/* ***** BEGIN LICENSE BLOCK *****
 * Source last modified: $Id: aacdec.c,v 1.1 2005/02/26 01:47:31 jrecker Exp $
 *
 * Portions Copyright (c) 1995-2005 RealNetworks, Inc. All Rights Reserved.
 *
 * The contents of this file, and the files included with this file,
 * are subject to the current version of the RealNetworks Public
 * Source License (the "RPSL") available at
 * http://www.helixcommunity.org/content/rpsl unless you have licensed
 * the file under the current version of the RealNetworks Community
 * Source License (the "RCSL") available at
 * http://www.helixcommunity.org/content/rcsl, in which case the RCSL
 * will apply. You may also obtain the license terms directly from
 * RealNetworks.  You may not use this file except in compliance with
 * the RPSL or, if you have a valid RCSL with RealNetworks applicable
 * to this file, the RCSL.  Please see the applicable RPSL or RCSL for
 * the rights, obligations and limitations governing use of the
 * contents of the file.
 *
 * This file is part of the Helix DNA Technology. RealNetworks is the
 * developer of the Original Code and owns the copyrights in the
 * portions it created.
 *
 * This file, and the files included with this file, is distributed
 * and made available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY
 * KIND, EITHER EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS
 * ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET
 * ENJOYMENT OR NON-INFRINGEMENT.
 *
 * Technology Compatibility Kit Test Suite(s) Location:
 *    http://www.helixcommunity.org/content/tck
 *
 * Contributor(s):
 *
 * ***** END LICENSE BLOCK ***** */

/**************************************************************************************
 * Fixed-point HE-AAC decoder
 * Jon Recker (jrecker@real.com), Ken Cooke (kenc@real.com)
 * February 2005
 *
 * aacdec.c - platform-independent top level decoder API
 **************************************************************************************/
#include "aaccommon.h"
#include "bitstream.h"
#include <stdio.h>
#include "aacdec.h"

#define HELIX_MAX_DECODE_CH_NUM (6)

/**************************************************************************************
 * Function:    AACInitDecoder
 *
 * Description: allocate memory for platform-specific data
 *              clear all the user-accessible fields
 *              initialize SBR decoder if enabled
 *
 * Inputs:      none
 *
 * Outputs:     none
 *
 * Return:      handle to AAC decoder instance, 0 if malloc fails
 **************************************************************************************/
HAACDecoder AACInitDecoder(void)
{
    AACDecInfo *aacDecInfo;

    aacDecInfo = AllocateBuffers();
    if (!aacDecInfo) {
        return 0;
    }

#ifdef AAC_ENABLE_SBR
    if (InitSBR(aacDecInfo)) {
        AACFreeDecoder(aacDecInfo);
        return 0;
    }
#endif

    return (HAACDecoder)aacDecInfo;
}

/**************************************************************************************
 * Function:    AACFreeDecoder
 *
 * Description: free platform-specific data allocated by AACInitDecoder
 *              free SBR decoder if enabled
 *
 * Inputs:      valid AAC decoder instance pointer (HAACDecoder)
 *
 * Outputs:     none
 *
 * Return:      none
 **************************************************************************************/
void AACFreeDecoder(HAACDecoder hAACDecoder)
{
    AACDecInfo *aacDecInfo = (AACDecInfo *)hAACDecoder;

    if (!aacDecInfo) {
        return;
    }

#ifdef AAC_ENABLE_SBR
    FreeSBR(aacDecInfo);
#endif
    FreeBuffers(aacDecInfo);
}

/**************************************************************************************
 * Function:    AACFindSyncWord
 *
 * Description: locate the next byte-alinged sync word in the raw AAC stream
 *
 * Inputs:      buffer to search for sync word
 *              max number of bytes to search in buffer
 *
 * Outputs:     none
 *
 * Return:      offset to first sync word (bytes from start of buf)
 *              -1 if sync not found after searching nBytes
 **************************************************************************************/
int AACFindSyncWord(unsigned char *buf, int nBytes)
{
    int i;

