audio.tex

linux TV 源码

  AUDIO\_CONTINUE or AUDIO\_PLAY is performed.
  }{
  int fd & File descriptor returned by a previous call to open().\\
  int request& Equals AUDIO\_PAUSE for this command.
  }{
  EBADF&      fd is not a valid open file descriptor.\\
  EINTERNAL & Internal error.
}

\ifunction{AUDIO\_SELECT\_SOURCE}{
  int ioctl(int fd, int request = AUDIO\_SELECT\_SOURCE, 
  audio\_stream\_source\_t source);}{
  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.
  }{
  int fd & File descriptor returned by a previous call to open().\\
  int request & Equals AUDIO\_SELECT\_SOURCE for this command.\\
  audio\_stream\_source\_t source& Indicates the source that shall be used for the
  Audio stream.
  }{
  EBADF&      fd is not a valid open file descriptor.\\
  EINTERNAL & Internal error.\\
  EINVAL    & Illegal input parameter.
}

\ifunction{AUDIO\_SET\_MUTE}{
  int ioctl(int fd, int request = AUDIO\_SET\_MUTE, boolean state);}{
  This ioctl call asks the audio device to mute the stream that is 
  currently being played.
  }{
  int fd & File descriptor returned by a previous call to open().\\
  int request & Equals AUDIO\_SET\_MUTE for this command.\\
  boolean state & Indicates if audio device shall mute or not.\\
  &TRUE     Audio Mute\\
  &FALSE   Audio Un-mute\\
  }{
  EBADF&      fd is not a valid open file descriptor.\\
  EINTERNAL & Internal error.\\
  EINVAL    & Illegal input parameter.
}

\ifunction{AUDIO\_SET\_AV\_SYNC}{
  int ioctl(int fd, int request = AUDIO\_SET\_AV\_SYNC, boolean state);}{
  This ioctl call asks the Audio Device to turn ON or OFF A/V synchronization.
  }{
  int fd & File descriptor returned by a previous call to open().\\
  int request & Equals AUDIO\_AV\_SYNC for this command.\\
  boolean state& Tells the DVB subsystem if A/V 
  synchronization shall be ON or OFF.\\
  & TRUE   AV-sync ON \\
  & FALSE  AV-sync OFF\\
  }{
  EBADF&      fd is not a valid open file descriptor.\\
  EINTERNAL & Internal error.\\
  EINVAL    & Illegal input parameter.
}

\ifunction{AUDIO\_SET\_BYPASS\_MODE}{
  int ioctl(int fd, int request = AUDIO\_SET\_BYPASS\_MODE, boolean mode);}{
  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.
  }{
  int fd & File descriptor returned by a previous call to open().\\
  int request & Equals AUDIO\_SET\_BYPASS\_MODE for this command.\\
  boolean mode& Enables or disables the decoding of the current
  Audio stream in the DVB subsystem.\\
  &TRUE    Bypass is disabled\\
  &FALSE  Bypass is enabled\\
  }{
  EBADF&      fd is not a valid open file descriptor.\\
  EINTERNAL & Internal error.\\
  EINVAL    & Illegal input parameter.
}

\ifunction{AUDIO\_CHANNEL\_SELECT}{
  int ioctl(int fd, int request = AUDIO\_CHANNEL\_SELECT, 
  audio\_channel\_select\_t);}{
  This ioctl call asks the Audio Device to select the requested channel 
  if possible.
  }{
  int fd & File descriptor returned by a previous call to open().\\
  int request & Equals AUDIO\_CHANNEL\_SELECT for this command.\\
  audio\_channel\_select\_t ch &
  Select the output format of the audio (mono left/right, stereo).
  }{
  EBADF&      fd is not a valid open file descriptor.\\
  EINTERNAL & Internal error.\\
  EINVAL    & Illegal input parameter ch.
}

\ifunction{AUDIO\_GET\_STATUS}{
  int ioctl(int fd, int request = AUDIO\_GET\_STATUS, 
  struct audio\_status *status);}{
  This ioctl call asks the Audio Device to return the current state 
  of the Audio Device.
  }{
  int fd & File descriptor returned by a previous call to open().\\
  int request & Equals AUDIO\_GET\_STATUS for this command.\\
  struct audio\_status *status & Returns the current state of Audio Device.
  }{
  EBADF&      fd is not a valid open file descriptor.\\
  EINTERNAL & Internal error.\\
  EFAULT & status points to invalid address.
}

