Function avifTilesCanBeDecodedWithSameCodecInstance

src/read.c:5389–5422

}

static avifBool avifTilesCanBeDecodedWithSameCodecInstance(const avifDecoderData * data)
{
    int32_t numImageBuffers = 0, numStolenImageBuffers = 0;
    for (int c = 0; c < AVIF_ITEM_CATEGORY_COUNT; ++c) {
        if (data->tileInfos[c].tileCount > 0) {
            ++numImageBuffers;
        }
        // The sample operations require multiple buffers for compositing so no plane is stolen
        // when there is a 'sato' Sample Transform derived image item.
        if (c >= AVIF_SAMPLE_TRANSFORM_MIN_CATEGORY && c <= AVIF_SAMPLE_TRANSFORM_MAX_CATEGORY && data->tileInfos[c].tileCount > 0) {
            continue;
        }
        if (data->tileInfos[c].tileCount == 1) {
            ++numStolenImageBuffers;
        }
    }
    if (numStolenImageBuffers > 0 && numImageBuffers > 1) {
        // Single tile image with single tile alpha plane or gain map. In this case each tile needs its own decoder since the planes will be
        // "stolen". Stealing either the color or the alpha plane (or gain map) will invalidate the other ones when decode is called the second
        // (or third) time.
        return AVIF_FALSE;
    }
    const uint8_t firstTileOperatingPoint = data->tiles.tile[0].operatingPoint;
    const avifBool firstTileAllLayers = data->tiles.tile[0].input->allLayers;
    for (unsigned int i = 1; i < data->tiles.count; ++i) {
        const avifTile * tile = &data->tiles.tile[i];
        if (tile->operatingPoint != firstTileOperatingPoint || tile->input->allLayers != firstTileAllLayers) {
            return AVIF_FALSE;
        }
        // avifDecoderItemValidateProperties() verified during avifDecoderParse() that all tiles
        // share the same coding format so no need to check for codecType equality here.
    }
    return AVIF_TRUE;
}

static avifResult avifDecoderCreateCodecs(avifDecoder * decoder)
{