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1304 lines
40 KiB
C
1304 lines
40 KiB
C
/* GStreamer
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* Copyright (C) 2004 Benjamin Otte <otte@gnome.org>
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* 2005 Wim Taymans <wim@fluendo.com>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
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* Boston, MA 02110-1301, USA.
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*/
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/**
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* SECTION:gstadapter
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* @short_description: adapts incoming data on a sink pad into chunks of N bytes
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*
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* This class is for elements that receive buffers in an undesired size.
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* While for example raw video contains one image per buffer, the same is not
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* true for a lot of other formats, especially those that come directly from
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* a file. So if you have undefined buffer sizes and require a specific size,
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* this object is for you.
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*
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* An adapter is created with gst_adapter_new(). It can be freed again with
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* g_object_unref().
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*
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* The theory of operation is like this: All buffers received are put
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* into the adapter using gst_adapter_push() and the data is then read back
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* in chunks of the desired size using gst_adapter_map()/gst_adapter_unmap()
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* and/or gst_adapter_copy(). After the data has been processed, it is freed
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* using gst_adapter_unmap().
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*
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* Other methods such as gst_adapter_take() and gst_adapter_take_buffer()
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* combine gst_adapter_map() and gst_adapter_unmap() in one method and are
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* potentially more convenient for some use cases.
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*
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* For example, a sink pad's chain function that needs to pass data to a library
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* in 512-byte chunks could be implemented like this:
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* |[
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* static GstFlowReturn
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* sink_pad_chain (GstPad *pad, GstObject *parent, GstBuffer *buffer)
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* {
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* MyElement *this;
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* GstAdapter *adapter;
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* GstFlowReturn ret = GST_FLOW_OK;
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*
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* this = MY_ELEMENT (parent);
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*
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* adapter = this->adapter;
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*
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* // put buffer into adapter
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* gst_adapter_push (adapter, buffer);
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*
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* // while we can read out 512 bytes, process them
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* while (gst_adapter_available (adapter) >= 512 && ret == GST_FLOW_OK) {
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* const guint8 *data = gst_adapter_map (adapter, 512);
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* // use flowreturn as an error value
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* ret = my_library_foo (data);
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* gst_adapter_unmap (adapter);
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* gst_adapter_flush (adapter, 512);
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* }
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* return ret;
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* }
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* ]|
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*
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* For another example, a simple element inside GStreamer that uses GstAdapter
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* is the libvisual element.
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*
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* An element using GstAdapter in its sink pad chain function should ensure that
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* when the FLUSH_STOP event is received, that any queued data is cleared using
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* gst_adapter_clear(). Data should also be cleared or processed on EOS and
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* when changing state from #GST_STATE_PAUSED to #GST_STATE_READY.
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*
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* Also check the GST_BUFFER_FLAG_DISCONT flag on the buffer. Some elements might
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* need to clear the adapter after a discontinuity.
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*
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* The adapter will keep track of the timestamps of the buffers
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* that were pushed. The last seen timestamp before the current position
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* can be queried with gst_adapter_prev_pts(). This function can
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* optionally return the number of bytes between the start of the buffer that
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* carried the timestamp and the current adapter position. The distance is
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* useful when dealing with, for example, raw audio samples because it allows
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* you to calculate the timestamp of the current adapter position by using the
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* last seen timestamp and the amount of bytes since. Additionally, the
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* gst_adapter_prev_pts_at_offset() can be used to determine the last
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* seen timestamp at a particular offset in the adapter.
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*
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* A last thing to note is that while GstAdapter is pretty optimized,
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* merging buffers still might be an operation that requires a malloc() and
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* memcpy() operation, and these operations are not the fastest. Because of
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* this, some functions like gst_adapter_available_fast() are provided to help
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* speed up such cases should you want to. To avoid repeated memory allocations,
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* gst_adapter_copy() can be used to copy data into a (statically allocated)
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* user provided buffer.
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*
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* GstAdapter is not MT safe. All operations on an adapter must be serialized by
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* the caller. This is not normally a problem, however, as the normal use case
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* of GstAdapter is inside one pad's chain function, in which case access is
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* serialized via the pad's STREAM_LOCK.
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*
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* Note that gst_adapter_push() takes ownership of the buffer passed. Use
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* gst_buffer_ref() before pushing it into the adapter if you still want to
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* access the buffer later. The adapter will never modify the data in the
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* buffer pushed in it.
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*
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* Last reviewed on 2009-05-13 (0.10.24).
