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GstBase-1.0.gir
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<?xml version="1.0"?>
<!-- This file was automatically generated from C sources - DO NOT EDIT!
To affect the contents of this file, edit the original C definitions,
and/or use gtk-doc annotations. -->
<repository xmlns="http://www.gtk.org/introspection/core/1.0" xmlns:c="http://www.gtk.org/introspection/c/1.0" xmlns:glib="http://www.gtk.org/introspection/glib/1.0" version="1.2">
<include name="GLib" version="2.0"/>
<include name="GModule" version="2.0"/>
<include name="GObject" version="2.0"/>
<include name="Gst" version="1.0"/>
<package name="gstreamer-base-1.0"/>
<c:include name="gst/base/base.h"/>
<namespace name="GstBase" version="1.0" shared-library="libgstbase-1.0.so.0" c:identifier-prefixes="Gst" c:symbol-prefixes="gst">
<function-macro name="ADAPTER" c:identifier="GST_ADAPTER" introspectable="0">
<parameters>
<parameter name="obj">
</parameter>
</parameters>
</function-macro>
<function-macro name="ADAPTER_CLASS" c:identifier="GST_ADAPTER_CLASS" introspectable="0">
<parameters>
<parameter name="klass">
</parameter>
</parameters>
</function-macro>
<function-macro name="ADAPTER_GET_CLASS" c:identifier="GST_ADAPTER_GET_CLASS" introspectable="0">
<parameters>
<parameter name="obj">
</parameter>
</parameters>
</function-macro>
<function-macro name="AGGREGATOR" c:identifier="GST_AGGREGATOR" introspectable="0">
<parameters>
<parameter name="obj">
</parameter>
</parameters>
</function-macro>
<function-macro name="AGGREGATOR_CAST" c:identifier="GST_AGGREGATOR_CAST" introspectable="0">
<parameters>
<parameter name="obj">
</parameter>
</parameters>
</function-macro>
<function-macro name="AGGREGATOR_CLASS" c:identifier="GST_AGGREGATOR_CLASS" introspectable="0">
<parameters>
<parameter name="klass">
</parameter>
</parameters>
</function-macro>
<function-macro name="AGGREGATOR_GET_CLASS" c:identifier="GST_AGGREGATOR_GET_CLASS" introspectable="0">
<parameters>
<parameter name="obj">
</parameter>
</parameters>
</function-macro>
<function-macro name="AGGREGATOR_PAD" c:identifier="GST_AGGREGATOR_PAD" introspectable="0">
<parameters>
<parameter name="obj">
</parameter>
</parameters>
</function-macro>
<function-macro name="AGGREGATOR_PAD_CAST" c:identifier="GST_AGGREGATOR_PAD_CAST" introspectable="0">
<parameters>
<parameter name="obj">
</parameter>
</parameters>
</function-macro>
<function-macro name="AGGREGATOR_PAD_CLASS" c:identifier="GST_AGGREGATOR_PAD_CLASS" introspectable="0">
<parameters>
<parameter name="klass">
</parameter>
</parameters>
</function-macro>
<function-macro name="AGGREGATOR_PAD_GET_CLASS" c:identifier="GST_AGGREGATOR_PAD_GET_CLASS" introspectable="0">
<parameters>
<parameter name="obj">
</parameter>
</parameters>
</function-macro>
<function-macro name="AGGREGATOR_SRC_PAD" c:identifier="GST_AGGREGATOR_SRC_PAD" version="1.6" introspectable="0">
<doc xml:space="preserve">Convenience macro to access the source pad of #GstAggregator</doc>
<parameters>
<parameter name="agg">
<doc xml:space="preserve">a #GstAggregator</doc>
</parameter>
</parameters>
</function-macro>
<class name="Adapter" c:symbol-prefix="adapter" c:type="GstAdapter" parent="GObject.Object" glib:type-name="GstAdapter" glib:get-type="gst_adapter_get_type" glib:type-struct="AdapterClass">
<doc xml:space="preserve">This class is for elements that receive buffers in an undesired size.
While for example raw video contains one image per buffer, the same is not
true for a lot of other formats, especially those that come directly from
a file. So if you have undefined buffer sizes and require a specific size,
this object is for you.
An adapter is created with gst_adapter_new(). It can be freed again with
g_object_unref().
The theory of operation is like this: All buffers received are put
into the adapter using gst_adapter_push() and the data is then read back
in chunks of the desired size using gst_adapter_map()/gst_adapter_unmap()
and/or gst_adapter_copy(). After the data has been processed, it is freed
using gst_adapter_unmap().
Other methods such as gst_adapter_take() and gst_adapter_take_buffer()
combine gst_adapter_map() and gst_adapter_unmap() in one method and are
potentially more convenient for some use cases.
