Function rav1eCodecEncodeImage

src/codec_rav1e.c:60–287

}

static avifResult rav1eCodecEncodeImage(avifCodec * codec,
                                        avifEncoder * encoder,
                                        const avifImage * image,
                                        avifBool alpha,
                                        int tileRowsLog2,
                                        int tileColsLog2,
                                        int quality,
                                        avifEncoderChanges encoderChanges,
                                        avifBool disableLaggedOutput,
                                        uint32_t addImageFlags,
                                        avifCodecEncodeOutput * output)
{
    // rav1e does not support changing encoder settings.
    if (encoderChanges) {
        return AVIF_RESULT_NOT_IMPLEMENTED;
    }

    // rav1e does not support changing image dimensions.
    if (!codec->internal->rav1eContext) {
        codec->internal->encodeWidth = image->width;
        codec->internal->encodeHeight = image->height;
    } else if ((codec->internal->encodeWidth != image->width) || (codec->internal->encodeHeight != image->height)) {
        return AVIF_RESULT_NOT_IMPLEMENTED;
    }

    // rav1e does not support encoding layered image.
    if (encoder->extraLayerCount > 0) {
        return AVIF_RESULT_NOT_IMPLEMENTED;
    }

    // rav1e does not support disabling lagged output. See https://github.com/xiph/rav1e/issues/2267. Ignore this setting.
    (void)disableLaggedOutput;

    avifResult result = AVIF_RESULT_UNKNOWN_ERROR;

    RaConfig * rav1eConfig = NULL;
    RaFrame * rav1eFrame = NULL;

    if (!codec->internal->rav1eContext) {
        const avifBool supports400 = rav1eSupports400();
        RaPixelRange rav1eRange;
        if (alpha) {
            // AV1-AVIF specification, Section 4 "Auxiliary Image Items and Sequences":
            //   The color_range field in the Sequence Header OBU shall be set to 1.
            rav1eRange = RA_PIXEL_RANGE_FULL;

            // AV1-AVIF specification, Section 4 "Auxiliary Image Items and Sequences":
            //   The mono_chrome field in the Sequence Header OBU shall be set to 1.
            // Some encoders do not support 4:0:0 and encode alpha as 4:2:0 so it is not always respected.
            codec->internal->chromaSampling = supports400 ? RA_CHROMA_SAMPLING_CS400 : RA_CHROMA_SAMPLING_CS420;
            codec->internal->yShift = 1;

            // CICP (CP/TC/MC) does not apply to the alpha auxiliary image.
            // Use Unspecified (2) colour primaries, transfer characteristics, and matrix coefficients below.
        } else {
            // AV1-ISOBMFF specification, Section 2.3.4:
            //   The value of full_range_flag in the 'colr' box SHALL match the color_range
            //   flag in the Sequence Header OBU.