968" /><title>Audio Function Calls</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /><link rel="home" href="index.html" title="LINUX MEDIA INFRASTRUCTURE API" /><link rel="up" href="ch12.html" title="Chapter 12. DVB Audio Device" /><link rel="prev" href="ch12.html" title="Chapter 12. DVB Audio Device" /><link rel="next" href="ch13.html" title="Chapter 13. DVB CA Device" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Audio Function Calls</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ch12.html">Prev</a> </td><th width="60%" align="center">Chapter 12. DVB Audio Device</th><td width="20%" align="right"> <a accesskey="n" href="ch13.html">Next</a></td></tr></table><hr /></div><div class="section" title="Audio Function Calls"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="audio_function_calls"></a>Audio Function Calls</h2></div></div></div><div class="toc"><dl><dt><span class="section"><a href="ch12s02.html#audio_fopen">open()</a></span></dt><dt><span class="section"><a href="ch12s02.html#audio_fclose">close()</a></span></dt><dt><span class="section"><a href="ch12s02.html#audio_fwrite">write()</a></span></dt><dt><span class="section"><a href="ch12s02.html#id2864906">AUDIO_STOP</a></span></dt><dt><span class="section"><a href="ch12s02.html#id2865047">AUDIO_PLAY</a></span></dt><dt><span class="section"><a href="ch12s02.html#id2865188">AUDIO_PAUSE</a></span></dt><dt><span class="section"><a href="ch12s02.html#id2865345">AUDIO_SELECT_SOURCE</a></span></dt><dt><span class="section"><a href="ch12s02.html#id2865527">AUDIO_SET_MUTE</a></span></dt><dt><span class="section"><a href="ch12s02.html#id2865734">AUDIO_SET_AV_SYNC</a></span></dt><dt><span class="section"><a href="ch12s02.html#id2865942">AUDIO_SET_BYPASS_MODE</a></span></dt><dt><span class="section"><a href="ch12s02.html#id2866154">AUDIO_CHANNEL_SELECT</a></span></dt><dt><span class="section"><a href="ch12s02.html#id2866334">AUDIO_GET_STATUS</a></span></dt><dt><span class="section"><a href="ch12s02.html#id2866514">AUDIO_GET_CAPABILITIES</a></span></dt><dt><span class="section"><a href="ch12s02.html#id2866695">AUDIO_CLEAR_BUFFER</a></span></dt><dt><span class="section"><a href="ch12s02.html#id2866837">AUDIO_SET_ID</a></span></dt><dt><span class="section"><a href="ch12s02.html#id2867020">AUDIO_SET_MIXER</a></span></dt><dt><span class="section"><a href="ch12s02.html#id2867199">AUDIO_SET_STREAMTYPE</a></span></dt><dt><span class="section"><a href="ch12s02.html#id2867360">AUDIO_SET_EXT_ID</a></span></dt><dt><span class="section"><a href="ch12s02.html#id2867521">AUDIO_SET_ATTRIBUTES</a></span></dt><dt><span class="section"><a href="ch12s02.html#id2867682">AUDIO_SET_KARAOKE</a></span></dt></dl></div><div class="section" title="open()"><div class="titlepage"><div><div><h3 class="title"><a id="audio_fopen"></a>open()</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This system call opens a named audio device (e.g. /dev/dvb/adapter0/audio0) for subsequent use. When an open() call has succeeded, the device will be ready for use. The significance of blocking or non-blocking mode is described in the documentation for functions where there is a difference. It does not affect the semantics of the open() call itself. A device opened in blocking mode can later be put into non-blocking mode (and vice versa) using the F_SETFL command of the fcntl system call. This is a standard system call, documented in the Linux manual page for fcntl. Only one user can open the Audio Device in O_RDWR mode. All other attempts to open the device in this mode will fail, and an error code will be returned. If the Audio Device is opened in O_RDONLY mode, the only ioctl call that can be used is AUDIO_GET_STATUS. All other call will return with an error code.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int open(const char ⋆deviceName, int flags);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>const char *deviceName</p> </td><td align="char"> <p>Name of specific audio device.</p> </td></tr><tr><td align="char"> <p>int flags</p> </td><td align="char"> <p>A bit-wise OR of the following flags:</p> </td></tr><tr><td align="char"> </td><td align="char"> <p>O_RDONLY read-only access</p> </td></tr><tr><td align="char"> </td><td align="char"> <p>O_RDWR read/write access</p> </td></tr><tr><td align="char"> </td><td align="char"> <p>O_NONBLOCK open in non-blocking mode</p> </td></tr><tr><td align="char"> </td><td align="char"> <p>(blocking mode is the default)</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>ENODEV</p> </td><td align="char"> <p>Device driver not loaded/available.</p> </td></tr><tr><td align="char"> <p>EINTERNAL</p> </td><td align="char"> <p>Internal error.</p> </td></tr><tr><td align="char"> <p>EBUSY</p> </td><td align="char"> <p>Device or resource busy.</p> </td></tr><tr><td align="char"> <p>EINVAL</p> </td><td align="char"> <p>Invalid argument.