decoder.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.

        hDecoder->forceUpSampling = mp4ASC.forceUpSampling;
    else
        hDecoder->forceUpSampling = 0;

    /* AAC core decoder samplerate is 2 times as low */
    if (((hDecoder->sbr_present_flag == 1)&&(!hDecoder->downSampledSBR)) || hDecoder->forceUpSampling == 1)
    {
        hDecoder->sf_index = get_sr_index(mp4ASC.samplingFrequency / 2);
    }
#endif

    if (rc != 0)
    {
        return rc;
    }
    hDecoder->channelConfiguration = mp4ASC.channelsConfiguration;
    if (mp4ASC.frameLengthFlag)
#ifdef ALLOW_SMALL_FRAMELENGTH
        hDecoder->frameLength = 960;
#else
        return -1;
#endif

    /* must be done before frameLength is divided by 2 for LD */
#ifdef SSR_DEC
    if (hDecoder->object_type == SSR)
        hDecoder->fb = ssr_filter_bank_init(hDecoder->frameLength/SSR_BANDS);
    else
#endif
#ifdef LIBPAAC
		AAC_Filter_Init(&hDecoder->Lib,hDecoder->frameLength);
#else
        hDecoder->fb = filter_bank_init(hDecoder->frameLength);
#endif

#ifdef LD_DEC
    if (hDecoder->object_type == LD)
        hDecoder->frameLength >>= 1;
#endif

    return 0;
}

#ifdef DRM
int8_t NEAACDECAPI NeAACDecInitDRM(NeAACDecHandle *hDecoder, uint32_t samplerate,
                                   uint8_t channels)
{
    if (hDecoder == NULL)
        return 1; /* error */

    NeAACDecClose(*hDecoder);

    *hDecoder = NeAACDecOpen();

    /* Special object type defined for DRM */
    (*hDecoder)->config.defObjectType = DRM_ER_LC;

    (*hDecoder)->config.defSampleRate = samplerate;
#ifdef ERROR_RESILIENCE // This shoudl always be defined for DRM
    (*hDecoder)->aacSectionDataResilienceFlag = 1; /* VCB11 */
    (*hDecoder)->aacScalefactorDataResilienceFlag = 0; /* no RVLC */
    (*hDecoder)->aacSpectralDataResilienceFlag = 1; /* HCR */
#endif
    (*hDecoder)->frameLength = 960;
    (*hDecoder)->sf_index = get_sr_index((*hDecoder)->config.defSampleRate);
    (*hDecoder)->object_type = (*hDecoder)->config.defObjectType;

    if ((channels == DRMCH_STEREO) || (channels == DRMCH_SBR_STEREO))
        (*hDecoder)->channelConfiguration = 2;
    else
        (*hDecoder)->channelConfiguration = 1;

#ifdef SBR_DEC
    if ((channels == DRMCH_MONO) || (channels == DRMCH_STEREO))
        (*hDecoder)->sbr_present_flag = 0;
    else
        (*hDecoder)->sbr_present_flag = 1;    
#endif        

#ifdef LIBPAAC
	AAC_Filter_Init(&hDecoder->Lib,hDecoder->frameLength);
#else
    (*hDecoder)->fb = filter_bank_init((*hDecoder)->frameLength);
#endif

    return 0;
}
#endif

void NEAACDECAPI NeAACDecClose(NeAACDecHandle hDecoder)
{
    uint8_t i;

    if (hDecoder == NULL)
        return;

#ifdef PROFILE
    printf("AAC decoder total:  %I64d cycles\n", hDecoder->cycles);
    printf("requant:            %I64d cycles\n", hDecoder->requant_cycles);
    printf("spectral_data:      %I64d cycles\n", hDecoder->spectral_cycles);
    printf("scalefactors:       %I64d cycles\n", hDecoder->scalefac_cycles);
    printf("output:             %I64d cycles\n", hDecoder->output_cycles);
#endif

    for (i = 0; i < MAX_CHANNELS; i++)
    {
        if (hDecoder->time_out[i]) faad_free(hDecoder->time_out[i]);
        if (hDecoder->fb_intermed[i]) faad_free(hDecoder->fb_intermed[i]);
#ifdef SSR_DEC
        if (hDecoder->ssr_overlap[i]) faad_free(hDecoder->ssr_overlap[i]);
        if (hDecoder->prev_fmd[i]) faad_free(hDecoder->prev_fmd[i]);
#endif
#ifdef MAIN_DEC
        if (hDecoder->pred_stat[i]) faad_free(hDecoder->pred_stat[i]);
#endif
#ifdef LTP_DEC
        if (hDecoder->lt_pred_stat[i]) faad_free(hDecoder->lt_pred_stat[i]);
#endif
    }

#ifdef SSR_DEC
    if (hDecoder->object_type == SSR)
        ssr_filter_bank_end(hDecoder->fb);
    else
#endif
#ifndef LIBPAAC
        filter_bank_end(hDecoder->fb);
#endif

    drc_end(hDecoder->drc);

    if (hDecoder->sample_buffer) faad_free(hDecoder->sample_buffer);

