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design/memory: add missing markup to gst keywords

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Reynaldo H. Verdejo Pinochet 2016-12-19 14:19:13 -08:00
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markdown/design/memory.md
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@ -2,7 +2,7 @@
This document describes the design of the memory objects. This document describes the design of the memory objects.
GstMemory objects are usually added to GstBuffer objects and contain the `GstMemory` objects are usually added to `GstBuffer` objects and contain the
multimedia data passed around in the pipeline. multimedia data passed around in the pipeline.
## Requirements ## Requirements
@ -15,9 +15,9 @@ multimedia data passed around in the pipeline.
`GstMemory` manages a memory region. The accessible part of the managed region is `GstMemory` manages a memory region. The accessible part of the managed region is
defined by an offset relative to the start of the region and a size. This defined by an offset relative to the start of the region and a size. This
means that the managed region can be larger than what is visible to the user of means that the managed region can be larger than what is visible to the user of
GstMemory API. `GstMemory` API.
Schematically, GstMemory has a pointer to a memory region of _maxsize_. The area Schematically, `GstMemory` has a pointer to a memory region of _maxsize_. The area
starting from `offset` and `size` is accessible. starting from `offset` and `size` is accessible.
``` ```
@ -43,8 +43,8 @@ The offset and size can be changed with:
## Allocators ## Allocators
GstMemory objects are created by allocators. Allocators are a subclass `GstMemory` objects are created by allocators. Allocators are a subclass
of GstObject and can be subclassed to make custom allocators. of `GstObject` and can be subclassed to make custom allocators.
``` c ``` c
struct _GstAllocator { struct _GstAllocator {
@ -60,7 +60,7 @@ struct _GstAllocator {
}; };
``` ```
The allocator class has 2 virtual methods. One to create a GstMemory, The allocator class has 2 virtual methods. One to create a `GstMemory`,
another to free it again. another to free it again.
``` c ``` c
@ -76,7 +76,7 @@ struct _GstAllocatorClass {
Allocators are refcounted. It is also possible to register the allocator to the Allocators are refcounted. It is also possible to register the allocator to the
GStreamer system. This way, the allocator can be retrieved by name. GStreamer system. This way, the allocator can be retrieved by name.
After an allocator is created, new GstMemory can be created with After an allocator is created, new `GstMemory` can be created with
``` c ``` c
GstMemory * gst_allocator_alloc (const GstAllocator * allocator, GstMemory * gst_allocator_alloc (const GstAllocator * allocator,
@ -84,18 +84,18 @@ After an allocator is created, new GstMemory can be created with
GstAllocationParams *params); GstAllocationParams *params);
``` ```
GstAllocationParams contain extra info such as flags, alignment, prefix and `GstAllocationParams` contain extra info such as flags, alignment, prefix and
padding. padding.
The GstMemory object is a refcounted object that must be freed with The `GstMemory` object is a refcounted object that must be freed with
gst_memory_unref (). `gst_memory_unref()`.
The GstMemory keeps a ref to the allocator that allocated it. Inside the The `GstMemory` keeps a ref to the allocator that allocated it. Inside the
allocator are the most common GstMemory operations listed. Custom allocator are the most common `GstMemory` operations listed. Custom
GstAllocator implementations must implement the various operations on `GstAllocator` implementations must implement the various operations on
the memory they allocate. the memory they allocate.
It is also possible to create a new GstMemory object that wraps existing It is also possible to create a new `GstMemory` object that wraps existing
memory with: memory with:
``` c ``` c
@ -108,7 +108,7 @@ memory with:
## Lifecycle ## Lifecycle
GstMemory extends from GstMiniObject and therefore uses its lifecycle `GstMemory` extends from `GstMiniObject` and therefore uses its lifecycle
management (See [miniobject](design/miniobject.md)). management (See [miniobject](design/miniobject.md)).
## Data Access ## Data Access
@ -118,7 +118,7 @@ call. This allows the implementation to monitor the access patterns or set up
the required memory mappings when needed. the required memory mappings when needed.
The access of the memory object is controlled with the locking mechanism on The access of the memory object is controlled with the locking mechanism on
GstMiniObject (See [miniobject](design/miniobject.md)). `GstMiniObject` (See [miniobject](design/miniobject.md)).
Mapping a memory region requires the caller to specify the access method: READ Mapping a memory region requires the caller to specify the access method: READ
and/or WRITE. Mapping a memory region will first try to get a lock on the and/or WRITE. Mapping a memory region will first try to get a lock on the
@ -145,11 +145,11 @@ is valid until the last unmap call is done.
When the final reference on a memory object is dropped, all outstanding When the final reference on a memory object is dropped, all outstanding
mappings should have been unmapped. mappings should have been unmapped.
Resizing a GstMemory does not influence any current mappings in any way. Resizing a `GstMemory` does not influence any current mappings in any way.
## Copy ## Copy
A GstMemory copy can be made with the `gst_memory_copy()` call. Normally, A `GstMemory` copy can be made with the `gst_memory_copy()` call. Normally,
allocators will implement a custom version of this function to make a copy of allocators will implement a custom version of this function to make a copy of
the same kind of memory as the original one. the same kind of memory as the original one.
@ -161,5 +161,5 @@ block.
## Share ## Share
A memory region can be shared between GstMemory object with the A memory region can be shared between `GstMemory` object with the
`gst_memory_share()` operation. `gst_memory_share()` operation.