gstreamer/docs/random/porting-to-0.11.txt

The 0.11 porting guide
----------------------

* All deprecated methods were removed. Recompile against 0.10 with
  DISABLE_DEPRECATED and fix issues before attempting to port to 0.11.

* GST_BOILERPLATE is gone, use G_DEFINE_TYPE instead.

* various methods take a gsize instead of a guint when talking about memory
  sizes.

* multifdsink, tcpclientsink, tcpclientsrc, tcpserversrc the protocol property
  is removed, use gdppay and gdpdepay.

* Presets and plugins moved to $XDG_DATA_HOME/gstreamer-0.11/ root
  directory. Registry moved to $XDG_CACHE_HOME/gstreamer-0.11/.
  XDG_CACHE_HOME usually points to $HOME/.cache and XDG_DATA_HOME
  usually is $HOME/.local/share/.

* GstObject:
    GST_OBJECT_DISPOSING flag removed
    GST_OBJECT_IS_DISPOSING removed
    GST_OBJECT_FLOATING flag remove, GstObject is now GInitiallyUnowned
    GST_OBJECT_IS_FLOATING removed, use g_object_is_floating()

    GST_CLASS_GET_LOCK, GST_CLASS_LOCK, GST_CLASS_TRYLOCK, GST_CLASS_UNLOCK,
    used to be a workaround for thread-unsafe glib < 2.8

    gst_object_ref_sink() has gpointer as result to make it more like the
    GObject version.

    gst_object_sink() removed, use gst_object_ref_sink() instead.

    gst_class_signal_connect() removed, was only used for XML

    parent-set and parent-unset signals removed. Use notify:parent. Currently
    still disabled because of deep notify locking issues.

* GstElement:
    GstElementDetails is removed and replaced with more generic metadata.

    gst_element_class_set_details_simple() -> gst_element_class_set_metadata()
    gst_element_class_set_documentation_uri -> gst_element_class_add_metadata
    gst_element_class_set_icon_name -> gst_element_class_add_metadata
    also gst_element_class_get_metadata()

    gst_element_factory_get_longname -> gst_element_factory_get_metadata
    gst_element_factory_get_klass -> gst_element_factory_get_metadata
    gst_element_factory_get_description -> gst_element_factory_get_metadata
    gst_element_factory_get_author -> gst_element_factory_get_metadata
    gst_element_factory_get_documentation_uri -> gst_element_factory_get_metadata
    gst_element_factory_get_icon_name -> gst_element_factory_get_metadata

    gstelementmetadata.h contains the keys for all standard metadata.

    gst_element_factory_can_{src,sink}_caps() => gst_element_factory_can_{src,sink}_{any,all}_caps()

    Element metadata and pad templates are inherited from parent classes and
    should be added in class_init instead of base_init.

    gst_element_class_add_pad_template() takes ownership of the template

    Elements that change the duration must post DURATION messages on the
    bus when the duration changes in PAUSED or PLAYING.

    gst_element_lost_state_full() -> gst_element_lost_state()
    gst_element_lost_state() -> gst_element_lost_state(, TRUE)

    request_new_pad_full() -> request_new_pad()

* GstPad:
    gst_pad_get_caps() does not return writable caps anymore and an explicit
    gst_caps_make_writable() needs to be performed. This was the functionality
    of gst_pad_get_caps_reffed(), which is removed now.

    A similar change was done for gst_pad_peer_get_caps() and
    gst_pad_peer_get_caps_reffed()

    gst_pad_set_bufferalloc_function(), gst_pad_alloc_buffer() and
    gst_pad_alloc_buffer_and_set_caps() are removed. Use the ALLOCATION query
    now to obtain a reference to a bufferpool object that can be used to
    allocate buffers.

    removed sched_private, it should not be used, use g_object_set_qdata() or
    use element_private.

    Removed GST_PAD_CAPS() use gst_pad_get_current_caps() to get a handle to the
    currently configured caps.

    GstPadGetCapsFunction, gst_pad_get_caps(), gst_pad_peer_get_caps(),
    gst_pad_proxy_getcaps() now takes a GstCaps* parameter to inform
    the other side about the possible caps and preferences.

    gst_pad_get_pad_template_caps() and gst_pad_get_pad_template()
    return a new reference of the caps or template now and the return
    value needs to be unreffed after usage.

    gst_pad_set_caps() now pushes a CAPS event for backward compatibility.
    Consider sending the CAPS event yourself. It is not possible anymore to set
    NULL caps.

    gst_pad_set_checkgetrange_function() and gst_pad_check_pull_range() are
    gone, use the SCHEDULING query now.

