.. SPDX-FileCopyrightText: 2019-2020 Intel Corporation .. .. SPDX-License-Identifier: CC-BY-4.0 .. _sdk-session: ============== oneVPL Session ============== Before calling any oneVPL functions, the application must initialize the library and create a oneVPL session. A oneVPL session maintains context for the use of any of :term:`DECODE`, :term:`ENCODE`, :term:`VPP`, :term:`DECODE_VPP` functions. ------------------------------------ |msdk_full_name| Dispatcher (Legacy) ------------------------------------ The :cpp:func:`MFXInit` or :cpp:func:`MFXInitEx` function starts (initializes) a session. The :cpp:func:`MFXClose` function closes (de-initializes) the session. To avoid memory leaks, always call :cpp:func:`MFXClose` after :cpp:func:`MFXInit`. .. important:: :cpp:func:`MFXInit` and :cpp:func:`MFXInitEx` are deprecated starting from API 2.0. Applications must use :cpp:func:`MFXLoad` and :cpp:func:`MFXCreateSession` to initialize implementations. .. important:: For backward compatibility with existent |msdk_full_name| applications oneVPL session can be created and initialized by the legacy dispatcher through :cpp:func:`MFXInit` or :cpp:func:`MFXInitEx` calls. In this case, the reported API version will be 1.255 on |intel_r| platforms with X\ :sup:`e` architecture. The application can initialize a session as a software-based session (:cpp:enumerator:`MFX_IMPL_SOFTWARE`) or a hardware-based session (:cpp:enumerator:`MFX_IMPL_HARDWARE`). In a software-based session, the SDK functions execute on a CPU. In a hardware-base session, the SDK functions use platform acceleration capabilities. For platforms that expose multiple graphic devices, the application can initialize a session on any alternative graphic device using the :cpp:enumerator:`MFX_IMPL_HARDWARE`, :cpp:enumerator:`MFX_IMPL_HARDWARE2`, :cpp:enumerator:`MFX_IMPL_HARDWARE3`, or :cpp:enumerator:`MFX_IMPL_HARDWARE4` values of :cpp:type:`mfxIMPL`. The application can also initialize a session to be automatic ( :cpp:enumerator:`MFX_IMPL_AUTO` or :cpp:enumerator:`MFX_IMPL_AUTO_ANY`), instructing the dispatcher library to detect the platform capabilities and choose the best SDK library available. After initialization, the SDK returns the actual implementation through the :cpp:func:`MFXQueryIMPL` function. Internally, the dispatcher works as follows: #. Dispatcher searches for the shared library with the specific name: ========= =============== ==================================== **OS** **Name** **Description** ========= =============== ==================================== Linux\* libmfxsw64.so.1 64-bit software-based implementation Linux libmfxsw32.so.1 32-bit software-based implementation Linux libmfxhw64.so.1 64-bit hardware-based implementation Linux libmfxhw64.so.1 32-bit hardware-based implementation Windows\* libmfxsw32.dll 64-bit software-based implementation Windows libmfxsw32.dll 32-bit software-based implementation Windows libmfxhw64.dll 64-bit hardware-based implementation Windows libmfxhw64.dll 32-bit hardware-based implementation ========= =============== ==================================== #. Once the library is loaded, the dispatcher obtains addresses for each SDK function. See the :ref:`Exported Functions/API Version table ` for the list of functions to expose. .. _legacy_search_order: How the shared library is identified using the implementation search strategy will vary according to the OS. * On Windows, the dispatcher searches the following locations, in the specified order, to find the correct implementation library: #. The :file:`Driver Store` directory for the current adapter. All types of graphics drivers can install libraries in this directory. `Learn more about Driver Store `__. #. The directory specified for the current hardware under the registry key ``HKEY_CURRENT_USER\Software\Intel\MediaSDK\Dispatch``. #. The directory specified for the current hardware under the registry key ``HKEY_LOCAL_MACHINE\Software\Intel\MediaSDK\Dispatch``. #. The directory that is stored in these registry keys: :file:`C:\Program Files\Intel\Media SDK`. This directory is where legacy graphics drivers install libraries. #. The directory where the current module (the module that links the dispatcher) is located (only if the current module is a dll). After the dispatcher completes the main search, it additionally checks: #. The directory of the exe file of the current process, where it looks for software implementation only, regardless of which implementation the application requested. #. Default dll search. This provides loading from the directory of the application's exe file and from the :file:`System32` and :file:`SysWOW64` directories. `Learn more about default dll search order `__. #. The :file:`System32` and :file:`SysWOW64` directories, which is where DCH graphics drivers install libraries. * On Linux, the dispatcher searches the following locations, in the specified order, to find the correct implementation library: #. Directories provided by the environment variable ``LD_LIBRARY_PATH``. #. Content of the :file:`/etc/ld.so.cache` cache file. #. Default path :file:`/lib`, then :file:`/usr/lib` or :file:`/lib64`, and then :file:`/usr/lib64` on some 64 bit OSs. On Debian: :file:`/usr/lib/x86_64-linux-gnu`. #. SDK installation folder. ----------------- oneVPL Dispatcher ----------------- The oneVPL dispatcher extends the legacy dispatcher by providing additional ability to select the appropriate implementation based on the implementation capabilities. Implementation capabilities include information about supported decoders, encoders, and VPP filters. For each supported encoder, decoder, and filter, capabilities include information about supported memory types, color formats, and image (frame) size in pixels. The recommended approach to configure the dispatcher's capabilities search filters and to create a session based on a suitable implementation is as follows: #. Create loader with :cpp:func:`MFXLoad`. #. Create loader's configuration with :cpp:func:`MFXCreateConfig`. #. Add configuration properties with :cpp:func:`MFXSetConfigFilterProperty`. #. Explore available implementations with :cpp:func:`MFXEnumImplementations`. #. Create a suitable session with :cpp:func:`MFXCreateSession`. The procedure to terminate an application is as follows: #. Destroy session with :cpp:func:`MFXClose`. #. Destroy loader with :cpp:func:`MFXUnload`. .. note:: Multiple loader instances can be created. .. note:: Each loader may have multiple configuration objects associated with it. When a configuration object is modified through :cpp:func:`MFXSetConfigFilterProperty` it implicitly impacts the state and configuration of the associated loader. .. important:: One configuration object can handle only one filter property. .. note:: Multiple sessions can be created by using one loader object. When the dispatcher searches for the implementation, it uses the following priority rules: #. Hardware implementation has priority over software implementation. #. General hardware implementation has priority over VSI hardware implementation. #. Highest API version has higher priority over lower API version. .. note:: Implementation has priority over the API version. In other words, the dispatcher must return the implementation with the highest API priority (greater than or equal to the implementation requested). How the shared library is identified using the implementation search strategy will vary according to the OS. * On Windows, the dispatcher searches the following locations, in the specified order, to find the correct implementation library: #. The :file:`Driver Store` directory for all available adapters. All types of graphics drivers can install libraries in this directory. `Learn more about Driver Store `__. Applicable only for Intel implementations. #. The directory of the exe file of the current process. #. Current working directory. #. `PATH` environmental variable. #. For backward compatibility with older spec versions, dispatcher also checks user-defined search folders which are provided by `ONEVPL_SEARCH_PATH` environmental variable. * On Linux, the dispatcher searches the following locations, in the specified order, to find the correct implementation library: #. Directories provided by the environment variable ``LD_LIBRARY_PATH``. #. Default path :file:`/lib`, then :file:`/usr/lib` or :file:`/lib64`, and then :file:`/usr/lib64` on some 64 bit OSs. On Debian: :file:`/usr/lib/x86_64-linux-gnu`. #. Current working directory. #. For backward compatibility with older spec versions, dispatcher also checks user-defined search folders which are provided by `ONEVPL_SEARCH_PATH` environmental variable. .. important:: To prioritize loading of custom oneVPL library, users may set environment variable `ONEVPL_PRIORITY_PATH` with the path to the user-defined folder. All libraries found in the ONEVPL_PRIORITY_PATH have the same priority (higher than any others, and HW/SW or API version rules are not applied) and should be loaded/filtered according to :cpp:func:`MFXSetConfigFilterProperty`. When oneVPL dispatcher searchers for the legacy |msdk_full_name| implementation it uses :ref:`legacy dispatcher search order `. The dispatcher supports different software implementations. The user can use the :cpp:member:`mfxImplDescription::VendorID` field, the :cpp:member:`mfxImplDescription::VendorImplID` field, or the :cpp:member:`mfxImplDescription::ImplName` field to search for the specific implementation. Internally, the dispatcher works as follows: #. Dispatcher loads all shared libraries in the given search folders, whose names match any of the patterns in the following table: ================== ================== ================= ========================================= Windows 64-bit Windows 32-bit Linux 64-bit Description ================== ================== ================= ========================================= libvpl\*.dll libvpl\*.dll libvpl\*.so\* Runtime library for any platform libmfx64-gen.dll libmfx32-gen.dll libmfx-gen.so.1.2 Runtime library for oneVPL for |intel_r| platforms with X\ :sup:`e` architecture libmfxhw64.dll libmfxhw32.dll libmfxhw64.so.1 Runtime library for |msdk_full_name| ================== ================== ================= ========================================= #. For each loaded library, the dispatcher tries to resolve address of the :cpp:func:`MFXQueryImplsDescription` function to collect the implementation's capabilities. #. Once the user has requested to create the session based on this implementation, the dispatcher obtains addresses of each oneVPL function. See the :ref:`Exported Functions/API Version table ` for the list of functions to export. ------------------------------------------ oneVPL Dispatcher Configuration Properties ------------------------------------------ The :ref:`Dispatcher Configuration Properties Table ` shows property strings supported by the dispatcher. Table organized in the hierarchy way, to create the string, go from the left to right from column to column and concatenate strings by using `.` (dot) as the separator. .. _dsp-conf-prop-table: .. container:: stripe-table .. table:: Dispatcher Configuration Properties :widths: 25 25 30 20 +---------------------------------------+----------------------------+----------------------+---------------------------+ | Structure name | Property | Value Data Type | Comment | +=======================================+============================+======================+===========================+ | :cpp:struct:`mfxImplDescription` | | mfxImplDescription | MFX_VARIANT_TYPE_U32 | | | | | .Impl | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U32 | The mode will be used for | | | | .AccelerationMode | | session initialization | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U32 | | | | | .ApiVersion | | | | | | .Version | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U16 | | | | | .ApiVersion | | | | | | .Major | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U16 | | | | | .ApiVersion | | | | | | .Minor | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_PTR | Pointer to the | | | | .ImplName | | null-terminated string. | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_PTR | Pointer to the | | | | .License | | null-terminated string. | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_PTR | Pointer to the | | | | .Keywords | | null-terminated string. | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U32 | | | | | .VendorID | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U32 | | | | | .VendorImplID | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U32 | | | | | .mfxSurfacePoolMode | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_PTR | Pointer to the | | | | .mfxDeviceDescription | | null-terminated string. | | | | .device | | | | | | .DeviceID | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U16 | | | | | .mfxDeviceDescription | | | | | | .device | | | | | | .MediaAdapterType | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U32 | | | | | .mfxDecoderDescription | | | | | | .decoder | | | | | | .CodecID | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U16 | | | | | .mfxDecoderDescription | | | | | | .decoder | | | | | | .MaxcodecLevel | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U32 | | | | | .mfxDecoderDescription | | | | | | .decoder | | | | | | .decprofile | | | | | | .Profile | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U32 | | | | | .mfxDecoderDescription | | | | | | .decoder | | | | | | .decprofile | | | | | | .Profile | | | | | | .decmemdesc | | | | | | .MemHandleType | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_PTR | Pointer to the | | | | .mfxDecoderDescription | | :cpp:struct:`mfxRange32U` | | | | .decoder | | object | | | | .decprofile | | | | | | .Profile | | | | | | .decmemdesc | | | | | | .Width | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_PTR | Pointer to the | | | | .mfxDecoderDescription | | :cpp:struct:`mfxRange32U` | | | | .decoder | | object | | | | .decprofile | | | | | | .Profile | | | | | | .decmemdesc | | | | | | .Height | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U32 | | | | | .mfxDecoderDescription | | | | | | .decoder | | | | | | .decprofile | | | | | | .Profile | | | | | | .decmemdesc | | | | | | .ColorFormats | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U32 | | | | | .mfxEncoderDescription | | | | | | .encoder | | | | | | .CodecID | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U16 | | | | | .mfxEncoderDescription | | | | | | .encoder | | | | | | .MaxcodecLevel | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U16 | | | | | .mfxEncoderDescription | | | | | | .encoder | | | | | | .BiDirectionalPrediction | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U16 | | | | | .mfxEncoderDescription | | | | | | .encoder | | | | | | .ReportedStats | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U32 | | | | | .mfxEncoderDescription | | | | | | .encoder | | | | | | .encprofile | | | | | | .Profile | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U32 | | | | | .mfxEncoderDescription | | | | | | .encoder | | | | | | .encprofile | | | | | | .Profile | | | | | | .encmemdesc | | | | | | .MemHandleType | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_PTR | Pointer to the | | | | .mfxEncoderDescription | | :cpp:struct:`mfxRange32U` | | | | .encoder | | object | | | | .encprofile | | | | | | .Profile | | | | | | .encmemdesc | | | | | | .Width | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_PTR | Pointer to the | | | | .mfxEncoderDescription | | :cpp:struct:`mfxRange32U` | | | | .encoder | | object | | | | .encprofile | | | | | | .Profile | | | | | | .encmemdesc | | | | | | .Height | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U32 | | | | | .mfxEncoderDescription | | | | | | .encoder | | | | | | .encprofile | | | | | | .Profile | | | | | | .encmemdesc | | | | | | .ColorFormats | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U32 | | | | | .mfxVPPDescription | | | | | | .filter | | | | | | .FilterFourCC | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U16 | | | | | .mfxVPPDescription | | | | | | .filter | | | | | | .MaxDelayInFrames | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U32 | | | | | .mfxVPPDescription | | | | | | .filter | | | | | | .memdesc | | | | | | .MemHandleType | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_PTR | Pointer to the | | | | .mfxVPPDescription | | :cpp:struct:`mfxRange32U` | | | | .filter | | object | | | | .memdesc | | | | | | .Width | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_PTR | Pointer to the | | | | .mfxVPPDescription | | :cpp:struct:`mfxRange32U` | | | | .filter | | object | | | | .memdesc | | | | | | .Height | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U32 | | | | | .mfxVPPDescription | | | | | | .filter | | | | | | .memdesc | | | | | | .format | | | | | | .InFormat | | | | +----------------------------+----------------------+---------------------------+ | | | mfxImplDescription | MFX_VARIANT_TYPE_U32 | | | | | .mfxVPPDescription | | | | | | .filter | | | | | | .memdesc | | | | | | .format | | | | | | .OutFormats | | | +---------------------------------------+----------------------------+----------------------+---------------------------+ | :cpp:struct:`mfxImplementedFunctions` | | mfxImplementedFunctions | MFX_VARIANT_TYPE_PTR | Pointer to the buffer | | | | .FunctionsName | | with string | +---------------------------------------+----------------------------+----------------------+---------------------------+ | N/A | | DXGIAdapterIndex | MFX_VARIANT_TYPE_U32 | Adapter index according | | | | | | to | | | | | | IDXGIFactory::EnumAdapters| +---------------------------------------+----------------------------+----------------------+---------------------------+ .. important:: DXGIAdapterIndex property is available for Windows only and filters only hardware implementations. Examples of the property name strings: - mfxImplDescription.mfxDecoderDescription.decoder.decprofile.Profile - mfxImplDescription.mfxDecoderDescription.decoder.decprofile.decmemdesc.MemHandleType - mfxImplementedFunctions.FunctionsName Following properties are supported in a special manner: they are used to send additional data to the implementation through the dispatcher. Application needs to use :cpp:func:`MFXSetConfigFilterProperty` to set them up but they don't influence on the implementation selection. They are used during the :cpp:func:`MFXCreateSession` function call to fine tune the implementation. .. list-table:: Dispatcher's Special Properties :header-rows: 1 :widths: auto * - **Property Name** - **Property Value** - **Value data type** * - mfxHandleType - :cpp:enum:`mfxHandleType` - :cpp:enumerator:`mfxVariantType::MFX_VARIANT_TYPE_U32` * - mfxHDL - :cpp:type:`mfxHDL` - :cpp:enumerator:`mfxVariantType::MFX_VARIANT_TYPE_PTR` * - NumThread - Unsigned fixed-point integer value - :cpp:enumerator:`mfxVariantType::MFX_VARIANT_TYPE_U32` * - DeviceCopy - :ref:`Device copy ` - :cpp:enumerator:`mfxVariantType::MFX_VARIANT_TYPE_U16` * - ExtBuffer - Pointer to the extension buffer - :cpp:enumerator:`mfxVariantType::MFX_VARIANT_TYPE_PTR` .. _onevpl-dispatcher-interactions: ------------------------------ oneVPL Dispatcher Interactions ------------------------------ This sequence diagram visualize how application communicates with implementations via the dispatcher. Dispatcher API This API is implemented in the dispatcher. Implementation API This API is provided by the any implementation. .. uml:: @startuml actor Application as A participant "oneVPL Dispatcher" as D participant "oneVPL Implementation 1" as I1 participant "oneVPL Implementation 2" as I2 participant "oneVPL Implementation 3" as I3 ref over A, D : Dispatcher API ref over D, I1, I2, I3 : Implementation API activate A == Initialization == group Dispatcher API [Enumerate and load implementations] A -> D: mfxLoad() activate D D -> D: Search for the available runtimes A -> D: MFXCreateConfig() A -> D: MFXSetConfigProperty() A -> D: MFXCreateConfig() A -> D: MFXSetConfigProperty() A -> D: MFXEnumImplementations() note right of A MFXEnumImplementations() may also be called after MFXCreateSession(). end note Activate I1 D -> I1: MFXQueryImplsDescription() I1 --> D: mfxImplDescription Activate I2 D -> I2: MFXQueryImplsDescription() I2 --> D: mfxImplDescription Activate I3 D -> I3: MFXQueryImplsDescription() I3 --> D: mfxImplDescription D --> A: list of mfxImplDescription structures es for all implementations A -> D: MFXCreateSession(i=0) D -> I1: MFXInitilize() Activate I1 #DarkSalmon I1 --> D: mfxSession1 D --> A: mfxSession1 A -> D: MFXCreateSession(i=1) D -> I2: MFXInitilize() Activate I2 #DarkSalmon I2 --> D: mfxSession2 D --> A: mfxSession2 A -> D: MFXCreateSession(i=2) D -> I3: MFXInitilize() I3 --> D: mfxSession3 