decoder.c

mpeg4 video codec mpeg4 video codec

#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
        filter_bank_end(hDecoder->fb);

    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) faad_free(hDecoder);
}

void FAADAPI faacDecPostSeekReset(faacDecHandle hDecoder, int32_t frame)
{
    if (hDecoder)
    {
        hDecoder->postSeekResetFlag = 1;

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

static void create_channel_config(faacDecHandle hDecoder, faacDecFrameInfo *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;
                }
            }
            break;
        }
    }
}

void* FAADAPI faacDecDecode(faacDecHandle hDecoder,
                            faacDecFrameInfo *hInfo,
                            uint8_t *buffer, uint32_t buffer_size)
{
    uint8_t channels = 0;
    uint8_t output_channels = 0;
    bitfile ld;
    uint32_t bitsconsumed;
    uint16_t frame_len;
    void *sample_buffer;

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

    /* safety checks */
    if ((hDecoder == NULL) || (hInfo == NULL) || (buffer == NULL))
    {
        return NULL;
    }

    frame_len = hDecoder->frameLength;


    memset(hInfo, 0, sizeof(faacDecFrameInfo));
    memset(hDecoder->internal_channel, 0, MAX_CHANNELS*sizeof(hDecoder->internal_channel[0]));

    /* initialize the bitstream */
    faad_initbits(&ld, buffer, buffer_size);

#ifdef DRM
    if (hDecoder->object_type == DRM_ER_LC)
    {
        /* We do not support stereo right now */
        if (hDecoder->channelConfiguration == 2)
        {
            hInfo->error = 8; // Throw CRC error
            goto error;
        }

        faad_getbits(&ld, 8
            DEBUGVAR(1,1,"faacDecDecode(): skip CRC"));
    }
#endif

    if (hDecoder->adts_header_present)
    {
        adts_header adts;

        adts.old_format = hDecoder->config.useOldADTSFormat;
        if ((hInfo->error = adts_frame(&adts, &ld)) > 0)
            goto error;

        /* MPEG2 does byte_alignment() here,
         * but ADTS header is always multiple of 8 bits in MPEG2
         * so not needed to actually do it.
         */
    }

#ifdef ANALYSIS
    dbg_count = 0;
#endif

    /* decode the complete bitstream */
#ifdef SCALABLE_DEC
    if ((hDecoder->object_type == 6) || (hDecoder->object_type == DRM_ER_LC))
    {
        aac_scalable_main_element(hDecoder, hInfo, &ld, &hDecoder->pce, hDecoder->drc);
    } else {
#endif
        raw_data_block(hDecoder, hInfo, &ld, &hDecoder->pce, hDecoder->drc);
#ifdef SCALABLE_DEC
    }
#endif

    channels = hDecoder->fr_channels;

    if (hInfo->error > 0)
        goto error;

    /* safety check */
    if (channels == 0 || channels > MAX_CHANNELS)
    {
        /* invalid number of channels */
        hInfo->error = 12;
        goto error;
    }

    /* no more bit reading after this */
    bitsconsumed = faad_get_processed_bits(&ld);
    hInfo->bytesconsumed = bit2byte(bitsconsumed);
    if (ld.error)
    {
        hInfo->error = 14;
        goto error;
    }
    faad_endbits(&ld);


    if (!hDecoder->adts_header_present && !hDecoder->adif_header_present)
    {
        if (channels != hDecoder->channelConfiguration)
            hDecoder->channelConfiguration = channels;

        if (channels == 8) /* 7.1 */
            hDecoder->channelConfiguration = 7;
        if (channels == 7) /* not a standard channelConfiguration */
            hDecoder->channelConfiguration = 0;
    }

    if ((channels == 5 || channels == 6) && hDecoder->config.downMatrix)
    {
        hDecoder->downMatrix = 1;
        output_channels = 2;
    } else {
        output_channels = channels;
    }

    /* Make a channel configuration based on either a PCE or a channelConfiguration */
    create_channel_config(hDecoder, hInfo);

    /* number of samples in this frame */
    hInfo->samples = frame_len*output_channels;
    /* number of channels in this frame */
    hInfo->channels = output_channels;
    /* samplerate */
    hInfo->samplerate = get_sample_rate(hDecoder->sf_index);
    /* object type */
    hInfo->object_type = hDecoder->object_type;
    /* sbr */
    hInfo->sbr = NO_SBR;
    /* header type */
    hInfo->header_type = RAW;
    if (hDecoder->adif_header_present)
        hInfo->header_type = ADIF;
    if (hDecoder->adts_header_present)
        hInfo->header_type = ADTS;

    /* check if frame has channel elements */
    if (channels == 0)
    {
        hDecoder->frame++;
        return NULL;
    }

    /* allocate the buffer for the final samples */
    if ((hDecoder->sample_buffer == NULL) ||
        (hDecoder->alloced_channels != output_channels))
    {
        static const uint8_t str[] = { sizeof(int16_t), sizeof(int32_t), sizeof(int32_t),
            sizeof(float32_t), sizeof(double), sizeof(int16_t), sizeof(int16_t),
            sizeof(int16_t), sizeof(int16_t), 0, 0, 0
        };
        uint8_t stride = str[hDecoder->config.outputFormat-1];
#ifdef SBR_DEC
        if ((hDecoder->sbr_present_flag == 1) || (hDecoder->forceUpSampling == 1))
            stride = 2 * stride;
#endif
        if (hDecoder->sample_buffer)
            faad_free(hDecoder->sample_buffer);
        hDecoder->sample_buffer = NULL;
        hDecoder->sample_buffer = faad_malloc(frame_len*output_channels*stride);
        hDecoder->alloced_channels = output_channels;
    }

    sample_buffer = hDecoder->sample_buffer;

#ifdef SBR_DEC
    if ((hDecoder->sbr_present_flag == 1) || (hDecoder->forceUpSampling == 1))
    {
        uint8_t ele;

        /* this data is different when SBR is used or when the data is upsampled */
        frame_len *= 2;
        hInfo->samples *= 2;
        hInfo->samplerate *= 2;

        /* check if every element was provided with SBR data */
        for (ele = 0; ele < hDecoder->fr_ch_ele; ele++)
        {
            if (hDecoder->sbr[ele] == NULL)
            {
                hInfo->error = 25;
                goto error;
            }
        }

        /* sbr */
        if (hDecoder->sbr_present_flag == 1)
        {
            hInfo->object_type = HE_AAC;
            hInfo->sbr = SBR_UPSAMPLED;
        } else {
            hInfo->sbr = NO_SBR_UPSAMPLED;
        }
    }
#endif

    sample_buffer = output_to_PCM(hDecoder, hDecoder->time_out, sample_buffer,
        output_channels, frame_len, hDecoder->config.outputFormat);


    hDecoder->postSeekResetFlag = 0;

    hDecoder->frame++;
#ifdef LD_DEC
    if (hDecoder->object_type != LD)
    {
#endif
        if (hDecoder->frame <= 1)
            hInfo->samples = 0;
#ifdef LD_DEC
    } else {
        /* LD encoders will give lower delay */
        if (hDecoder->frame <= 0)
            hInfo->samples = 0;
    }
#endif

    /* cleanup */
#ifdef ANALYSIS
    fflush(stdout);
#endif

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

    return sample_buffer;

error:

    faad_endbits(&ld);

    /* cleanup */
#ifdef ANALYSIS
    fflush(stdout);
#endif

    return NULL;
}