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STM32F769IDiscovery
1.00
uDANTE Audio Networking with STM32F7 DISCO board
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STM32F769IDiscovery
1.00
uDANTE Audio Networking with STM32F7 DISCO board
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JPEG HAL module driver. This file provides firmware functions to manage the following functionalities of the JPEG encoder/decoder peripheral: More...
#include "stm32f7xx_hal.h"Go to the source code of this file.
JPEG HAL module driver. This file provides firmware functions to manage the following functionalities of the JPEG encoder/decoder peripheral:
==============================================================================
##### How to use this driver #####
==============================================================================
[..]
(#) Initialize the JPEG peripheral using HAL_JPEG_Init : No initialization parameters are required.
Only the call to HAL_JPEG_Init is necessary to initialize the JPEG peripheral.
(#) If operation is JPEG encoding use function HAL_JPEG_ConfigEncoding to set
the encoding parameters (mandatory before calling the encoding function).
the application can change the encoding parameter "ImageQuality" from
1 to 100 to obtain a more or less quality (visual quality vs the original row image),
and inversely more or less jpg file size.
(#) Note that for decoding operation the JPEG peripheral output data are organized in
YCbCr blocks called MCU (Minimum Coded Unit) as defioned in the JPEG specification
ISO/IEC 10918-1 standard.
It is up to the application to transform these YCbCr blocks to RGB data that can be display.
Respectively, for Encoding operation the JPEG peripheral input should be organized
in YCbCr MCU blocks. It is up to the application to perform the necessary RGB to YCbCr
MCU blocks transformation before feeding the JPEG peripheral with data.
(#) Use functions HAL_JPEG_Encode and HAL_JPEG_Decode to start respectively
a JPEG encoding/decoding operation in polling method (blocking).
(#) Use functions HAL_JPEG_Encode_IT and HAL_JPEG_Decode_IT to start respectively
a JPEG encoding/decoding operation with Interrupt method (not blocking).
(#) Use functions HAL_JPEG_Encode_DMA and HAL_JPEG_Decode_DMA to start respectively
a JPEG encoding/decoding operation with DMA method (not blocking).
(#) Callback HAL_JPEG_InfoReadyCallback is asserted if the current operation
is a JPEG decoding to provide the application with JPEG image parameters.
This callback is asserted when the JPEG peripheral successfully parse the
JPEG header.
(#) Callback HAL_JPEG_GetDataCallback is asserted for both encoding and decoding
operations to inform the application that the input buffer has been
consumed by the peripheral and to ask for a new data chunk if the operation
(encoding/decoding) has not been complete yet.
This CallBack should be implemented in the application side. It should
call the function HAL_JPEG_ConfigInputBuffer if new input data are available,
or call HAL_JPEG_Pause with parameter XferSelection set to "JPEG_PAUSE_RESUME_INPUT"
to inform the JPEG HAL driver that the ongoing operation shall pause waiting for the
application to provide a new input data chunk.
Once the application succeed getting new data and if the input has been paused,
the application can call the function HAL_JPEG_ConfigInputBuffer to set the new
input buffer and size, then resume the JPEG HAL input by calling new function HAL_JPEG_Resume.
If the application has ended feeding the HAL JPEG with input data (no more input data), the application
Should call the function “HAL_JPEG_ConfigInputBuffer” (within the callback HAL_JPEG_GetDataCallback)
with the parameter “InDataLength” set to zero.
The mechanism of HAL_JPEG_ConfigInputBuffer/HAL_JPEG_Pause/HAL_JPEG_Resume allows
to the application to provide the input data (for encoding or decoding) by chunks.
If the new input data chunk is not available (because data should be read from an input file
for example) the application can pause the JPEG input (using function HAL_JPEG_Pause)
Once the new input data chunk is available ( read from a file for example), the application
can call the function "HAL_JPEG_ConfigInputBuffer" to provide the HAL with the new chunk
then resume the JPEG HAL input by calling function "HAL_JPEG_Resume".
