gstreamer/docs/gst/tmpl/gstbufferpool.sgml
Wim Taymans 9ee943b389 Added more API docs to Autoplug, Buffer, Bin, BufferPool.
Original commit message from CVS:
Added more API docs to Autoplug, Buffer, Bin, BufferPool.
Fixed some compile problems with videosink
2001-04-18 20:16:53 +00:00

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<!-- ##### SECTION Title ##### -->
GstBufferPool
<!-- ##### SECTION Short_Description ##### -->
Create buffers from a pool
<!-- ##### SECTION Long_Description ##### -->
<para>
A bufferpool is used to create buffers in an efficient way. En element
can maintain a bufferpool with a fixed number of buffers. This will reduce
the g_malloc and g_free overhead.
</para>
<para>
A bufferpool can also be used to implement direct access. A bufferpool can be
sent from one element to another so that the latter can directly write into
the memory of the element that maintains the bufferpool. This can greatly reduce
the number of memcpy operations.
</para>
<para>
A bufferpool is created with gst_buffer_pool_new(). You'll have to set the
buffer allocation and destroy function afterwards with gst_buffer_pool_set_create_function() and
gst_buffer_pool_set_destroy_function().
</para>
<para>
To create a buffer from the bufferpool use gst_buffer_pool_new_buffer(), which is
functionally equivalent to gst_buffer_new_from_pool().
</para>
<para>
When the buffer is unreffed and has reached a refcount of 0, the bufferpools destroy
function is called with the buffer as an argument.
</para>
<para>
A bufferpool can store private data in the buffer it creates with the GST_BUFFER_POOL_PRIVATE()
macro. To check it a buffer was made by a specific bufferpool, use the GST_BUFFER_BUFFERPOOL()
macro to get it's bufferpool.
</para>
<para>
Destroy the bufferpool with gst_buffer_pool_destroy().
</para>
<para>
A bufferpool can be requested from a pad with the gst_pad_get_bufferpool() function.
</para>
<!-- ##### SECTION See_Also ##### -->
<para>
#GstBuffer, #GstPad
</para>
<!-- ##### STRUCT GstBufferPool ##### -->
<para>
</para>
@new_buffer:
@new_user_data:
@destroy_user_data:
@destroy_buffer:
<!-- ##### USER_FUNCTION GstBufferPoolCreateFunction ##### -->
<para>
The function called when a buffer has to be created for this pool.
</para>
@pool: the pool from which to create the buffer
@user_data: any user data
@Returns: a new buffer from the pool
<!-- ##### USER_FUNCTION GstBufferPoolDestroyFunction ##### -->
<para>
This function will be called when the given buffer has to be returned to
the pool.
</para>
@pool: the pool to return the buffer to
@buffer: the buffer to return
@user_data: any user data
<!-- ##### FUNCTION gst_buffer_pool_new ##### -->
<para>
</para>
@Returns:
<!-- ##### FUNCTION gst_buffer_pool_new_buffer ##### -->
<para>
</para>
@pool:
@Returns:
<!-- ##### FUNCTION gst_buffer_pool_destroy_buffer ##### -->
<para>
</para>
@pool:
@buffer:
<!-- ##### FUNCTION gst_buffer_pool_set_create_function ##### -->
<para>
</para>
@pool:
@create:
@user_data:
<!-- ##### FUNCTION gst_buffer_pool_set_destroy_function ##### -->
<para>
</para>
@pool:
@destroy:
@user_data:
<!-- ##### FUNCTION gst_buffer_pool_destroy ##### -->
<para>
</para>
@pool: