nvjpeg2kStreamParse()

This function is the first step in the decoding of a JPEG2000 bitstream. It accepts the bitstream buffer on host memory as input and parses the JPEG2000 header information. The parsed information is stored in the nvjpeg2kStream_t handle and can be retrieved by the APIs documented in this section.

Signature:

nvjpeg2kStatus_t nvjpeg2kStreamParse(nvjpeg2kHandle_t handle,
        const unsigned char *data,
        size_t length,
        int save_metadata,
        int save_stream,
        nvjpeg2kStream_t *stream_handle);

Parameters:

Parameter	Input/Output	Memory	Description
nvjpeg2kHandle_t handle	Input	Host	library handle
const unsigned char *data	Input	Host	bitstream buffer
size_t length	Input	Host	bitstream size in bytes
int save_metadata	Input	Host	Set to 0. Added for future use
int save_stream	Input	Host	Set to 0. Added for future use
nvjpeg2kStream_t *stream_handle	Input	Host	bitstream handle

Returns:

nvjpeg2kStatus_t - An error code as specified in API Return Status Codes

nvjpeg2kStreamGetImageInfo()

Retrieves the image information defined in nvjpeg2kImageInfo_t. This information is useful in allocating output buffers on device memory.

Signature:

nvjpeg2kStatus_t nvjpeg2kStreamGetImageInfo(nvjpeg2kStream_t stream_handle,
        nvjpeg2kImageInfo_t* image_info);

Parameters:

Parameter	Input/Output	Memory	Description
nvjpeg2kStream_t *stream_handle	Input	Host	bitstream handle
nvjpeg2kImageInfo_t* image_info	Input/Output	Host	Pointer to nvjpeg2kImageInfo_t

Returns:

nvjpeg2kStatus_t - An error code as specified in API Return Status Codes

nvjpeg2kStreamGetImageComponentInfo()

Retrieves the component level information defined in nvjpeg2kImageComponentInfo_t This information can be used in allocating output buffers on device memory. Component level information is useful when the dimensions vary across components.

Signature:

nvjpeg2kStatus_t nvjpeg2kStreamGetImageComponentInfo(nvjpeg2kStream_t stream_handle,
        nvjpeg2kImageComponentInfo_t* component_info,
        uint32_t component_id);

Parameters:

Parameter	Input/Output	Memory	Description
nvjpeg2kStream_t stream_handle	Input	Host	bitstream handle
nvjpeg2kImageComponentInfo_t* component_info	Input/Output	Host	Pointer to nvjpeg2kImageInfo_t
uint32_t component_id	Input	Host	Component index

Returns:

nvjpeg2kStatus_t - An error code as specified in API Return Status Codes

nvjpeg2kStreamGetResolutionsInTile()

Retrieves the number of resolutions present in a tile. The number of resolutions is defined as: numResolutions = numWaveletDecompositionLevels + 1. Tiles in jpeg 2000 are indexed in raster scan order. nvjpeg2kStreamGetImageInfo retrieves the number of tiles present along both the x and y directions. For tile coordinates tile_x, tile_y: tile_id = tile_y * num_tiles_x + tile_x, where tile_x and tile_y are in tile units.

Signature:

nvjpeg2kStatus_t nvjpeg2kStreamGetResolutionsInTile(
        nvjpeg2kStream *stream_handle,
        uint32_t tile_id,
        uint32_t* num_res);

Parameters:

Parameter	Input/Output	Memory	Description
nvjpeg2kStream_t stream_handle	Input	Host	bitstream handle
uint32_t tile_id	Input	Host	Raster scan based tile index
uint32_t* num_res	Output	Host	Number of resolutions present in the tile

Returns:

nvjpeg2kStatus_t - An error code as specified in API Return Status Codes

nvjpeg2kStreamGetTileComponentDim()

Retrieves the tile width and tile height for a tile component. This function is useful when the tile dimensions in Image Information are not a multiple of the image dimensions.

Signature:

nvjpeg2kStatus_t nvjpeg2kStreamGetTileComponentDim(
        nvjpeg2kStream *stream_handle,
        uint32_t component_id,
        uint32_t tile_id,
        uint32_t* tile_width,
        uint32_t* tile_height);

Parameters:

Returns:

nvjpeg2kStatus_t - An error code as specified in API Return Status Codes

nvjpeg2kStreamGetResolutionComponentDim()

Retrieves the dimensions at a resolution level for a tile component. The formula is as follows:

res_scale = 1 << (num_resolutions - res_level - 1)
res_width   = (tile_width  + res_scale - 1) >> res_scale
res_height  = (tile_height + res_scale - 1) >> res_scale

Signature:

nvjpeg2kStatus_t nvjpeg2kStreamGetResolutionComponentDim(
        nvjpeg2kStream_t   stream_handle,
        uint32_t component_id,
        uint32_t tile_id,
        uint32_t res_level,
        uint32_t* res_width,
        uint32_t* res_height);

Returns:

nvjpeg2kStatus_t - An error code as specified in API Return Status Codes

nvjpeg2kStreamGetColorSpace()

Retrieves color space information from a parsed JP2 file. For a jpeg 2000 codestream (.j2k file), this function will retrieve NVJPEG2K_COLORSPACE_UNKNOWN since color space information is not available.

Signature:

nvjpeg2kStatus_t nvjpeg2kStreamGetColorSpace(nvjpeg2kStream_t stream_handle,
        nvjpeg2kColorSpace_t* color_space);

Parameters:

Parameter	Input/Output	Memory	Description
nvjpeg2kStream_t stream_handle	Input	Host	bitstream handle
nvjpeg2kColorSpace_t* color_space	Input/Output	Host	Color space of the parsed image

Returns:

nvjpeg2kStatus_t - An error code as specified in API Return Status Codes