diff options
| -rw-r--r-- | main/display.c | 12 | ||||
| -rw-r--r-- | main/jpeg_decoder.c | 11 |
2 files changed, 13 insertions, 10 deletions
diff --git a/main/display.c b/main/display.c index c37ea52..13babdb 100644 --- a/main/display.c +++ b/main/display.c @@ -424,13 +424,17 @@ esp_err_t display_wake(void) return err; } -// RGB565 → RGB888 in R,G,B byte order. TC358762's LCDCTRL = RGB888 path -// expects channel-order matching the DSI 24bpp packing. +// RGB565 → RGB888 in B,G,R byte order. The ESP32-P4 DSI engine + TC358762 +// bridge pipeline expects BGR on the wire for the panel's RGB channels — +// writing R first paints pure blue as solid red on the panel (verified +// with the M5 self-test: decoded buffer holds 0x001F, panel showed red). +// Symmetric pixels (white text on black) don't expose this; saturated +// channel inputs do. static inline void rgb565_to_rgb888(uint16_t px, uint8_t *out) { - out[0] = (uint8_t)(((px >> 11) & 0x1F) * 255 / 31); // R + out[0] = (uint8_t)(( px & 0x1F) * 255 / 31); // B out[1] = (uint8_t)(((px >> 5) & 0x3F) * 255 / 63); // G - out[2] = (uint8_t)(( px & 0x1F) * 255 / 31); // B + out[2] = (uint8_t)(((px >> 11) & 0x1F) * 255 / 31); // R } esp_err_t display_fill(uint16_t rgb565) diff --git a/main/jpeg_decoder.c b/main/jpeg_decoder.c index 259af65..f2a7d92 100644 --- a/main/jpeg_decoder.c +++ b/main/jpeg_decoder.c @@ -70,12 +70,11 @@ esp_err_t jpeg_decoder_decode(size_t jpeg_len, jpeg_decode_cfg_t dec_cfg = { .output_format = JPEG_DECODE_OUT_FORMAT_RGB565, - .rgb_order = JPEG_DEC_RGB_ELEMENT_ORDER_RGB, - // TODO: known color bug on M5 — solid red renders correctly but solid - // green renders ~black and solid blue renders green. Likely a JPEG - // colorspace / channel-permutation issue, not a byte-order one - // (swapping to BGR turns red into blue, confirming RGB is the right - // element ordering). Needs follow-up. + // Empirically: _RGB emits the RGB565 word in big-endian byte order + // (red 0xF800 → bytes f8 00) which our LE uint16 painter reads + // swapped. _BGR emits little-endian to match (despite the + // misleading "BGR" name) — verified by the decode-byte dump. + .rgb_order = JPEG_DEC_RGB_ELEMENT_ORDER_BGR, .conv_std = JPEG_YUV_RGB_CONV_STD_BT601, }; |