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.

/*
** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
** Copyright (C) 2003-2004 M. Bakker, Ahead Software AG, http://www.nero.com
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
**
** Any non-GPL usage of this software or parts of this software is strictly
** forbidden.
**
** Commercial non-GPL licensing of this software is possible.
** For more info contact Ahead Software through [e-mail].
**
** $Id: decoder.c,v 1.107 2004/09/08 09:43:11 gcp Exp $
**/

#include "common.h"
#include "structs.h"

#include <stdlib.h>
#include <string.h>

#include "decoder.h"
#include "mp4.h"
#include "syntax.h"
#include "error.h"
#include "output.h"
#include "filtbank.h"
#include "drc.h"
#ifdef SBR_DEC
#include "sbr_dec.h"
#include "sbr_syntax.h"
#endif
#ifdef SSR_DEC
#include "ssr.h"
#endif

#ifdef ANALYSIS
uint16_t dbg_count;
#endif

/* static function declarations */
static void* aac_frame_decode(NeAACDecHandle hDecoder, NeAACDecFrameInfo *hInfo,
                              uint8_t *buffer, uint32_t buffer_size,
                              void **sample_buffer, uint32_t sample_buffer_size);
static void create_channel_config(NeAACDecHandle hDecoder, NeAACDecFrameInfo *hInfo);


/*char* NEAACDECAPI NeAACDecGetErrorMessage(uint8_t errcode)
{
    if (errcode >= NUM_ERROR_MESSAGES)
        return NULL;
    return err_msg[errcode];
}
*/

uint32_t NEAACDECAPI NeAACDecGetCapabilities(void)
{
    uint32_t cap = 0;

    /* can't do without it */
    cap += LC_DEC_CAP;

#ifdef MAIN_DEC
    cap += MAIN_DEC_CAP;
#endif
#ifdef LTP_DEC
    cap += LTP_DEC_CAP;
#endif
#ifdef LD_DEC
    cap += LD_DEC_CAP;
#endif
#ifdef ERROR_RESILIENCE
    cap += ERROR_RESILIENCE_CAP;
#endif
#ifdef FIXED_POINT
    cap += FIXED_POINT_CAP;
#endif

    return cap;
}

NeAACDecHandle NEAACDECAPI NeAACDecOpen(void)
{
    uint8_t i;
    NeAACDecHandle hDecoder = NULL;

    if ((hDecoder = (NeAACDecHandle)faad_malloc(sizeof(NeAACDecStruct))) == NULL)
        return NULL;

    memset(hDecoder, 0, sizeof(NeAACDecStruct));

    hDecoder->config.outputFormat  = FAAD_FMT_16BIT;
    hDecoder->config.defObjectType = MAIN;
    hDecoder->config.defSampleRate = 44100; /* Default: 44.1kHz */
    hDecoder->config.downMatrix = 0;
    hDecoder->adts_header_present = 0;
    hDecoder->adif_header_present = 0;
#ifdef ERROR_RESILIENCE
    hDecoder->aacSectionDataResilienceFlag = 0;
    hDecoder->aacScalefactorDataResilienceFlag = 0;
    hDecoder->aacSpectralDataResilienceFlag = 0;
#endif
    hDecoder->frameLength = 1024;

    hDecoder->frame = 0;
    hDecoder->sample_buffer = NULL;

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

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

    hDecoder->drc = drc_init(REAL_CONST(1.0), REAL_CONST(1.0));

    return hDecoder;
}

NeAACDecConfigurationPtr NEAACDECAPI NeAACDecGetCurrentConfiguration(NeAACDecHandle hDecoder)
{
    if (hDecoder)
    {
        NeAACDecConfigurationPtr config = &(hDecoder->config);

        return config;
    }

    return NULL;
}

uint8_t NEAACDECAPI NeAACDecSetConfiguration(NeAACDecHandle hDecoder,
                                             NeAACDecConfigurationPtr config)
{
    if (hDecoder && config)
    {
        /* check if we can decode this object type */
        if (can_decode_ot(config->defObjectType) < 0)
            return 0;
        hDecoder->config.defObjectType = config->defObjectType;

        /* samplerate: anything but 0 should be possible */
        if (config->defSampleRate == 0)
            return 0;
        hDecoder->config.defSampleRate = config->defSampleRate;

        /* check output format */
#ifdef FIXED_POINT
        if ((config->outputFormat < 1) || (config->outputFormat > 4))
            return 0;
#else
        if ((config->outputFormat < 1) || (config->outputFormat > 5))
            return 0;
#endif
        hDecoder->config.outputFormat = config->outputFormat;

        if (config->downMatrix > 1)
            return 0;
        hDecoder->config.downMatrix = config->downMatrix;

