GstDmaBufAllocator

GstDmaBufAllocator 

GObject
    ╰──GInitiallyUnowned
        ╰──GstObject
            ╰──GstAllocator
                ╰──GstFdAllocator
                    ╰──GstDmaBufAllocator

Base class for allocators with dmabuf-backed memory

Members

parent (GstFdAllocator) –
No description available

Since : 1.12

Class structure

GstDmaBufAllocatorClass

Fields
parent_class (GstFdAllocatorClass) –
No description available

GstAllocators.DmaBufAllocatorClass

Attributes
parent_class (GstAllocators.FdAllocatorClass) –
No description available

GstAllocators.DmaBufAllocatorClass

Attributes
parent_class (GstAllocators.FdAllocatorClass) –
No description available

GstAllocators.DmaBufAllocator 

GObject.Object
    ╰──GObject.InitiallyUnowned
        ╰──Gst.Object
            ╰──Gst.Allocator
                ╰──GstAllocators.FdAllocator
                    ╰──GstAllocators.DmaBufAllocator

Base class for allocators with dmabuf-backed memory

Members

No description available

Since : 1.12

GstAllocators.DmaBufAllocator 

GObject.Object
    ╰──GObject.InitiallyUnowned
        ╰──Gst.Object
            ╰──Gst.Allocator
                ╰──GstAllocators.FdAllocator
                    ╰──GstAllocators.DmaBufAllocator

Base class for allocators with dmabuf-backed memory

Members

No description available

Since : 1.12

Constructors

gst_dmabuf_allocator_new 

GstAllocator *
gst_dmabuf_allocator_new ()

Return a new dmabuf allocator.

Returns ( [transfer: full]) –

a new dmabuf allocator. Use gst_object_unref to release the allocator after usage

Since : 1.2

GstAllocators.DmaBufAllocator.prototype.new 

function GstAllocators.DmaBufAllocator.prototype.new(): {
    // javascript wrapper for 'gst_dmabuf_allocator_new'
}

Return a new dmabuf allocator.

Returns (Gst.Allocator) –

a new dmabuf allocator. Use Gst.Object.prototype.unref to release the allocator after usage

Since : 1.2

GstAllocators.DmaBufAllocator.new 

def GstAllocators.DmaBufAllocator.new ():
    #python wrapper for 'gst_dmabuf_allocator_new'

Return a new dmabuf allocator.

Returns (Gst.Allocator) –

a new dmabuf allocator. Use Gst.Object.unref to release the allocator after usage

Since : 1.2

Functions

gst_dmabuf_allocator_alloc 

GstMemory *
gst_dmabuf_allocator_alloc (GstAllocator * allocator,
                            gint fd,
                            gsize size)

Return a GstMemory that wraps a dmabuf file descriptor.

Parameters:

allocator –

allocator to be used for this memory

fd –

dmabuf file descriptor

size –

memory size

Returns ( [transfer: full][nullable]) –

a GstMemory based on allocator. When the buffer will be released dmabuf allocator will close the fd. The memory is only mmapped on gst_buffer_map request.

Since : 1.2

GstAllocators.DmaBufAllocator.prototype.alloc 

function GstAllocators.DmaBufAllocator.prototype.alloc(allocator: Gst.Allocator, fd: Number, size: Number): {
    // javascript wrapper for 'gst_dmabuf_allocator_alloc'
}

Return a Gst.Memory that wraps a dmabuf file descriptor.

Parameters:

allocator (Gst.Allocator) –

allocator to be used for this memory

fd (Number) –

dmabuf file descriptor

size (Number) –

memory size

Returns (Gst.Memory) –

a GstMemory based on allocator. When the buffer will be released dmabuf allocator will close the fd. The memory is only mmapped on Gst.Buffer.prototype.map request.

Since : 1.2

GstAllocators.DmaBufAllocator.alloc 

def GstAllocators.DmaBufAllocator.alloc (allocator, fd, size):
    #python wrapper for 'gst_dmabuf_allocator_alloc'

Return a Gst.Memory that wraps a dmabuf file descriptor.

Parameters:

allocator (Gst.Allocator) –

allocator to be used for this memory

fd (int) –

dmabuf file descriptor

size (int) –

memory size

Returns (Gst.Memory) –

a GstMemory based on allocator. When the buffer will be released dmabuf allocator will close the fd. The memory is only mmapped on Gst.Buffer.map request.