</p> </td></tr></tbody></table></div></div><div class="section" title="close()"><div class="titlepage"><div><div><h3 class="title"><a id="audio_fclose"></a>close()</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This system call closes a previously opened audio device.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int close(int fd);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor.</p> </td></tr></tbody></table></div></div><div class="section" title="write()"><div class="titlepage"><div><div><h3 class="title"><a id="audio_fwrite"></a>write()</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This system call can only be used if AUDIO_SOURCE_MEMORY is selected in the ioctl call AUDIO_SELECT_SOURCE. The data provided shall be in PES format. If O_NONBLOCK is not specified the function will block until buffer space is available. The amount of data to be transferred is implied by count.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>size_t write(int fd, const void ⋆buf, size_t count);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr><tr><td align="char"> <p>void *buf</p> </td><td align="char"> <p>Pointer to the buffer containing the PES data.</p> </td></tr><tr><td align="char"> <p>size_t count</p> </td><td align="char"> <p>Size of buf.</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EPERM</p> </td><td align="char"> <p>Mode AUDIO_SOURCE_MEMORY not selected.</p> </td></tr><tr><td align="char"> <p>ENOMEM</p> </td><td align="char"> <p>Attempted to write more data than the internal buffer can hold.</p> </td></tr><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor.</p> </td></tr></tbody></table></div></div><div class="section" title="AUDIO_STOP"><div class="titlepage"><div><div><h3 class="title"><a id="id2864906"></a>AUDIO_STOP</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This ioctl call asks the Audio Device to stop playing the current stream.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int ioctl(int fd, int request = AUDIO_STOP);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr><tr><td align="char"> <p>int request</p> </td><td align="char"> <p>Equals AUDIO_STOP for this command.</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor</p> </td></tr><tr><td align="char"> <p>EINTERNAL</p> </td><td align="char"> <p>Internal error.</p> </td></tr></tbody></table></div></div><div class="section" title="AUDIO_PLAY"><div class="titlepage"><div><div><h3 class="title"><a id="id2865047"></a>AUDIO_PLAY</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This ioctl call asks the Audio Device to start playing an audio stream from the selected source.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int ioctl(int fd, int request = AUDIO_PLAY);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr><tr><td align="char"> <p>int request</p> </td><td align="char"> <p>Equals AUDIO_PLAY for this command.</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor</p> </td></tr><tr><td align="char"> <p>EINTERNAL</p> </td><td align="char"> <p>Internal error.</p> </td></tr></tbody></table></div></div><div class="section" title="AUDIO_PAUSE"><div class="titlepage"><div><div><h3 class="title"><a id="id2865188"></a>AUDIO_PAUSE</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This ioctl call suspends the audio stream being played. Decoding and playing are paused. It is then possible to restart again decoding and playing process of the audio stream using AUDIO_CONTINUE command.</p> </td></tr><tr><td align="char"> <p>If AUDIO_SOURCE_MEMORY is selected in the ioctl call AUDIO_SELECT_SOURCE, the DVB-subsystem will not decode (consume) any more data until the ioctl call AUDIO_CONTINUE or AUDIO_PLAY is performed.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int ioctl(int fd, int request = AUDIO_PAUSE);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr><tr><td align="char"> <p>int request</p> </td><td align="char"> <p>Equals AUDIO_PAUSE for this command.</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor.</p> </td></tr><tr><td align="char"> <p>EINTERNAL</p> </td><td align="char"> <p>Internal error.</p> </td></tr></tbody></table></div></div><div class="section" title="AUDIO_SELECT_SOURCE"><div class="titlepage"><div><div><h3 class="title"><a id="id2865345"></a>AUDIO_SELECT_SOURCE</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This ioctl call informs the audio device which source shall be used for the input data. The possible sources are demux or memory. If AUDIO_SOURCE_MEMORY is selected, the data is fed to the Audio Device through the write command.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int ioctl(int fd, int request = AUDIO_SELECT_SOURCE, audio_stream_source_t source);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr><tr><td align="char"> <p>int request</p> </td><td align="char"> <p>Equals AUDIO_SELECT_SOURCE for this command.