bandlimited.c

video linux conference

                    p_filter->input.i_bytes_per_frame );          
            p_in += i_nb_channels;
            p_out += i_nb_channels;
            i_out++;
            continue;
        }

        while( p_filter->p_sys->i_remainder < p_filter->output.i_rate )
        {

            if( p_filter->p_sys->d_old_factor >= 1 )
            {
                /* FilterFloatUP() is faster if we can use it */

                /* Perform left-wing inner product */
                FilterFloatUP( SMALL_FILTER_FLOAT_IMP, SMALL_FILTER_FLOAT_IMPD,
                               SMALL_FILTER_NWING, p_in, p_out,
                               p_filter->p_sys->i_remainder,
                               p_filter->output.i_rate,
                               -1, i_nb_channels );
                /* Perform right-wing inner product */
                FilterFloatUP( SMALL_FILTER_FLOAT_IMP, SMALL_FILTER_FLOAT_IMPD,
                               SMALL_FILTER_NWING, p_in + i_nb_channels, p_out,
                               p_filter->output.i_rate -
                               p_filter->p_sys->i_remainder,
                               p_filter->output.i_rate,
                               1, i_nb_channels );

#if 0
                /* Normalize for unity filter gain */
                for( i = 0; i < i_nb_channels; i++ )
                {
                    *(p_out+i) *= d_old_scale_factor;
                }
#endif

                /* Sanity check */
                if( p_out_buf->i_size/p_filter->input.i_bytes_per_frame
                    <= (unsigned int)i_out+1 )
                {
                    p_out += i_nb_channels;
                    i_out++;
                    p_filter->p_sys->i_remainder += p_filter->input.i_rate;
                    break;
                }
            }
            else
            {
                /* Perform left-wing inner product */
                FilterFloatUD( SMALL_FILTER_FLOAT_IMP, SMALL_FILTER_FLOAT_IMPD,
                               SMALL_FILTER_NWING, p_in, p_out,
                               p_filter->p_sys->i_remainder,
                               p_filter->output.i_rate, p_filter->input.i_rate,
                               -1, i_nb_channels );
                /* Perform right-wing inner product */
                FilterFloatUD( SMALL_FILTER_FLOAT_IMP, SMALL_FILTER_FLOAT_IMPD,
                               SMALL_FILTER_NWING, p_in + i_nb_channels, p_out,
                               p_filter->output.i_rate -
                               p_filter->p_sys->i_remainder,
                               p_filter->output.i_rate, p_filter->input.i_rate,
                               1, i_nb_channels );
            }

            p_out += i_nb_channels;
            i_out++;

            p_filter->p_sys->i_remainder += p_filter->input.i_rate;
        }

        p_in += i_nb_channels;
        p_filter->p_sys->i_remainder -= p_filter->output.i_rate;
    }

    /* Apply the new rate for the rest of the samples */
    if( i_in < i_in_nb - i_filter_wing )
    {
        p_filter->p_sys->i_old_rate   = p_filter->input.i_rate;
        p_filter->p_sys->d_old_factor = d_factor;
        p_filter->p_sys->i_old_wing   = i_filter_wing;
    }
    for( ; i_in < i_in_nb - i_filter_wing; i_in++ )
    {
        while( p_filter->p_sys->i_remainder < p_filter->output.i_rate )
        {

            if( d_factor >= 1 )
            {
                /* FilterFloatUP() is faster if we can use it */

                /* Perform left-wing inner product */
                FilterFloatUP( SMALL_FILTER_FLOAT_IMP, SMALL_FILTER_FLOAT_IMPD,
                               SMALL_FILTER_NWING, p_in, p_out,
                               p_filter->p_sys->i_remainder,
                               p_filter->output.i_rate,
                               -1, i_nb_channels );

                /* Perform right-wing inner product */
                FilterFloatUP( SMALL_FILTER_FLOAT_IMP, SMALL_FILTER_FLOAT_IMPD,
                               SMALL_FILTER_NWING, p_in + i_nb_channels, p_out,
                               p_filter->output.i_rate -
                               p_filter->p_sys->i_remainder,
                               p_filter->output.i_rate,
                               1, i_nb_channels );

#if 0
                /* Normalize for unity filter gain */
                for( i = 0; i < i_nb_channels; i++ )
                {
                    *(p_out+i) *= d_old_scale_factor;
                }
#endif
                /* Sanity check */
                if( p_out_buf->i_size/p_filter->input.i_bytes_per_frame
                    <= (unsigned int)i_out+1 )
                {
                    p_out += i_nb_channels;
                    i_out++;
                    p_filter->p_sys->i_remainder += p_filter->input.i_rate;
                    break;
                }
            }
            else
            {
                /* Perform left-wing inner product */
                FilterFloatUD( SMALL_FILTER_FLOAT_IMP, SMALL_FILTER_FLOAT_IMPD,
                               SMALL_FILTER_NWING, p_in, p_out,
                               p_filter->p_sys->i_remainder,
                               p_filter->output.i_rate, p_filter->input.i_rate,
                               -1, i_nb_channels );
                /* Perform right-wing inner product */
                FilterFloatUD( SMALL_FILTER_FLOAT_IMP, SMALL_FILTER_FLOAT_IMPD,
                               SMALL_FILTER_NWING, p_in + i_nb_channels, p_out,
                               p_filter->output.i_rate -
                               p_filter->p_sys->i_remainder,
                               p_filter->output.i_rate, p_filter->input.i_rate,
                               1, i_nb_channels );
            }

            p_out += i_nb_channels;
            i_out++;

            p_filter->p_sys->i_remainder += p_filter->input.i_rate;
        }

        p_in += i_nb_channels;
        p_filter->p_sys->i_remainder -= p_filter->output.i_rate;
    }