For example, a sink pad's chain function that needs to pass data to a library
in 512-byte chunks could be implemented like this:
|[<!-- language="C" -->
static GstFlowReturn
sink_pad_chain (GstPad *pad, GstObject *parent, GstBuffer *buffer)
{
MyElement *this;
GstAdapter *adapter;
GstFlowReturn ret = GST_FLOW_OK;
this = MY_ELEMENT (parent);
adapter = this->adapter;
// put buffer into adapter
gst_adapter_push (adapter, buffer);
// while we can read out 512 bytes, process them
while (gst_adapter_available (adapter) >= 512 && ret == GST_FLOW_OK) {
const guint8 *data = gst_adapter_map (adapter, 512);
// use flowreturn as an error value
ret = my_library_foo (data);
gst_adapter_unmap (adapter);
gst_adapter_flush (adapter, 512);
}
return ret;
}
]|
For another example, a simple element inside GStreamer that uses #GstAdapter
is the libvisual element.
An element using #GstAdapter in its sink pad chain function should ensure that
when the FLUSH_STOP event is received, that any queued data is cleared using
gst_adapter_clear(). Data should also be cleared or processed on EOS and
when changing state from %GST_STATE_PAUSED to %GST_STATE_READY.
Also check the GST_BUFFER_FLAG_DISCONT flag on the buffer. Some elements might
need to clear the adapter after a discontinuity.
The adapter will keep track of the timestamps of the buffers
that were pushed. The last seen timestamp before the current position
can be queried with gst_adapter_prev_pts(). This function can
optionally return the number of bytes between the start of the buffer that
carried the timestamp and the current adapter position. The distance is
useful when dealing with, for example, raw audio samples because it allows
you to calculate the timestamp of the current adapter position by using the
last seen timestamp and the amount of bytes since. Additionally, the
gst_adapter_prev_pts_at_offset() can be used to determine the last
seen timestamp at a particular offset in the adapter.
The adapter will also keep track of the offset of the buffers
(#GST_BUFFER_OFFSET) that were pushed. The last seen offset before the
current position can be queried with gst_adapter_prev_offset(). This function
can optionally return the number of bytes between the start of the buffer
that carried the offset and the current adapter position.
Additionally the adapter also keeps track of the PTS, DTS and buffer offset
at the last discontinuity, which can be retrieved with
gst_adapter_pts_at_discont(), gst_adapter_dts_at_discont() and
gst_adapter_offset_at_discont(). The number of bytes that were consumed
since then can be queried with gst_adapter_distance_from_discont().
A last thing to note is that while #GstAdapter is pretty optimized,
merging buffers still might be an operation that requires a `malloc()` and
`memcpy()` operation, and these operations are not the fastest. Because of
this, some functions like gst_adapter_available_fast() are provided to help
speed up such cases should you want to. To avoid repeated memory allocations,
gst_adapter_copy() can be used to copy data into a (statically allocated)
user provided buffer.
#GstAdapter is not MT safe. All operations on an adapter must be serialized by
the caller. This is not normally a problem, however, as the normal use case
of #GstAdapter is inside one pad's chain function, in which case access is
serialized via the pad's STREAM_LOCK.
Note that gst_adapter_push() takes ownership of the buffer passed. Use
gst_buffer_ref() before pushing it into the adapter if you still want to
access the buffer later. The adapter will never modify the data in the
buffer pushed in it.</doc>
<constructor name="new" c:identifier="gst_adapter_new">
<doc xml:space="preserve">Creates a new #GstAdapter. Free with g_object_unref().</doc>
<return-value transfer-ownership="full">
<doc xml:space="preserve">a new #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</return-value>
</constructor>
<method name="available" c:identifier="gst_adapter_available">
<doc xml:space="preserve">Gets the maximum amount of bytes available, that is it returns the maximum
value that can be supplied to gst_adapter_map() without that function
returning %NULL.</doc>
<return-value transfer-ownership="none">
<doc xml:space="preserve">number of bytes available in @adapter</doc>
<type name="gsize" c:type="gsize"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
</parameters>
</method>
<method name="available_fast" c:identifier="gst_adapter_available_fast">
<doc xml:space="preserve">Gets the maximum number of bytes that are immediately available without
requiring any expensive operations (like copying the data into a
temporary buffer).</doc>
<return-value transfer-ownership="none">
<doc xml:space="preserve">number of bytes that are available in @adapter without expensive
operations</doc>
<type name="gsize" c:type="gsize"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
</parameters>
</method>
<method name="clear" c:identifier="gst_adapter_clear">
<doc xml:space="preserve">Removes all buffers from @adapter.</doc>
<return-value transfer-ownership="none">
<type name="none" c:type="void"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
</parameters>
</method>
<method name="copy" c:identifier="gst_adapter_copy" shadowed-by="copy_bytes" introspectable="0">
<doc xml:space="preserve">Copies @size bytes of data starting at @offset out of the buffers
contained in #GstAdapter into an array @dest provided by the caller.
The array @dest should be large enough to contain @size bytes.
The user should check that the adapter has (@offset + @size) bytes
available before calling this function.</doc>
<return-value transfer-ownership="none">
<type name="none" c:type="void"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="dest" direction="out" caller-allocates="1" transfer-ownership="none">
<doc xml:space="preserve">
the memory to copy into</doc>
<array length="2" zero-terminated="0" c:type="gpointer">
<type name="guint8"/>
</array>
</parameter>
<parameter name="offset" transfer-ownership="none">
<doc xml:space="preserve">the bytes offset in the adapter to start from</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
<parameter name="size" transfer-ownership="none">
<doc xml:space="preserve">the number of bytes to copy</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
</parameters>
</method>
<method name="copy_bytes" c:identifier="gst_adapter_copy_bytes" shadows="copy" version="1.4">
<doc xml:space="preserve">Similar to gst_adapter_copy, but more suitable for language bindings. @size
bytes of data starting at @offset will be copied out of the buffers contained
in @adapter and into a new #GBytes structure which is returned. Depending on
the value of the @size argument an empty #GBytes structure may be returned.</doc>
<return-value transfer-ownership="full">
<doc xml:space="preserve">A new #GBytes structure containing the copied data.</doc>
<type name="GLib.Bytes" c:type="GBytes*"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="offset" transfer-ownership="none">
<doc xml:space="preserve">the bytes offset in the adapter to start from</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
<parameter name="size" transfer-ownership="none">
<doc xml:space="preserve">the number of bytes to copy</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
</parameters>
</method>
<method name="distance_from_discont" c:identifier="gst_adapter_distance_from_discont" version="1.10">
<doc xml:space="preserve">Get the distance in bytes since the last buffer with the
%GST_BUFFER_FLAG_DISCONT flag.
The distance will be reset to 0 for all buffers with
%GST_BUFFER_FLAG_DISCONT on them, and then calculated for all other
following buffers based on their size.</doc>
<return-value transfer-ownership="none">
<doc xml:space="preserve">The offset. Can be %GST_BUFFER_OFFSET_NONE.</doc>
<type name="guint64" c:type="guint64"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
</parameters>
</method>
<method name="dts_at_discont" c:identifier="gst_adapter_dts_at_discont" version="1.10">
<doc xml:space="preserve">Get the DTS that was on the last buffer with the GST_BUFFER_FLAG_DISCONT
flag, or GST_CLOCK_TIME_NONE.</doc>
<return-value transfer-ownership="none">
<doc xml:space="preserve">The DTS at the last discont or GST_CLOCK_TIME_NONE.</doc>
<type name="Gst.ClockTime" c:type="GstClockTime"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
</parameters>
</method>
<method name="flush" c:identifier="gst_adapter_flush">
<doc xml:space="preserve">Flushes the first @flush bytes in the @adapter. The caller must ensure that
at least this many bytes are available.
See also: gst_adapter_map(), gst_adapter_unmap()</doc>
<return-value transfer-ownership="none">
<type name="none" c:type="void"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="flush" transfer-ownership="none">
<doc xml:space="preserve">the number of bytes to flush</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
</parameters>
</method>
<method name="get_buffer" c:identifier="gst_adapter_get_buffer" version="1.6">
<doc xml:space="preserve">Returns a #GstBuffer containing the first @nbytes of the @adapter, but
does not flush them from the adapter. See gst_adapter_take_buffer()
for details.
Caller owns a reference to the returned buffer. gst_buffer_unref() after
usage.
Free-function: gst_buffer_unref</doc>
<return-value transfer-ownership="full" nullable="1">
<doc xml:space="preserve">a #GstBuffer containing the first
@nbytes of the adapter, or %NULL if @nbytes bytes are not available.
gst_buffer_unref() when no longer needed.</doc>
<type name="Gst.Buffer" c:type="GstBuffer*"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="nbytes" transfer-ownership="none">
<doc xml:space="preserve">the number of bytes to get</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
</parameters>
</method>
<method name="get_buffer_fast" c:identifier="gst_adapter_get_buffer_fast" version="1.6">
<doc xml:space="preserve">Returns a #GstBuffer containing the first @nbytes of the @adapter, but
does not flush them from the adapter. See gst_adapter_take_buffer_fast()
for details.
Caller owns a reference to the returned buffer. gst_buffer_unref() after
usage.
