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fix(jpeg): JPEG can encode and decode in encryption situation

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C.S.M
2026-07-13 15:00:31 +08:00
parent 41582e1777
commit e92e669dee
14 changed files with 559 additions and 20 deletions
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docs/en/api-reference/peripherals/jpeg.rst
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@@ -25,6 +25,7 @@ This document covers the following sections:
- :ref:`jpeg-pixel-storage-layout` - covers color space order overview required in this JPEG decoder and encoder.
- :ref:`jpeg-thread-safety` - lists which APIs are guaranteed to be thread safe by the driver.
- :ref:`jpeg-power-management` - describes how JPEG driver would be affected by power consumption.
- :ref:`jpeg-flash-encryption` - describes how to use the JPEG codec correctly when flash/PSRAM encryption is enabled.
- :ref:`jpeg-kconfig-options` - lists the supported Kconfig options that can bring different effects to the driver.
.. _jpeg-resource-allocation:
@@ -573,6 +574,24 @@ When power management is enabled (i.e., :ref:`CONFIG_PM_ENABLE` is set), the sys
Whenever the user is decoding or encoding via JPEG (i.e., calling :cpp:func:`jpeg_encoder_process` or :cpp:func:`jpeg_decoder_process`), the driver guarantees that the power management lock is acquired by setting it to :cpp:enumerator:`esp_pm_lock_type_t::ESP_PM_CPU_FREQ_MAX`. Once the encoding or decoding is finished, the driver releases the lock and the system can enter Light-sleep.
.. _jpeg-flash-encryption:
Usage Under Encryption
^^^^^^^^^^^^^^^^^^^^^^
The JPEG codec moves data via the 2D-DMA, and the JPEG codec **cannot process encrypted data**. Therefore, when PSRAM encryption is enabled, the JPEG input/output buffers must reside in an unencrypted memory region, otherwise encoding/decoding fails.
To support the encrypted scenario, the driver does the following:
- When ``CONFIG_SPIRAM_ENC_EXEMPT`` is enabled, :cpp:func:`jpeg_alloc_decoder_mem` and :cpp:func:`jpeg_alloc_encoder_mem` allocate buffers from the unencrypted PSRAM region (``MALLOC_CAP_SPIRAM_NO_ENC``) automatically.
- The allocated buffers satisfy both the cache line alignment and the byte alignment required by the 2D-DMA.
Please note the following when using it:
1. It is recommended to always allocate buffers via :cpp:func:`jpeg_alloc_encoder_mem` / :cpp:func:`jpeg_alloc_decoder_mem` to ensure correct alignment and memory region.
2. The size of the unencrypted region is determined by ``CONFIG_SPIRAM_ENC_EXEMPT_SIZE``. Since the JPEG buffer size depends on the image resolution and cannot be predicted automatically, configure it according to the largest image you actually process. If the region is insufficient, the allocation fails and an error log is printed, suggesting to enlarge ``CONFIG_SPIRAM_ENC_EXEMPT_SIZE``. Also note that this value must not be greater than or equal to the actual PSRAM size, otherwise the unencrypted region is disabled.
.. _jpeg-kconfig-options:
Kconfig Options