    /* find byte-aligned syncword (12 bits = 0xFFF) */
    for (i = 0; i < nBytes - 1; i++) {
        if ((buf[i + 0] & SYNCWORDH) == SYNCWORDH && (buf[i + 1] & SYNCWORDL) == SYNCWORDL) {
            return i;
        }
    }

    return -1;
}

/**************************************************************************************
 * Function:    AACGetLastFrameInfo
 *
 * Description: get info about last AAC frame decoded (number of samples decoded,
 *                sample rate, bit rate, etc.)
 *
 * Inputs:      valid AAC decoder instance pointer (HAACDecoder)
 *              pointer to AACFrameInfo struct
 *
 * Outputs:     filled-in AACFrameInfo struct
 *
 * Return:      none
 *
 * Notes:       call this right after calling AACDecode()
 **************************************************************************************/
void AACGetLastFrameInfo(HAACDecoder hAACDecoder, AACFrameInfo *aacFrameInfo)
{
    AACDecInfo *aacDecInfo = (AACDecInfo *)hAACDecoder;

    if (!aacDecInfo) {
        aacFrameInfo->format =       0;
        aacFrameInfo->bitRate =       0;
        aacFrameInfo->nChans =        0;
        aacFrameInfo->sampRateCore =  0;
        aacFrameInfo->sampRateOut =   0;
        aacFrameInfo->bitsPerSample = 0;
        aacFrameInfo->outputSamps =   0;
        aacFrameInfo->profile =       0;
        aacFrameInfo->tnsUsed =       0;
        aacFrameInfo->pnsUsed =       0;
    } else {
        aacFrameInfo->format =       aacDecInfo->format;
        aacFrameInfo->nChans =        aacDecInfo->nChans;
        aacFrameInfo->sampRateCore =  aacDecInfo->sampRate;
        aacFrameInfo->sampRateOut =   aacDecInfo->sampRate * (aacDecInfo->sbrEnabled ? 2 : 1);
        aacFrameInfo->bitsPerSample = 16;
        aacFrameInfo->outputSamps =   aacDecInfo->nChans * AAC_MAX_NSAMPS * (aacDecInfo->sbrEnabled ? 2 : 1);
        aacFrameInfo->profile =       aacDecInfo->profile;
        aacFrameInfo->tnsUsed =       aacDecInfo->tnsUsed;
        aacFrameInfo->pnsUsed =       aacDecInfo->pnsUsed;
    }
}

void AACGetDecoderInfo(HAACDecoder hAACDecoder, AACFrameInfo *aacFrameInfo)
{
    AACDecInfo *aacDecInfo = (AACDecInfo *)hAACDecoder;

    if (aacDecInfo) {
        aacFrameInfo->format =       aacDecInfo->format;
        aacFrameInfo->nChans =        aacDecInfo->nChans;
        aacFrameInfo->sampRateCore =  aacDecInfo->sampRate;
        aacFrameInfo->sampRateOut =   aacDecInfo->sampRate * (aacDecInfo->sbrEnabled ? 2 : 1);
        aacFrameInfo->bitsPerSample = 16;
        aacFrameInfo->outputSamps =   aacDecInfo->nChans * AAC_MAX_NSAMPS * (aacDecInfo->sbrEnabled ? 2 : 1);
        aacFrameInfo->profile =       aacDecInfo->profile;
        aacFrameInfo->tnsUsed =       aacDecInfo->tnsUsed;
        aacFrameInfo->pnsUsed =       aacDecInfo->pnsUsed;
        aacFrameInfo->total_byte_parsed = aacDecInfo->byteParsed;
        aacFrameInfo->total_sample_decoded = aacDecInfo->sampleDecoded;

        if (aacDecInfo->bitRate) {
            aacFrameInfo->bitRate = aacDecInfo->bitRate;
        } else if (aacDecInfo->sampleDecoded > 0) {
            aacFrameInfo->bitRate = (int)(((float)(aacDecInfo->byteParsed)) / ((float)aacDecInfo->sampleDecoded / (float)aacFrameInfo->sampRateOut)) << 3;
        }
    }
}