Free-function: gst_buffer_unref</doc>
<return-value transfer-ownership="full" nullable="1">
<doc xml:space="preserve">a #GstBuffer containing the first
@nbytes of the adapter, or %NULL if @nbytes bytes are not available.
gst_buffer_unref() when no longer needed.</doc>
<type name="Gst.Buffer" c:type="GstBuffer*"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="nbytes" transfer-ownership="none">
<doc xml:space="preserve">the number of bytes to get</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
</parameters>
</method>
<method name="get_buffer_list" c:identifier="gst_adapter_get_buffer_list" version="1.6">
<doc xml:space="preserve">Returns a #GstBufferList of buffers containing the first @nbytes bytes of
the @adapter but does not flush them from the adapter. See
gst_adapter_take_buffer_list() for details.
Caller owns the returned list. Call gst_buffer_list_unref() to free
the list after usage.</doc>
<return-value transfer-ownership="full" nullable="1">
<doc xml:space="preserve">a #GstBufferList of buffers containing
the first @nbytes of the adapter, or %NULL if @nbytes bytes are not
available</doc>
<type name="Gst.BufferList" c:type="GstBufferList*"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="nbytes" transfer-ownership="none">
<doc xml:space="preserve">the number of bytes to get</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
</parameters>
</method>
<method name="get_list" c:identifier="gst_adapter_get_list" version="1.6">
<doc xml:space="preserve">Returns a #GList of buffers containing the first @nbytes bytes of the
@adapter, but does not flush them from the adapter. See
gst_adapter_take_list() for details.
Caller owns returned list and contained buffers. gst_buffer_unref() each
buffer in the list before freeing the list after usage.</doc>
<return-value transfer-ownership="full" nullable="1">
<doc xml:space="preserve">a #GList of
buffers containing the first @nbytes of the adapter, or %NULL if @nbytes
bytes are not available</doc>
<type name="GLib.List" c:type="GList*">
<type name="Gst.Buffer"/>
</type>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="nbytes" transfer-ownership="none">
<doc xml:space="preserve">the number of bytes to get</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
</parameters>
</method>
<method name="map" c:identifier="gst_adapter_map">
<doc xml:space="preserve">Gets the first @size bytes stored in the @adapter. The returned pointer is
valid until the next function is called on the adapter.
Note that setting the returned pointer as the data of a #GstBuffer is
incorrect for general-purpose plugins. The reason is that if a downstream
element stores the buffer so that it has access to it outside of the bounds
of its chain function, the buffer will have an invalid data pointer after
your element flushes the bytes. In that case you should use
gst_adapter_take(), which returns a freshly-allocated buffer that you can set
as #GstBuffer memory or the potentially more performant
gst_adapter_take_buffer().
Returns %NULL if @size bytes are not available.</doc>
<return-value transfer-ownership="none" nullable="1">
<doc xml:space="preserve">
a pointer to the first @size bytes of data, or %NULL</doc>
<array length="0" zero-terminated="0" c:type="gconstpointer">
<type name="guint8"/>
</array>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="size" direction="out" caller-allocates="0" transfer-ownership="full">
<doc xml:space="preserve">the number of bytes to map/peek</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
</parameters>
</method>
<method name="masked_scan_uint32" c:identifier="gst_adapter_masked_scan_uint32">
<doc xml:space="preserve">Scan for pattern @pattern with applied mask @mask in the adapter data,
starting from offset @offset.
The bytes in @pattern and @mask are interpreted left-to-right, regardless
of endianness. All four bytes of the pattern must be present in the
adapter for it to match, even if the first or last bytes are masked out.
It is an error to call this function without making sure that there is
enough data (offset+size bytes) in the adapter.
This function calls gst_adapter_masked_scan_uint32_peek() passing %NULL
for value.</doc>
<return-value transfer-ownership="none">
<doc xml:space="preserve">offset of the first match, or -1 if no match was found.
