Commit 5e664670 authored by Dominik Weckbecker's avatar Dominik Weckbecker 💬
Browse files

re-purpose sba-order bits to signal the number of objects in OSBA at low BR

parent fa43fa46

lib_dec/ivas_init_dec.c

+16 −0
Original line number Diff line number Diff line
@@ -430,6 +430,22 @@ ivas_error ivas_dec_setup( 
            /* read Ambisonic (SBA) order */

            st_ivas->sba_order = st_ivas->bit_stream[num_bits_read + 1];

            st_ivas->sba_order += 2 * st_ivas->bit_stream[num_bits_read];

            if ( ivas_total_brate >= IVAS_256k )

            {

                st_ivas->sba_order = st_ivas->bit_stream[num_bits_read + 1];

                st_ivas->sba_order += 2 * st_ivas->bit_stream[num_bits_read];

                st_ivas->ism_mode = ISM_SBA_MODE_DISC;

            }

            else

            {

                st_ivas->sba_order = 3;



                st_ivas->nchan_ism = st_ivas->bit_stream[num_bits_read + 1];

                st_ivas->nchan_ism += 2 * st_ivas->bit_stream[num_bits_read];

                st_ivas->nchan_ism++;

                st_ivas->ivas_format = SBA_FORMAT;

                st_ivas->ism_mode = ISM_MODE_NONE;

            }



            /* set Ambisonic (SBA) order used for analysis and coding */

            st_ivas->sba_analysis_order = ivas_sba_get_analysis_order( ivas_total_brate, st_ivas->sba_order );

lib_enc/ivas_enc.c

+2 −2
Original line number Diff line number Diff line
@@ -436,8 +436,8 @@ ivas_error ivas_enc( 
            /* Write SBA planar flag */

            push_indice( st->hBstr, IND_SMODE, hEncoderConfig->sba_planar, SBA_PLANAR_BITS );



            /* Write SBA order */

            push_indice( st->hBstr, IND_SMODE, hEncoderConfig->sba_order, SBA_ORDER_BITS );

            /* Previously used to signal the SBA order, now re-purposed for the number of objects */

            push_indice( st->hBstr, IND_SMODE, hEncoderConfig->nchan_ism - 1, NO_BITS_MASA_ISM_NO_OBJ );



            /* SBA metadata encoding and SBA metadata bitstream writing */

            if ( ( error = ivas_spar_enc( st_ivas, data_f, input_frame, nb_bits_metadata, hMetaData ) ) != IVAS_ERR_OK )