adpcm.c

video linux conference

/*****************************************************************************
 * adpcm.c : adpcm variant audio decoder
 *****************************************************************************
 * Copyright (C) 2001, 2002 VideoLAN
 * $Id: adpcm.c 10321 2005-03-13 13:29:45Z courmisch $
 *
 * Authors: Laurent Aimar <[e-mail]>
 *          Remi Denis-Courmont <rem # videolan.org>
 *
 * 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, USA.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *
 * Documentation: http://www.pcisys.net/~melanson/codecs/adpcm.txt
 *****************************************************************************/
#include <vlc/vlc.h>
#include <vlc/decoder.h>

/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
static int  OpenDecoder( vlc_object_t * );
static void CloseDecoder( vlc_object_t * );

static aout_buffer_t *DecodeBlock( decoder_t *, block_t ** );

vlc_module_begin();
    set_description( _("ADPCM audio decoder") );
    set_capability( "decoder", 50 );
    set_category( CAT_INPUT );
    set_subcategory( SUBCAT_INPUT_ACODEC );
    set_callbacks( OpenDecoder, CloseDecoder );
vlc_module_end();

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
enum adpcm_codec_e
{
    ADPCM_IMA_QT,
    ADPCM_IMA_WAV,
    ADPCM_MS,
    ADPCM_DK3,
    ADPCM_DK4,
    ADPCM_EA
};

struct decoder_sys_t
{
    enum adpcm_codec_e codec;

    int                 i_block;
    int                 i_samplesperblock;

    audio_date_t        end_date;
};

static void DecodeAdpcmMs    ( decoder_t *, int16_t *, uint8_t * );
static void DecodeAdpcmImaWav( decoder_t *, int16_t *, uint8_t * );
static void DecodeAdpcmImaQT ( decoder_t *, int16_t *, uint8_t * );
static void DecodeAdpcmDk4   ( decoder_t *, int16_t *, uint8_t * );
static void DecodeAdpcmDk3   ( decoder_t *, int16_t *, uint8_t * );
static void DecodeAdpcmEA    ( decoder_t *, int16_t *, uint8_t * );

static int pi_channels_maps[6] =
{
    0,
    AOUT_CHAN_CENTER,
    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT,
    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER,
    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARLEFT,
    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
     | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARLEFT
};

/* Various table from http://www.pcisys.net/~melanson/codecs/adpcm.txt */
static int i_index_table[16] =
{
    -1, -1, -1, -1, 2, 4, 6, 8,
    -1, -1, -1, -1, 2, 4, 6, 8
};

static int i_step_table[89] =
{
    7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
    19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
    50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
    130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
    337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
    876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
    2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
    5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
    15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
};

static int i_adaptation_table[16] =
{
    230, 230, 230, 230, 307, 409, 512, 614,
    768, 614, 512, 409, 307, 230, 230, 230
};

static int i_adaptation_coeff1[7] =
{
    256, 512, 0, 192, 240, 460, 392
};

static int i_adaptation_coeff2[7] =
{
    0, -256, 0, 64, 0, -208, -232
};

/*****************************************************************************
 * OpenDecoder: probe the decoder and return score
 *****************************************************************************/
static int OpenDecoder( vlc_object_t *p_this )
{
    decoder_t *p_dec = (decoder_t*)p_this;
    decoder_sys_t *p_sys;

    switch( p_dec->fmt_in.i_codec )
    {
        case VLC_FOURCC('i','m','a', '4'): /* IMA ADPCM */
        case VLC_FOURCC('m','s',0x00,0x02): /* MS ADPCM */
        case VLC_FOURCC('m','s',0x00,0x11): /* IMA ADPCM */
        case VLC_FOURCC('m','s',0x00,0x61): /* Duck DK4 ADPCM */
        case VLC_FOURCC('m','s',0x00,0x62): /* Duck DK3 ADPCM */
        case VLC_FOURCC('X','A','J', 0): /* EA ADPCM */
            break;
        default:
            return VLC_EGENERIC;
    }

    if( p_dec->fmt_in.audio.i_channels <= 0 ||
        p_dec->fmt_in.audio.i_channels > 5 )
    {
        msg_Err( p_dec, "bad channels count(1-5)" );
        return VLC_EGENERIC;
    }

    if( p_dec->fmt_in.audio.i_rate <= 0 )
    {
        msg_Err( p_dec, "bad samplerate" );
        return VLC_EGENERIC;
    }

    /* Allocate the memory needed to store the decoder's structure */
    if( ( p_dec->p_sys = p_sys =
          (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
    {
        msg_Err( p_dec, "out of memory" );
        return VLC_ENOMEM;
    }

    switch( p_dec->fmt_in.i_codec )
    {
        case VLC_FOURCC('i','m','a', '4'): /* IMA ADPCM */
            p_sys->codec = ADPCM_IMA_QT;
            break;
        case VLC_FOURCC('m','s',0x00,0x11): /* IMA ADPCM */
            p_sys->codec = ADPCM_IMA_WAV;
            break;
        case VLC_FOURCC('m','s',0x00,0x02): /* MS ADPCM */
            p_sys->codec = ADPCM_MS;
            break;
        case VLC_FOURCC('m','s',0x00,0x61): /* Duck DK4 ADPCM */
            p_sys->codec = ADPCM_DK4;
            break;
        case VLC_FOURCC('m','s',0x00,0x62): /* Duck DK3 ADPCM */
            p_sys->codec = ADPCM_DK3;
            break;
        case VLC_FOURCC('X','A','J', 0): /* EA ADPCM */
            p_sys->codec = ADPCM_EA;
            p_dec->fmt_in.p_extra = calloc( 2 * p_dec->fmt_in.audio.i_channels,
                                            sizeof( int16_t ) );
            if( p_dec->fmt_in.p_extra == NULL )
            {
                free( p_sys );
                return VLC_ENOMEM;
            }
            break;
    }