Example:
|[
// Assume the adapter contains 0x00 0x01 0x02 ... 0xfe 0xff
gst_adapter_masked_scan_uint32 (adapter, 0xffffffff, 0x00010203, 0, 256);
// -> returns 0
gst_adapter_masked_scan_uint32 (adapter, 0xffffffff, 0x00010203, 1, 255);
// -> returns -1
gst_adapter_masked_scan_uint32 (adapter, 0xffffffff, 0x01020304, 1, 255);
// -> returns 1
gst_adapter_masked_scan_uint32 (adapter, 0xffff, 0x0001, 0, 256);
// -> returns -1
gst_adapter_masked_scan_uint32 (adapter, 0xffff, 0x0203, 0, 256);
// -> returns 0
gst_adapter_masked_scan_uint32 (adapter, 0xffff0000, 0x02030000, 0, 256);
// -> returns 2
gst_adapter_masked_scan_uint32 (adapter, 0xffff0000, 0x02030000, 0, 4);
// -> returns -1
]|</doc>
<type name="gssize" c:type="gssize"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="mask" transfer-ownership="none">
<doc xml:space="preserve">mask to apply to data before matching against @pattern</doc>
<type name="guint32" c:type="guint32"/>
</parameter>
<parameter name="pattern" transfer-ownership="none">
<doc xml:space="preserve">pattern to match (after mask is applied)</doc>
<type name="guint32" c:type="guint32"/>
</parameter>
<parameter name="offset" transfer-ownership="none">
<doc xml:space="preserve">offset into the adapter data from which to start scanning, returns
the last scanned position.</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
<parameter name="size" transfer-ownership="none">
<doc xml:space="preserve">number of bytes to scan from offset</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
</parameters>
</method>
<method name="masked_scan_uint32_peek" c:identifier="gst_adapter_masked_scan_uint32_peek">
<doc xml:space="preserve">Scan for pattern @pattern with applied mask @mask in the adapter data,
starting from offset @offset. If a match is found, the value that matched
is returned through @value, otherwise @value is left untouched.
The bytes in @pattern and @mask are interpreted left-to-right, regardless
of endianness. All four bytes of the pattern must be present in the
adapter for it to match, even if the first or last bytes are masked out.
It is an error to call this function without making sure that there is
enough data (offset+size bytes) in the adapter.</doc>
<return-value transfer-ownership="none">
<doc xml:space="preserve">offset of the first match, or -1 if no match was found.</doc>
<type name="gssize" c:type="gssize"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="mask" transfer-ownership="none">
<doc xml:space="preserve">mask to apply to data before matching against @pattern</doc>
<type name="guint32" c:type="guint32"/>
</parameter>
<parameter name="pattern" transfer-ownership="none">
<doc xml:space="preserve">pattern to match (after mask is applied)</doc>
<type name="guint32" c:type="guint32"/>
</parameter>
<parameter name="offset" transfer-ownership="none">
<doc xml:space="preserve">offset into the adapter data from which to start scanning, returns
the last scanned position.</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
<parameter name="size" transfer-ownership="none">
<doc xml:space="preserve">number of bytes to scan from offset</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
<parameter name="value" direction="out" caller-allocates="0" transfer-ownership="full" optional="1" allow-none="1">
<doc xml:space="preserve">pointer to uint32 to return matching data</doc>
<type name="guint32" c:type="guint32*"/>
</parameter>
</parameters>
</method>
<method name="offset_at_discont" c:identifier="gst_adapter_offset_at_discont" version="1.10">
<doc xml:space="preserve">Get the offset that was on the last buffer with the GST_BUFFER_FLAG_DISCONT
flag, or GST_BUFFER_OFFSET_NONE.</doc>
<return-value transfer-ownership="none">
<doc xml:space="preserve">The offset at the last discont or GST_BUFFER_OFFSET_NONE.</doc>
<type name="guint64" c:type="guint64"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
</parameters>
</method>
<method name="prev_dts" c:identifier="gst_adapter_prev_dts">
<doc xml:space="preserve">Get the dts that was before the current byte in the adapter. When
@distance is given, the amount of bytes between the dts and the current
position is returned.
The dts is reset to GST_CLOCK_TIME_NONE and the distance is set to 0 when
the adapter is first created or when it is cleared. This also means that before
the first byte with a dts is removed from the adapter, the dts
and distance returned are GST_CLOCK_TIME_NONE and 0 respectively.</doc>
<return-value transfer-ownership="none">
<doc xml:space="preserve">The previously seen dts.</doc>
<type name="Gst.ClockTime" c:type="GstClockTime"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="distance" direction="out" caller-allocates="0" transfer-ownership="full" optional="1" allow-none="1">
<doc xml:space="preserve">pointer to location for distance, or %NULL</doc>
<type name="guint64" c:type="guint64*"/>
</parameter>
</parameters>
</method>
<method name="prev_dts_at_offset" c:identifier="gst_adapter_prev_dts_at_offset" version="1.2">
<doc xml:space="preserve">Get the dts that was before the byte at offset @offset in the adapter. When
@distance is given, the amount of bytes between the dts and the current
position is returned.
