Aryan Salmanpour
40 wiersze
1.9 KiB
ReStructuredText
40 wiersze
1.9 KiB
ReStructuredText
.. meta::
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:description: Using rocJPEG
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:keywords: parse JPEG, parse, decode, JPEG decoder, JPEG decoding, rocJPEG, AMD, ROCm
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********************************************************************
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Using rocJPEG
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********************************************************************
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To learn how to use the rocJPEG SDK library, follow these instructions:
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1. API overview
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====================================================
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All rocJPEG APIs are exposed in the header file ``rocjpeg.h``. You can find
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this file in the `api` folder in the rocJPEG repository.
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2. Create a decoder
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====================================================
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``rocJpegCreate()`` creates an instance of the hardware JPEG decoder object and provides you
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with a handle upon successful creation. The decoder handle
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returned by ``rocJpegCreate()`` must be retained for the entire decode session because the
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handle is passed along with the other decoding APIs.
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3. Retrieve the image info
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====================================================
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``rocJpegGetImageInfo()`` retrieves the image info, including channel, width and height of each component, and chroma subsampling.
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4. Decode a JPEG stream
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====================================================
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``rocJpegDecode()`` decodes single image based on the backend used to create the rocJpeg handle in rocJpegCreate API.
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Destination buffers should be large enough to be able to store output of specified format. These buffers should be pre-allocted by the user in the device memories.
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For each color plane (channel) sizes could be retrieved for image using ``rocJpegGetImageInfo()`` API
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and minimum required memory buffer for each plane is plane_height * plane_pitch where plane_pitch >= plane_width for
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planar output formats and plane_pitch >= plane_width * num_components for interleaved output format.
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5. Destroy the decoder
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====================================================
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You must call the ``rocJpegDestroy()`` to destroy the session and free up resources. |