Since : 1.2

gst_dmabuf_allocator_alloc_with_flags 

GstMemory *
gst_dmabuf_allocator_alloc_with_flags (GstAllocator * allocator,
                                       gint fd,
                                       gsize size,
                                       GstFdMemoryFlags flags)

Return a GstMemory that wraps a dmabuf file descriptor.

Parameters:

allocator –

allocator to be used for this memory

fd –

dmabuf file descriptor

size –

memory size

flags –

extra GstFdMemoryFlags

Returns ( [transfer: full][nullable]) –

a GstMemory based on allocator.

When the buffer will be released the allocator will close the fd unless the GST_FD_MEMORY_FLAG_DONT_CLOSE flag is specified. The memory is only mmapped on gst_buffer_mmap request.

Since : 1.16

GstAllocators.DmaBufAllocator.prototype.alloc_with_flags 

function GstAllocators.DmaBufAllocator.prototype.alloc_with_flags(allocator: Gst.Allocator, fd: Number, size: Number, flags: GstAllocators.FdMemoryFlags): {
    // javascript wrapper for 'gst_dmabuf_allocator_alloc_with_flags'
}

Return a Gst.Memory that wraps a dmabuf file descriptor.

Parameters:

allocator (Gst.Allocator) –

allocator to be used for this memory

fd (Number) –

dmabuf file descriptor

size (Number) –

memory size

extra GstAllocators.FdMemoryFlags

Returns (Gst.Memory) –

a GstMemory based on allocator.

When the buffer will be released the allocator will close the fd unless the GstAllocators.FdMemoryFlags.DONT_CLOSE flag is specified. The memory is only mmapped on gst_buffer_mmap request.

Since : 1.16

GstAllocators.DmaBufAllocator.alloc_with_flags 

def GstAllocators.DmaBufAllocator.alloc_with_flags (allocator, fd, size, flags):
    #python wrapper for 'gst_dmabuf_allocator_alloc_with_flags'

Return a Gst.Memory that wraps a dmabuf file descriptor.

Parameters:

allocator (Gst.Allocator) –

allocator to be used for this memory

fd (int) –

dmabuf file descriptor

size (int) –

memory size

extra GstAllocators.FdMemoryFlags

Returns (Gst.Memory) –

a GstMemory based on allocator.

When the buffer will be released the allocator will close the fd unless the GstAllocators.FdMemoryFlags.DONT_CLOSE flag is specified. The memory is only mmapped on gst_buffer_mmap request.

Since : 1.16

Functions

gst_dmabuf_memory_get_fd 

gint
gst_dmabuf_memory_get_fd (GstMemory * mem)

Return the file descriptor associated with mem.

Parameters:

mem –

the memory to get the file descriptor

Returns –

the file descriptor associated with the memory, or -1. The file descriptor is still owned by the GstMemory. Use dup to take a copy if you intend to use it beyond the lifetime of this GstMemory.

Since : 1.2

GstAllocators.prototype.dmabuf_memory_get_fd 

function GstAllocators.prototype.dmabuf_memory_get_fd(mem: Gst.Memory): {
    // javascript wrapper for 'gst_dmabuf_memory_get_fd'
}

Return the file descriptor associated with mem.

Parameters:

mem (Gst.Memory) –

the memory to get the file descriptor

Returns (Number) –

the file descriptor associated with the memory, or -1. The file descriptor is still owned by the GstMemory. Use dup to take a copy if you intend to use it beyond the lifetime of this GstMemory.

Since : 1.2

GstAllocators.dmabuf_memory_get_fd 

def GstAllocators.dmabuf_memory_get_fd (mem):
    #python wrapper for 'gst_dmabuf_memory_get_fd'

Return the file descriptor associated with mem.

Parameters:

mem (Gst.Memory) –

the memory to get the file descriptor

Returns (int) –

the file descriptor associated with the memory, or -1. The file descriptor is still owned by the GstMemory. Use dup to take a copy if you intend to use it beyond the lifetime of this GstMemory.

Since : 1.2

gst_is_dmabuf_memory 

gboolean
gst_is_dmabuf_memory (GstMemory * mem)

Check if mem is dmabuf memory.

Parameters:

mem –

the memory to be check

Returns –

TRUE if mem is dmabuf memory, otherwise FALSE

Since : 1.2

GstAllocators.prototype.is_dmabuf_memory 

function GstAllocators.prototype.is_dmabuf_memory(mem: Gst.Memory): {
    // javascript wrapper for 'gst_is_dmabuf_memory'
}

Check if mem is dmabuf memory.

Parameters:

mem (Gst.Memory) –

the memory to be check

Returns (Number) –

true if mem is dmabuf memory, otherwise false

Since : 1.2

GstAllocators.is_dmabuf_memory 

def GstAllocators.is_dmabuf_memory (mem):
    #python wrapper for 'gst_is_dmabuf_memory'

Check if mem is dmabuf memory.

Parameters:

mem (Gst.Memory) –

the memory to be check

Returns (bool) –

True if mem is dmabuf memory, otherwise False

Since : 1.2

Function Macros

GST_DMABUF_ALLOCATOR_CAST 

#define GST_DMABUF_ALLOCATOR_CAST(obj)         ((GstDmaBufAllocator *)(obj))

Constants

GST_ALLOCATOR_DMABUF 

#define GST_ALLOCATOR_DMABUF "dmabuf"

GstAllocators.ALLOCATOR_DMABUF

GstAllocators.ALLOCATOR_DMABUF

GST_CAPS_FEATURE_MEMORY_DMABUF 

#define GST_CAPS_FEATURE_MEMORY_DMABUF "memory:DMABuf"

Constant that defines the caps feature name for DMA buffer sharing.

It has to be used for non-mappable dma-buf only, i.e. when the underlying memory is not mappable to user space. Or when the mapped memory contains non meaningful data. It can be the case for protected content or when the user wants explicitly avoid any software post processing.

In these cases all elements between the exported and the importer has to work in passthrough mode. This is done by adding this caps feature.

When the memory is mappable for read and write requests then it is assumes to be a fast path and so this caps feature should not be used. Though according to the dma-buf protocol, while it is mapped it prevents the exporter to migrate the buffer.

This caps feature should not serve at all the purpose of selecting the GST_ALLOCATOR_DMABUF allocator during caps negotiation. When the exporter is the upstream element from the importer point of view, the exporter should try to map the dma buffer at runtime (preferably during decide_allocation phase). When it succeeds for GST_MAP_READWRITE this caps feature should not be used. This allows scalers, color converts and any image processing filters to work directly on the dma buffer. In this case the importer element should check all incoming memory using gst_is_dmabuf_memory.

Since : 1.12

GstAllocators.CAPS_FEATURE_MEMORY_DMABUF

Constant that defines the caps feature name for DMA buffer sharing.

It has to be used for non-mappable dma-buf only, i.e. when the underlying memory is not mappable to user space. Or when the mapped memory contains non meaningful data. It can be the case for protected content or when the user wants explicitly avoid any software post processing.

In these cases all elements between the exported and the importer has to work in passthrough mode. This is done by adding this caps feature.

When the memory is mappable for read and write requests then it is assumes to be a fast path and so this caps feature should not be used. Though according to the dma-buf protocol, while it is mapped it prevents the exporter to migrate the buffer.

This caps feature should not serve at all the purpose of selecting the GST_ALLOCATOR_DMABUF allocator during caps negotiation. When the exporter is the upstream element from the importer point of view, the exporter should try to map the dma buffer at runtime (preferably during decide_allocation phase). When it succeeds for Gst.MAP_READWRITE this caps feature should not be used. This allows scalers, color converts and any image processing filters to work directly on the dma buffer. In this case the importer element should check all incoming memory using GstAllocators.prototype.is_dmabuf_memory.

Since : 1.12

GstAllocators.CAPS_FEATURE_MEMORY_DMABUF

Constant that defines the caps feature name for DMA buffer sharing.

It has to be used for non-mappable dma-buf only, i.e. when the underlying memory is not mappable to user space. Or when the mapped memory contains non meaningful data. It can be the case for protected content or when the user wants explicitly avoid any software post processing.

In these cases all elements between the exported and the importer has to work in passthrough mode. This is done by adding this caps feature.

When the memory is mappable for read and write requests then it is assumes to be a fast path and so this caps feature should not be used. Though according to the dma-buf protocol, while it is mapped it prevents the exporter to migrate the buffer.

This caps feature should not serve at all the purpose of selecting the GST_ALLOCATOR_DMABUF allocator during caps negotiation. When the exporter is the upstream element from the importer point of view, the exporter should try to map the dma buffer at runtime (preferably during decide_allocation phase). When it succeeds for Gst.MAP_READWRITE this caps feature should not be used. This allows scalers, color converts and any image processing filters to work directly on the dma buffer. In this case the importer element should check all incoming memory using GstAllocators.is_dmabuf_memory.

Since : 1.12

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