The dts is reset to GST_CLOCK_TIME_NONE and the distance is set to 0 when
the adapter is first created or when it is cleared. This also means that before
the first byte with a dts is removed from the adapter, the dts
and distance returned are GST_CLOCK_TIME_NONE and 0 respectively.</doc>
<return-value transfer-ownership="none">
<doc xml:space="preserve">The previously seen dts at given offset.</doc>
<type name="Gst.ClockTime" c:type="GstClockTime"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="offset" transfer-ownership="none">
<doc xml:space="preserve">the offset in the adapter at which to get timestamp</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
<parameter name="distance" direction="out" caller-allocates="0" transfer-ownership="full" optional="1" allow-none="1">
<doc xml:space="preserve">pointer to location for distance, or %NULL</doc>
<type name="guint64" c:type="guint64*"/>
</parameter>
</parameters>
</method>
<method name="prev_offset" c:identifier="gst_adapter_prev_offset" version="1.10">
<doc xml:space="preserve">Get the offset that was before the current byte in the adapter. When
@distance is given, the amount of bytes between the offset and the current
position is returned.
The offset is reset to GST_BUFFER_OFFSET_NONE and the distance is set to 0
when the adapter is first created or when it is cleared. This also means that
before the first byte with an offset is removed from the adapter, the offset
and distance returned are GST_BUFFER_OFFSET_NONE and 0 respectively.</doc>
<return-value transfer-ownership="none">
<doc xml:space="preserve">The previous seen offset.</doc>
<type name="guint64" c:type="guint64"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="distance" direction="out" caller-allocates="0" transfer-ownership="full" optional="1" allow-none="1">
<doc xml:space="preserve">pointer to a location for distance, or %NULL</doc>
<type name="guint64" c:type="guint64*"/>
</parameter>
</parameters>
</method>
<method name="prev_pts" c:identifier="gst_adapter_prev_pts">
<doc xml:space="preserve">Get the pts that was before the current byte in the adapter. When
@distance is given, the amount of bytes between the pts and the current
position is returned.
The pts is reset to GST_CLOCK_TIME_NONE and the distance is set to 0 when
the adapter is first created or when it is cleared. This also means that before
the first byte with a pts is removed from the adapter, the pts
and distance returned are GST_CLOCK_TIME_NONE and 0 respectively.</doc>
<return-value transfer-ownership="none">
<doc xml:space="preserve">The previously seen pts.</doc>
<type name="Gst.ClockTime" c:type="GstClockTime"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="distance" direction="out" caller-allocates="0" transfer-ownership="full" optional="1" allow-none="1">
<doc xml:space="preserve">pointer to location for distance, or %NULL</doc>
<type name="guint64" c:type="guint64*"/>
</parameter>
</parameters>
</method>
<method name="prev_pts_at_offset" c:identifier="gst_adapter_prev_pts_at_offset" version="1.2">
<doc xml:space="preserve">Get the pts that was before the byte at offset @offset in the adapter. When
@distance is given, the amount of bytes between the pts and the current
position is returned.
The pts is reset to GST_CLOCK_TIME_NONE and the distance is set to 0 when
the adapter is first created or when it is cleared. This also means that before
the first byte with a pts is removed from the adapter, the pts
and distance returned are GST_CLOCK_TIME_NONE and 0 respectively.</doc>
<return-value transfer-ownership="none">
<doc xml:space="preserve">The previously seen pts at given offset.</doc>
<type name="Gst.ClockTime" c:type="GstClockTime"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="offset" transfer-ownership="none">
<doc xml:space="preserve">the offset in the adapter at which to get timestamp</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
<parameter name="distance" direction="out" caller-allocates="0" transfer-ownership="full" optional="1" allow-none="1">
<doc xml:space="preserve">pointer to location for distance, or %NULL</doc>
<type name="guint64" c:type="guint64*"/>
</parameter>
</parameters>
</method>
<method name="pts_at_discont" c:identifier="gst_adapter_pts_at_discont" version="1.10">
<doc xml:space="preserve">Get the PTS that was on the last buffer with the GST_BUFFER_FLAG_DISCONT
flag, or GST_CLOCK_TIME_NONE.</doc>
<return-value transfer-ownership="none">
<doc xml:space="preserve">The PTS at the last discont or GST_CLOCK_TIME_NONE.</doc>
<type name="Gst.ClockTime" c:type="GstClockTime"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
</parameters>
</method>
<method name="push" c:identifier="gst_adapter_push">
<doc xml:space="preserve">Adds the data from @buf to the data stored inside @adapter and takes
ownership of the buffer.</doc>
<return-value transfer-ownership="none">
<type name="none" c:type="void"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="buf" transfer-ownership="full">
<doc xml:space="preserve">a #GstBuffer to add to queue in the adapter</doc>
<type name="Gst.Buffer" c:type="GstBuffer*"/>
</parameter>
</parameters>
</method>
<method name="take" c:identifier="gst_adapter_take">
<doc xml:space="preserve">Returns a freshly allocated buffer containing the first @nbytes bytes of the
@adapter. The returned bytes will be flushed from the adapter.
