The color channel of the palette, red and blue reverse，Only the following code is the correct color result

[horch-E]

    LodePNGState state;
    lodepng_state_init(&state);
    state.info_raw.colortype = LCT_PALETTE;
    state.info_raw.bitdepth = 8;
    state.info_png.color.colortype = LCT_PALETTE;
    state.info_png.color.bitdepth = 8;
    state.encoder.auto_convert = 0;

    for(int i=0; i < palette->count; i++) {
        auto r = palette->entries[i].b;
        auto g = palette->entries[i].g;
        auto b = palette->entries[i].r;
        auto a = palette->entries[i].a;
        lodepng_palette_add(&state.info_png.color, r, g, b, a);
        lodepng_palette_add(&state.info_raw, r, g, b, a);
    }

[kornelski]

auto r = palette->entries[i].b; note r != b

[horch-E]

auto r = palette->entries[i].b; note r != b

yes, but only by writing like this can I get the correct output file.
i have send email about the problem detail

[kornelski]

In that case you have a BGR <> RGB mixup elsewhere. I'm 100% sure the library handles color order correctly.

Note that pixels must be in the RGBA order. There are operating systems and graphics frameworks which operate with ABGR or ARGB and other such combinations. Make sure you pass RGBA data in.

[horch-E]

I understand, thank you