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*/
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#include <gst/gst_private.h>
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#include "gstadapter.h"
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#include <string.h>
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/* default size for the assembled data buffer */
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#define DEFAULT_SIZE 4096
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static void gst_adapter_flush_unchecked (GstAdapter * adapter, gsize flush);
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GST_DEBUG_CATEGORY_STATIC (gst_adapter_debug);
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#define GST_CAT_DEFAULT gst_adapter_debug
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struct _GstAdapter
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{
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GObject object;
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/*< private > */
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GSList *buflist;
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GSList *buflist_end;
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gsize size;
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gsize skip;
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/* we keep state of assembled pieces */
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gpointer assembled_data;
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gsize assembled_size;
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gsize assembled_len;
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GstClockTime pts;
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guint64 pts_distance;
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GstClockTime dts;
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guint64 dts_distance;
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gsize scan_offset;
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GSList *scan_entry;
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GstMapInfo info;
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};
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struct _GstAdapterClass
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{
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GObjectClass parent_class;
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};
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#define _do_init \
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GST_DEBUG_CATEGORY_INIT (gst_adapter_debug, "adapter", 0, "object to splice and merge buffers to desired size")
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#define gst_adapter_parent_class parent_class
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G_DEFINE_TYPE_WITH_CODE (GstAdapter, gst_adapter, G_TYPE_OBJECT, _do_init);
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static void gst_adapter_dispose (GObject * object);
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static void gst_adapter_finalize (GObject * object);
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static void
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gst_adapter_class_init (GstAdapterClass * klass)
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{
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GObjectClass *object = G_OBJECT_CLASS (klass);
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object->dispose = gst_adapter_dispose;
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object->finalize = gst_adapter_finalize;
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}
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static void
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gst_adapter_init (GstAdapter * adapter)
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{
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adapter->assembled_data = g_malloc (DEFAULT_SIZE);
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adapter->assembled_size = DEFAULT_SIZE;
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adapter->pts = GST_CLOCK_TIME_NONE;
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adapter->pts_distance = 0;
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adapter->dts = GST_CLOCK_TIME_NONE;
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adapter->dts_distance = 0;
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}
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static void
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gst_adapter_dispose (GObject * object)
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{
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GstAdapter *adapter = GST_ADAPTER (object);
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gst_adapter_clear (adapter);
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GST_CALL_PARENT (G_OBJECT_CLASS, dispose, (object));
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}
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static void
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gst_adapter_finalize (GObject * object)
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{
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GstAdapter *adapter = GST_ADAPTER (object);
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g_free (adapter->assembled_data);
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GST_CALL_PARENT (G_OBJECT_CLASS, finalize, (object));
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}
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/**
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* gst_adapter_new:
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*
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* Creates a new #GstAdapter. Free with g_object_unref().
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*
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* Returns: (transfer full): a new #GstAdapter
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*/
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GstAdapter *
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gst_adapter_new (void)
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{
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return g_object_newv (GST_TYPE_ADAPTER, 0, NULL);
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}
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/**
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* gst_adapter_clear:
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* @adapter: a #GstAdapter
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*
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* Removes all buffers from @adapter.
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*/
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void
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gst_adapter_clear (GstAdapter * adapter)
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{
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g_return_if_fail (GST_IS_ADAPTER (adapter));
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if (adapter->info.memory)
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gst_adapter_unmap (adapter);
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g_slist_foreach (adapter->buflist, (GFunc) gst_mini_object_unref, NULL);
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g_slist_free (adapter->buflist);
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adapter->buflist = NULL;
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adapter->buflist_end = NULL;
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adapter->size = 0;
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adapter->skip = 0;
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adapter->assembled_len = 0;
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adapter->pts = GST_CLOCK_TIME_NONE;
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adapter->pts_distance = 0;
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adapter->dts = GST_CLOCK_TIME_NONE;
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adapter->dts_distance = 0;
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adapter->scan_offset = 0;
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adapter->scan_entry = NULL;
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}
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static inline void
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update_timestamps (GstAdapter * adapter, GstBuffer * buf)
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{
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GstClockTime pts, dts;
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pts = GST_BUFFER_PTS (buf);
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if (GST_CLOCK_TIME_IS_VALID (pts)) {
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GST_LOG_OBJECT (adapter, "new pts %" GST_TIME_FORMAT, GST_TIME_ARGS (pts));
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adapter->pts = pts;
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adapter->pts_distance = 0;
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}
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dts = GST_BUFFER_DTS (buf);
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if (GST_CLOCK_TIME_IS_VALID (dts)) {
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GST_LOG_OBJECT (adapter, "new dts %" GST_TIME_FORMAT, GST_TIME_ARGS (dts));
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adapter->dts = dts;
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adapter->dts_distance = 0;
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}
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}
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/* copy data into @dest, skipping @skip bytes from the head buffers */
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static void
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copy_into_unchecked (GstAdapter * adapter, guint8 * dest, gsize skip,
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gsize size)
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{
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GSList *g;
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GstBuffer *buf;
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gsize bsize, csize;
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/* first step, do skipping */
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/* we might well be copying where we were scanning */
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if (adapter->scan_entry && (adapter->scan_offset <= skip)) {
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g = adapter->scan_entry;
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skip -= adapter->scan_offset;
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} else {
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g = adapter->buflist;
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}
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buf = g->data;
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bsize = gst_buffer_get_size (buf);
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while (G_UNLIKELY (skip >= bsize)) {
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skip -= bsize;
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g = g_slist_next (g);
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buf = g->data;
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bsize = gst_buffer_get_size (buf);
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}
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/* copy partial buffer */
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csize = MIN (bsize - skip, size);
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GST_DEBUG ("bsize %" G_GSIZE_FORMAT ", skip %" G_GSIZE_FORMAT ", csize %"
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G_GSIZE_FORMAT, bsize, skip, csize);
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GST_CAT_LOG_OBJECT (GST_CAT_PERFORMANCE, adapter, "extract %" G_GSIZE_FORMAT
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" bytes", csize);
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gst_buffer_extract (buf, skip, dest, csize);
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size -= csize;
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dest += csize;
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/* second step, copy remainder */
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while (size > 0) {
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g = g_slist_next (g);
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buf = g->data;
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bsize = gst_buffer_get_size (buf);
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if (G_LIKELY (bsize > 0)) {
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csize = MIN (bsize, size);
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GST_CAT_LOG_OBJECT (GST_CAT_PERFORMANCE, adapter,
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"extract %" G_GSIZE_FORMAT " bytes", csize);
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gst_buffer_extract (buf, 0, dest, csize);
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size -= csize;
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dest += csize;
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}
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}
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}
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/**
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* gst_adapter_push:
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* @adapter: a #GstAdapter
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* @buf: (transfer full): a #GstBuffer to add to queue in the adapter
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*
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* Adds the data from @buf to the data stored inside @adapter and takes
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* ownership of the buffer.