Caller owns returned value. g_free after usage.
Free-function: g_free</doc>
<return-value transfer-ownership="full" nullable="1">
<doc xml:space="preserve">
oven-fresh hot data, or %NULL if @nbytes bytes are not available</doc>
<array length="0" zero-terminated="0" c:type="gpointer">
<type name="guint8"/>
</array>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="nbytes" direction="out" caller-allocates="0" transfer-ownership="full">
<doc xml:space="preserve">the number of bytes to take</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
</parameters>
</method>
<method name="take_buffer" c:identifier="gst_adapter_take_buffer">
<doc xml:space="preserve">Returns a #GstBuffer containing the first @nbytes bytes of the
@adapter. The returned bytes will be flushed from the adapter.
This function is potentially more performant than
gst_adapter_take() since it can reuse the memory in pushed buffers
by subbuffering or merging. This function will always return a
buffer with a single memory region.
Note that no assumptions should be made as to whether certain buffer
flags such as the DISCONT flag are set on the returned buffer, or not.
The caller needs to explicitly set or unset flags that should be set or
unset.
Since 1.6 this will also copy over all GstMeta of the input buffers except
for meta with the %GST_META_FLAG_POOLED flag or with the "memory" tag.
Caller owns a reference to the returned buffer. gst_buffer_unref() after
usage.
Free-function: gst_buffer_unref</doc>
<return-value transfer-ownership="full" nullable="1">
<doc xml:space="preserve">a #GstBuffer containing the first
@nbytes of the adapter, or %NULL if @nbytes bytes are not available.
gst_buffer_unref() when no longer needed.</doc>
<type name="Gst.Buffer" c:type="GstBuffer*"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="nbytes" transfer-ownership="none">
<doc xml:space="preserve">the number of bytes to take</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
</parameters>
</method>
<method name="take_buffer_fast" c:identifier="gst_adapter_take_buffer_fast" version="1.2">
<doc xml:space="preserve">Returns a #GstBuffer containing the first @nbytes of the @adapter.
The returned bytes will be flushed from the adapter. This function
is potentially more performant than gst_adapter_take_buffer() since
it can reuse the memory in pushed buffers by subbuffering or
merging. Unlike gst_adapter_take_buffer(), the returned buffer may
be composed of multiple non-contiguous #GstMemory objects, no
copies are made.
Note that no assumptions should be made as to whether certain buffer
flags such as the DISCONT flag are set on the returned buffer, or not.
The caller needs to explicitly set or unset flags that should be set or
unset.
This will also copy over all GstMeta of the input buffers except
for meta with the %GST_META_FLAG_POOLED flag or with the "memory" tag.
This function can return buffer up to the return value of
gst_adapter_available() without making copies if possible.
Caller owns a reference to the returned buffer. gst_buffer_unref() after
usage.
Free-function: gst_buffer_unref</doc>
<return-value transfer-ownership="full" nullable="1">
<doc xml:space="preserve">a #GstBuffer containing the first
@nbytes of the adapter, or %NULL if @nbytes bytes are not available.
gst_buffer_unref() when no longer needed.</doc>
<type name="Gst.Buffer" c:type="GstBuffer*"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="nbytes" transfer-ownership="none">
<doc xml:space="preserve">the number of bytes to take</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
</parameters>
</method>
<method name="take_buffer_list" c:identifier="gst_adapter_take_buffer_list" version="1.6">
<doc xml:space="preserve">Returns a #GstBufferList of buffers containing the first @nbytes bytes of
the @adapter. The returned bytes will be flushed from the adapter.
When the caller can deal with individual buffers, this function is more
performant because no memory should be copied.
Caller owns the returned list. Call gst_buffer_list_unref() to free
the list after usage.</doc>
<return-value transfer-ownership="full" nullable="1">
<doc xml:space="preserve">a #GstBufferList of buffers containing
the first @nbytes of the adapter, or %NULL if @nbytes bytes are not
available</doc>
<type name="Gst.BufferList" c:type="GstBufferList*"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="nbytes" transfer-ownership="none">
<doc xml:space="preserve">the number of bytes to take</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
</parameters>
</method>
<method name="take_list" c:identifier="gst_adapter_take_list">
<doc xml:space="preserve">Returns a #GList of buffers containing the first @nbytes bytes of the
@adapter. The returned bytes will be flushed from the adapter.
When the caller can deal with individual buffers, this function is more
performant because no memory should be copied.
