GstBase.BaseParse

GObject.Object
    ╰──GObject.InitiallyUnowned
        ╰──Gst.Object
            ╰──Gst.Element
                ╰──GstBase.BaseParse

GstBase.BaseParse.prototype.add_index_entry

function GstBase.BaseParse.prototype.add_index_entry(offset: Number, ts: Number, key: Number, force: Number): {
    // javascript wrapper for 'gst_base_parse_add_index_entry'
}

Adds an entry to the index associating offset to ts. It is recommended to only add keyframe entries. force allows to bypass checks, such as whether the stream is (upstream) seekable, another entry is already "close" to the new entry, etc.

GstBase.BaseParse.prototype.convert_default

function GstBase.BaseParse.prototype.convert_default(src_format: Gst.Format, src_value: Number, dest_format: Gst.Format): {
    // javascript wrapper for 'gst_base_parse_convert_default'
}

Default implementation of vfunc_convert.

GstBase.BaseParse.prototype.drain

function GstBase.BaseParse.prototype.drain(): {
    // javascript wrapper for 'gst_base_parse_drain'
}

Drains the adapter until it is empty. It decreases the min_frame_size to match the current adapter size and calls chain method until the adapter is emptied or chain returns with error.

Since : 1.12

GstBase.BaseParse.prototype.finish_frame

function GstBase.BaseParse.prototype.finish_frame(frame: GstBase.BaseParseFrame, size: Number): {
    // javascript wrapper for 'gst_base_parse_finish_frame'
}

Collects parsed data and pushes it downstream. Source pad caps must be set when this is called.

If frame's out_buffer is set, that will be used as subsequent frame data, and size amount will be flushed from the input data. The output_buffer size can differ from the consumed size indicated by size.

Otherwise, size samples will be taken from the input and used for output, and the output's metadata (timestamps etc) will be taken as (optionally) set by the subclass on frame's (input) buffer (which is otherwise ignored for any but the above purpose/information).

Note that the latter buffer is invalidated by this call, whereas the caller retains ownership of frame.

GstBase.BaseParse.prototype.merge_tags

function GstBase.BaseParse.prototype.merge_tags(tags: Gst.TagList, mode: Gst.TagMergeMode): {
    // javascript wrapper for 'gst_base_parse_merge_tags'
}

Sets the parser subclass's tags and how they should be merged with any upstream stream tags. This will override any tags previously-set with GstBase.BaseParse.prototype.merge_tags.

Note that this is provided for convenience, and the subclass is not required to use this and can still do tag handling on its own.

Since : 1.6

GstBase.BaseParse.prototype.push_frame

function GstBase.BaseParse.prototype.push_frame(frame: GstBase.BaseParseFrame): {
    // javascript wrapper for 'gst_base_parse_push_frame'
}

Pushes the frame's buffer downstream, sends any pending events and does some timestamp and segment handling. Takes ownership of frame's buffer, though caller retains ownership of frame.

This must be called with sinkpad STREAM_LOCK held.

GstBase.BaseParse.prototype.set_average_bitrate

function GstBase.BaseParse.prototype.set_average_bitrate(bitrate: Number): {
    // javascript wrapper for 'gst_base_parse_set_average_bitrate'
}

Optionally sets the average bitrate detected in media (if non-zero), e.g. based on metadata, as it will be posted to the application.

By default, announced average bitrate is estimated. The average bitrate is used to estimate the total duration of the stream and to estimate a seek position, if there's no index and the format is syncable (see GstBase.BaseParse.prototype.set_syncable).

GstBase.BaseParse.prototype.set_duration

function GstBase.BaseParse.prototype.set_duration(fmt: Gst.Format, duration: Number, interval: Number): {
    // javascript wrapper for 'gst_base_parse_set_duration'
}

Sets the duration of the currently playing media. Subclass can use this when it is able to determine duration and/or notices a change in the media duration. Alternatively, if interval is non-zero (default), then stream duration is determined based on estimated bitrate, and updated every interval frames.

GstBase.BaseParse.prototype.set_frame_rate

function GstBase.BaseParse.prototype.set_frame_rate(fps_num: Number, fps_den: Number, lead_in: Number, lead_out: Number): {
    // javascript wrapper for 'gst_base_parse_set_frame_rate'
}

If frames per second is configured, parser can take care of buffer duration and timestamping. When performing segment clipping, or seeking to a specific location, a corresponding decoder might need an initial lead_in and a following lead_out number of frames to ensure the desired segment is entirely filled upon decoding.