</p> </td></tr><tr><td align="char"> <p>audio_stream_source_t source</p> </td><td align="char"> <p>Indicates the source that shall be used for the Audio stream.</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor.</p> </td></tr><tr><td align="char"> <p>EINTERNAL</p> </td><td align="char"> <p>Internal error.</p> </td></tr><tr><td align="char"> <p>EINVAL</p> </td><td align="char"> <p>Illegal input parameter.</p> </td></tr></tbody></table></div></div><div class="section" title="AUDIO_SET_MUTE"><div class="titlepage"><div><div><h3 class="title"><a id="id2865527"></a>AUDIO_SET_MUTE</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This ioctl call asks the audio device to mute the stream that is currently being played.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int ioctl(int fd, int request = AUDIO_SET_MUTE, boolean state);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr><tr><td align="char"> <p>int request</p> </td><td align="char"> <p>Equals AUDIO_SET_MUTE for this command.</p> </td></tr><tr><td align="char"> <p>boolean state</p> </td><td align="char"> <p>Indicates if audio device shall mute or not.</p> </td></tr><tr><td align="char"> </td><td align="char"> <p>TRUE Audio Mute</p> </td></tr><tr><td align="char"> </td><td align="char"> <p>FALSE Audio Un-mute</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor.</p> </td></tr><tr><td align="char"> <p>EINTERNAL</p> </td><td align="char"> <p>Internal error.</p> </td></tr><tr><td align="char"> <p>EINVAL</p> </td><td align="char"> <p>Illegal input parameter.</p> </td></tr></tbody></table></div></div><div class="section" title="AUDIO_SET_AV_SYNC"><div class="titlepage"><div><div><h3 class="title"><a id="id2865734"></a>AUDIO_SET_AV_SYNC</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This ioctl call asks the Audio Device to turn ON or OFF A/V synchronization.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int ioctl(int fd, int request = AUDIO_SET_AV_SYNC, boolean state);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr><tr><td align="char"> <p>int request</p> </td><td align="char"> <p>Equals AUDIO_AV_SYNC for this command.</p> </td></tr><tr><td align="char"> <p>boolean state</p> </td><td align="char"> <p>Tells the DVB subsystem if A/V synchronization shall be ON or OFF.</p> </td></tr><tr><td align="char"> </td><td align="char"> <p>TRUE AV-sync ON</p> </td></tr><tr><td align="char"> </td><td align="char"> <p>FALSE AV-sync OFF</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor.</p> </td></tr><tr><td align="char"> <p>EINTERNAL</p> </td><td align="char"> <p>Internal error.</p> </td></tr><tr><td align="char"> <p>EINVAL</p> </td><td align="char"> <p>Illegal input parameter.</p> </td></tr></tbody></table></div></div><div class="section" title="AUDIO_SET_BYPASS_MODE"><div class="titlepage"><div><div><h3 class="title"><a id="id2865942"></a>AUDIO_SET_BYPASS_MODE</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This ioctl call asks the Audio Device to bypass the Audio decoder and forward the stream without decoding. This mode shall be used if streams that can’t be handled by the DVB system shall be decoded. Dolby DigitalTM streams are automatically forwarded by the DVB subsystem if the hardware can handle it.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int ioctl(int fd, int request = AUDIO_SET_BYPASS_MODE, boolean mode);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr><tr><td align="char"> <p>int request</p> </td><td align="char"> <p>Equals AUDIO_SET_BYPASS_MODE for this command.</p> </td></tr><tr><td align="char"> <p>boolean mode</p> </td><td align="char"> <p>Enables or disables the decoding of the current Audio stream in the DVB subsystem.</p> </td></tr><tr><td align="char"> </td><td align="char"> <p>TRUE Bypass is disabled</p> </td></tr><tr><td align="char"> </td><td align="char"> <p>FALSE Bypass is enabled</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor.</p> </td></tr><tr><td align="char"> <p>EINTERNAL</p> </td><td align="char"> <p>Internal error.</p> </td></tr><tr><td align="char"> <p>EINVAL</p> </td><td align="char"> <p>Illegal input parameter.</p> </td></tr></tbody></table></div></div><div class="section" title="AUDIO_CHANNEL_SELECT"><div class="titlepage"><div><div><h3 class="title"><a id="id2866154"></a>AUDIO_CHANNEL_SELECT</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This ioctl call asks the Audio Device to select the requested channel if possible.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int ioctl(int fd, int request = AUDIO_CHANNEL_SELECT, audio_channel_select_t);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr><tr><td align="char"> <p>int request</p> </td><td align="char"> <p>Equals AUDIO_CHANNEL_SELECT for this command.</p> </td></tr><tr><td align="char"> <p>audio_channel_select_t ch</p> </td><td align="char"> <p>Select the output format of the audio (mono left/right, stereo).</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor.