GstAudioCdSrc

Provides a base class for CD digital audio (CDDA) sources, which handles things like seeking, querying, discid calculation, tags, and buffer timestamping.

Using GstAudioCdSrc-based elements in applications

GstAudioCdSrc registers two GstFormats of its own, namely the "track" format and the "sector" format. Applications will usually only find the "track" format interesting. You can retrieve that GstFormat for use in seek events or queries with gst_format_get_by_nick("track").

In order to query the number of tracks, for example, an application would set the CDDA source element to READY or PAUSED state and then query the the number of tracks via gst_element_query_duration using the track format acquired above. Applications can query the currently playing track in the same way.

Alternatively, applications may retrieve the currently playing track and the total number of tracks from the taglist that will posted on the bus whenever the CD is opened or the currently playing track changes. The taglist will contain GST_TAG_TRACK_NUMBER and GST_TAG_TRACK_COUNT tags.

Applications playing back CD audio using playbin and cdda://n URIs should issue a seek command in track format to change between tracks, rather than setting a new cdda://n+1 URI on playbin (as setting a new URI on playbin involves closing and re-opening the CD device, which is much much slower).

Tags and meta-information

CDDA sources will automatically emit a number of tags, details about which can be found in the libgsttag documentation. Those tags are: GST_TAG_CDDA_CDDB_DISCID, GST_TAG_CDDA_CDDB_DISCID_FULL, GST_TAG_CDDA_MUSICBRAINZ_DISCID, GST_TAG_CDDA_MUSICBRAINZ_DISCID_FULL, among others.

Tracks and Table of Contents (TOC)

Applications will be informed of the available tracks via a TOC message on the pipeline's GstBus. The GstToc will contain a GstTocEntry for each track, with information about each track. The duration for each track can be retrieved via the GST_TAG_DURATION tag from each entry's tag list, or calculated via gst_toc_entry_get_start_stop_times. The track entries in the TOC will be sorted by track number.

GstAudioCdSrc 

GObject
    ╰──GInitiallyUnowned
        ╰──GstObject
            ╰──GstElement
                ╰──GstBaseSrc
                    ╰──GstPushSrc
                        ╰──GstAudioCdSrc

Members

pushsrc (GstPushSrc) –
No description available
tags (GstTagList *) –
No description available

Class structure

GstAudioCdSrcClass

Audio CD source base class.

Fields
pushsrc_class (GstPushSrcClass) –

the parent class

GstAudio.AudioCdSrcClass

Audio CD source base class.

Attributes
pushsrc_class (GstBase.PushSrcClass) –

the parent class

GstAudio.AudioCdSrcClass

Audio CD source base class.

Attributes
pushsrc_class (GstBase.PushSrcClass) –

the parent class

GstAudio.AudioCdSrc 

GObject.Object
    ╰──GObject.InitiallyUnowned
        ╰──Gst.Object
            ╰──Gst.Element
                ╰──GstBase.BaseSrc
                    ╰──GstBase.PushSrc
                        ╰──GstAudio.AudioCdSrc

Members

pushsrc (GstBase.PushSrc) –
No description available
tags (Gst.TagList) –
No description available

GstAudio.AudioCdSrc 

GObject.Object
    ╰──GObject.InitiallyUnowned
        ╰──Gst.Object
            ╰──Gst.Element
                ╰──GstBase.BaseSrc
                    ╰──GstBase.PushSrc
                        ╰──GstAudio.AudioCdSrc

Members

pushsrc (GstBase.PushSrc) –
No description available
tags (Gst.TagList) –
No description available

Methods

gst_audio_cd_src_add_track 

gboolean
gst_audio_cd_src_add_track (GstAudioCdSrc * src,
                            GstAudioCdSrcTrack * track)

CDDA sources use this function from their start vfunc to announce the available data and audio tracks to the base source class. The caller should allocate track on the stack, the base source will do a shallow copy of the structure (and take ownership of the taglist if there is one).

Parameters:

src –

a GstAudioCdSrc

track –

address of GstAudioCdSrcTrack to add

Returns –

FALSE on error, otherwise TRUE.

GstAudio.AudioCdSrc.prototype.add_track 

function GstAudio.AudioCdSrc.prototype.add_track(track: GstAudio.AudioCdSrcTrack): {
    // javascript wrapper for 'gst_audio_cd_src_add_track'
}

CDDA sources use this function from their start vfunc to announce the available data and audio tracks to the base source class. The caller should allocate track on the stack, the base source will do a shallow copy of the structure (and take ownership of the taglist if there is one).

Parameters:

a GstAudio.AudioCdSrc

address of GstAudio.AudioCdSrcTrack to add

Returns (Number) –

FALSE on error, otherwise TRUE.

GstAudio.AudioCdSrc.add_track 

def GstAudio.AudioCdSrc.add_track (self, track):
    #python wrapper for 'gst_audio_cd_src_add_track'

CDDA sources use this function from their start vfunc to announce the available data and audio tracks to the base source class. The caller should allocate track on the stack, the base source will do a shallow copy of the structure (and take ownership of the taglist if there is one).