/**************************************************************************************
 * Function:    AACSetRawBlockParams
 *
 * Description: set internal state variables for decoding a stream of raw data blocks
 *
 * Inputs:      valid AAC decoder instance pointer (HAACDecoder)
 *              flag indicating source of parameters
 *              AACFrameInfo struct, with the members nChans, sampRate, and profile
 *                optionally filled-in
 *
 * Outputs:     updated codec state
 *
 * Return:      0 if successful, error code (< 0) if error
 *
 * Notes:       if copyLast == 1, then the codec sets up its internal state (for
 *                decoding raw blocks) based on previously-decoded ADTS header info
 *              if copyLast == 0, then the codec uses the values passed in
 *                aacFrameInfo to configure its internal state (useful when the
 *                source is MP4 format, for example)
 **************************************************************************************/
int AACSetRawBlockParams(HAACDecoder hAACDecoder, int copyLast, AACFrameInfo *aacFrameInfo)
{
    AACDecInfo *aacDecInfo = (AACDecInfo *)hAACDecoder;

    if (!aacDecInfo) {
        return ERR_AAC_NULL_POINTER;
    }

    aacDecInfo->format = AAC_FF_RAW;
    aacDecInfo->audio_send_by_frame = aacFrameInfo->audio_send_by_frame;
    if (copyLast) {
        return SetRawBlockParams(aacDecInfo, 1, 0, 0, 0);
    } else {
        return SetRawBlockParams(aacDecInfo, 0, aacFrameInfo->nChans, aacFrameInfo->sampRateCore, aacFrameInfo->profile);
    }
}

/**************************************************************************************
 * Function:    AACFlushCodec
 *
 * Description: flush internal codec state (after seeking, for example)
 *
 * Inputs:      valid AAC decoder instance pointer (HAACDecoder)
 *
 * Outputs:     updated state variables in aacDecInfo
 *
 * Return:      0 if successful, error code (< 0) if error
 **************************************************************************************/
int AACFlushCodec(HAACDecoder hAACDecoder)
{
    int ch;
    AACDecInfo *aacDecInfo = (AACDecInfo *)hAACDecoder;

    if (!aacDecInfo) {
        return ERR_AAC_NULL_POINTER;
    }
    /* reset common state variables which change per-frame
     * don't touch state variables which are (usually) constant for entire clip
     *   (nChans, sampRate, profile, format, sbrEnabled)
     */
    aacDecInfo->prevBlockID = AAC_ID_INVALID;
    aacDecInfo->currBlockID = AAC_ID_INVALID;
    aacDecInfo->currInstTag = -1;
    for (ch = 0; ch < MAX_NCHANS_ELEM; ch++) {
        aacDecInfo->sbDeinterleaveReqd[ch] = 0;
    }
    aacDecInfo->adtsBlocksLeft = 0;
    aacDecInfo->tnsUsed = 0;
    aacDecInfo->pnsUsed = 0;

    /* reset internal codec state (flush overlap buffers, etc.) */
    FlushCodec(aacDecInfo);
#ifdef AAC_ENABLE_SBR
    FlushCodecSBR(aacDecInfo);
#endif

    return ERR_AAC_NONE;
}

/**************************************************************************************
 * Function:    AACDecode
 *
 * Description: decode AAC frame
 *
 * Inputs:      valid AAC decoder instance pointer (HAACDecoder)
 *              double pointer to buffer of AAC data
 *              pointer to number of valid bytes remaining in inbuf
 *              pointer to outbuf, big enough to hold one frame of decoded PCM samples
 *                (outbuf must be double-sized if SBR enabled)
 *
 * Outputs:     PCM data in outbuf, interleaved LRLRLR... if stereo
 *                number of output samples = 1024 per channel (2048 if SBR enabled)
 *              updated inbuf pointer
 *              updated bytesLeft
 *
 * Return:      0 if successful, error code (< 0) if error
 *
 * Notes:       inbuf pointer and bytesLeft are not updated until whole frame is
 *                successfully decoded, so if ERR_AAC_INDATA_UNDERFLOW is returned
 *                just call AACDecode again with more data in inbuf
 **************************************************************************************/
int AACDecode(HAACDecoder hAACDecoder, unsigned char **inbuf, int *bytesLeft, short *outbuf)
{
    int err, offset, bitOffset, bitsAvail;
    int ch, baseChan, baseChanSBR, elementChans;
    unsigned char *inptr;
    AACDecInfo *aacDecInfo = (AACDecInfo *)hAACDecoder;
#ifdef AAC_ENABLE_SBR
    int elementChansSBR;
#endif

