Video and Vision Processing Suite Intel® FPGA IP User Guide

ID 683329
Date 4/04/2022
Public

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Document Table of Contents

9.5. Chroma Resampler IP Software API

The IP includes software for run-time control. The IP does not fit any of the generic device models provided by the Nios II HAL and it exposes a set of dedicated accessors to the control and status registers. The IP driver structure inherits the base driver structure so all common methods defined in Video and Vision Processing IPs Software API are applicable.

Register definition header file: intel_vvp_crs_regs.h

Include file: intel_vvp_crs.h

Table 75.  Chroma Resampler IP API reference
Name Description
intel_vvp_crs_init Initialize the Chroma Resampler instance
intel_vvp_core_* Accessors defined in Video and Vision Processing IPs Software Programming Model. Writable when Lite is on. Readable when Lite is off and Debug features is on.
intel_vvp_crs_get_lite_mode Returns if Lite Mode is on.
intel_vvp_crs_get_debug_enabled Returns if Debug features is on.
intel_vvp_crs_is_conversion_supported Returns if the IP supports a specified chroma resampling.
intel_vvp_crs_is_running Returns if the IP is currently processing video data.
intel_vvp_crs_get_commit_status Returns uncommitted writes.
intel_vvp_crs_get_status Reads the status register.
intel_vvp_crs_set_output_subsampling Selects the current output subsampling.
intel_vvp_crs_get_output_subsampling Returns the current selected output subsampling.
intel_vvp_crs_commit_writes Commit all outstanding writes.

enum eIntelCrsSubsampling

Members

kIntelVvpCrsSubsampling420 (0) – 4:2:0 subsampling, chroma planes resolution is halved vertically and horizontally

kIntelVvpCrsSubsampling422 (2) – 4:2:2 subsampling, chroma planes resolution is halved horizontally

kIntelVvpCrsSubsampling444 (3) – 4:4:4 subsampling, chroma planes are fully sampled

kIntelVvpCrsSubsamplingInvalid (1) – Invalid subsampling (used to indicate errors)

Description

Enumeration for the supported chroma subsamplings

intel_vvp_crs_init

Prototype
int intel_vvp_crs_init(intel_vvp_crs_instance *instance, intel_vvp_core_base base);
Description

Initializes a Chroma Resampler instance. The initialization stops early if the vendor ID or product ID read at the base address are not a match or if the register map version is not supported. Otherwise, the function proceeds to read and store the IP compile-time parameterization. The instance will not be fully initialized and should not be used further by the application if returning a non-zero error code.

Arguments

instance – pointer to the intel_vvp_crs_instance software driver instance structure

base – base address of the register map

Returns

kIntelVvpCoreOk (0) in case of success, a negative error code in case of error

kIntelVvpCoreVidErr if the vendor id of the core is not the IntelFPGA vendor ID (0x6AF7).

kIntelVvpCorePidErr if the product_id does not match with the Chroma Resamplerproduct ID

kIntelVvpCoreInstanceErr if the instance is a null pointer

kIntelVvpCrsRegMapVersionErr if the register map is not supported

intel_vvp_crs_get_lite_mode

Prototype
bool intel_vvp_crs_get_lite_mode(intel_vvp_crs_instance *instance);
Description

Returns the value of the LITE_MODE register. The instance must be a valid intel_vvp_crs_instance fully initialized

Arguments

instance – pointer to the intel_vvp_crs_instance software driver instance structure

Returns

true if the IP is parameterized in lite mode

intel_vvp_crs_get_debug_enabled

Prototype
bool intel_vvp_crs_get_debug_enabled(intel_vvp_crs_instance *instance);
Description

Returns the value of the DEBUG_ENABLED register. The instance must be a valid intel_vvp_crs_instance fully initialized.

Arguments

instance – pointer to the intel_vvp_crs_instance software driver instance structure

Returns

true if the IP is parameterized with debug features enabled

intel_vvp_crs_is_conversion_supported

Prototype
 bool intel_vvp_crs_is_conversion_supported (intel_vvp_crs_instance *instance, eIntelCrsSubsampling input_subsampling, eIntelCrsSubsampling output_subsampling);
Description

Returns the value of the MAX_WIDTH register. The instance must be a valid intel_vvp_crs_instance fully initialized.

Arguments

instance – pointer to the intel_vvp_crs_instance software driver instance structure

input_subsampling – the input subsampling

output_subsampling – the output subsampling

Returns

if chroma resampling, or pass-through, from the input subsampling to the output subsampling is supported

intel_vvp_crs_is_running

Prototype
bool intel_vvp_crs_is_running(intel_vvp_crs_instance* instance);
Description

Reads and returns the running bit of the STATUS register. The instance must be a valid intel_vvp_crs_instance fully initialized.

Arguments

instance – pointer to the intel_vvp_crs_instance software driver instance structure

Returns

True is the IP is currently receiving/storing an input field, false when between two input fields

intel_vvp_crs_get_commit_status

Prototype
bool intel_vvp_crs_get_commit_status(intel_vvp_clipper_instance* instance);
Description

Reads and returns the commit pending bit of the STATUS register. The instance must be a valid intel_vvp_crs_instance fully initialized and configured in full mode.

Arguments

instance – pointer to the intel_vvp_crs_instance software driver instance structure

Returns

True is the IP is configured in full mode and if the agent interface contains uncommitted writes.

intel_vvp_crs_get_status

Prototype
uint32_t intel_vvp_crs_get_status(intel_vvp_crs_instance* instance);
Description

Reads the STATUS register. The instance must be a valid intel_vvp_crs_instance fully initialized.

Arguments

instance – pointer to the intel_vvp_crs_instance software driver instance structure

Returns

The content of the STATUS register

intel_vvp_crs_set_output_subsampling

Prototype
int intel_vvp_crs_set_output_subsampling(intel_vvp_crs_instance* instance, eIntelCrsSubsampling output_subsampling);
Description

Selects the required output subsampling. Use intel_vvp_core_set img_info_subsampling to set the input subsampling in lite mode. The instance must be a valid intel_vvp_crs_instance fully initialized. The call does not check if the IP supports the requested chroma resampling conversion and a default conversion will be used if the input/output selections are unsupported.

Arguments

instance – pointer to the intel_vvp_crs_instance software driver instance structure

output_subsampling – requested output subsampling

Returns

kIntelVvpCoreOk or a negative error code in case of error

kIntelVvpCoreInstanceErr, if the instance is the NULL pointer

kIntelVvpCrsParamErr, if one, or both, subsampling is/are invalid

intel_vvp_crs_get_output_subsampling

Prototype

eIntelCrsSubsampling intel_vvp_crs_get_output_subsampling(intel_vvp_crs_instance* instance);

Description

Reads the OUTPUT_SUBSAMPLING register. The instance must be a valid intel_vvp_crs_instance fully initialized and configured in debug mode.

Arguments

instance – pointer to the intel_vvp_crs_instance software driver instance structure

Returns

the last value written to the OUTPUT_SUBSAMPLING register or kIntelVvpCrsSubsamplingInvalid in case of errors

intel_vvp_crs_commit_writes

Prototype
int intel_vvp_crs_commit_writes(intel_vvp_crs_instance* instance)
Description

Commits all pending writes before processing the next field. The instance must be valid and parameterized in full mode.

Arguments

instance – pointer to the intel_vvp_crs_instance software driver instance structure

Returns

kIntelVvpCoreOk (0) for success, negative error code otherwise