Parameters:

a GstAudio.AudioCdSrc

address of GstAudio.AudioCdSrcTrack to add

Returns (bool) –

FALSE on error, otherwise TRUE.

Properties

device 

“device” gchar *

Flags : Read / Write

device 

“device” String

Flags : Read / Write

device 

“self.props.device” str

Flags : Read / Write

mode 

“mode” GstAudioCdSrcMode *

Flags : Read / Write

mode 

“mode” GstAudio.AudioCdSrcMode

Flags : Read / Write

mode 

“self.props.mode” GstAudio.AudioCdSrcMode

Flags : Read / Write

track 

“track” guint

Flags : Read / Write

track 

“track” Number

Flags : Read / Write

track 

“self.props.track” int

Flags : Read / Write

Virtual Methods

close 

close (GstAudioCdSrc * src)

closing the device

Parameters:

src –
No description available

vfunc_close 

function vfunc_close(src: GstAudio.AudioCdSrc): {
    // javascript implementation of the 'close' virtual method
}

closing the device

Parameters:

No description available

do_close 

def do_close (src):
    #python implementation of the 'close' virtual method

closing the device

Parameters:

No description available

open 

gboolean
open (GstAudioCdSrc * src,
      const gchar * device)

opening the device

Parameters:

src –
No description available
device –
No description available
Returns –
No description available

vfunc_open 

function vfunc_open(src: GstAudio.AudioCdSrc, device: String): {
    // javascript implementation of the 'open' virtual method
}

opening the device

Parameters:

No description available
device (String) –
No description available
Returns (Number) –
No description available

do_open 

def do_open (src, device):
    #python implementation of the 'open' virtual method

opening the device

Parameters:

No description available
device (str) –
No description available
Returns (bool) –
No description available

read_sector 

GstBuffer *
read_sector (GstAudioCdSrc * src,
             gint sector)

reading a sector

Parameters:

src –
No description available
sector –
No description available
Returns –
No description available

vfunc_read_sector 

function vfunc_read_sector(src: GstAudio.AudioCdSrc, sector: Number): {
    // javascript implementation of the 'read_sector' virtual method
}

reading a sector

Parameters:

No description available
sector (Number) –
No description available
Returns (Gst.Buffer) –
No description available

do_read_sector 

def do_read_sector (src, sector):
    #python implementation of the 'read_sector' virtual method

reading a sector

Parameters:

No description available
sector (int) –
No description available
Returns (Gst.Buffer) –
No description available

GstAudioCdSrcTrack

CD track abstraction to communicate TOC entries to the base class.

This structure is only for use by sub-classed in connection with gst_audio_cd_src_add_track.

Applications will be informed of the available tracks via a TOC message on the pipeline's GstBus instead.

Members

is_audio (gboolean) –

Whether this is an audio track

num (guint) –

Track number in TOC (usually starts from 1, but not always)

start (guint) –

The first sector of this track (LBA)

end (guint) –

The last sector of this track (LBA)

tags (GstTagList *) –

Track-specific tags (e.g. from cd-text information), or NULL

GstAudio.AudioCdSrcTrack

CD track abstraction to communicate TOC entries to the base class.

This structure is only for use by sub-classed in connection with GstAudio.AudioCdSrc.prototype.add_track.

Applications will be informed of the available tracks via a TOC message on the pipeline's Gst.Bus instead.

Members

is_audio (Number) –

Whether this is an audio track

num (Number) –

Track number in TOC (usually starts from 1, but not always)

start (Number) –

The first sector of this track (LBA)

end (Number) –

The last sector of this track (LBA)

tags (Gst.TagList) –

Track-specific tags (e.g. from cd-text information), or NULL

GstAudio.AudioCdSrcTrack

CD track abstraction to communicate TOC entries to the base class.

This structure is only for use by sub-classed in connection with GstAudio.AudioCdSrc.add_track.

Applications will be informed of the available tracks via a TOC message on the pipeline's Gst.Bus instead.

Members

is_audio (bool) –

Whether this is an audio track

num (int) –

Track number in TOC (usually starts from 1, but not always)

start (int) –

The first sector of this track (LBA)

end (int) –

The last sector of this track (LBA)

tags (Gst.TagList) –

Track-specific tags (e.g. from cd-text information), or NULL

Enumerations

GstAudioCdSrcMode

Mode in which the CD audio source operates. Influences timestamping, EOS handling and seeking.

Members
GST_AUDIO_CD_SRC_MODE_NORMAL (0) –

each single track is a stream

GST_AUDIO_CD_SRC_MODE_CONTINUOUS (1) –

the entire disc is a single stream

GstAudio.AudioCdSrcMode

Mode in which the CD audio source operates. Influences timestamping, EOS handling and seeking.

Members
GstAudio.AudioCdSrcMode.NORMAL (0) –

each single track is a stream

GstAudio.AudioCdSrcMode.CONTINUOUS (1) –

the entire disc is a single stream

GstAudio.AudioCdSrcMode

Mode in which the CD audio source operates. Influences timestamping, EOS handling and seeking.

Members
GstAudio.AudioCdSrcMode.NORMAL (0) –

each single track is a stream

GstAudio.AudioCdSrcMode.CONTINUOUS (1) –

the entire disc is a single stream

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