    if (!aacDecInfo) {
        return ERR_AAC_NULL_POINTER;
    }

    /* make local copies (see "Notes" above) */
    inptr = *inbuf;
    bitOffset = 0;
    bitsAvail = (*bytesLeft) << 3;

    /* first time through figure out what the file format is */
    if (aacDecInfo->format == AAC_FF_Unknown) {
        if (bitsAvail < 32) {
            return ERR_AAC_INDATA_UNDERFLOW;
        }

        if (IS_ADIF(inptr)) {
            /* unpack ADIF header */
            aacDecInfo->format = AAC_FF_ADIF;
            //printk("ADIF_DBG:ready step into UnpackADIFHeader()!\n");
            err = UnpackADIFHeader(aacDecInfo, &inptr, &bitOffset, &bitsAvail);
            if (err) {
                return err;
            }
        } else {
            /* assume ADTS by default */
            aacDecInfo->format = AAC_FF_ADTS;
        }
    }
    //printk("ADIF_DBG:aacDecInfo->format1=%d\n",aacDecInfo->format);

    /* if ADTS, search for start of next frame */
    if (aacDecInfo->format == AAC_FF_ADTS) {
        /* can have 1-4 raw data blocks per ADTS frame (header only present for first one) */
        if (/*aacDecInfo->adtsBlocksLeft == 0*/1) {
            offset = AACFindSyncWord(inptr, bitsAvail >> 3);
            if (AACDataSource == 1) {
                if (offset < 0) { //not find sync word in current buffer
                    return ERR_AAC_INVALID_ADTS_SYNCWORD;    //ERR_AAC_INDATA_UNDERFLOW;
                }
                inptr += offset;
                bitsAvail -= (offset << 3);
            }
            err = UnpackADTSHeader(aacDecInfo, &inptr, &bitOffset, &bitsAvail);
            if (err) {
                return err;
            }

            if (aacDecInfo->nChans == -1) {
                /* figure out implicit channel mapping if necessary */
                err = GetADTSChannelMapping(aacDecInfo, inptr, bitOffset, bitsAvail);
                if (err) {
                    return err;
                }
            }
        }
        aacDecInfo->adtsBlocksLeft--;
    } else if (aacDecInfo->format == AAC_FF_RAW) {
        err = PrepareRawBlock(aacDecInfo);
        if (err) {
            return err;
        }
    }

    //printk("ADIF_DBG:aacDecInfo->nChans=%d aacDecInfo->sampRate=%d\n",aacDecInfo->nChans,aacDecInfo->sampRate);
    /* check for valid number of channels */
    if (aacDecInfo->nChans > AAC_MAX_NCHANS || aacDecInfo->nChans <= 0) {
        printk("AAC ERR: ERR_AAC_NCHANS_TOO_HIGH\n");
        return ERR_AAC_NCHANS_TOO_HIGH;
    }

    /* will be set later if active in this frame */
    aacDecInfo->tnsUsed = 0;
    aacDecInfo->pnsUsed = 0;

    bitOffset = 0;
    baseChan = 0;
    baseChanSBR = 0;
    do {
        /* parse next syntactic element */
        err = DecodeNextElement(aacDecInfo, &inptr, &bitOffset, &bitsAvail);
        if (err) {
            return err;
        }

        elementChans = elementNumChans[aacDecInfo->currBlockID];
        if (baseChan + elementChans > AAC_MAX_NCHANS) {
            return ERR_AAC_NCHANS_TOO_HIGH;
        }