Caller owns returned list and contained buffers. gst_buffer_unref() each
buffer in the list before freeing the list after usage.</doc>
<return-value transfer-ownership="full" nullable="1">
<doc xml:space="preserve">a #GList of
buffers containing the first @nbytes of the adapter, or %NULL if @nbytes
bytes are not available</doc>
<type name="GLib.List" c:type="GList*">
<type name="Gst.Buffer"/>
</type>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
<parameter name="nbytes" transfer-ownership="none">
<doc xml:space="preserve">the number of bytes to take</doc>
<type name="gsize" c:type="gsize"/>
</parameter>
</parameters>
</method>
<method name="unmap" c:identifier="gst_adapter_unmap">
<doc xml:space="preserve">Releases the memory obtained with the last gst_adapter_map().</doc>
<return-value transfer-ownership="none">
<type name="none" c:type="void"/>
</return-value>
<parameters>
<instance-parameter name="adapter" transfer-ownership="none">
<doc xml:space="preserve">a #GstAdapter</doc>
<type name="Adapter" c:type="GstAdapter*"/>
</instance-parameter>
</parameters>
</method>
</class>
<record name="AdapterClass" c:type="GstAdapterClass" disguised="1" opaque="1" glib:is-gtype-struct-for="Adapter"/>
<class name="Aggregator" c:symbol-prefix="aggregator" c:type="GstAggregator" version="1.14" parent="Gst.Element" abstract="1" glib:type-name="GstAggregator" glib:get-type="gst_aggregator_get_type" glib:type-struct="AggregatorClass">
<doc xml:space="preserve">Manages a set of pads with the purpose of aggregating their buffers.
Control is given to the subclass when all pads have data.
* Base class for mixers and muxers. Subclasses should at least implement
the #GstAggregatorClass::aggregate virtual method.
* Installs a #GstPadChainFunction, a #GstPadEventFullFunction and a
#GstPadQueryFunction to queue all serialized data packets per sink pad.
Subclasses should not overwrite those, but instead implement
#GstAggregatorClass::sink_event and #GstAggregatorClass::sink_query as
needed.
* When data is queued on all pads, the aggregate vmethod is called.
* One can peek at the data on any given GstAggregatorPad with the
gst_aggregator_pad_peek_buffer() method, and remove it from the pad
with the gst_aggregator_pad_pop_buffer () method. When a buffer
has been taken with pop_buffer (), a new buffer can be queued
on that pad.
* When gst_aggregator_pad_peek_buffer() or gst_aggregator_pad_has_buffer()
are called, a reference is taken to the returned buffer, which stays
valid until either:
- gst_aggregator_pad_pop_buffer() is called, in which case the caller
is guaranteed that the buffer they receive is the same as the peeked
buffer.
- gst_aggregator_pad_drop_buffer() is called, in which case the caller
is guaranteed that the dropped buffer is the one that was peeked.
- the subclass implementation of #GstAggregatorClass.aggregate returns.
Subsequent calls to gst_aggregator_pad_peek_buffer() or
gst_aggregator_pad_has_buffer() return / check the same buffer that was
returned / checked, until one of the conditions listed above is met.
Subclasses are only allowed to call these methods from the aggregate
thread.
* If the subclass wishes to push a buffer downstream in its aggregate
implementation, it should do so through the
gst_aggregator_finish_buffer() method. This method will take care
of sending and ordering mandatory events such as stream start, caps
and segment. Buffer lists can also be pushed out with
gst_aggregator_finish_buffer_list().
* Same goes for EOS events, which should not be pushed directly by the
subclass, it should instead return GST_FLOW_EOS in its aggregate
implementation.
* Note that the aggregator logic regarding gap event handling is to turn
these into gap buffers with matching PTS and duration. It will also
flag these buffers with GST_BUFFER_FLAG_GAP and GST_BUFFER_FLAG_DROPPABLE
to ease their identification and subsequent processing.
In addition, if the gap event was flagged with GST_GAP_FLAG_MISSING_DATA,
a custom meta is added to the resulting gap buffer (GstAggregatorMissingDataMeta).
* Subclasses must use (a subclass of) #GstAggregatorPad for both their
sink and source pads.
See gst_element_class_add_static_pad_template_with_gtype().
This class used to live in gst-plugins-bad and was moved to core.</doc>
<virtual-method name="aggregate">
<return-value transfer-ownership="none">
<type name="Gst.FlowReturn" c:type="GstFlowReturn"/>
</return-value>
<parameters>
<instance-parameter name="aggregator" transfer-ownership="none">
<type name="Aggregator" c:type="GstAggregator*"/>
</instance-parameter>
<parameter name="timeout" transfer-ownership="none">
<type name="gboolean" c:type="gboolean"/>
</parameter>
</parameters>
</virtual-method>
<virtual-method name="clip">
<return-value transfer-ownership="full">