    gst_pad_set_blocked(), gst_pad_set_blocked_async(),
    gst_pad_set_blocked_async_full() are removed, use the gst_pad_add_probe()
    method with the GST_PROBE_TYPE_BLOCK to get the same result as the async
    blocking version. There is no more sync version of blocking, this is in
    general dangerous and can be implemented using the callbacks if needed.

    gst_pad_add_data_probe(), gst_pad_add_data_probe_full(),
    gst_pad_remove_data_probe(), gst_pad_add_event_probe(),
    gst_pad_add_event_probe_full(), gst_pad_remove_event_probe(),
    gst_pad_add_buffer_probe(), gst_pad_add_buffer_probe_full(),
    gst_pad_remove_buffer_probe() are removed. Use gst_pad_add_probe() and
    gst_pad_remove_probe() for equivalent functionality.

    The have-data signal was removed from pads, it was never supposed to be used
    without calling the _add_.*_probe() methods.

    The request-link signal was removed. It was never used.

* GstPadTemplate
    gst_pad_template_get_caps() returns a new reference of the caps
    and the return value needs to be unreffed after usage.

    gst_pad_template_new() does not take ownership of the caps anymore.

    GstPadTemplate is now created with a floating ref and
    gst_element_class_add_pad_template() takes ownership of this floating ref.

    GstPadTemplate instances are considered immutable and must not be
    changed.

* GstMiniObject
    A miniobject is now a simple refcounted structure holding the information
    common to buffers, events, messages, queries and caps.

    There is no more GST_TYPE_MINIOBJECT as the type for subclasses.
    G_TYPE_BOXED can be used as the type of all GstMiniObject based types such
    as buffers, events, messages, caps, etc. Signals, for example, would use the
    boxed type if the argument include GstMiniObject derived types.

    gst_mini_object_new() is removed. You would allocate memory with the the
    methods specific for the derived type.

    GstParamSpecMiniObject is removed, use boxed param spec now with the GType
    of the specific GstMiniObject derived type. Also
    gst_param_spec_mini_object().

    gst_param_spec_mini_object() -> g_param_spec_boxed()

    The specific gst_value_*_mini_object() methods are removed, used the generic
    boxed methods instead.

    gst_value_set_mini_object() -> g_value_set_boxed()
    gst_value_take_mini_object() -> g_value_take_boxed()
    gst_value_take_get_object() -> g_value_get_boxed()
    gst_value_take_dup_object() -> g_value_dup_boxed()

    GST_VALUE_HOLDS_MINI_OBJECT() was removed, use G_VALUE_HOLDS_BOXED() or
    type-specific GST_VALUE_HOLDS_{BUFFER,CAPS,etc.}() instead.

    The GST_MINI_OBJECT_READONLY flag was removed as it used to mark the
    memory in buffers as READONLY. Marking memory READONLY can now be done
    with the GstMemory API. Writability of miniobjects is now only done by using
    the refcount.

* GstBuffer
    A GstBuffer is now a simple boxed type this means that subclassing is not
    possible anymore. 

    To add data to the buffer you would now use gst_buffer_take_memory() with
    a GstMemory object containing the data. Multiple memory blocks can added to
    a GstBuffer that can then be retrieved with gst_buffer_peek_memory().

    GST_BUFFER_DATA(), GST_BUFFER_MALLOCDATA(), GST_BUFFER_FREE_FUNC() and
    GST_BUFFER_SIZE() are gone, along with the fields in GstBuffer. Use the
    memory API to get access to the buffer data. GST_BUFFER_SIZE() can be
    replaced with gst_buffer_get_size() but if also access to the data is
    required, gst_buffer_map() can return both the size and data in one go.

    The most common way to access all the data in a buffer is by using
    gst_buffer_map() and gst_buffer_unmap(). These calls require you to specify
    the access mode required to the data and will automatically merge and return
    a writable copy of the data.

    The buffer must be writable (gst_buffer_is_writable()) in order to modify
    the fields, metadata or buffer memory. gst_buffer_make_writable() will not
    automatically make a writable copy of the memory but will instead increase
    the refcount of the memory. The _map() and _peek_memory() methods will
    automatically create writable copies when needed.
    
    gst_buffer_make_metadata_writable() is gone, you can replace this safely
    with gst_buffer_make_writable().

    gst_buffer_create_sub() is gone and can be safely replaced with
    gst_buffer_copy_region(). 

    Changing the size of the buffer data can be done with gst_buffer_resize(),
    which will also update the metadata fields correctly. gst_buffer_set_size()
    is #defined to a special case of gst_buffer_resize() with a 0 offset.

    gst_buffer_try_new_and_alloc() is replaced with gst_buffer_new_and_alloc(),
    which now returns NULL when memory allocation fails.