</p> </td></tr><tr><td align="char"> <p>EINTERNAL</p> </td><td align="char"> <p>Internal error.</p> </td></tr><tr><td align="char"> <p>EINVAL</p> </td><td align="char"> <p>Illegal input parameter ch.</p> </td></tr></tbody></table></div></div><div class="section" title="AUDIO_GET_STATUS"><div class="titlepage"><div><div><h3 class="title"><a id="id2866334"></a>AUDIO_GET_STATUS</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This ioctl call asks the Audio Device to return the current state of the Audio Device.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int ioctl(int fd, int request = AUDIO_GET_STATUS, struct audio_status ⋆status);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr><tr><td align="char"> <p>int request</p> </td><td align="char"> <p>Equals AUDIO_GET_STATUS for this command.</p> </td></tr><tr><td align="char"> <p>struct audio_status *status</p> </td><td align="char"> <p>Returns the current state of Audio Device.</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor.</p> </td></tr><tr><td align="char"> <p>EINTERNAL</p> </td><td align="char"> <p>Internal error.</p> </td></tr><tr><td align="char"> <p>EFAULT</p> </td><td align="char"> <p>status points to invalid address.</p> </td></tr></tbody></table></div></div><div class="section" title="AUDIO_GET_CAPABILITIES"><div class="titlepage"><div><div><h3 class="title"><a id="id2866514"></a>AUDIO_GET_CAPABILITIES</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This ioctl call asks the Audio Device to tell us about the decoding capabilities of the audio hardware.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int ioctl(int fd, int request = AUDIO_GET_CAPABILITIES, unsigned int ⋆cap);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr><tr><td align="char"> <p>int request</p> </td><td align="char"> <p>Equals AUDIO_GET_CAPABILITIES for this command.</p> </td></tr><tr><td align="char"> <p>unsigned int *cap</p> </td><td align="char"> <p>Returns a bit array of supported sound formats.</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor.</p> </td></tr><tr><td align="char"> <p>EINTERNAL</p> </td><td align="char"> <p>Internal error.</p> </td></tr><tr><td align="char"> <p>EFAULT</p> </td><td align="char"> <p>cap points to an invalid address.</p> </td></tr></tbody></table></div></div><div class="section" title="AUDIO_CLEAR_BUFFER"><div class="titlepage"><div><div><h3 class="title"><a id="id2866695"></a>AUDIO_CLEAR_BUFFER</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This ioctl call asks the Audio Device to clear all software and hardware buffers of the audio decoder device.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int ioctl(int fd, int request = AUDIO_CLEAR_BUFFER);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr><tr><td align="char"> <p>int request</p> </td><td align="char"> <p>Equals AUDIO_CLEAR_BUFFER for this command.</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor.</p> </td></tr><tr><td align="char"> <p>EINTERNAL</p> </td><td align="char"> <p>Internal error.</p> </td></tr></tbody></table></div></div><div class="section" title="AUDIO_SET_ID"><div class="titlepage"><div><div><h3 class="title"><a id="id2866837"></a>AUDIO_SET_ID</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This ioctl selects which sub-stream is to be decoded if a program or system stream is sent to the video device. If no audio stream type is set the id has to be in [0xC0,0xDF] for MPEG sound, in [0x80,0x87] for AC3 and in [0xA0,0xA7] for LPCM. More specifications may follow for other stream types. If the stream type is set the id just specifies the substream id of the audio stream and only the first 5 bits are recognized.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int ioctl(int fd, int request = AUDIO_SET_ID, int id);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr><tr><td align="char"> <p>int request</p> </td><td align="char"> <p>Equals AUDIO_SET_ID for this command.</p> </td></tr><tr><td align="char"> <p>int id</p> </td><td align="char"> <p>audio sub-stream id</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor.</p> </td></tr><tr><td align="char"> <p>EINTERNAL</p> </td><td align="char"> <p>Internal error.</p> </td></tr><tr><td align="char"> <p>EINVAL</p> </td><td align="char"> <p>Invalid sub-stream id.</p> </td></tr></tbody></table></div></div><div class="section" title="AUDIO_SET_MIXER"><div class="titlepage"><div><div><h3 class="title"><a id="id2867020"></a>AUDIO_SET_MIXER</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This ioctl lets you adjust the mixer settings of the audio decoder.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int ioctl(int fd, int request = AUDIO_SET_MIXER, audio_mixer_t ⋆mix);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr><tr><td align="char"> <p>int request</p> </td><td align="char"> <p>Equals AUDIO_SET_ID for this command.