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72 lines
2.5 KiB
C
72 lines
2.5 KiB
C
/* SPI Master example: jpeg decoder.
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This example code is in the Public Domain (or CC0 licensed, at your option.)
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Unless required by applicable law or agreed to in writing, this
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software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
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CONDITIONS OF ANY KIND, either express or implied.
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*/
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/*
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The image used for the effect on the LCD in the SPI master example is stored in flash
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as a jpeg file. This file contains the decode_image routine, which uses the tiny JPEG
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decoder library to decode this JPEG into a format that can be sent to the display.
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Keep in mind that the decoder library cannot handle progressive files (will give
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``Image decoder: jd_prepare failed (8)`` as an error) so make sure to save in the correct
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format if you want to use a different image file.
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*/
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#include "decode_image.h"
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#include "jpeg_decoder.h"
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#include "esp_log.h"
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#include "esp_check.h"
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#include <string.h>
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#include "freertos/FreeRTOS.h"
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//Reference the binary-included jpeg file
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extern const uint8_t image_jpg_start[] asm("_binary_image_jpg_start");
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extern const uint8_t image_jpg_end[] asm("_binary_image_jpg_end");
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//Define the height and width of the jpeg file. Make sure this matches the actual jpeg
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//dimensions.
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const char *TAG = "ImageDec";
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//Decode the embedded image into pixel lines that can be used with the rest of the logic.
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esp_err_t decode_image(uint16_t **pixels)
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{
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*pixels = NULL;
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esp_err_t ret = ESP_OK;
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//Alocate pixel memory. Each line is an array of IMAGE_W 16-bit pixels; the `*pixels` array itself contains pointers to these lines.
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*pixels = calloc(IMAGE_H * IMAGE_W, sizeof(uint16_t));
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ESP_GOTO_ON_FALSE((*pixels), ESP_ERR_NO_MEM, err, TAG, "Error allocating memory for lines");
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//JPEG decode config
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esp_jpeg_image_cfg_t jpeg_cfg = {
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.indata = (uint8_t *)image_jpg_start,
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.indata_size = image_jpg_end - image_jpg_start,
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.outbuf = (uint8_t*)(*pixels),
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.outbuf_size = IMAGE_W * IMAGE_H * sizeof(uint16_t),
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.out_format = JPEG_IMAGE_FORMAT_RGB565,
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.out_scale = JPEG_IMAGE_SCALE_0,
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.flags = {
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.swap_color_bytes = 1,
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}
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};
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//JPEG decode
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esp_jpeg_image_output_t outimg;
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esp_jpeg_decode(&jpeg_cfg, &outimg);
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ESP_LOGI(TAG, "JPEG image decoded! Size of the decoded image is: %dpx x %dpx", outimg.width, outimg.height);
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return ret;
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err:
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//Something went wrong! Exit cleanly, de-allocating everything we allocated.
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if (*pixels != NULL) {
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free(*pixels);
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}
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return ret;
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}
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