Function avifDecoderCheckGainMapProperties

src/read.c:5966–6001

}

static avifResult avifDecoderCheckGainMapProperties(avifDecoder * decoder, const avifPropertyArray * gainMapProperties)
{
    const avifImage * image = decoder->image;
    // libavif requires the bitstream contain the same 'pasp', 'clap', 'irot', 'imir'
    // properties for both the base and gain map image items used as input to
    // the tone-mapped derived image item. libavif also requires the tone-mapped
    // derived image item itself not be associated with these properties. This is
    // enforced at encoding. Other patterns are rejected at decoding.
    const avifProperty * paspProp = avifPropertyArrayFind(gainMapProperties, "pasp");
    if (!paspProp != !(image->transformFlags & AVIF_TRANSFORM_PASP) ||
        (paspProp && (paspProp->u.pasp.hSpacing != image->pasp.hSpacing || paspProp->u.pasp.vSpacing != image->pasp.vSpacing))) {
        avifDiagnosticsPrintf(&decoder->diag,
                              "Pixel aspect ratio property mismatch between input items of tone-mapping derived image item");
        return AVIF_RESULT_DECODE_GAIN_MAP_FAILED;
    }
    const avifProperty * clapProp = avifPropertyArrayFind(gainMapProperties, "clap");
    if (!clapProp != !(image->transformFlags & AVIF_TRANSFORM_CLAP) ||
        (clapProp && (clapProp->u.clap.widthN != image->clap.widthN || clapProp->u.clap.widthD != image->clap.widthD ||
                      clapProp->u.clap.heightN != image->clap.heightN || clapProp->u.clap.heightD != image->clap.heightD ||
                      clapProp->u.clap.horizOffN != image->clap.horizOffN || clapProp->u.clap.horizOffD != image->clap.horizOffD ||
                      clapProp->u.clap.vertOffN != image->clap.vertOffN || clapProp->u.clap.vertOffD != image->clap.vertOffD))) {
        avifDiagnosticsPrintf(&decoder->diag, "Clean aperture property mismatch between input items of tone-mapping derived image item");
        return AVIF_RESULT_DECODE_GAIN_MAP_FAILED;
    }
    const avifProperty * irotProp = avifPropertyArrayFind(gainMapProperties, "irot");
    if (!irotProp != !(image->transformFlags & AVIF_TRANSFORM_IROT) || (irotProp && irotProp->u.irot.angle != image->irot.angle)) {
        avifDiagnosticsPrintf(&decoder->diag, "Rotation property mismatch between input items of tone-mapping derived image item");
        return AVIF_RESULT_DECODE_GAIN_MAP_FAILED;
    }
    const avifProperty * imirProp = avifPropertyArrayFind(gainMapProperties, "imir");
    if (!imirProp != !(image->transformFlags & AVIF_TRANSFORM_IMIR) || (imirProp && imirProp->u.imir.axis != image->imir.axis)) {
        avifDiagnosticsPrintf(&decoder->diag, "Mirroring property mismatch between input items of tone-mapping derived image item");
        return AVIF_RESULT_DECODE_GAIN_MAP_FAILED;
    }
    return AVIF_RESULT_OK;
}

// Finds any 'sato' Sample Transform derived image item, distinct from the primary image item,
// and in the same 'altr' group as the primary image item. Returns NULL otherwise.