Function avifParseSampleTransformImageBox

src/read.c:2277–2302

Parses the raw bitstream of the 'sato' Sample Transform derived image item and extracts the expression.

// Parses the raw bitstream of the 'sato' Sample Transform derived image item and extracts the expression.
static avifResult avifParseSampleTransformImageBox(const uint8_t * raw,
                                                   size_t rawLen,
                                                   uint32_t numInputImageItems,
                                                   avifSampleTransformExpression * expression,
                                                   avifDiagnostics * diag)
{
    BEGIN_STREAM(s, raw, rawLen, diag, "Box[sato]");

    uint8_t version, reserved, bitDepth;
    AVIF_CHECKERR(avifROStreamReadBitsU8(&s, &version, /*bitCount=*/2), AVIF_RESULT_BMFF_PARSE_FAILED); // unsigned int(2) version = 0;
    AVIF_CHECKERR(avifROStreamReadBitsU8(&s, &reserved, /*bitCount=*/4), AVIF_RESULT_BMFF_PARSE_FAILED); // unsigned int(4) reserved;
    AVIF_CHECKERR(avifROStreamReadBitsU8(&s, &bitDepth, /*bitCount=*/2), AVIF_RESULT_BMFF_PARSE_FAILED); // unsigned int(2) bit_depth;
    AVIF_CHECKERR(version == 0, AVIF_RESULT_NOT_IMPLEMENTED);
    AVIF_CHECKERR(bitDepth == AVIF_SAMPLE_TRANSFORM_BIT_DEPTH_32, AVIF_RESULT_NOT_IMPLEMENTED);

    const avifResult result = avifParseSampleTransformTokens(&s, expression);
    if (result != AVIF_RESULT_OK) {
        avifArrayDestroy(expression);
        return result;
    }
    if (!avifSampleTransformExpressionIsValid(expression, numInputImageItems)) {
        avifArrayDestroy(expression);
        return AVIF_RESULT_BMFF_PARSE_FAILED;
    }
    return AVIF_RESULT_OK;
}

static const avifProperty * avifDecoderItemCodecConfigOrFirstCellCodecConfig(const avifDecoderItem * item)
{