</p> </td></tr><tr><td align="char"> <p>audio_mixer_t *mix</p> </td><td align="char"> <p>mixer settings.</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor.</p> </td></tr><tr><td align="char"> <p>EINTERNAL</p> </td><td align="char"> <p>Internal error.</p> </td></tr><tr><td align="char"> <p>EFAULT</p> </td><td align="char"> <p>mix points to an invalid address.</p> </td></tr></tbody></table></div></div><div class="section" title="AUDIO_SET_STREAMTYPE"><div class="titlepage"><div><div><h3 class="title"><a id="id2867199"></a>AUDIO_SET_STREAMTYPE</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This ioctl tells the driver which kind of audio stream to expect. This is useful if the stream offers several audio sub-streams like LPCM and AC3.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int ioctl(fd, int request = AUDIO_SET_STREAMTYPE, int type);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr><tr><td align="char"> <p>int request</p> </td><td align="char"> <p>Equals AUDIO_SET_STREAMTYPE for this command.</p> </td></tr><tr><td align="char"> <p>int type</p> </td><td align="char"> <p>stream type</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor</p> </td></tr><tr><td align="char"> <p>EINVAL</p> </td><td align="char"> <p>type is not a valid or supported stream type.</p> </td></tr></tbody></table></div></div><div class="section" title="AUDIO_SET_EXT_ID"><div class="titlepage"><div><div><h3 class="title"><a id="id2867360"></a>AUDIO_SET_EXT_ID</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This ioctl can be used to set the extension id for MPEG streams in DVD playback. Only the first 3 bits are recognized.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int ioctl(fd, int request = AUDIO_SET_EXT_ID, int id);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr><tr><td align="char"> <p>int request</p> </td><td align="char"> <p>Equals AUDIO_SET_EXT_ID for this command.</p> </td></tr><tr><td align="char"> <p>int id</p> </td><td align="char"> <p>audio sub_stream_id</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor</p> </td></tr><tr><td align="char"> <p>EINVAL</p> </td><td align="char"> <p>id is not a valid id.</p> </td></tr></tbody></table></div></div><div class="section" title="AUDIO_SET_ATTRIBUTES"><div class="titlepage"><div><div><h3 class="title"><a id="id2867521"></a>AUDIO_SET_ATTRIBUTES</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This ioctl is intended for DVD playback and allows you to set certain information about the audio stream.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int ioctl(fd, int request = AUDIO_SET_ATTRIBUTES, audio_attributes_t attr );</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr><tr><td align="char"> <p>int request</p> </td><td align="char"> <p>Equals AUDIO_SET_ATTRIBUTES for this command.</p> </td></tr><tr><td align="char"> <p>audio_attributes_t attr</p> </td><td align="char"> <p>audio attributes according to section ??</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor</p> </td></tr><tr><td align="char"> <p>EINVAL</p> </td><td align="char"> <p>attr is not a valid or supported attribute setting.</p> </td></tr></tbody></table></div></div><div class="section" title="AUDIO_SET_KARAOKE"><div class="titlepage"><div><div><h3 class="title"><a id="id2867682"></a>AUDIO_SET_KARAOKE</h3></div></div></div><p>DESCRIPTION </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>This ioctl allows one to set the mixer settings for a karaoke DVD.</p> </td></tr></tbody></table></div><p>SYNOPSIS </p><div class="informaltable"><table border="1"><colgroup><col /></colgroup><tbody><tr><td align="char"> <p>int ioctl(fd, int request = AUDIO_SET_STREAMTYPE, audio_karaoke_t ⋆karaoke);</p> </td></tr></tbody></table></div><p>PARAMETERS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>int fd</p> </td><td align="char"> <p>File descriptor returned by a previous call to open().</p> </td></tr><tr><td align="char"> <p>int request</p> </td><td align="char"> <p>Equals AUDIO_SET_STREAMTYPE for this command.</p> </td></tr><tr><td align="char"> <p>audio_karaoke_t *karaoke</p> </td><td align="char"> <p>karaoke settings according to section ??.</p> </td></tr></tbody></table></div><p>ERRORS </p><div class="informaltable"><table border="1"><colgroup><col /><col /></colgroup><tbody><tr><td align="char"> <p>EBADF</p> </td><td align="char"> <p>fd is not a valid open file descriptor</p> </td></tr><tr><td align="char"> <p>EINVAL</p> </td><td align="char"> <p>karaoke is not a valid or supported karaoke setting.</p> </td></tr></tbody></table></div></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ch12.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch12.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ch13.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 12. DVB Audio Device </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 13. DVB CA Device</td></tr></table></div></body></html>