Activate I3 #DarkSalmon D --> A: mfxSession3 A -> D: MFXDispReleaseImplDescription(hdl=0) D -> I1: MFXReleaseImplDescription() A -> D: MFXDispReleaseImplDescription(hdl=1) D -> I2: MFXReleaseImplDescription() A -> D: MFXDispReleaseImplDescription(hdl=2) D -> I3: MFXReleaseImplDescription() end == Processing == group Implementation API [Process the data] A -> I1: MFXVideoDECODE_Init() A -> I1: MFXVideoDECODE_Query() A -> I1: MFXVideoDECODE_DecodeFrameAsync() ... A -> I1: MFXVideoDECODE_Close() ||| deactivate I1 A -> I2: MFXVideoENCODE_Init() A -> I2: MFXVideoENCODE_Query() A -> I2: MFXVideoENCODE_EncodeFrameAsync() ... A -> I2: MFXVideoENCODE_Close() ||| deactivate I2 A -> I3: MFXVideoENCODE_Init() A -> I3: MFXVideoENCODE_Query() A -> I3: MFXVideoENCODE_EncodeFrameAsync() ... A -> I3: MFXVideoENCODE_Close() ||| deactivate I3 end == Finalization == group Implementation API [Release the implementations] A -> I1: MFXClose() deactivate I1 A -> I2: MFXClose() deactivate I2 A -> I3: MFXClose() deactivate I3 group Dispatcher API [Release the dispatcher's instance] A -> D: MFXUnload() end deactivate D @enduml The oneVPL dispatcher is capable to load and initialize |msdk_full_name| legacy library. The sequence diagram below demonstrates the approach. .. uml:: @startuml actor Application as A participant "oneVPL Dispatcher" as D participant "MediaSDK (legacy)" as M A -> D: MFXLoad activate D D -> D: Search for the available runtimes A -> D: MFXCreateConfig note left of D Setting properties to filter implementation. MediaSDK supports only general parameters, no filtering for Decode/VPP/Encoder details. end note group MediaSDK LegacyAPI D -> M: MFXInitEx activate M M --> D: mfxSession D -> M: MFXQueryIMPL M --> D: Implementation speciefic D -> M: MFXQueryVersion M --> D: mfxVersion end D -> D: Fill mfxImplDescription for MediaSDK impl A -> D: mfxEnumImplementations D --> A: MediaSDK caps description A -> D: MFXCreateSession D --> A: mfxSession A -> M: MFXVideoDECODE_Init() A -> M: MFXVideoDECODE_Query() A -> M: MFXVideoDECODE_DecodeFrameAsync() ... A -> M: MFXVideoDECODE_Close() A -> M: MFXClose() deactivate M A -> D: MFXUnload() deactivate D @enduml .. important:: The dispatcher doesn't filter and report :cpp:struct:`mfxDeviceDescription`, :cpp:struct:`mfxDecoderDescription`, :cpp:struct:`mfxEncoderDescription`, :cpp:struct:`mfxVPPDescription` when enumerates or creates |msdk_full_name| implementation. Once |msdk_full_name| is loaded applications have to use legacy approach to query capabilities. --------------------------- oneVPL Dispatcher Debug Log --------------------------- The debug output of the dispatcher is controlled with the `ONEVPL_DISPATCHER_LOG` environment variable. To enable log output, set the `ONEVPL_DISPATCHER_LOG` environment variable value equals to "ON". By default, oneVPL dispatcher prints all log messages to the console. To redirect log output to the desired file, set the `ONEVPL_DISPATCHER_LOG_FILE` environmental variable with the file name of the log file. ------------------------------ Examples of Dispatcher's Usage ------------------------------ This code illustrates simple usage of dispatcher to load first available library: .. literalinclude:: ../snippets/prg_disp.c :language: c++ :start-after: /*beg1*/ :end-before: /*end1*/ :lineno-start: 1 This code illustrates simple usage of dispatcher to load first available HW accelerated library: .. literalinclude:: ../snippets/prg_disp.c :language: c++ :start-after: /*beg2*/ :end-before: /*end2*/ :lineno-start: 1 This code illustrates how multiple sessions from multiple loaders can be created: .. literalinclude:: ../snippets/prg_disp.c :language: c++ :start-after: /*beg3*/ :end-before: /*end3*/ :lineno-start: 1 This code illustrates how multiple decoders from single loader can be created: .. literalinclude:: ../snippets/prg_disp.c :language: c++ :start-after: /*beg4*/ :end-before: /*end4*/ :lineno-start: 1 --------------------------------------- How To Check If Function is Implemented --------------------------------------- There are two ways to check if particular function is implemented or not by the implementation. This code illustrates how