diff options
Diffstat (limited to 'Documentation/DocBook')
122 files changed, 36715 insertions, 1 deletions
diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile index 9632444f6c6..ad07875febc 100644 --- a/Documentation/DocBook/Makefile +++ b/Documentation/DocBook/Makefile @@ -14,7 +14,7 @@ DOCBOOKS := z8530book.xml mcabook.xml device-drivers.xml \ genericirq.xml s390-drivers.xml uio-howto.xml scsi.xml \ mac80211.xml debugobjects.xml sh.xml regulator.xml \ alsa-driver-api.xml writing-an-alsa-driver.xml \ - tracepoint.xml + tracepoint.xml media.xml ### # The build process is as follows (targets): diff --git a/Documentation/DocBook/dvb/audio.xml b/Documentation/DocBook/dvb/audio.xml new file mode 100644 index 00000000000..eeb96b8a086 --- /dev/null +++ b/Documentation/DocBook/dvb/audio.xml @@ -0,0 +1,1473 @@ +<title>DVB Audio Device</title> +<para>The DVB audio device controls the MPEG2 audio decoder of the DVB hardware. It +can be accessed through <emphasis role="tt">/dev/dvb/adapter0/audio0</emphasis>. Data types and and +ioctl definitions can be accessed by including <emphasis role="tt">linux/dvb/video.h</emphasis> in your +application. +</para> +<para>Please note that some DVB cards don’t have their own MPEG decoder, which results in +the omission of the audio and video device. +</para> + +<section id="audio_data_types"> +<title>Audio Data Types</title> +<para>This section describes the structures, data types and defines used when talking to the +audio device. +</para> + +<section id="audio_stream_source_t"> +<title>audio_stream_source_t</title> +<para>The audio stream source is set through the AUDIO_SELECT_SOURCE call and can take +the following values, depending on whether we are replaying from an internal (demux) or +external (user write) source. +</para> +<programlisting> + typedef enum { + AUDIO_SOURCE_DEMUX, + AUDIO_SOURCE_MEMORY + } audio_stream_source_t; +</programlisting> +<para>AUDIO_SOURCE_DEMUX selects the demultiplexer (fed either by the frontend or the +DVR device) as the source of the video stream. If AUDIO_SOURCE_MEMORY +is selected the stream comes from the application through the <emphasis role="tt">write()</emphasis> system +call. +</para> + +</section> +<section id="audio_play_state_t"> +<title>audio_play_state_t</title> +<para>The following values can be returned by the AUDIO_GET_STATUS call representing the +state of audio playback. +</para> +<programlisting> + typedef enum { + AUDIO_STOPPED, + AUDIO_PLAYING, + AUDIO_PAUSED + } audio_play_state_t; +</programlisting> + +</section> +<section id="audio_channel_select_t"> +<title>audio_channel_select_t</title> +<para>The audio channel selected via AUDIO_CHANNEL_SELECT is determined by the +following values. +</para> +<programlisting> + typedef enum { + AUDIO_STEREO, + AUDIO_MONO_LEFT, + AUDIO_MONO_RIGHT, + } audio_channel_select_t; +</programlisting> + +</section> +<section id="struct_audio_status"> +<title>struct audio_status</title> +<para>The AUDIO_GET_STATUS call returns the following structure informing about various +states of the playback operation. +</para> +<programlisting> + typedef struct audio_status { + boolean AV_sync_state; + boolean mute_state; + audio_play_state_t play_state; + audio_stream_source_t stream_source; + audio_channel_select_t channel_select; + boolean bypass_mode; + } audio_status_t; +</programlisting> + +</section> +<section id="struct_audio_mixer"> +<title>struct audio_mixer</title> +<para>The following structure is used by the AUDIO_SET_MIXER call to set the audio +volume. +</para> +<programlisting> + typedef struct audio_mixer { + unsigned int volume_left; + unsigned int volume_right; + } audio_mixer_t; +</programlisting> + +</section> +<section id="audio_encodings"> +<title>audio encodings</title> +<para>A call to AUDIO_GET_CAPABILITIES returns an unsigned integer with the following +bits set according to the hardwares capabilities. +</para> +<programlisting> + #define AUDIO_CAP_DTS 1 + #define AUDIO_CAP_LPCM 2 + #define AUDIO_CAP_MP1 4 + #define AUDIO_CAP_MP2 8 + #define AUDIO_CAP_MP3 16 + #define AUDIO_CAP_AAC 32 + #define AUDIO_CAP_OGG 64 + #define AUDIO_CAP_SDDS 128 + #define AUDIO_CAP_AC3 256 +</programlisting> + +</section> |