        /* noiseless decoder and dequantizer */
        for (ch = 0; ch < elementChans; ch++) {
            err = DecodeNoiselessData(aacDecInfo, &inptr, &bitOffset, &bitsAvail, ch);
            if (err) {
                return err;
            }

            if (Dequantize(aacDecInfo, ch)) {
                return ERR_AAC_DEQUANT;
            }
        }

        /* mid-side and intensity stereo */
        if (aacDecInfo->currBlockID == AAC_ID_CPE) {
            if (StereoProcess(aacDecInfo)) {
                return ERR_AAC_STEREO_PROCESS;
            }
        }

        /* PNS, TNS, inverse transform */
        for (ch = 0; ch < elementChans; ch++) {
            if (PNS(aacDecInfo, ch)) {
                return ERR_AAC_PNS;
            }

            if (aacDecInfo->sbDeinterleaveReqd[ch]) {
                /* deinterleave short blocks, if required */
                if (DeinterleaveShortBlocks(aacDecInfo, ch)) {
                    return ERR_AAC_SHORT_BLOCK_DEINT;
                }
                aacDecInfo->sbDeinterleaveReqd[ch] = 0;
            }

            if (TNSFilter(aacDecInfo, ch)) {
                return ERR_AAC_TNS;
            }

            if (IMDCT(aacDecInfo, ch, baseChan + ch, outbuf)) {
                return ERR_AAC_IMDCT;
            }
        }

#ifdef AAC_ENABLE_SBR
        if (aacDecInfo->sbrEnabled && (aacDecInfo->currBlockID == AAC_ID_FIL || aacDecInfo->currBlockID == AAC_ID_LFE)) {
            if (aacDecInfo->currBlockID == AAC_ID_LFE) {
                elementChansSBR = elementNumChans[AAC_ID_LFE];
            } else if (aacDecInfo->currBlockID == AAC_ID_FIL && (aacDecInfo->prevBlockID == AAC_ID_SCE || aacDecInfo->prevBlockID == AAC_ID_CPE)) {
                elementChansSBR = elementNumChans[aacDecInfo->prevBlockID];
            } else {
                elementChansSBR = 0;
            }

            if (baseChanSBR + elementChansSBR > AAC_MAX_NCHANS) {
                return ERR_AAC_SBR_NCHANS_TOO_HIGH;
            }

            /* parse SBR extension data if present (contained in a fill element) */
            if (DecodeSBRBitstream(aacDecInfo, baseChanSBR)) {
                return ERR_AAC_SBR_BITSTREAM;
            }

            /* apply SBR */
            if (DecodeSBRData(aacDecInfo, baseChanSBR, outbuf)) {
                return ERR_AAC_SBR_DATA;
            }

            baseChanSBR += elementChansSBR;
        }
#endif

        baseChan += elementChans;
    } while (aacDecInfo->currBlockID != AAC_ID_END);

    /* byte align after each raw_data_block */
    if (bitOffset) {
        inptr++;
        bitsAvail -= (8 - bitOffset);
        bitOffset = 0;
        if (bitsAvail < 0) {
            return ERR_AAC_INDATA_UNDERFLOW;
        }
    }

    /* update pointers */
    if (AACDataSource == 1) {
        aacDecInfo->frameCount++;
        aacDecInfo->byteParsed += inptr - *inbuf;
        //printk(" decode one frame cost byte %d \n",inptr - *inbuf);
        aacDecInfo->sampleDecoded += AAC_MAX_NSAMPS * (aacDecInfo->sbrEnabled ? 2 : 1);
        *bytesLeft -= (inptr - *inbuf);
        *inbuf = inptr;
    } else {
        aacDecInfo->frameCount++;
        aacDecInfo->byteParsed = CalcBitsUsed(0, 0, 0) >> 3;
        aacDecInfo->sampleDecoded += AAC_MAX_NSAMPS * (aacDecInfo->sbrEnabled ? 2 : 1);
        *bytesLeft -= (CalcBitsUsed(0, 0, 0) >> 3);
        //  *inbuf = *inbuf+;
    }



    return ERR_AAC_NONE;
}