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*/
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void
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gst_adapter_push (GstAdapter * adapter, GstBuffer * buf)
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{
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gsize size;
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g_return_if_fail (GST_IS_ADAPTER (adapter));
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g_return_if_fail (GST_IS_BUFFER (buf));
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size = gst_buffer_get_size (buf);
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adapter->size += size;
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/* Note: merging buffers at this point is premature. */
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if (G_UNLIKELY (adapter->buflist == NULL)) {
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GST_LOG_OBJECT (adapter, "pushing %p first %" G_GSIZE_FORMAT " bytes",
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buf, size);
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adapter->buflist = adapter->buflist_end = g_slist_append (NULL, buf);
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update_timestamps (adapter, buf);
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} else {
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/* Otherwise append to the end, and advance our end pointer */
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GST_LOG_OBJECT (adapter, "pushing %p %" G_GSIZE_FORMAT " bytes at end, "
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"size now %" G_GSIZE_FORMAT, buf, size, adapter->size);
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adapter->buflist_end = g_slist_append (adapter->buflist_end, buf);
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adapter->buflist_end = g_slist_next (adapter->buflist_end);
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}
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}
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#if 0
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/* Internal method only. Tries to merge buffers at the head of the queue
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* to form a single larger buffer of size 'size'.
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*
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* Returns TRUE if it managed to merge anything.
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*/
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static gboolean
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gst_adapter_try_to_merge_up (GstAdapter * adapter, gsize size)
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{
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GstBuffer *cur, *head;
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GSList *g;
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gboolean ret = FALSE;
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gsize hsize;
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g = adapter->buflist;
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if (g == NULL)
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return FALSE;
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head = g->data;
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hsize = gst_buffer_get_size (head);
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/* Remove skipped part from the buffer (otherwise the buffer might grow indefinitely) */
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head = gst_buffer_make_writable (head);
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gst_buffer_resize (head, adapter->skip, hsize - adapter->skip);
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hsize -= adapter->skip;
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adapter->skip = 0;
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g->data = head;
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g = g_slist_next (g);
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while (g != NULL && hsize < size) {
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cur = g->data;
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/* Merge the head buffer and the next in line */
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GST_LOG_OBJECT (adapter, "Merging buffers of size %" G_GSIZE_FORMAT " & %"
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G_GSIZE_FORMAT " in search of target %" G_GSIZE_FORMAT,
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hsize, gst_buffer_get_size (cur), size);
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head = gst_buffer_append (head, cur);
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hsize = gst_buffer_get_size (head);
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ret = TRUE;
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/* Delete the front list item, and store our new buffer in the 2nd list
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* item */
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adapter->buflist = g_slist_delete_link (adapter->buflist, adapter->buflist);
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g->data = head;
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/* invalidate scan position */
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adapter->scan_offset = 0;
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adapter->scan_entry = NULL;
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g = g_slist_next (g);
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}
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return ret;
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}
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#endif
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/**
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* gst_adapter_map:
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* @adapter: a #GstAdapter
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* @size: the number of bytes to map/peek
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*
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* Gets the first @size bytes stored in the @adapter. The returned pointer is
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* valid until the next function is called on the adapter.
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*
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* Note that setting the returned pointer as the data of a #GstBuffer is
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* incorrect for general-purpose plugins. The reason is that if a downstream
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* element stores the buffer so that it has access to it outside of the bounds
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* of its chain function, the buffer will have an invalid data pointer after
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* your element flushes the bytes. In that case you should use
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* gst_adapter_take(), which returns a freshly-allocated buffer that you can set
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* as #GstBuffer memory or the potentially more performant
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* gst_adapter_take_buffer().
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*
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* Returns #NULL if @size bytes are not available.
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*
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* Returns: (transfer none) (array length=size) (element-type guint8):
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* a pointer to the first @size bytes of data, or NULL
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*/
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gconstpointer
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gst_adapter_map (GstAdapter * adapter, gsize size)
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{
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GstBuffer *cur;
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gsize skip, csize;
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gsize toreuse, tocopy;
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guint8 *data;
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g_return_val_if_fail (GST_IS_ADAPTER (adapter), NULL);
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g_return_val_if_fail (size > 0, NULL);
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if (adapter->info.memory)
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gst_adapter_unmap (adapter);
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/* we don't have enough data, return NULL. This is unlikely
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* as one usually does an _available() first instead of peeking a
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* random size. */
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if (G_UNLIKELY (size > adapter->size))
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return NULL;
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/* we have enough assembled data, return it */
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if (adapter->assembled_len >= size)
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return adapter->assembled_data;
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#if 0
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do {
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#endif
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cur = adapter->buflist->data;
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skip = adapter->skip;
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csize = gst_buffer_get_size (cur);
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if (csize >= size + skip) {
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if (!gst_buffer_map (cur, &adapter->info, GST_MAP_READ))
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return FALSE;
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return (guint8 *) adapter->info.data + skip;
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}
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/* We may be able to efficiently merge buffers in our pool to
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* gather a big enough chunk to return it from the head buffer directly */
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#if 0
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} while (gst_adapter_try_to_merge_up (adapter, size));
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#endif
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/* see how much data we can reuse from the assembled memory and how much
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* we need to copy */
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toreuse = adapter->assembled_len;
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tocopy = size - toreuse;
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/* Gonna need to copy stuff out */
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if (G_UNLIKELY (adapter->assembled_size < size)) {
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adapter->assembled_size = (size / DEFAULT_SIZE + 1) * DEFAULT_SIZE;
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GST_DEBUG_OBJECT (adapter, "resizing internal buffer to %" G_GSIZE_FORMAT,
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adapter->assembled_size);
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if (toreuse == 0) {
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GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "alloc new buffer");
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/* no g_realloc to avoid a memcpy that is not desired here since we are
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* not going to reuse any data here */
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g_free (adapter->assembled_data);
|
|
adapter->assembled_data = g_malloc (adapter->assembled_size);
|
|
} else {
|
|
/* we are going to reuse all data, realloc then */
|
|
GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "reusing %" G_GSIZE_FORMAT " bytes",
|
|
toreuse);
|
|
adapter->assembled_data =
|
|
g_realloc (adapter->assembled_data, adapter->assembled_size);
|
|
}
|
|
}
|
|
GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy remaining %" G_GSIZE_FORMAT
|
|
" bytes from adapter", tocopy);
|
|
data = adapter->assembled_data;
|
|
copy_into_unchecked (adapter, data + toreuse, skip + toreuse, tocopy);
|
|
adapter->assembled_len = size;
|
|
|
|
return adapter->assembled_data;
|
|
}
|
|
|
|
/**
|
|
* gst_adapter_unmap:
|
|
* @adapter: a #GstAdapter
|
|
*
|
|
* Releases the memory obtained with the last gst_adapter_map().