#ifdef SBR_DEC
    for (i = 0; i < MAX_SYNTAX_ELEMENTS; i++)
    {
        if (hDecoder->sbr[i])
            sbrDecodeEnd(hDecoder->sbr[i]);
    }
#endif

	if (hDecoder->stack)
		faad_free(hDecoder->stack);

    if (hDecoder) faad_free(hDecoder);
}

void NEAACDECAPI NeAACDecPostSeekReset(NeAACDecHandle hDecoder, int32_t frame)
{
    if (hDecoder)
    {
        hDecoder->postSeekResetFlag = 1;

        if (frame != -1)
            hDecoder->frame = frame;
    }
}

static void create_channel_config(NeAACDecHandle hDecoder, NeAACDecFrameInfo *hInfo)
{
    hInfo->num_front_channels = 0;
    hInfo->num_side_channels = 0;
    hInfo->num_back_channels = 0;
    hInfo->num_lfe_channels = 0;
    memset(hInfo->channel_position, 0, MAX_CHANNELS*sizeof(uint8_t));

    if (hDecoder->downMatrix)
    {
        hInfo->num_front_channels = 2;
        hInfo->channel_position[0] = FRONT_CHANNEL_LEFT;
        hInfo->channel_position[1] = FRONT_CHANNEL_RIGHT;
        return;
    }

    /* check if there is a PCE */
    if (hDecoder->pce_set)
    {
        uint8_t i, chpos = 0;
        uint8_t chdir, back_center = 0;

        hInfo->num_front_channels = hDecoder->pce.num_front_channels;
        hInfo->num_side_channels = hDecoder->pce.num_side_channels;
        hInfo->num_back_channels = hDecoder->pce.num_back_channels;
        hInfo->num_lfe_channels = hDecoder->pce.num_lfe_channels;

        chdir = hInfo->num_front_channels;
        if (chdir & 1)
        {
            hInfo->channel_position[chpos++] = FRONT_CHANNEL_CENTER;
            chdir--;
        }
        for (i = 0; i < chdir; i += 2)
        {
            hInfo->channel_position[chpos++] = FRONT_CHANNEL_LEFT;
            hInfo->channel_position[chpos++] = FRONT_CHANNEL_RIGHT;
        }

        for (i = 0; i < hInfo->num_side_channels; i += 2)
        {
            hInfo->channel_position[chpos++] = SIDE_CHANNEL_LEFT;
            hInfo->channel_position[chpos++] = SIDE_CHANNEL_RIGHT;
        }

        chdir = hInfo->num_back_channels;
        if (chdir & 1)
        {
            back_center = 1;
            chdir--;
        }
        for (i = 0; i < chdir; i += 2)
        {
            hInfo->channel_position[chpos++] = BACK_CHANNEL_LEFT;
            hInfo->channel_position[chpos++] = BACK_CHANNEL_RIGHT;
        }
        if (back_center)
        {
            hInfo->channel_position[chpos++] = BACK_CHANNEL_CENTER;
        }

        for (i = 0; i < hInfo->num_lfe_channels; i++)
        {
            hInfo->channel_position[chpos++] = LFE_CHANNEL;
        }