        /* OK */
        return 1;
    }

    return 0;
}

int32_t NEAACDECAPI NeAACDecInit(NeAACDecHandle hDecoder, uint8_t *buffer,
                                 uint32_t buffer_size,
                                 uint32_t *samplerate, uint8_t *channels)
{
    uint32_t bits = 0;
    bitfile ld;
    adif_header adif;
    adts_header adts;

    if ((hDecoder == NULL) || (samplerate == NULL) || (channels == NULL))
        return -1;

    hDecoder->sf_index = get_sr_index(hDecoder->config.defSampleRate);
    hDecoder->object_type = hDecoder->config.defObjectType;
    *samplerate = get_sample_rate(hDecoder->sf_index);
    *channels = 1;

    if (buffer != NULL)
    {
        faad_initbits(&ld, buffer, buffer_size, 0);

        /* Check if an ADIF header is present */
        if ((buffer[0] == 'A') && (buffer[1] == 'D') &&
            (buffer[2] == 'I') && (buffer[3] == 'F'))
        {
            hDecoder->adif_header_present = 1;

            get_adif_header(&adif, &ld);
            faad_byte_align(&ld);

            hDecoder->sf_index = adif.pce[0].sf_index;
            hDecoder->object_type = adif.pce[0].object_type + 1;

            *samplerate = get_sample_rate(hDecoder->sf_index);
            *channels = adif.pce[0].channels;

            memcpy(&(hDecoder->pce), &(adif.pce[0]), sizeof(program_config));
            hDecoder->pce_set = 1;

            bits = bit2byte(faad_get_processed_bits(&ld));

        /* Check if an ADTS header is present */
        } else if (faad_showbits(&ld, 12) == 0xfff) {
            hDecoder->adts_header_present = 1;

            adts.old_format = hDecoder->config.useOldADTSFormat;
            adts_frame(&adts, &ld);

            hDecoder->sf_index = adts.sf_index;
            hDecoder->object_type = adts.profile + 1;

            *samplerate = get_sample_rate(hDecoder->sf_index);
            *channels = (adts.channel_configuration > 6) ?
                2 : adts.channel_configuration;
        }

        if (ld.error)
        {
            faad_endbits(&ld);
            return -1;
        }
        faad_endbits(&ld);
    }
    hDecoder->channelConfiguration = *channels;

#if (defined(PS_DEC) || defined(DRM_PS))
    /* check if we have a mono file */
    if (*channels == 1)
    {
        /* upMatrix to 2 channels for implicit signalling of PS */
        *channels = 2;
    }
#endif

#ifdef SBR_DEC
    /* implicit signalling */
    if (*samplerate <= 24000 && !(hDecoder->config.dontUpSampleImplicitSBR))
    {
        *samplerate *= 2;
        hDecoder->forceUpSampling = 1;
    } else if (*samplerate > 24000 && !(hDecoder->config.dontUpSampleImplicitSBR)) {
        hDecoder->downSampledSBR = 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

    if (can_decode_ot(hDecoder->object_type) < 0)
        return -1;

    return bits;
}

/* Init the library using a DecoderSpecificInfo */
int8_t NEAACDECAPI NeAACDecInit2(NeAACDecHandle hDecoder, uint8_t *pBuffer,
                                 uint32_t SizeOfDecoderSpecificInfo,
                                 uint32_t *samplerate, uint8_t *channels)
{
    int8_t rc;
    mp4AudioSpecificConfig mp4ASC;

    if((hDecoder == NULL)
        || (pBuffer == NULL)
        || (SizeOfDecoderSpecificInfo < 2)
        || (samplerate == NULL)
        || (channels == NULL))
    {
        return -1;
    }

    hDecoder->adif_header_present = 0;
    hDecoder->adts_header_present = 0;

    /* decode the audio specific config */
    rc = AudioSpecificConfig2(pBuffer, SizeOfDecoderSpecificInfo, &mp4ASC,
        &(hDecoder->pce));

    /* copy the relevant info to the decoder handle */
    *samplerate = mp4ASC.samplingFrequency;
    if (mp4ASC.channelsConfiguration)
    {
        *channels = mp4ASC.channelsConfiguration;
    } else {
        *channels = hDecoder->pce.channels;
        hDecoder->pce_set = 1;
    }
#if (defined(PS_DEC) || defined(DRM_PS))
    /* check if we have a mono file */
    if (*channels == 1)
    {
        /* upMatrix to 2 channels for implicit signalling of PS */
        *channels = 2;
    }
#endif
    hDecoder->sf_index = mp4ASC.samplingFrequencyIndex;
    hDecoder->object_type = mp4ASC.objectTypeIndex;
#ifdef ERROR_RESILIENCE
    hDecoder->aacSectionDataResilienceFlag = mp4ASC.aacSectionDataResilienceFlag;
    hDecoder->aacScalefactorDataResilienceFlag = mp4ASC.aacScalefactorDataResilienceFlag;
    hDecoder->aacSpectralDataResilienceFlag = mp4ASC.aacSpectralDataResilienceFlag;
#endif
#ifdef SBR_DEC
    hDecoder->sbr_present_flag = mp4ASC.sbr_present_flag;
    hDecoder->downSampledSBR = mp4ASC.downSampledSBR;
    if (hDecoder->config.dontUpSampleImplicitSBR == 0)