|
|
*/
|
|
void
|
|
gst_adapter_unmap (GstAdapter * adapter)
|
|
{
|
|
g_return_if_fail (GST_IS_ADAPTER (adapter));
|
|
|
|
if (adapter->info.memory) {
|
|
GstBuffer *cur = adapter->buflist->data;
|
|
GST_LOG_OBJECT (adapter, "unmap memory buffer %p", cur);
|
|
gst_buffer_unmap (cur, &adapter->info);
|
|
adapter->info.memory = NULL;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gst_adapter_copy:
|
|
* @adapter: a #GstAdapter
|
|
* @dest: (out caller-allocates) (array length=size) (element-type guint8):
|
|
* the memory to copy into
|
|
* @offset: the bytes offset in the adapter to start from
|
|
* @size: the number of bytes to copy
|
|
*
|
|
* 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.
|
|
*/
|
|
void
|
|
gst_adapter_copy (GstAdapter * adapter, gpointer dest, gsize offset, gsize size)
|
|
{
|
|
g_return_if_fail (GST_IS_ADAPTER (adapter));
|
|
g_return_if_fail (size > 0);
|
|
g_return_if_fail (offset + size <= adapter->size);
|
|
|
|
copy_into_unchecked (adapter, dest, offset + adapter->skip, size);
|
|
}
|
|
|
|
/*Flushes the first @flush bytes in the @adapter*/
|
|
static void
|
|
gst_adapter_flush_unchecked (GstAdapter * adapter, gsize flush)
|
|
{
|
|
GstBuffer *cur;
|
|
gsize size;
|
|
GSList *g;
|
|
|
|
GST_LOG_OBJECT (adapter, "flushing %" G_GSIZE_FORMAT " bytes", flush);
|
|
|
|
if (adapter->info.memory)
|
|
gst_adapter_unmap (adapter);
|
|
|
|
/* clear state */
|
|
adapter->size -= flush;
|
|
adapter->assembled_len = 0;
|
|
|
|
/* take skip into account */
|
|
flush += adapter->skip;
|
|
/* distance is always at least the amount of skipped bytes */
|
|
adapter->pts_distance -= adapter->skip;
|
|
adapter->dts_distance -= adapter->skip;
|
|
|
|
g = adapter->buflist;
|
|
cur = g->data;
|
|
size = gst_buffer_get_size (cur);
|
|
while (flush >= size) {
|
|
/* can skip whole buffer */
|
|
GST_LOG_OBJECT (adapter, "flushing out head buffer");
|
|
adapter->pts_distance += size;
|
|
adapter->dts_distance += size;
|
|
flush -= size;
|
|
|
|
gst_buffer_unref (cur);
|
|
g = g_slist_delete_link (g, g);
|
|
|
|
if (G_UNLIKELY (g == NULL)) {
|
|
GST_LOG_OBJECT (adapter, "adapter empty now");
|
|
adapter->buflist_end = NULL;
|
|
break;
|
|
}
|
|
/* there is a new head buffer, update the timestamps */
|
|
cur = g->data;
|
|
update_timestamps (adapter, cur);
|
|
size = gst_buffer_get_size (cur);
|
|
}
|
|
adapter->buflist = g;
|
|
/* account for the remaining bytes */
|
|
adapter->skip = flush;
|
|
adapter->pts_distance += flush;
|
|
adapter->dts_distance += flush;
|
|
/* invalidate scan position */
|
|
adapter->scan_offset = 0;
|
|
adapter->scan_entry = NULL;
|
|
}
|
|
|
|
/**
|
|
* gst_adapter_flush:
|
|
* @adapter: a #GstAdapter
|
|
* @flush: the number of bytes to flush
|
|
*
|
|
* 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()
|
|
*/
|
|
void
|
|
gst_adapter_flush (GstAdapter * adapter, gsize flush)
|
|
{
|
|
g_return_if_fail (GST_IS_ADAPTER (adapter));
|
|
g_return_if_fail (flush <= adapter->size);
|
|
|
|
/* flushing out 0 bytes will do nothing */
|
|
if (G_UNLIKELY (flush == 0))
|
|
return;
|
|
|
|
gst_adapter_flush_unchecked (adapter, flush);
|
|
}
|
|
|
|
/* internal function, nbytes should be flushed after calling this function */
|
|
static guint8 *
|
|
gst_adapter_take_internal (GstAdapter * adapter, gsize nbytes)
|
|
{
|
|
guint8 *data;
|
|
gsize toreuse, tocopy;
|
|
|
|
/* see how much data we can reuse from the assembled memory and how much
|
|
* we need to copy */
|
|
toreuse = MIN (nbytes, adapter->assembled_len);
|
|
tocopy = nbytes - toreuse;
|
|
|
|
/* find memory to return */
|
|
if (adapter->assembled_size >= nbytes && toreuse > 0) {
|
|
/* we reuse already allocated memory but only when we're going to reuse
|
|
* something from it because else we are worse than the malloc and copy
|
|
* case below */
|
|
GST_LOG_OBJECT (adapter, "reusing %" G_GSIZE_FORMAT " bytes of assembled"
|
|
" data", toreuse);
|
|
/* we have enough free space in the assembled array */