application can iterate through the whole list of implemented functions: .. literalinclude:: ../snippets/prg_session.cpp :language: c++ :start-after: /*beg1*/ :end-before: /*end1*/ :lineno-start: 1 This code illustrates how application can check that specific functions are implemented: .. literalinclude:: ../snippets/prg_session.cpp :language: c++ :start-after: /*beg2*/ :end-before: /*end2*/ :lineno-start: 1 -------------------------------------------------------------- How To Search For The Available encoder/decoder implementation -------------------------------------------------------------- The :ref:`CodecFormatFourCC ` enum specifies codec's FourCC values. Application needs to assign this value to the field of :cpp:member:`mfxDecoderDescription::decoder::CodecID` to search for the decoder or :cpp:member:`mfxEncoderDescription::encoder::CodecID` to search for the encoder. This code illustrates decoder's implementation search procedure: .. literalinclude:: ../snippets/prg_session.cpp :language: c++ :start-after: /*beg3*/ :end-before: /*end3*/ :lineno-start: 1 --------------------------------------------------------- How To Search For The Available VPP Filter implementation --------------------------------------------------------- Each VPP filter identified by the filter ID. Filter ID is defined by corresponding to the filter extension buffer ID value which is defined in a form of FourCC value. Filter ID values are subset of the general :ref:`ExtendedBufferID ` enum. The :ref:`table ` references available IDs of VPP filters to search. Application needs to assign this value to the field of :cpp:member:`mfxVPPDescription::filter::FilterFourCC` to search for the needed VPP filter. .. _vpp-filters-ids: .. list-table:: VPP Filters ID :header-rows: 1 :widths: 58 42 * - **Filter ID** - **Description** * - :cpp:enumerator:`MFX_EXTBUFF_VPP_DENOISE2` - Denoise filter * - :cpp:enumerator:`MFX_EXTBUFF_VPP_MCTF` - Motion-Compensated Temporal Filter (MCTF). * - :cpp:enumerator:`MFX_EXTBUFF_VPP_DETAIL` - Detail/edge enhancement filter. * - :cpp:enumerator:`MFX_EXTBUFF_VPP_FRAME_RATE_CONVERSION` - Frame rate conversion filter * - :cpp:enumerator:`MFX_EXTBUFF_VPP_IMAGE_STABILIZATION` - Image stabilization filter * - :cpp:enumerator:`MFX_EXTBUFF_VPP_PROCAMP` - ProcAmp filter * - :cpp:enumerator:`MFX_EXTBUFF_VPP_FIELD_PROCESSING` - Field processing filter * - :cpp:enumerator:`MFX_EXTBUFF_VPP_COLOR_CONVERSION` - Color Conversion filter * - :cpp:enumerator:`MFX_EXTBUFF_VPP_SCALING` - Resize filter * - :cpp:enumerator:`MFX_EXTBUFF_VPP_COMPOSITE` - Surfaces composition filter * - :cpp:enumerator:`MFX_EXTBUFF_VPP_DEINTERLACING` - Deinterlace filter * - :cpp:enumerator:`MFX_EXTBUFF_VPP_ROTATION` - Rotation filter * - :cpp:enumerator:`MFX_EXTBUFF_VPP_MIRRORING` - Mirror filter * - :cpp:enumerator:`MFX_EXTBUFF_VPP_COLORFILL` - ColorFill filter This code illustrates VPP mirror filter implementation search procedure: .. literalinclude:: ../snippets/prg_session.cpp :language: c++ :start-after: /*beg4*/ :end-before: /*end4*/ :lineno-start: 1 ------------------------------------------------------------- How To Get Path to the Shared Library With the Implementation ------------------------------------------------------------- Sessions can be created from different implementations, each implementations can be located in different shared libraries. To get path of the shared library with the implementation from which session can be or was created, application can use :cpp:func:`MFXEnumImplementations` and pass :cpp:enumerator:`MFX_IMPLCAPS_IMPLPATH` value as the output data request. This code illustrates collection and print out path of implementations's shared library: .. literalinclude:: ../snippets/prg_session.cpp :language: c++ :start-after: /*beg5*/ :end-before: /*end5*/ :lineno-start: 1 .. _onevpl_coexistense: ----------------------------------------------------------------------------------------------------------- oneVPL implementation on |intel_r| platforms with X\ :sup:`e` architecture and |msdk_full_name| Coexistence ----------------------------------------------------------------------------------------------------------- oneVPL