syntax.c

从FFMPEG转换而来的H264解码程序,VC下编译..

        if ((result = (uint8_t)faad_check_CRC(ld, (uint16_t)faad_get_processed_bits(ld) - 8)) > 0)
            return result;
    }
#endif

#ifdef ERROR_RESILIENCE
    if (hDecoder->aacSpectralDataResilienceFlag)
    {
        /* error resilient spectral data decoding */
        if ((result = reordered_spectral_data(hDecoder, ics, ld, spec_data)) > 0)
        {
            return result;
        }
    } else {
#endif
        /* decode the spectral data */
        if ((result = spectral_data(hDecoder, ics, ld, spec_data)) > 0)
        {
            return result;
        }
#ifdef ERROR_RESILIENCE
    }
#endif

    /* pulse coding reconstruction */
    if (ics->pulse_data_present)
    {
        if (ics->window_sequence != EIGHT_SHORT_SEQUENCE)
        {
            if ((result = pulse_decode(ics, spec_data, hDecoder->frameLength)) > 0)
                return result;
        } else {
            return 2; /* pulse coding not allowed for short blocks */
        }
    }

    return 0;
}

/* Table 4.4.25 */
static uint8_t section_data(NeAACDecHandle hDecoder, ic_stream *ics, bitfile *ld)
{
    uint8_t g;
    uint8_t sect_esc_val, sect_bits;

    if (ics->window_sequence == EIGHT_SHORT_SEQUENCE)
        sect_bits = 3;
    else
        sect_bits = 5;
    sect_esc_val = (1<<sect_bits) - 1;

#if 0
    printf("\ntotal sfb %d\n", ics->max_sfb);
    printf("   sect    top     cb\n");
#endif

    for (g = 0; g < ics->num_window_groups; g++)
    {
        uint8_t k = 0;
        uint8_t i = 0;

        while (k < ics->max_sfb)
        {
#ifdef ERROR_RESILIENCE
            uint8_t vcb11 = 0;
#endif
            uint8_t sfb;
            uint8_t sect_len_incr;
            uint16_t sect_len = 0;
            uint8_t sect_cb_bits = 4;

            /* if "faad_getbits" detects error and returns "0", "k" is never
               incremented and we cannot leave the while loop */
            if (ld->error != 0)
                return 14;

#ifdef ERROR_RESILIENCE
            if (hDecoder->aacSectionDataResilienceFlag)
                sect_cb_bits = 5;
#endif

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

            if (ics->sect_cb[g][i] == 12)
                return 32;

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

#ifndef DRM
            if (ics->sect_cb[g][i] == NOISE_HCB)
                ics->noise_used = 1;
#else
            /* PNS not allowed in DRM */
            if (ics->sect_cb[g][i] == NOISE_HCB)
                return 29;
#endif
            if (ics->sect_cb[g][i] == INTENSITY_HCB2 || ics->sect_cb[g][i] == INTENSITY_HCB)
                ics->is_used = 1;

#ifdef ERROR_RESILIENCE
            if (hDecoder->aacSectionDataResilienceFlag)
            {
                if ((ics->sect_cb[g][i] == 11) ||
                    ((ics->sect_cb[g][i] >= 16) && (ics->sect_cb[g][i] <= 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;

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

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

            if (ics->window_sequence == EIGHT_SHORT_SEQUENCE)
            {
                if (k + sect_len > 8*15)
                    return 15;
                if (i >= 8*15)
                    return 15;
            } else {
                if (k + sect_len > MAX_SFB)
                    return 15;
                if (i >= MAX_SFB)
                    return 15;
            }

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

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

            k += sect_len;
            i++;
        }
        ics->num_sec[g] = i;

        /* the sum of all sect_len_incr elements for a given window
         * group shall equal max_sfb */
        if (k != ics->max_sfb)
        {
            return 32;
        }
#if 0
        printf("%d\n", ics->num_sec[g]);
#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 g, 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;

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

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

                break;
            case NOISE_HCB: /* noise books */

#ifndef DRM
                /* 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;
                ics->scale_factors[g][sfb] = noise_energy;
#ifdef SF_PRINT
                printf("%d\n", ics->scale_factors[g][sfb]);
#endif
#else
                /* PNS not allowed in DRM */
                return 29;
#endif

                break;
            default: /* spectral books */

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

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

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