The application can call functions “HAL_JPEG_ConfigInputBuffer “ then "HAL_JPEG_Resume".
any time (outside the HAL_JPEG_GetDataCallback) Once the new input chunk data available.
However, to keep data coherency, the function “HAL_JPEG_Pause” must be imperatively called
(if necessary) within the callback “HAL_JPEG_GetDataCallback”, i.e when the HAL JPEG has ended
Transferring the previous chunk buffer to the JPEG peripheral.
(#) Callback HAL_JPEG_DataReadyCallback is asserted when the HAL JPEG driver
has filled the given output buffer with the given size.
This CallBack should be implemented in the application side. It should
call the function HAL_JPEG_ConfigOutputBuffer to provide the HAL JPEG driver
with the new output buffer location and size to be used to store next data chunk.
if the application is not ready to provide the output chunk location then it can
call the function "HAL_JPEG_Pause" with parameter XferSelection set to "JPEG_PAUSE_RESUME_OUTPUT"
to inform the JPEG HAL driver that it shall pause output data. Once the application
is ready to receive the new data chunk (output buffer location free or available) it should call
the function "HAL_JPEG_ConfigOutputBuffer" to provide the HAL JPEG driver
with the new output chunk buffer location and size, then call "HAL_JPEG_Resume"
to inform the HAL that it shall resume outputting data in the given output buffer.
The mechanism of HAL_JPEG_ConfigOutputBuffer/HAL_JPEG_Pause/HAL_JPEG_Resume allows
the application to receive data from the JPEG peripheral by chunks. when a chunk
is received, the application can pause the HAL JPEG output data to be able to process
these received data (YCbCr to RGB conversion in case of decoding or data storage in case
of encoding).
The application can call functions “HAL_JPEG_ ConfigOutputBuffer“ then "HAL_JPEG_Resume".
any time (outside the HAL_JPEG_ DataReadyCallback) Once the output data buffer is free to use.
However, to keep data coherency, the function “HAL_JPEG_Pause” must be imperatively called
(if necessary) within the callback “HAL_JPEG_ DataReadyCallback”, i.e when the HAL JPEG has ended
Transferring the previous chunk buffer from the JPEG peripheral to the application.
(#) Callback HAL_JPEG_EncodeCpltCallback is asserted when the HAL JPEG driver has
ended the current JPEG encoding operation, and all output data has been transmitted
to the application.
(#) Callback HAL_JPEG_DecodeCpltCallback is asserted when the HAL JPEG driver has
ended the current JPEG decoding operation. and all output data has been transmitted
to the application.
(#) Callback HAL_JPEG_ErrorCallback is asserted when an error occurred during
the current operation. the application can call the function "HAL_JPEG_GetError"
to retrieve the error codes.
(#) By default the HAL JPEG driver uses the default quantization tables
as provide in the JPEG specification (ISO/IEC 10918-1 standard) for encoding.
User can change these default tables if necessary using the function "HAL_JPEG_SetUserQuantTables"
Note that for decoding the quantization tables are automatically extracted from
the JPEG header.
(#) To control JPEG state you can use the following function: HAL_JPEG_GetState()
*** JPEG HAL driver macros list ***
=============================================
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Below the list of most used macros in JPEG HAL driver.
(+) __HAL_JPEG_RESET_HANDLE_STATE : Reset JPEG handle state.
(+) __HAL_JPEG_ENABLE : Enable the JPEG peripheral.
(+) __HAL_JPEG_DISABLE : Disable the JPEG peripheral.
(+) __HAL_JPEG_GET_FLAG : Check the specified JPEG status flag.
(+) __HAL_JPEG_CLEAR_FLAG : Clear the specified JPEG status flag.
(+) __HAL_JPEG_ENABLE_IT : Enable the specified JPEG Interrupt.
(+) __HAL_JPEG_DISABLE_IT : Disable the specified JPEG Interrupt.
(+) __HAL_JPEG_GET_IT_SOURCE : returns the state of the specified JPEG Interrupt (Enabled or disabled).Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Definition in file stm32f7xx_hal_jpeg.c.
1.8.11