[fix] ambisonics upmix for stereo

    else if ( st_ivas->ivas_format == STEREO_FORMAT )

#endif

    {

#ifdef FIX_1419_MONO_STEREO_UMX

        *nSamplesRendered = min( st_ivas->hTcBuffer->n_samples_available, nSamplesAskedLocal );

#endif

        /* Rendering */

        if ( st_ivas->renderer_type == RENDERER_MC )

        {

#ifndef FIX_1419_MONO_STEREO_UMX

            *nSamplesRendered = min( st_ivas->hTcBuffer->n_samples_available, nSamplesAskedLocal );

#endif

            ivas_ls_setup_conversion( st_ivas, st_ivas->nchan_transport, *nSamplesRendered, p_tc, p_output );

        }

#ifdef FIX_1419_MONO_STEREO_UMX

        else if ( st_ivas->renderer_type == RENDERER_SBA_LINEAR_ENC )

        {

            /* Only upmix to ambisonics if spatial parameters exist */

            // TODO default render config is not enabled here, the GetDefault API func is never used

            if ( st_ivas->hRenderConfig != NULL && !st_ivas->hRenderConfig->mono_stereo_upmix_config.spatialEnabled )

            {

                ivas_mc2sba( st_ivas->hIntSetup, p_output, p_output, *nSamplesRendered, st_ivas->hOutSetup.ambisonics_order, 0.f );

            }

            else

        {

            if ( st_ivas->ivas_format == MONO_FORMAT )

            {

                    // TODO route mono to W; probably same as ivas_jbm_dec_tc_buffer_playout

                /* routed to W */

                ivas_jbm_dec_tc_buffer_playout( st_ivas, nSamplesAskedLocal, nSamplesRendered, p_output );

            }

            else if ( st_ivas->ivas_format == STEREO_FORMAT )

            {

                    // TODO route stereo to W±Y

                    // p_output[0] = 0.5f * ( p_output[0] + p_output[1] ); // W = (L + R ) / 2

                    // p_output[1] = 0.5f * ( p_output[0] - p_output[1] ); // Y = (L - R ) / 2

                for ( n = 0; n < *nSamplesRendered; n++ )

                {

                    p_output[0][n] = 0.5f * ( p_output[0][n] + p_output[1][n] ); /* W = 0.5 * ( L + R ) */

                    p_output[1][n] = 0.5f * ( p_output[0][n] - p_output[1][n] ); /* Y = 0.5 * ( L - R ) */

                }

            }

        }