    /* Buffer i_filter_wing * 2 samples for next time */
    if( p_filter->p_sys->i_old_wing )
    {
        memcpy( p_filter->p_sys->p_buf,
                p_in_orig + (i_in_nb - 2 * p_filter->p_sys->i_old_wing) *
                i_nb_channels, (2 * p_filter->p_sys->i_old_wing) *
                p_filter->input.i_bytes_per_frame );
    }

#if 0
    msg_Err( p_filter, "p_out size: %i, nb bytes out: %i", p_out_buf->i_size,
             i_out * p_filter->input.i_bytes_per_frame );
#endif

    /* Free the temp buffer */
#ifndef HAVE_ALLOCA
    free( p_in_orig );
#endif

    /* Finalize aout buffer */
    p_out_buf->i_nb_samples = i_out;
    p_out_buf->start_date = aout_DateGet( &p_filter->p_sys->end_date );
    p_out_buf->end_date = aout_DateIncrement( &p_filter->p_sys->end_date,
                                              p_out_buf->i_nb_samples );

    p_out_buf->i_nb_bytes = p_out_buf->i_nb_samples *
        i_nb_channels * sizeof(int32_t);

}

void FilterFloatUP( float Imp[], float ImpD[], uint16_t Nwing, float *p_in,
                    float *p_out, uint32_t ui_remainder,
                    uint32_t ui_output_rate, int16_t Inc, int i_nb_channels )
{
    float *Hp, *Hdp, *End;
    float t, temp;
    uint32_t ui_linear_remainder;
    int i;

    Hp = &Imp[(ui_remainder<<Nhc)/ui_output_rate];
    Hdp = &ImpD[(ui_remainder<<Nhc)/ui_output_rate];

    End = &Imp[Nwing];

    ui_linear_remainder = (ui_remainder<<Nhc) -
                            (ui_remainder<<Nhc)/ui_output_rate*ui_output_rate;

    if (Inc == 1)               /* If doing right wing...              */
    {                           /* ...drop extra coeff, so when Ph is  */
        End--;                  /*    0.5, we don't do too many mult's */
        if (ui_remainder == 0)  /* If the phase is zero...           */
        {                       /* ...then we've already skipped the */
            Hp += Npc;          /*    first sample, so we must also  */
            Hdp += Npc;         /*    skip ahead in Imp[] and ImpD[] */
        }
    }

    while (Hp < End) {
        t = *Hp;                /* Get filter coeff */
                                /* t is now interp'd filter coeff */
        t += *Hdp * ui_linear_remainder / ui_output_rate / Npc;
        for( i = 0; i < i_nb_channels; i++ )
        {
            temp = t;
            temp *= *(p_in+i);  /* Mult coeff by input sample */
            *(p_out+i) += temp; /* The filter output */
        }
        Hdp += Npc;             /* Filter coeff differences step */
        Hp += Npc;              /* Filter coeff step */
        p_in += (Inc * i_nb_channels); /* Input signal step */
    }
}

void FilterFloatUD( float Imp[], float ImpD[], uint16_t Nwing, float *p_in,
                    float *p_out, uint32_t ui_remainder,
                    uint32_t ui_output_rate, uint32_t ui_input_rate,
                    int16_t Inc, int i_nb_channels )
{
    float *Hp, *Hdp, *End;
    float t, temp;
    uint32_t ui_linear_remainder;
    int i, ui_counter = 0;

    Hp = Imp + (ui_remainder<<Nhc) / ui_input_rate;
    Hdp = ImpD  + (ui_remainder<<Nhc) / ui_input_rate;

    End = &Imp[Nwing];

    if (Inc == 1)               /* If doing right wing...              */
    {                           /* ...drop extra coeff, so when Ph is  */
        End--;                  /*    0.5, we don't do too many mult's */
        if (ui_remainder == 0)  /* If the phase is zero...           */
        {                       /* ...then we've already skipped the */
            Hp = Imp +          /* first sample, so we must also  */
                  (ui_output_rate << Nhc) / ui_input_rate;
            Hdp = ImpD +        /* skip ahead in Imp[] and ImpD[] */
                  (ui_output_rate << Nhc) / ui_input_rate;
            ui_counter++;
        }
    }

    while (Hp < End) {
        t = *Hp;                /* Get filter coeff */
                                /* t is now interp'd filter coeff */
        ui_linear_remainder =
          ((ui_output_rate * ui_counter + ui_remainder)<< Nhc) -
          ((ui_output_rate * ui_counter + ui_remainder)<< Nhc) /
          ui_input_rate * ui_input_rate;
        t += *Hdp * ui_linear_remainder / ui_input_rate / Npc;
        for( i = 0; i < i_nb_channels; i++ )
        {
            temp = t;
            temp *= *(p_in+i);  /* Mult coeff by input sample */
            *(p_out+i) += temp; /* The filter output */
        }

        ui_counter++;

        /* Filter coeff step */
        Hp = Imp + ((ui_output_rate * ui_counter + ui_remainder)<< Nhc)
                    / ui_input_rate;
        /* Filter coeff differences step */
        Hdp = ImpD + ((ui_output_rate * ui_counter + ui_remainder)<< Nhc)
                     / ui_input_rate;

        p_in += (Inc * i_nb_channels); /* Input signal step */
    }
}