syntax.c

这是著名的TCPMP播放器在WINDWOWS,和WINCE下编译通过的源程序.笔者对其中的LIBMAD库做了针对ARM MPU的优化. 并增加了词幕功能.

#endif

            g->sect[i].sect_cb = (uint8_t)faad_getbits(ld, sect_cb_bits
                DEBUGVAR(1,71,"section_data(): sect_cb"));

#if 0
            printf("%d\n", g->sect[i].sect_cb);
#endif

            if (g->sect[i].sect_cb == NOISE_HCB)
                ics->noise_used = 1;
			else
            if (g->sect[i].sect_cb == INTENSITY_HCB || g->sect[i].sect_cb == INTENSITY_HCB2)
                ics->intensity_used = 1;

#ifdef ERROR_RESILIENCE
            if (hDecoder->aacSectionDataResilienceFlag)
            {
                if ((g->sect[i].sect_cb == 11) ||
                    ((g->sect[i].sect_cb >= 16) && (g->sect[i].sect_cb <= 32)))
                {
                    vcb11 = 1;
                }
            }
            if (vcb11)
            {
                sect_len_incr = 1;
            } else {
#endif
                sect_len_incr = (uint8_t)faad_getbits(ld, sect_bits
                    DEBUGVAR(1,72,"section_data(): sect_len_incr"));
#ifdef ERROR_RESILIENCE
            }
#endif
            while ((sect_len_incr == sect_esc_val) /* &&
                (k+sect_len < ics->max_sfb)*/)
            {
                sect_len += sect_len_incr;
                sect_len_incr = (uint8_t)faad_getbits(ld, sect_bits
                    DEBUGVAR(1,72,"section_data(): sect_len_incr"));
            }

            sect_len += sect_len_incr;

            g->sect[i].sect_start = k;
            g->sect[i].sect_end = k + sect_len;

#if 0
            printf("%d\n", ics->group[g].sect[i].sect_start);
#endif
#if 0
            printf("%d\n", ics->group[g].sect[i].sect_end);
#endif

            if (k + sect_len > MAX_SFB)
                return 15;
            if (i > MAX_SFB)
                return 15;

            for (sfb = k; sfb < k + sect_len; sfb++)
            {
                g->sfb[sfb].sfb_cb = g->sect[i].sect_cb;
#if 0
                printf("%d\n", g->sfb[sfb].sfb_cb);
#endif
            }

#if 0
            printf(" %6d %6d %6d\n",
                i,
                g->sect[i].sect_end,
                g->sect[i].sect_cb);
#endif

            k += sect_len;
            i++;
        }
        g->num_sec = i;
#if 0
        printf("%d\n", ics->group[g].num_sec);
#endif
    }

#if 0
    printf("\n");
#endif

    return 0;
}

/*
 *  decode_scale_factors()
 *   decodes the scalefactors from the bitstream
 */
/*
 * All scalefactors (and also the stereo positions and pns energies) are
 * transmitted using Huffman coded DPCM relative to the previous active
 * scalefactor (respectively previous stereo position or previous pns energy,
 * see subclause 4.6.2 and 4.6.3). The first active scalefactor is
 * differentially coded relative to the global gain.
 */
static uint8_t decode_scale_factors(ic_stream *ics, bitfile *ld)
{
    uint8_t sfb;
    int16_t t;
    int8_t noise_pcm_flag = 1;

    int16_t scale_factor = ics->global_gain;
    int16_t is_position = 0;
    int16_t noise_energy = ics->global_gain - 90;

	ic_group *g;

    for (g = ics->group; g != ics->group_end; g++)
    {
        for (sfb = 0; sfb < ics->max_sfb; sfb++)
        {
            switch (g->sfb[sfb].sfb_cb)
            {
            case ZERO_HCB: /* zero book */
                g->sfb[sfb].scale_factors = 0;
//#define SF_PRINT
#ifdef SF_PRINT
                printf("%d\n", g->sfb[sfb].scale_factors);
#endif
                break;
            case INTENSITY_HCB: /* intensity books */
            case INTENSITY_HCB2:

                /* decode intensity position */
                t = huffman_scale_factor(ld);
                is_position += (t - 60);
                g->sfb[sfb].scale_factors = is_position;
#ifdef SF_PRINT
                printf("%d\n", g->sfb[sfb].scale_factors);
#endif

                break;
            case NOISE_HCB: /* noise books */

                /* decode noise energy */
                if (noise_pcm_flag)
                {
                    noise_pcm_flag = 0;
                    t = (int16_t)faad_getbits(ld, 9
                        DEBUGVAR(1,73,"scale_factor_data(): first noise")) - 256;
                } else {
                    t = huffman_scale_factor(ld);
                    t -= 60;
                }
                noise_energy += t;
                g->sfb[sfb].scale_factors = noise_energy;
#ifdef SF_PRINT
                printf("%d\n", g->sfb[sfb].scale_factors);
#endif

                break;
            default: /* spectral books */

                /* ics->scale_factors[g][sfb] must be between 0 and 255 */

                g->sfb[sfb].scale_factors = 0;

                /* decode scale factor */
                t = huffman_scale_factor(ld);
                scale_factor += (t - 60);
                if (scale_factor < 0 || scale_factor > 255)
                    return 4;
                g->sfb[sfb].scale_factors = scale_factor;
#ifdef SF_PRINT
                printf("%d\n", g->sfb[sfb].scale_factors);
#endif

                break;
            }
        }
    }

    return 0;
}

/* Table 4.4.26 */
static uint8_t scale_factor_data(NeAACDecHandle hDecoder, ic_stream *ics, bitfile *ld)
{
    uint8_t ret = 0;
#ifdef PROFILE
    int64_t count = faad_get_ts();
#endif

#ifdef ERROR_RESILIENCE
    if (!hDecoder->aacScalefactorDataResilienceFlag)
    {
#endif
        ret = decode_scale_factors(ics, ld);
#ifdef ERROR_RESILIENCE
    } else {
        /* In ER AAC the parameters for RVLC are seperated from the actual
           data that holds the scale_factors.
           Strangely enough, 2 parameters for HCR are put inbetween them.
        */
        ret = rvlc_scale_factor_data(ics, ld);
    }
#endif

#ifdef PROFILE
    count = faad_get_ts() - count;
    hDecoder->scalefac_cycles += count;
#endif

    return ret;
}

/* Table 4.4.27 */
static void tns_data(ic_stream *ics, tns_info *tns, bitfile *ld)
{
    uint8_t w, filt, i, start_coef_bits, coef_bits;
    uint8_t n_filt_bits = 2;
    uint8_t length_bits = 6;
    uint8_t order_bits = 5;

    if (ics->window_sequence == EIGHT_SHORT_SEQUENCE)
    {
        n_filt_bits = 1;
        length_bits = 4;
        order_bits = 3;
    }

    for (w = 0; w < ics->num_windows; w++)
    {
        tns->n_filt[w] = (uint8_t)faad_getbits(ld, n_filt_bits
            DEBUGVAR(1,74,"tns_data(): n_filt"));
#if 0
        printf("%d\n", tns->n_filt[w]);
#endif

        if (tns->n_filt[w])
        {
            if ((tns->coef_res[w] = faad_get1bit(ld
                DEBUGVAR(1,75,"tns_data(): coef_res"))) & 1)
            {
                start_coef_bits = 4;
            } else {
                start_coef_bits = 3;
            }
#if 0
            printf("%d\n", tns->coef_res[w]);
#endif
        }

        for (filt = 0; filt < tns->n_filt[w]; filt++)
        {
            tns->length[w][filt] = (uint8_t)faad_getbits(ld, length_bits
                DEBUGVAR(1,76,"tns_data(): length"));
#if 0
            printf("%d\n", tns->length[w][filt]);
#endif
            tns->order[w][filt]  = (uint8_t)faad_getbits(ld, order_bits
                DEBUGVAR(1,77,"tns_data(): order"));
#if 0
            printf("%d\n", tns->order[w][filt]);
#endif
            if (tns->order[w][filt])
            {
                tns->direction[w][filt] = faad_get1bit(ld
                    DEBUGVAR(1,78,"tns_data(): direction"));
#if 0
                printf("%d\n", tns->direction[w][filt]);
#endif
                tns->coef_compress[w][filt] = faad_get1bit(ld
                    DEBUGVAR(1,79,"tns_data(): coef_compress"));
#if 0
                printf("%d\n", tns->coef_compress[w][filt]);
#endif