\ifunction{AUDIO\_GET\_CAPABILITIES}{
  int ioctl(int fd, int request = AUDIO\_GET\_CAPABILITIES, 
  unsigned int *cap);}{
  This ioctl call asks the Audio Device to tell us about the 
  decoding capabilities of the audio hardware.
  }{
  int fd & File descriptor returned by a previous call to open().\\
  int request & Equals AUDIO\_GET\_CAPABILITIES for this command.\\
  unsigned int *cap & Returns a bit array of supported sound formats.
  }{
  EBADF&      fd is not a valid open file descriptor.\\
  EINTERNAL & Internal error.\\
  EFAULT & cap points to an invalid address.
}

\ifunction{AUDIO\_CLEAR\_BUFFER}{
  int ioctl(int fd, int request = AUDIO\_CLEAR\_BUFFER);}{
  This ioctl call asks the Audio Device to clear all software 
  and hardware buffers of the audio decoder device.
  }{
  int fd & File descriptor returned by a previous call to open().\\
  int request & Equals AUDIO\_CLEAR\_BUFFER for this command.
  }{
  EBADF&      fd is not a valid open file descriptor.\\
  EINTERNAL & Internal error.
}

\ifunction{AUDIO\_SET\_ID}{
  int ioctl(int fd, int request = AUDIO\_SET\_ID, int id);}{
  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.
  }{
  int fd & File descriptor returned by a previous call to open().\\
  int request & Equals AUDIO\_SET\_ID for this command.\\
  int id& audio sub-stream id
  }{
  EBADF&      fd is not a valid open file descriptor.\\
  EINTERNAL & Internal error.\\
  EINVAL & Invalid sub-stream id.
}

\ifunction{AUDIO\_SET\_MIXER}{
  int ioctl(int fd, int request = AUDIO\_SET\_MIXER, audio\_mixer\_t *mix);}{
  This ioctl lets you adjust the mixer settings of the audio decoder.
  }{
  int fd & File descriptor returned by a previous call to open().\\
  int request & Equals AUDIO\_SET\_ID for this command.\\
  audio\_mixer\_t *mix& mixer settings.
  }{
  EBADF&      fd is not a valid open file descriptor.\\
  EINTERNAL & Internal error.\\
  EFAULT & mix points to an invalid address.
}

\ifunction{AUDIO\_SET\_STREAMTYPE}{
  int ioctl(fd, int request = AUDIO\_SET\_STREAMTYPE, int type);}{
  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.
  }{
  int fd      & File descriptor returned by a previous call to open().\\
  int request & Equals AUDIO\_SET\_STREAMTYPE for this command.\\
  int type & stream type\\
  }{
  EBADF& fd is not a valid open file descriptor \\
  EINVAL& type is not a valid or supported stream type.\\
}


\ifunction{AUDIO\_SET\_EXT\_ID}{
  int ioctl(fd, int request = AUDIO\_SET\_EXT\_ID, int id);}{
  This ioctl can be used to set the extension id for MPEG streams in 
  DVD playback. Only the first 3 bits are recognized. 
  }{
  int fd      & File descriptor returned by a previous call to open().\\
  int request & Equals AUDIO\_SET\_EXT\_ID for this command.\\
  int id & audio sub\_stream\_id\\
  }{
  EBADF& fd is not a valid open file descriptor \\
  EINVAL& id  is not a valid id.\\
}

\ifunction{AUDIO\_SET\_ATTRIBUTES}{
  int ioctl(fd, int request = AUDIO\_SET\_ATTRIBUTES, audio\_attributes\_t attr );}{
  This ioctl is intended for DVD playback and allows you to set
  certain information about the audio stream.
  }{
  int fd      & File descriptor returned by a previous call to open().\\
  int request & Equals AUDIO\_SET\_ATTRIBUTES for this command.\\
  audio\_attributes\_t attr & audio attributes according to section \ref{aattrib}\\
  }{
  EBADF& fd is not a valid open file descriptor \\
  EINVAL& attr is not a valid or supported attribute setting.\\
}

\ifunction{AUDIO\_SET\_KARAOKE}{
  int ioctl(fd, int request = AUDIO\_SET\_STREAMTYPE, audio\_karaoke\_t *karaoke);}{
  This ioctl allows one to set the mixer settings for a karaoke DVD.
  }{
  int fd      & File descriptor returned by a previous call to open().\\
  int request & Equals AUDIO\_SET\_STREAMTYPE for this command.\\
  audio\_karaoke\_t *karaoke & karaoke settings according to section \ref{audiokaraoke}.\\
  }{
  EBADF & fd is not a valid open file descriptor \\
  EINVAL& karaoke is not a valid or supported karaoke setting.\\
}

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