Query

Object Hierarchy:

Description:

GstQuery *query;
gboolean res;
query = gst_query_new_duration (GST_FORMAT_TIME);
res = gst_element_query (pipeline, query);
if (res) {
gint64 duration;
gst_query_parse_duration (query, NULL, &duration);
g_print ("duration = %"GST_TIME_FORMAT, GST_TIME_ARGS (duration));
}
else {
g_print ("duration query failed...");
}
gst_query_unref (query);

            

Content:

Static methods:

• public static bool types_contains (QueryType types, QueryType type)
  See if the given QueryType is inside the types query types array.

Creation methods:

• public Query.application (QueryType type, owned Structure structure)
  Constructs a new custom application query object. Use unref when done with it.
• public Query.buffering (Format format)
  Constructs a new query object for querying the buffering status of a stream.
• public Query.convert (Format src_format, int64 value, Format dest_format)
  Constructs a new convert query object. Use unref when done with it. A convert query is used to ask for a conversion between one format and another.
• public Query.duration (Format format)
  Constructs a new stream duration query object to query in the given format. Use unref when done with it. A duration query will give the total length of the stream.
• public Query.formats ()
  Constructs a new query object for querying formats of the stream.
• public Query.latency ()
  Constructs a new latency query object. Use unref when done with it. A latency query is usually performed by sinks to compensate for additional latency introduced by elements in the pipeline.
• public Query.position (Format format)
  Constructs a new query stream position query object. Use unref when done with it. A position query is used to query the current position of playback in the streams, in some format.
• public Query.seeking (Format format)
  Constructs a new query object for querying seeking properties of the stream.
• public Query.segment (Format format)
  Constructs a new segment query object. Use unref when done with it. A segment query is used to discover information about the currently configured segment for playback.
• public Query.uri ()
  Constructs a new query URI query object. Use unref when done with it. An URI query is used to query the current URI that is used by the source or sink.

Methods:

• public bool add_buffering_range (int64 start, int64 stop)
  Set the buffering-ranges array field in query. The current last start position of the array should be inferior to start.
• public Query copy ()
• public uint get_n_buffering_ranges ()
  Retrieve the number of values currently stored in the buffered-ranges array of the query's structure.
• public unowned Structure get_structure ()
  Get the structure of a query. still owned by the query and will therefore be freed when the query is unreffed.
• public void make_writable ()
• public void parse_buffering_percent (out bool busy, out int percent)
  Get the percentage of buffered data. This is a value between 0 and 100. The busy indicator is true when the buffering is in progress.
• public void parse_buffering_range (out Format format, out int64 start, out int64 stop, out int64 estimated_total)
  Parse an available query, writing the format into format, and other results into the passed parameters, if the respective parameters are non-NULL
• public void parse_buffering_stats (out BufferingMode mode, out int avg_in, out int avg_out, out int64 buffering_left)
  Extracts the buffering stats values from query.
• public void parse_convert (out Format src_format, out int64 src_value, out Format dest_format, out int64 dest_value)
  Parse a convert query answer. Any of src_format, src_value, dest_format , and dest_value may be NULL, in which case that value is omitted.
• public void parse_duration (out Format format, out int64 duration)
  Parse a duration query answer. Write the format of the duration into format, and the value into duration, if the respective variables are non-NULL.
• public void parse_formats_length (out uint n_formats)
  Parse the number of formats in the formats query.
• public void parse_formats_nth (uint nth, out Format format)
  Parse the format query and retrieve the nth format from it into set to GST_FORMAT_UNDEFINED.
• public void parse_latency (out bool live, out ClockTime min_latency, out ClockTime max_latency)
  Parse a latency query answer.
• public bool parse_nth_buffering_range (uint index, int64 start, int64 stop)
  Parse an available query and get the start and stop values stored at the index of the buffered ranges array.
• public void parse_position (out Format format, out int64 cur)
  Parse a position query, writing the format into format, and the position into cur , if the respective parameters are non-NULL.
• public void parse_seeking (out Format format, out bool seekable, out int64 segment_start, out int64 segment_end)
  Parse a seeking query, writing the format into format, and other results into the passed parameters, if the respective parameters are non-NULL
• public void parse_segment (out double rate, out Format format, out int64 start_value, out int64 stop_value)
  Parse a segment query answer. Any of rate, format, start_value, and See set_segment for an explanation of the function arguments.
• public void parse_uri (out string uri)
  Parse an URI query, writing the URI into uri as a newly allocated string, if the respective parameters are non-NULL. Free the string with g_free after usage.
• public weak Query ref ()
• public void set_buffering_percent (bool busy, int percent)
  Set the percentage of buffered data. This is a value between 0 and 100. The busy indicator is true when the buffering is in progress.
• public void set_buffering_range (Format format, int64 start, int64 stop, int64 estimated_total)
  Set the available query result fields in query.
• public void set_buffering_stats (BufferingMode mode, int avg_in, int avg_out, int64 buffering_left)
  Configures the buffering stats values in query.
• public void set_convert (Format src_format, int64 src_value, Format dest_format, int64 dest_value)
  Answer a convert query by setting the requested values.
• public void set_duration (Format format, int64 duration)
  Answer a duration query by setting the requested value in the given format.
• public void set_formats (int n_formats, ...)
  Set the formats query result fields in query. The number of formats passed must be equal to n_formats.
• public void set_formatsv (Format[] formats)
  Set the formats query result fields in query. The number of formats passed in the formats array must be equal to n_formats.
• public void set_latency (bool live, ClockTime min_latency, ClockTime max_latency)
  Answer a latency query by setting the requested values in the given format.
• public void set_position (Format format, int64 cur)
  Answer a position query by setting the requested value in the given format.
• public void set_seeking (Format format, bool seekable, int64 segment_start, int64 segment_end)
  Set the seeking query result fields in query.
• public void set_segment (double rate, Format format, int64 start_value, int64 stop_value)
  Answer a segment query by setting the requested values. The normal playback segment of a pipeline is 0 to duration at the default rate of 1.0. If a seek was performed on the pipeline to play a different segment, this query will return the range specified in the last seek. playback range start and stop values expressed in format. The values are always between 0 and the duration of the media and negative rates, playback will actually happen from stop_value to
• public void set_uri (string uri)
  Answer a URI query by setting the requested URI.
• public void unref ()

Fields:

• public unowned Structure structure
• public QueryType type