|
|
data = adapter->assembled_data;
|
|
/* flush after this function should set the assembled_size to 0 */
|
|
adapter->assembled_data = g_malloc (adapter->assembled_size);
|
|
} else {
|
|
GST_LOG_OBJECT (adapter, "allocating %" G_GSIZE_FORMAT " bytes", nbytes);
|
|
/* not enough bytes in the assembled array, just allocate new space */
|
|
data = g_malloc (nbytes);
|
|
/* reuse what we can from the already assembled data */
|
|
if (toreuse) {
|
|
GST_LOG_OBJECT (adapter, "reusing %" G_GSIZE_FORMAT " bytes", toreuse);
|
|
GST_CAT_LOG_OBJECT (GST_CAT_PERFORMANCE, adapter,
|
|
"memcpy %" G_GSIZE_FORMAT " bytes", toreuse);
|
|
memcpy (data, adapter->assembled_data, toreuse);
|
|
}
|
|
}
|
|
if (tocopy) {
|
|
/* copy the remaining data */
|
|
copy_into_unchecked (adapter, toreuse + data, toreuse + adapter->skip,
|
|
tocopy);
|
|
}
|
|
return data;
|
|
}
|
|
|
|
/**
|
|
* gst_adapter_take:
|
|
* @adapter: a #GstAdapter
|
|
* @nbytes: the number of bytes to take
|
|
*
|
|
* 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
|
|
*
|
|
* Returns: (transfer full) (array length=nbytes) (element-type guint8):
|
|
* oven-fresh hot data, or #NULL if @nbytes bytes are not available
|
|
*/
|
|
gpointer
|
|
gst_adapter_take (GstAdapter * adapter, gsize nbytes)
|
|
{
|
|
gpointer data;
|
|
|
|
g_return_val_if_fail (GST_IS_ADAPTER (adapter), NULL);
|
|
g_return_val_if_fail (nbytes > 0, NULL);
|
|
|
|
/* we don't have enough data, return NULL. This is unlikely
|
|
* as one usually does an _available() first instead of peeking a
|
|
* random size. */
|
|
if (G_UNLIKELY (nbytes > adapter->size))
|
|
return NULL;
|
|
|
|
data = gst_adapter_take_internal (adapter, nbytes);
|
|
|
|
gst_adapter_flush_unchecked (adapter, nbytes);
|
|
|
|
return data;
|
|
}
|
|
|
|
/**
|
|
* gst_adapter_take_buffer_fast:
|
|
* @adapter: a #GstAdapter
|
|
* @nbytes: the number of bytes to take
|
|
*
|
|
* 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 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
|
|
*
|
|
* Returns: (transfer full): a #GstBuffer containing the first @nbytes of
|
|
* the adapter, or #NULL if @nbytes bytes are not available.
|
|
* gst_buffer_unref() when no longer needed.
|
|
*
|
|
* Since: 1.2
|
|
*/
|
|
|
|
GstBuffer *
|
|
gst_adapter_take_buffer_fast (GstAdapter * adapter, gsize nbytes)
|
|
{
|
|
GstBuffer *buffer = NULL;
|
|
GstBuffer *cur;
|
|
GSList *item;
|
|
gsize skip;
|
|
gsize left = nbytes;
|
|
|
|
g_return_val_if_fail (GST_IS_ADAPTER (adapter), NULL);
|
|
g_return_val_if_fail (nbytes > 0, NULL);
|
|
|
|
GST_LOG_OBJECT (adapter, "taking buffer of %" G_GSIZE_FORMAT " bytes",
|
|
nbytes);
|
|
|
|
/* we don't have enough data, return NULL. This is unlikely
|
|
* as one usually does an _available() first instead of grabbing a
|
|
* random size. */
|
|
if (G_UNLIKELY (nbytes > adapter->size))
|
|
return NULL;
|
|
|
|
skip = adapter->skip;
|
|
cur = adapter->buflist->data;
|
|
|
|
if (skip == 0 && gst_buffer_get_size (cur) == nbytes) {
|
|
GST_LOG_OBJECT (adapter, "providing buffer of %" G_GSIZE_FORMAT " bytes"
|
|
" as head buffer", nbytes);
|
|
buffer = gst_buffer_ref (cur);
|
|
goto done;
|
|
}
|
|
|
|
for (item = adapter->buflist; item && left > 0; item = item->next) {
|
|
gsize size;
|
|
|
|
cur = item->data;
|
|
size = MIN (gst_buffer_get_size (cur) - skip, left);
|
|
|
|
GST_LOG_OBJECT (adapter, "appending %" G_GSIZE_FORMAT " bytes"
|
|
" via region copy", size);
|
|
if (buffer)
|
|
gst_buffer_copy_into (buffer, cur, GST_BUFFER_COPY_MEMORY, skip, size);
|
|
else
|
|
buffer = gst_buffer_copy_region (cur, GST_BUFFER_COPY_ALL, skip, size);
|
|
skip = 0;
|
|
left -= size;
|
|
}
|
|
|
|
done:
|
|
gst_adapter_flush_unchecked (adapter, nbytes);
|
|
|
|
return buffer;
|
|
}
|
|
|
|
/**
|
|
* gst_adapter_take_buffer:
|
|
* @adapter: a #GstAdapter
|
|
* @nbytes: the number of bytes to take
|
|
*
|
|
* 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.