    } else {
        switch (hDecoder->channelConfiguration)
        {
        case 1:
            hInfo->num_front_channels = 1;
            hInfo->channel_position[0] = FRONT_CHANNEL_CENTER;
            break;
        case 2:
            hInfo->num_front_channels = 2;
            hInfo->channel_position[0] = FRONT_CHANNEL_LEFT;
            hInfo->channel_position[1] = FRONT_CHANNEL_RIGHT;
            break;
        case 3:
            hInfo->num_front_channels = 3;
            hInfo->channel_position[0] = FRONT_CHANNEL_CENTER;
            hInfo->channel_position[1] = FRONT_CHANNEL_LEFT;
            hInfo->channel_position[2] = FRONT_CHANNEL_RIGHT;
            break;
        case 4:
            hInfo->num_front_channels = 3;
            hInfo->num_back_channels = 1;
            hInfo->channel_position[0] = FRONT_CHANNEL_CENTER;
            hInfo->channel_position[1] = FRONT_CHANNEL_LEFT;
            hInfo->channel_position[2] = FRONT_CHANNEL_RIGHT;
            hInfo->channel_position[3] = BACK_CHANNEL_CENTER;
            break;
        case 5:
            hInfo->num_front_channels = 3;
            hInfo->num_back_channels = 2;
            hInfo->channel_position[0] = FRONT_CHANNEL_CENTER;
            hInfo->channel_position[1] = FRONT_CHANNEL_LEFT;
            hInfo->channel_position[2] = FRONT_CHANNEL_RIGHT;
            hInfo->channel_position[3] = BACK_CHANNEL_LEFT;
            hInfo->channel_position[4] = BACK_CHANNEL_RIGHT;
            break;
        case 6:
            hInfo->num_front_channels = 3;
            hInfo->num_back_channels = 2;
            hInfo->num_lfe_channels = 1;
            hInfo->channel_position[0] = FRONT_CHANNEL_CENTER;
            hInfo->channel_position[1] = FRONT_CHANNEL_LEFT;
            hInfo->channel_position[2] = FRONT_CHANNEL_RIGHT;
            hInfo->channel_position[3] = BACK_CHANNEL_LEFT;
            hInfo->channel_position[4] = BACK_CHANNEL_RIGHT;
            hInfo->channel_position[5] = LFE_CHANNEL;
            break;
        case 7:
            hInfo->num_front_channels = 3;
            hInfo->num_side_channels = 2;
            hInfo->num_back_channels = 2;
            hInfo->num_lfe_channels = 1;
            hInfo->channel_position[0] = FRONT_CHANNEL_CENTER;
            hInfo->channel_position[1] = FRONT_CHANNEL_LEFT;
            hInfo->channel_position[2] = FRONT_CHANNEL_RIGHT;
            hInfo->channel_position[3] = SIDE_CHANNEL_LEFT;
            hInfo->channel_position[4] = SIDE_CHANNEL_RIGHT;
            hInfo->channel_position[5] = BACK_CHANNEL_LEFT;
            hInfo->channel_position[6] = BACK_CHANNEL_RIGHT;
            hInfo->channel_position[7] = LFE_CHANNEL;
            break;
        default: /* channelConfiguration == 0 || channelConfiguration > 7 */
            {
                uint8_t i;
                uint8_t ch = hDecoder->fr_channels - hDecoder->has_lfe;
                if (ch & 1) /* there's either a center front or a center back channel */
                {
                    uint8_t ch1 = (ch-1)/2;
                    if (hDecoder->first_syn_ele == ID_SCE)
                    {
                        hInfo->num_front_channels = ch1 + 1;
                        hInfo->num_back_channels = ch1;
                        hInfo->channel_position[0] = FRONT_CHANNEL_CENTER;
                        for (i = 1; i <= ch1; i+=2)
                        {
                            hInfo->channel_position[i] = FRONT_CHANNEL_LEFT;
                            hInfo->channel_position[i+1] = FRONT_CHANNEL_RIGHT;
                        }
                        for (i = ch1+1; i < ch; i+=2)
                        {
                            hInfo->channel_position[i] = BACK_CHANNEL_LEFT;
                            hInfo->channel_position[i+1] = BACK_CHANNEL_RIGHT;
                        }
                    } else {
                        hInfo->num_front_channels = ch1;
                        hInfo->num_back_channels = ch1 + 1;
                        for (i = 0; i < ch1; i+=2)
                        {
                            hInfo->channel_position[i] = FRONT_CHANNEL_LEFT;
                            hInfo->channel_position[i+1] = FRONT_CHANNEL_RIGHT;
                        }
                        for (i = ch1; i < ch-1; i+=2)
                        {
                            hInfo->channel_position[i] = BACK_CHANNEL_LEFT;
                            hInfo->channel_position[i+1] = BACK_CHANNEL_RIGHT;
                        }
                        hInfo->channel_position[ch-1] = BACK_CHANNEL_CENTER;
                    }
                } else {
                    uint8_t ch1 = (ch)/2;
                    hInfo->num_front_channels = ch1;
                    hInfo->num_back_channels = ch1;
                    if (ch1 & 1)
                    {
                        hInfo->channel_position[0] = FRONT_CHANNEL_CENTER;
                        for (i = 1; i <= ch1; i+=2)
                        {
                            hInfo->channel_position[i] = FRONT_CHANNEL_LEFT;
                            hInfo->channel_position[i+1] = FRONT_CHANNEL_RIGHT;
                        }
                        for (i = ch1+1; i < ch-1; i+=2)
                        {
                            hInfo->channel_position[i] = BACK_CHANNEL_LEFT;
                            hInfo->channel_position[i+1] = BACK_CHANNEL_RIGHT;
                        }
                        hInfo->channel_position[ch-1] = BACK_CHANNEL_CENTER;
                    } else {
                        for (i = 0; i < ch1; i+=2)
                        {
                            hInfo->channel_position[i] = FRONT_CHANNEL_LEFT;
                            hInfo->channel_position[i+1] = FRONT_CHANNEL_RIGHT;
                        }
                        for (i = ch1; i < ch; i+=2)
                        {
                            hInfo->channel_position[i] = BACK_CHANNEL_LEFT;
                            hInfo->channel_position[i+1] = BACK_CHANNEL_RIGHT;
                        }
                    }
                }
                hInfo->num_lfe_channels = hDecoder->has_lfe;
                for (i = ch; i < hDecoder->fr_channels; i++)
                {
                    hInfo->channel_position[i] = LFE_CHANNEL;
                }