    GST_BUFFER_CAPS() is gone, caps are not set on buffers anymore but are set
    on the pads where the buffer is pushed on. Likewise GST_BUFFER_COPY_CAPS is
    not needed anymore. gst_buffer_get/set_caps() are gone too.

* GstBufferList
    The GstBufferList object is much simplified because most of the
    functionality in the groups is now part of the GstMemory in buffers.
    
    The object is reduced to encapsulating an array of buffers that you can send
    with the regular gst_pad_push_list. The iterator is not needed anymore
    because you can simply use gst_buffer_list_len() and gst_buffer_list_get()
    to iterate the array.

    For dealing with the groups, it's now needed to add the memory blocks to
    GstBuffer and use the normal buffer API to get and merge the groups.

* GstStructure

    The GArray of the structure fields are moved to private part and are not
    accessible from the application anymore. Use the methods to retrieve and
    modify fields from the array.

* GstEvent
    GST_EVENT_SRC is removed. Don't use this anymore.

    gst_event_new_qos_full() -> gst_event_new_qos()
    gst_event_parse_qos_full() -> gst_event_parse_qos()

    The GstStructure is removed from the public API, use the getters to get
    a handle to a GstStructure.

    GST_EVENT_NEWSEGMENT -> GST_EVENT_SEGMENT

    gst_event_new_new_segment () -> gst_event_new_segment() and it takes a
    GstSegment structure as an argument.
    gst_event_parse_new_segment() -> gst_event_parse_segment() to retrieve the
    GstSegment structure from the event.
    gst_event_copy_segment() to fill a GstSegment structure.

* GstQuery
    Boxed types derived from GstMiniObject.

    The GstStructure is removed from the public API, use the getters to get
    a handle to a GstStructure.

    gst_query_new_application() -> gst_query_new_custom()

    gst_query_parse_formats_length() -> gst_query_parse_n_formats()
    gst_query_parse_formats_nth() -> gst_query_parse_nth_format()

* GstBufferList
    Is now a boxed type derived from GstMiniObject.

* GstMessage
    Is now a boxed type derived from GstMiniObject

    The GstStructure is removed from the public API, use the getters to get
    a handle to a GstStructure.

* GstCaps
    Is now a boxed type derived from GstMiniObject. 

* GstSegment
    abs_rate was removed from the public fields, it can be trivially calculated
    from the rate field.

    accum was renamed to base. last_stop was renamed to position.

    The segment info now contains all the information needed to convert buffer
    timestamps to running_time and stream_time. There is no more segment
    accumulation, the GstSegment is completely self contained.

    gst_segment_set_duration() and gst_segment_set_last_stop() are removed,
    simply modify the structure members duration and position respectively.

    gst_segment_set_newsegment() is removed, it was used to accumulate segments
    and is not needed anymore, use gst_segment_copy_into() or modify the segment
    values directly.

    gst_segment_set_seek() -> gst_segment_do_seek(). Updates the segment values
    with seek parameters.

* GstPluginFeature
    GST_PLUGIN_FEATURE_NAME() was removed, use GST_OBJECT_NAME() instead.

* GstTypeFind
    gst_type_find_peek() returns a const guint8 * now.

* GstAdapter
    gst_adapter_peek() is removed, use gst_adapter_map() and gst_adapter_unmap()
    to get access to raw data from the adapter.

    Arguments renamed from guint to gsize.

* GstBitReader, GstByteReader, GstByteWriter
    gst_*_reader_new_from_buffer(), gst_*_reader_init_from_buffer() removed, get
    access to the buffer data with _map() and then use the _new() functions.

    gst_byte_reader_new_from_buffer() and gst_byte_reader_init_from_buffer()
    removed, get access to the buffer data and then use the _new() functions.

* GstCollectPads
    gst_collect_pads_read() removed, use _read_buffer() or _take_buffer() and
    then use the memory API to get to the memory.

* GstBaseSrc, GstBaseTransform, GstBaseSink
    GstBaseSrc::get_caps(), GstBaseTransform::transform_caps() and
    GstBaseSink::get_caps() now take a filter GstCaps* parameter to
    filter the caps and allow better negotiation decisions.
 
* GstBaseTransform
    GstBaseTransform::transform_caps() now gets the complete caps passed
    instead of getting it passed structure by structure.

    GstBaseTransform::event() was renamed to sink_event(). The old function
    uses the return value to determine if the event should be forwarded or not.
    The new function has a default implementation that always forwards the event
    and the return value is simply returned as a result from the event handler.
    The semantics of the sink_event are thus the same as those for the src_event
    function.

* GstImplementsInterface
    has been removed. Interfaces need to be updated to either have
    is_ready/usable/available() methods, or have GError arguments
    to their methods so we can return an appropriate error if a
    particular interface isn't supported for a particular device.