GstBase.BaseParse.prototype.set_has_timing_info

function GstBase.BaseParse.prototype.set_has_timing_info(has_timing: Number): {
    // javascript wrapper for 'gst_base_parse_set_has_timing_info'
}

Set if frames carry timing information which the subclass can (generally) parse and provide. In particular, intrinsic (rather than estimated) time can be obtained following a seek.

GstBase.BaseParse.prototype.set_infer_ts

function GstBase.BaseParse.prototype.set_infer_ts(infer_ts: Number): {
    // javascript wrapper for 'gst_base_parse_set_infer_ts'
}

By default, the base class might try to infer PTS from DTS and vice versa. While this is generally correct for audio data, it may not be otherwise. Sub-classes implementing such formats should disable timestamp inferring.

GstBase.BaseParse.prototype.set_latency

function GstBase.BaseParse.prototype.set_latency(min_latency: Number, max_latency: Number): {
    // javascript wrapper for 'gst_base_parse_set_latency'
}

Sets the minimum and maximum (which may likely be equal) latency introduced by the parsing process. If there is such a latency, which depends on the particular parsing of the format, it typically corresponds to 1 frame duration.

If the provided values changed from previously provided ones, this will also post a LATENCY message on the bus so the pipeline can reconfigure its global latency.

GstBase.BaseParse.prototype.set_min_frame_size

function GstBase.BaseParse.prototype.set_min_frame_size(min_size: Number): {
    // javascript wrapper for 'gst_base_parse_set_min_frame_size'
}

Subclass can use this function to tell the base class that it needs to be given buffers of at least min_size bytes.

GstBase.BaseParse.prototype.set_passthrough

function GstBase.BaseParse.prototype.set_passthrough(passthrough: Number): {
    // javascript wrapper for 'gst_base_parse_set_passthrough'
}

Set if the nature of the format or configuration does not allow (much) parsing, and the parser should operate in passthrough mode (which only applies when operating in push mode). That is, incoming buffers are pushed through unmodified, i.e. no vfunc_handle_frame will be invoked, but vfunc_pre_push_frame will still be invoked, so subclass can perform as much or as little is appropriate for passthrough semantics in vfunc_pre_push_frame.

GstBase.BaseParse.prototype.set_pts_interpolation

function GstBase.BaseParse.prototype.set_pts_interpolation(pts_interpolate: Number): {
    // javascript wrapper for 'gst_base_parse_set_pts_interpolation'
}

By default, the base class will guess PTS timestamps using a simple interpolation (previous timestamp + duration), which is incorrect for data streams with reordering, where PTS can go backward. Sub-classes implementing such formats should disable PTS interpolation.

GstBase.BaseParse.prototype.set_syncable

function GstBase.BaseParse.prototype.set_syncable(syncable: Number): {
    // javascript wrapper for 'gst_base_parse_set_syncable'
}

Set if frame starts can be identified. This is set by default and determines whether seeking based on bitrate averages is possible for a format/stream.

GstBase.BaseParse.prototype.set_ts_at_offset

function GstBase.BaseParse.prototype.set_ts_at_offset(offset: Number): {
    // javascript wrapper for 'gst_base_parse_set_ts_at_offset'
}

This function should only be called from a handle_frame implementation.

GstBase.BaseParse creates initial timestamps for frames by using the last timestamp seen in the stream before the frame starts. In certain cases, the correct timestamps will occur in the stream after the start of the frame, but before the start of the actual picture data. This function can be used to set the timestamps based on the offset into the frame data that the picture starts.

Since : 1.2

disable-passthrough

“disable-passthrough” Number

If set to true, baseparse will unconditionally force parsing of the incoming data. This can be required in the rare cases where the incoming side-data (caps, pts, dts, ...) is not trusted by the user and wants to force validation and parsing of the incoming data. If set to false, decision of whether to parse the data or not is up to the implementation (standard behaviour).

Flags : Read / Write

vfunc_convert

function vfunc_convert(parse: GstBase.BaseParse, src_format: Gst.Format, src_value: Number, dest_format: Gst.Format, dest_value: Number): {
    // javascript implementation of the 'convert' virtual method
}

Optional. Convert between formats.

vfunc_detect

function vfunc_detect(parse: GstBase.BaseParse, buffer: Gst.Buffer): {
    // javascript implementation of the 'detect' virtual method
}

Optional. Called until it doesn't return GST_FLOW_OK anymore for the first buffers. Can be used by the subclass to detect the stream format.

vfunc_get_sink_caps

function vfunc_get_sink_caps(parse: GstBase.BaseParse, filter: Gst.Caps): {
    // javascript implementation of the 'get_sink_caps' virtual method
}

Optional. Allows the subclass to do its own sink get caps if needed.

vfunc_handle_frame

function vfunc_handle_frame(parse: GstBase.BaseParse, frame: GstBase.BaseParseFrame): {
    // javascript implementation of the 'handle_frame' virtual method
}

Parses the input data into valid frames as defined by subclass which should be passed to GstBase.BaseParse.prototype.finish_frame. The frame's input buffer is guaranteed writable, whereas the input frame ownership is held by caller (so subclass should make a copy if it needs to hang on). Input buffer (data) is provided by baseclass with as much metadata set as possible by baseclass according to upstream information and/or subclass settings, though subclass may still set buffer timestamp and duration if desired.

vfunc_pre_push_frame

function vfunc_pre_push_frame(parse: GstBase.BaseParse, frame: GstBase.BaseParseFrame): {
    // javascript implementation of the 'pre_push_frame' virtual method
}

Optional. Called just prior to pushing a frame (after any pending events have been sent) to give subclass a chance to perform additional actions at this time (e.g. tag sending) or to decide whether this buffer should be dropped or not (e.g. custom segment clipping).

vfunc_set_sink_caps

function vfunc_set_sink_caps(parse: GstBase.BaseParse, caps: Gst.Caps): {
    // javascript implementation of the 'set_sink_caps' virtual method
}

Optional. Allows the subclass to be notified of the actual caps set.

vfunc_sink_event

function vfunc_sink_event(parse: GstBase.BaseParse, event: Gst.Event): {
    // javascript implementation of the 'sink_event' virtual method
}

Optional. Event handler on the sink pad. This function should chain up to the parent implementation to let the default handler run.

vfunc_sink_query

function vfunc_sink_query(parse: GstBase.BaseParse, query: Gst.Query): {
    // javascript implementation of the 'sink_query' virtual method
}

Optional. Query handler on the sink pad. This function should chain up to the parent implementation to let the default handler run (Since: 1.2)

vfunc_src_event

function vfunc_src_event(parse: GstBase.BaseParse, event: Gst.Event): {
    // javascript implementation of the 'src_event' virtual method
}

Optional. Event handler on the source pad. Should chain up to the parent to let the default handler run.

vfunc_src_query

function vfunc_src_query(parse: GstBase.BaseParse, query: Gst.Query): {
    // javascript implementation of the 'src_query' virtual method
}

Optional. Query handler on the source pad. Should chain up to the parent to let the default handler run (Since: 1.2)

vfunc_start

function vfunc_start(parse: GstBase.BaseParse): {
    // javascript implementation of the 'start' virtual method
}

Optional. Called when the element starts processing. Allows opening external resources.

vfunc_stop

function vfunc_stop(parse: GstBase.BaseParse): {
    // javascript implementation of the 'stop' virtual method
}

Optional. Called when the element stops processing. Allows closing external resources.

GstBase.BaseParseFrame

GstBase.BaseParseFrame.prototype.new

function GstBase.BaseParseFrame.prototype.new(buffer: Gst.Buffer, flags: GstBase.BaseParseFrameFlags, overhead: Number): {
    // javascript wrapper for 'gst_base_parse_frame_new'
}

Allocates a new GstBase.BaseParseFrame. This function is mainly for bindings, elements written in C should usually allocate the frame on the stack and then use GstBase.BaseParseFrame.prototype.init to initialise it.

GstBase.BaseParseFrame.prototype.copy

function GstBase.BaseParseFrame.prototype.copy(): {
    // javascript wrapper for 'gst_base_parse_frame_copy'
}

Copies a GstBase.BaseParseFrame.

Since : 1.12.1

GstBase.BaseParseFrame.prototype.free

function GstBase.BaseParseFrame.prototype.free(): {
    // javascript wrapper for 'gst_base_parse_frame_free'
}

Frees the provided frame.

GstBase.BaseParseFrame.prototype.init

function GstBase.BaseParseFrame.prototype.init(): {
    // javascript wrapper for 'gst_base_parse_frame_init'
}

Sets a GstBase.BaseParseFrame to initial state. Currently this means all public fields are zero-ed and a private flag is set to make sure GstBase.BaseParseFrame.prototype.free only frees the contents but not the actual frame. Use this function to initialise a GstBase.BaseParseFrame allocated on the stack.

GstBase.BaseParseFrameFlags

Flags to be used in a GstBase.BaseParseFrame.

GstBase.BASE_PARSE_FLAG_DRAINING

GstBase.BASE_PARSE_FLAG_LOST_SYNC