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docs: Gram and nit fixes for part-bufferpool.txt
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@ -4,7 +4,7 @@ Bufferpool
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This document details the design of how buffers are be allocated and
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managed in pools.
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Bufferpools increases performance by reducing allocation overhead and
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Bufferpools increase performance by reducing allocation overhead and
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improving possibilities to implement zero-copy memory transfer.
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Together with the ALLOCATION query, elements can negotiate allocation properties
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@ -40,7 +40,7 @@ GstBufferPool
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The bufferpool object manages a list of buffers with the same properties such
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as size, padding and alignment.
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The bufferpool has two states: active and inactive. In the in-active
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The bufferpool has two states: active and inactive. In the inactive
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state, the bufferpool can be configured with the required allocation
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preferences. In the active state, buffers can be retrieved from and
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returned to the pool.
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@ -99,13 +99,13 @@ Allocation query
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guint max_buffers;
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}
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use gst_query_parse_nth_allocation_pool() to get the values.
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Use gst_query_parse_nth_allocation_pool() to get the values.
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The allocator can contain multiple pool configurations. If need-pool
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was TRUE, the pool member might contain a GstBufferPool when the
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downstream element can provide one.
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Size contains the size of the bufferpool buffers and is never 0.
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Size contains the size of the bufferpool's buffers and is never 0.
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min_buffers and max_buffers contain the suggested min and max amount of
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buffers that should be managed by the pool.
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@ -125,7 +125,7 @@ Allocation query
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GstAllocationParams params;
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}
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use gst_query_parse_nth_allocation_param() to get the values
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Use gst_query_parse_nth_allocation_param() to get the values.
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The element performing the query can use the allocators and its
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parameters to allocate memory for the downstream element.
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@ -144,7 +144,7 @@ Allocation query
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These metadata items can be accepted by the downstream element when
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placed on buffers. There is also an arbitrary GstStructure associated
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with the metadata that contains metadata specific options.
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with the metadata that contains metadata-specific options.
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Some bufferpools have options to enable metadata on the buffers
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allocated by the pool.
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@ -214,7 +214,7 @@ of a caps change), alignment or number of buffers.
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RECONFIGURE event upstream. This instructs upstream to renegotiate both
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the format and the bufferpool when needed.
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A pipeline reconfiguration is when new elements are added or removed from
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A pipeline reconfiguration happens when new elements are added or removed from
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the pipeline or when the topology of the pipeline changes. Pipeline
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reconfiguration also triggers possible renegotiation of the bufferpool and
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caps.
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@ -293,13 +293,13 @@ Use cases
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those elements require more than that amount of buffers for temporary
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storage.
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The bufferpool of myvideosink will then be configured with the size of the
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Myvideosink's bufferpool will then be configured with the size of the
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buffers for the negotiated format and according to the padding and alignment
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rules. When videotestsrc sets the pool to active, the 3 video
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buffers will be preallocated in the pool.
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videotestsrc acquires a buffer from the configured pool on its srcpad and
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pushes this into the queue. When the videotestsrc has acquired and pushed
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pushes this into the queue. When videotestsrc has acquired and pushed
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3 frames, the next call to gst_buffer_pool_acquire_buffer() will block
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(assuming the GST_BUFFER_POOL_FLAG_DONTWAIT is not specified).
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@ -324,9 +324,9 @@ Use cases
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decoder linked to a fakesink but we will then dynamically change the
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sink to one that can provide a bufferpool.
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When it negotiates the size with the downstream element fakesink, it will
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When myvideodecoder negotiates the size with the downstream fakesink element, it will
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receive a NULL bufferpool because fakesink does not provide a bufferpool.
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It will then select its own custom bufferpool to start the datatransfer.
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It will then select its own custom bufferpool to start the data transfer.
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At some point we block the queue srcpad, unlink the queue from the
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fakesink, link a new sink and set the new sink to the PLAYING state.
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@ -334,7 +334,7 @@ Use cases
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and, through queue, inform myvideodecoder that it should renegotiate its
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bufferpool because downstream has been reconfigured.
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Before pushing the next buffer, myvideodecoder would renegotiate a new
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Before pushing the next buffer, myvideodecoder has to renegotiate a new
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bufferpool. To do this, it performs the usual bufferpool negotiation
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algorithm. If it can obtain and configure a new bufferpool from downstream,
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it sets its own (old) pool to inactive and unrefs it. This will eventually
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@ -348,13 +348,13 @@ Use cases
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myvideodecoder has negotiated a bufferpool with the downstream myvideosink
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to handle buffers of size 320x240. It has now detected a change in the
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video format and need to renegotiate to a resolution of 640x480. This
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requires it to negotiate a new bufferpool with a larger buffersize.
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video format and needs to renegotiate to a resolution of 640x480. This
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requires it to negotiate a new bufferpool with a larger buffer size.
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When myvideodecoder needs to get the bigger buffer, it starts the
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negotiation of a new bufferpool. It queries a bufferpool from downstream,
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reconfigures it with the new configuration (which includes the bigger buffer
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size) and it then sets the bufferpool to active. The old pool is inactivated
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size) and sets the bufferpool to active. The old pool is inactivated
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and unreffed, which causes the old format to drain.
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It then uses the new bufferpool for allocating new buffers of the new
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@ -371,7 +371,7 @@ Use cases
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change the resolution.
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myvideosink sends a RECONFIGURE event upstream to notify upstream that a
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new format is desirable. upstream elements try to negotiate a new format
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new format is desirable. Upstream elements try to negotiate a new format
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and bufferpool before pushing out a new buffer. The old bufferpools are
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drained in the regular way.
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