                coef_bits = start_coef_bits - tns->coef_compress[w][filt];
                for (i = 0; i < tns->order[w][filt]; i++)
                {
                    tns->coef[w][filt][i] = (uint8_t)faad_getbits(ld, coef_bits
                        DEBUGVAR(1,80,"tns_data(): coef"));
#if 0
                    printf("%d\n", tns->coef[w][filt][i]);
#endif
                }
            }
        }
    }
}

#ifdef LTP_DEC
/* Table 4.4.28 */
static uint8_t ltp_data(NeAACDecHandle hDecoder, ic_stream *ics, ltp_info *ltp, bitfile *ld)
{
    uint8_t sfb, w;

    ltp->lag = 0;

#ifdef LD_DEC
    if (hDecoder->object_type == LD)
    {
        ltp->lag_update = (uint8_t)faad_getbits(ld, 1
            DEBUGVAR(1,142,"ltp_data(): lag_update"));

        if (ltp->lag_update)
        {
            ltp->lag = (uint16_t)faad_getbits(ld, 10
                DEBUGVAR(1,81,"ltp_data(): lag"));
        }
    } else {
#endif
        ltp->lag = (uint16_t)faad_getbits(ld, 11
            DEBUGVAR(1,81,"ltp_data(): lag"));
#ifdef LD_DEC
    }
#endif

    /* Check length of lag */
    if (ltp->lag > (hDecoder->frameLength << 1))
        return 18;

    ltp->coef = (uint8_t)faad_getbits(ld, 3
        DEBUGVAR(1,82,"ltp_data(): coef"));

    if (ics->window_sequence == EIGHT_SHORT_SEQUENCE)
    {
        for (w = 0; w < ics->num_windows; w++)
        {
            if ((ltp->short_used[w] = faad_get1bit(ld
                DEBUGVAR(1,83,"ltp_data(): short_used"))) & 1)
            {
                ltp->short_lag_present[w] = faad_get1bit(ld
                    DEBUGVAR(1,84,"ltp_data(): short_lag_present"));
                if (ltp->short_lag_present[w])
                {
                    ltp->short_lag[w] = (uint8_t)faad_getbits(ld, 4
                        DEBUGVAR(1,85,"ltp_data(): short_lag"));
                }
            }
        }
    } else {
        ltp->last_band = (ics->max_sfb < MAX_LTP_SFB ? ics->max_sfb : MAX_LTP_SFB);

        for (sfb = 0; sfb < ltp->last_band; sfb++)
        {
            ltp->long_used[sfb] = faad_get1bit(ld
                DEBUGVAR(1,86,"ltp_data(): long_used"));
        }
    }

    return 0;
}
#endif

static uint8_t fillzero(bitfile *ld, int16_t *sp, int16_t *spe)
{
	for (;sp!=spe;++sp)
		*sp = 0;
	return 0;
}

static huffmanfunc const huffman[16] =
{
	fillzero,
	huffman_spectral_data1,
	huffman_spectral_data2,
	huffman_spectral_data3,
	huffman_spectral_data4,
	huffman_spectral_data5,
	huffman_spectral_data6,
	huffman_spectral_data7,
	huffman_spectral_data8,
	huffman_spectral_data9,
	huffman_spectral_data10,
	huffman_spectral_data11,
	huffman_spectral_data12,
	fillzero,
	fillzero,
	fillzero,
};


/* Table 4.4.29 */
static uint8_t spectral_data(NeAACDecHandle hDecoder, ic_stream *ics, bitfile *ld,
                             int16_t *spectral_data)
{
    ic_group *g;
    uint16_t inc, k, p = 0;
    uint8_t groups = 0;
    uint8_t sect_cb;
    uint8_t result;
    uint16_t nshort = hDecoder->frameLength/8;
	int16_t *data1 = spectral_data;

#ifdef PROFILE
    int64_t count = faad_get_ts();
#endif

    for(g = ics->group; g != ics->group_end; g++)
    {
		ic_grou