|
|
*
|
|
* Caller owns a reference to the returned buffer. gst_buffer_unref() after
|
|
* usage.
|
|
*
|
|
* Free-function: gst_buffer_unref
|
|
*
|
|
* Returns: (transfer full): a #GstBuffer containing the first @nbytes of
|
|
* the adapter, or #NULL if @nbytes bytes are not available.
|
|
* gst_buffer_unref() when no longer needed.
|
|
*/
|
|
GstBuffer *
|
|
gst_adapter_take_buffer (GstAdapter * adapter, gsize nbytes)
|
|
{
|
|
GstBuffer *buffer;
|
|
GstBuffer *cur;
|
|
gsize hsize, skip;
|
|
guint8 *data;
|
|
|
|
g_return_val_if_fail (GST_IS_ADAPTER (adapter), NULL);
|
|
g_return_val_if_fail (nbytes > 0, NULL);
|
|
|
|
GST_LOG_OBJECT (adapter, "taking buffer of %" G_GSIZE_FORMAT " bytes",
|
|
nbytes);
|
|
|
|
/* we don't have enough data, return NULL. This is unlikely
|
|
* as one usually does an _available() first instead of grabbing a
|
|
* random size. */
|
|
if (G_UNLIKELY (nbytes > adapter->size))
|
|
return NULL;
|
|
|
|
cur = adapter->buflist->data;
|
|
skip = adapter->skip;
|
|
hsize = gst_buffer_get_size (cur);
|
|
|
|
/* our head buffer has enough data left, return it */
|
|
if (skip == 0 && hsize == nbytes) {
|
|
GST_LOG_OBJECT (adapter, "providing buffer of %" G_GSIZE_FORMAT " bytes"
|
|
" as head buffer", nbytes);
|
|
buffer = gst_buffer_ref (cur);
|
|
goto done;
|
|
} else if (hsize >= nbytes + skip) {
|
|
GST_LOG_OBJECT (adapter, "providing buffer of %" G_GSIZE_FORMAT " bytes"
|
|
" via region copy", nbytes);
|
|
buffer = gst_buffer_copy_region (cur, GST_BUFFER_COPY_ALL, skip, nbytes);
|
|
goto done;
|
|
}
|
|
#if 0
|
|
if (gst_adapter_try_to_merge_up (adapter, nbytes)) {
|
|
/* Merged something, let's try again for sub-buffering */
|
|
cur = adapter->buflist->data;
|
|
skip = adapter->skip;
|
|
if (gst_buffer_get_size (cur) >= nbytes + skip) {
|
|
GST_LOG_OBJECT (adapter, "providing buffer of %" G_GSIZE_FORMAT " bytes"
|
|
" via sub-buffer", nbytes);
|
|
buffer = gst_buffer_copy_region (cur, GST_BUFFER_COPY_ALL, skip, nbytes);
|
|
goto done;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
data = gst_adapter_take_internal (adapter, nbytes);
|
|
|
|
buffer = gst_buffer_new_wrapped (data, nbytes);
|
|
|
|
done:
|
|
gst_adapter_flush_unchecked (adapter, nbytes);
|
|
|
|
return buffer;
|
|
}
|
|
|
|
/**
|
|
* gst_adapter_take_list:
|
|
* @adapter: a #GstAdapter
|
|
* @nbytes: the number of bytes to take
|
|
*
|
|
* 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.
|
|
*
|
|
* Returns: (element-type Gst.Buffer) (transfer full): a #GList of buffers
|
|
* containing the first @nbytes of the adapter, or #NULL if @nbytes bytes
|
|
* are not available
|
|
*/
|
|
GList *
|
|
gst_adapter_take_list (GstAdapter * adapter, gsize nbytes)
|
|
{
|
|
GQueue queue = G_QUEUE_INIT;
|
|
GstBuffer *cur;
|
|
gsize hsize, skip;
|
|
|
|
g_return_val_if_fail (GST_IS_ADAPTER (adapter), NULL);
|
|
g_return_val_if_fail (nbytes <= adapter->size, NULL);
|
|
|
|
GST_LOG_OBJECT (adapter, "taking %" G_GSIZE_FORMAT " bytes", nbytes);
|
|
|
|
while (nbytes > 0) {
|
|
cur = adapter->buflist->data;
|
|
skip = adapter->skip;
|
|
hsize = MIN (nbytes, gst_buffer_get_size (cur) - skip);
|
|
|
|
cur = gst_adapter_take_buffer (adapter, hsize);
|
|
|
|
g_queue_push_tail (&queue, cur);
|
|
|
|
nbytes -= hsize;
|
|
}
|
|
return queue.head;
|
|
}
|
|
|
|
/**
|
|
* gst_adapter_available:
|
|
* @adapter: a #GstAdapter
|
|
*
|
|
* 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.