supersedes |msdk_full_name| and is partially binary compatible with |msdk_full_name|. Both oneVPL and |msdk_full_name| includes own dispatcher and implementation. Coexistence of oneVPL and |msdk_full_name| dispatchers and implementations on single system is allowed until |msdk_full_name| is not EOL. Usage of the following combinations of dispatchers and implementations within the single application is permitted for the legacy purposes only. In that scenario legacy applications developed with |msdk_full_name| will continue to work on any HW supported either by |msdk_full_name| or by the oneVPL. .. attention:: Any application to work with the oneVPL API starting from version 2.0 must use only oneVPL dispatcher. |msdk_full_name| API |msdk_full_name| API of 1.x version. Removed API |msdk_full_name| :ref:`API ` which is removed from oneVPL. Core API |msdk_full_name| API without removed API. oneVPL API New :ref:`API ` introduced in oneVPL only started from API 2.0 version. oneVPL Dispatcher API Dispatcher :ref:`API ` introduced in oneVPL in 2.0 API version. This is subset of oneVPL API. .. list-table:: oneVPL for |intel_r| platforms with X\ :sup:`e` architecture and |msdk_full_name| :header-rows: 1 :widths: 25 25 25 25 * - **Dispatcher** - **Installed on the device** - **Loaded** - **Allowed API** * - oneVPL - oneVPL for |intel_r| platforms with X\ :sup:`e` architecture - oneVPL for |intel_r| platforms with X\ :sup:`e` architecture - Usage of any API except removed API is allowed. * - oneVPL - |msdk_full_name| - |msdk_full_name| - Usage of core API plus dispatcher API is allowed only. * - oneVPL - oneVPL for |intel_r| platforms with X\ :sup:`e` architecture and |msdk_full_name| - oneVPL for |intel_r| platforms with X\ :sup:`e` architecture - Usage of any API except removed API is allowed. * - |msdk_full_name| - oneVPL for |intel_r| platforms with X\ :sup:`e` architecture - oneVPL for |intel_r| platforms with X\ :sup:`e` architecture - Usage of core API is allowed only. * - |msdk_full_name| - oneVPL for |intel_r| platforms with X\ :sup:`e` architecture and |msdk_full_name| - |msdk_full_name| - Usage of |msdk_full_name| API is allowed. * - |msdk_full_name| - |msdk_full_name| - |msdk_full_name| - Usage of |msdk_full_name| API is allowed. .. note:: if system has multiple devices the logic of selection and loading implementations will be applied to each device accordingly to the system enumeration. ----------------- Multiple Sessions ----------------- Each oneVPL session can run exactly one instance of the DECODE, ENCODE, and VPP functions. This is adequate for a simple transcoding operation. If the application needs more than one instance of DECODE, ENCODE, or VPP in a complex transcoding setting or needs more simultaneous transcoding operations, the application can initialize multiple oneVPL sessions created from one or several oneVPL implementations. The application can use multiple oneVPL sessions independently or run a “joined” session. To join two sessions together, the application can use the function :cpp:func:`MFXJoinSession`. Alternatively, the application can use the :cpp:func:`MFXCloneSession` function to duplicate an existing session. Joined oneVPL sessions work together as a single session, sharing all session resources, threading control, and prioritization operations except hardware acceleration devices and external allocators. When joined, the first session (first join) serves as the parent session and will schedule execution resources with all other child sessions. Child sessions rely on the parent session for resource management. .. important:: Applications can join sessions created from the same oneVPL implementation only. With joined sessions, the application can set the priority of session operations through the :cpp:func:`MFXSetPriority` function. A lower priority session receives fewer CPU cycles. Session priority does not affect hardware accelerated processing. After the completion of all session operations, the application can use the :cpp:func:`MFXDisjoinSession` function to remove the joined state of a session. Do not close the parent session until all child sessions are disjoined or closed.