|
|
*
|
|
* Returns: number of bytes available in @adapter
|
|
*/
|
|
gsize
|
|
gst_adapter_available (GstAdapter * adapter)
|
|
{
|
|
g_return_val_if_fail (GST_IS_ADAPTER (adapter), 0);
|
|
|
|
return adapter->size;
|
|
}
|
|
|
|
/**
|
|
* gst_adapter_available_fast:
|
|
* @adapter: a #GstAdapter
|
|
*
|
|
* Gets the maximum number of bytes that are immediately available without
|
|
* requiring any expensive operations (like copying the data into a
|
|
* temporary buffer).
|
|
*
|
|
* Returns: number of bytes that are available in @adapter without expensive
|
|
* operations
|
|
*/
|
|
gsize
|
|
gst_adapter_available_fast (GstAdapter * adapter)
|
|
{
|
|
GstBuffer *cur;
|
|
gsize size;
|
|
GSList *g;
|
|
|
|
g_return_val_if_fail (GST_IS_ADAPTER (adapter), 0);
|
|
|
|
/* no data */
|
|
if (adapter->size == 0)
|
|
return 0;
|
|
|
|
/* some stuff we already assembled */
|
|
if (adapter->assembled_len)
|
|
return adapter->assembled_len;
|
|
|
|
/* take the first non-zero buffer */
|
|
g = adapter->buflist;
|
|
while (TRUE) {
|
|
cur = g->data;
|
|
size = gst_buffer_get_size (cur);
|
|
if (size != 0)
|
|
break;
|
|
g = g_slist_next (g);
|
|
}
|
|
|
|
/* we can quickly get the (remaining) data of the first buffer */
|
|
return size - adapter->skip;
|
|
}
|
|
|
|
/**
|
|
* gst_adapter_prev_pts:
|
|
* @adapter: a #GstAdapter
|
|
* @distance: (out) (allow-none): pointer to location for distance, or NULL
|
|
*
|
|
* 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.
|
|
*
|
|
* Returns: The previously seen pts.
|
|
*/
|
|
GstClockTime
|
|
gst_adapter_prev_pts (GstAdapter * adapter, guint64 * distance)
|
|
{
|
|
g_return_val_if_fail (GST_IS_ADAPTER (adapter), GST_CLOCK_TIME_NONE);
|
|
|
|
if (distance)
|
|
*distance = adapter->pts_distance;
|
|
|
|
return adapter->pts;
|
|
}
|
|
|
|
/**
|
|
* gst_adapter_prev_dts:
|
|
* @adapter: a #GstAdapter
|
|
* @distance: (out) (allow-none): pointer to location for distance, or NULL
|
|
*
|
|
* 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.
|
|
*
|
|
* Returns: The previously seen dts.
|
|
*/
|
|
GstClockTime
|
|
gst_adapter_prev_dts (GstAdapter * adapter, guint64 * distance)
|
|
{
|
|
g_return_val_if_fail (GST_IS_ADAPTER (adapter), GST_CLOCK_TIME_NONE);
|
|
|
|
if (distance)
|
|
*distance = adapter->dts_distance;
|
|
|
|
return adapter->dts;
|
|
}
|
|
|
|
/**
|
|
* gst_adapter_prev_pts_at_offset:
|
|
* @adapter: a #GstAdapter
|
|
* @offset: the offset in the adapter at which to get timestamp
|
|
* @distance: (out) (allow-none): pointer to location for distance, or NULL
|
|
*
|
|
* 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.
|
|
*
|
|
* Since: 1.2
|
|
* Returns: The previously seen pts at given offset.
|
|
*/
|
|
GstClockTime
|
|
gst_adapter_prev_pts_at_offset (GstAdapter * adapter, gsize offset,
|
|
guint64 * distance)
|
|
{
|
|
GstBuffer *cur;
|
|
GSList *g;
|
|
gsize read_offset = 0;
|
|
GstClockTime pts = adapter->pts;
|
|
|
|
g_return_val_if_fail (GST_IS_ADAPTER (adapter), GST_CLOCK_TIME_NONE);
|
|
g_return_val_if_fail (offset >= 0, GST_CLOCK_TIME_NONE);
|
|
|
|
g = adapter->buflist;
|
|
|
|
while (g && read_offset < offset + adapter->skip) {
|
|
cur = g->data;
|
|
|
|
read_offset += gst_buffer_get_size (cur);
|
|
if (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_PTS (cur))) {
|
|
pts = GST_BUFFER_PTS (cur);
|
|
}
|
|
|
|
g = g_slist_next (g);
|
|
}
|
|
|
|
if (distance)
|
|
*distance = adapter->dts_distance + offset;
|
|
|
|
return pts;
|
|
}
|
|
|
|
/**
|
|
* gst_adapter_prev_dts_at_offset:
|
|
* @adapter: a #GstAdapter
|
|
* @offset: the offset in the adapter at which to get timestamp
|
|
* @distance: (out) (allow-none): pointer to location for distance, or NULL
|
|
*
|
|
* 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.
|
|
*
|
|
* Since: 1.2
|
|
* Returns: The previously seen dts at given offset.
|
|
*/
|
|
GstClockTime
|
|
gst_adapter_prev_dts_at_offset (GstAdapter * adapter, gsize offset,
|
|
guint64 * distance)
|
|
{
|
|
GstBuffer *cur;
|
|
GSList *g;
|
|
gsize read_offset = 0;
|
|
GstClockTime dts = adapter->dts;
|
|
|
|
g_return_val_if_fail (GST_IS_ADAPTER (adapter), GST_CLOCK_TIME_NONE);
|
|
g_return_val_if_fail (offset >= 0, GST_CLOCK_TIME_NONE);
|
|
|
|
g = adapter->buflist;
|
|
|
|
while (g && read_offset < offset + adapter->skip) {
|
|
cur = g->data;
|
|
|
|
read_offset += gst_buffer_get_size (cur);
|
|
if (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_DTS (cur))) {
|
|
dts = GST_BUFFER_DTS (cur);
|
|
}
|
|
|
|
g = g_slist_next (g);
|
|
}
|
|
|
|
if (distance)
|
|
*distance = adapter->dts_distance + offset;
|
|
|
|
return dts;
|
|
}
|
|
|
|
/**
|
|
* gst_adapter_masked_scan_uint32_peek:
|
|
* @adapter: a #GstAdapter
|
|
* @mask: mask to apply to data before matching against @pattern
|
|
* @pattern: pattern to match (after mask is applied)
|
|
* @offset: offset into the adapter data from which to start scanning, returns
|
|
* the last scanned position.
|
|
* @size: number of bytes to scan from offset
|
|
* @value: pointer to uint32 to return matching data
|
|
*
|
|
* 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.
|
|
*
|
|
* Returns: offset of the first match, or -1 if no match was found.
|
|
*/
|
|
gssize
|
|
gst_adapter_masked_scan_uint32_peek (GstAdapter * adapter, guint32 mask,
|
|
guint32 pattern, gsize offset, gsize size, guint32 * value)
|
|
{
|
|
GSList *g;
|
|
gsize skip, bsize, i;
|
|
guint32 state;
|
|
GstMapInfo info;
|
|
guint8 *bdata;
|
|
GstBuffer *buf;
|
|
|
|
g_return_val_if_fail (size > 0, -1);
|
|
g_return_val_if_fail (offset + size <= adapter->size, -1);
|
|
g_return_val_if_fail (((~mask) & pattern) == 0, -1);
|
|
|
|
/* we can't find the pattern with less than 4 bytes */
|
|
if (G_UNLIKELY (size < 4))
|
|
return -1;
|
|
|
|
skip = offset + adapter->skip;
|
|
|
|
/* first step, do skipping and position on the first buffer */
|
|
/* optimistically assume scanning continues sequentially */
|
|
if (adapter->scan_entry && (adapter->scan_offset <= skip)) {
|
|
g = adapter->scan_entry;
|
|
skip -= adapter->scan_offset;
|
|
} else {
|
|
g = adapter->buflist;
|
|
adapter->scan_offset = 0;
|
|
adapter->scan_entry = NULL;
|
|
}
|
|
buf = g->data;
|
|
bsize = gst_buffer_get_size (buf);
|
|
while (G_UNLIKELY (skip >= bsize)) {
|
|
skip -= bsize;
|
|
g = g_slist_next (g);
|
|
adapter->scan_offset += bsize;
|
|
adapter->scan_entry = g;
|
|
buf = g->data;
|
|
bsize = gst_buffer_get_size (buf);
|
|
}
|
|
/* get the data now */
|
|
if (!gst_buffer_map (buf, &info, GST_MAP_READ))
|
|
return -1;
|
|
|
|
bdata = (guint8 *) info.data + skip;
|
|
bsize = info.size - skip;
|
|
skip = 0;
|
|
|
|
/* set the state to something that does not match */
|
|
state = ~pattern;
|
|
|
|
/* now find data */
|
|
do {
|
|
bsize = MIN (bsize, size);
|
|
for (i = 0; i < bsize; i++) {
|
|
state = ((state << 8) | bdata[i]);
|
|
if (G_UNLIKELY ((state & mask) == pattern)) {
|
|
/* we have a match but we need to have skipped at
|
|
* least 4 bytes to fill the state. */
|
|
if (G_LIKELY (skip + i >= 3)) {
|
|
if (G_LIKELY (value))
|
|
*value = state;
|
|
gst_buffer_unmap (buf, &info);
|
|
return offset + skip + i - 3;
|
|
}
|
|
}
|
|
}
|
|
size -= bsize;
|
|
if (size == 0)
|
|
break;
|
|
|
|
/* nothing found yet, go to next buffer */
|
|
skip += bsize;
|
|
g = g_slist_next (g);
|
|
adapter->scan_offset += info.size;
|
|
adapter->scan_entry = g;
|
|
gst_buffer_unmap (buf, &info);
|
|
buf = g->data;
|
|
|
|
if (!gst_buffer_map (buf, &info, GST_MAP_READ))
|
|
return -1;
|
|
|
|
bsize = info.size;
|
|
bdata = info.data;
|
|
} while (TRUE);
|
|
|
|
gst_buffer_unmap (buf, &info);
|
|
|
|
/* nothing found */
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* gst_adapter_masked_scan_uint32:
|
|
* @adapter: a #GstAdapter
|
|
* @mask: mask to apply to data before matching against @pattern
|
|
* @pattern: pattern to match (after mask is applied)
|
|
* @offset: offset into the adapter data from which to start scanning, returns
|
|
* the last scanned position.
|
|
* @size: number of bytes to scan from offset
|
|
*
|
|
* 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.
|
|
*
|
|
* Returns: offset of the first match, or -1 if no match was found.
|
|
*
|
|
* Example:
|
|
* <programlisting>
|
|
* // 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
|
|
* </programlisting>
|
|
*/
|
|
gssize
|
|
gst_adapter_masked_scan_uint32 (GstAdapter * adapter, guint32 mask,
|
|
guint32 pattern, gsize offset, gsize size)
|
|
{
|
|
return gst_adapter_masked_scan_uint32_peek (adapter, mask, pattern, offset,
|
|
size, NULL);
|
|
}
|