    if( p_dec->fmt_in.audio.i_blockalign <= 0 )
    {
        p_sys->i_block = (p_sys->codec == ADPCM_IMA_QT) ?
            34 * p_dec->fmt_in.audio.i_channels : 1024;
        msg_Warn( p_dec, "block size undefined, using %d", p_sys->i_block );
    }
    else
    {
        p_sys->i_block = p_dec->fmt_in.audio.i_blockalign;
    }

    /* calculate samples per block */
    switch( p_sys->codec )
    {
    case ADPCM_IMA_QT:
        p_sys->i_samplesperblock = 64;
        break;
    case ADPCM_IMA_WAV:
        p_sys->i_samplesperblock =
            2 * ( p_sys->i_block - 4 * p_dec->fmt_in.audio.i_channels ) /
            p_dec->fmt_in.audio.i_channels;
        break;
    case ADPCM_MS:
        p_sys->i_samplesperblock =
            2 * (p_sys->i_block - 7 * p_dec->fmt_in.audio.i_channels) /
            p_dec->fmt_in.audio.i_channels + 2;
        break;
    case ADPCM_DK4:
        p_sys->i_samplesperblock =
            2 * (p_sys->i_block - 4 * p_dec->fmt_in.audio.i_channels) /
            p_dec->fmt_in.audio.i_channels + 1;
        break;
    case ADPCM_DK3:
        p_dec->fmt_in.audio.i_channels = 2;
        p_sys->i_samplesperblock = ( 4 * ( p_sys->i_block - 16 ) + 2 )/ 3;
        break;
    case ADPCM_EA:
        p_sys->i_samplesperblock =
            2 * (p_sys->i_block - p_dec->fmt_in.audio.i_channels) /
            p_dec->fmt_in.audio.i_channels;
    }

    msg_Dbg( p_dec, "format: samplerate:%dHz channels:%d bits/sample:%d "
             "blockalign:%d samplesperblock:%d",
             p_dec->fmt_in.audio.i_rate, p_dec->fmt_in.audio.i_channels,
             p_dec->fmt_in.audio.i_bitspersample, p_sys->i_block,
             p_sys->i_samplesperblock );

    p_dec->fmt_out.i_codec = AOUT_FMT_S16_NE;
    p_dec->fmt_out.audio.i_rate = p_dec->fmt_in.audio.i_rate;
    p_dec->fmt_out.audio.i_channels = p_dec->fmt_in.audio.i_channels;
    p_dec->fmt_out.audio.i_physical_channels =
        p_dec->fmt_out.audio.i_original_channels =
            pi_channels_maps[p_dec->fmt_in.audio.i_channels];

    aout_DateInit( &p_sys->end_date, p_dec->fmt_out.audio.i_rate );
    aout_DateSet( &p_sys->end_date, 0 );

    p_dec->pf_decode_audio = DecodeBlock;

    return VLC_SUCCESS;
}

/*****************************************************************************
 * DecodeBlock:
 *****************************************************************************/
static aout_buffer_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
{
    decoder_sys_t *p_sys  = p_dec->p_sys;
    block_t *p_block;

    if( !pp_block || !*pp_block ) return NULL;

    p_block = *pp_block;

    if( p_block->i_pts != 0 &&
        p_block->i_pts != aout_DateGet( &p_sys->end_date ) )
    {
        aout_DateSet( &p_sys->end_date, p_block->i_pts );
    }
    else if( !aout_DateGet( &p_sys->end_date ) )
    {
        /* We've just started the stream, wait for the first PTS. */
        block_Release( p_block );
        return NULL;
    }

    /* Don't re-use the same pts twice */
    p_block->i_pts = 0;

    if( p_block->i_buffer >= p_sys->i_block )
    {
        aout_buffer_t *p_out;

        p_out = p_dec->pf_aout_buffer_new( p_dec, p_sys->i_samplesperblock );
        if( p_out == NULL )
        {
            block_Release( p_block );
            return NULL;
        }

        p_out->start_date = aout_DateGet( &p_sys->end_date );
        p_out->end_date =
            aout_DateIncrement( &p_sys->end_date, p_sys->i_samplesperblock );

        switch( p_sys->codec )
        {
        case ADPCM_IMA_QT:
            DecodeAdpcmImaQT( p_dec, (int16_t*)p_out->p_buffer,
                              p_block->p_buffer );
            break;
        case ADPCM_IMA_WAV:
            DecodeAdpcmImaWav( p_dec, (int16_t*)p_out->p_buffer,
                               p_block->p_buffer );
            break;
        case ADPCM_MS:
            DecodeAdpcmMs( p_dec, (int16_t*)p_out->p_buffer,
                           p_block->p_buffer );
            break;
        case ADPCM_DK4:
            DecodeAdpcmDk4( p_dec, (int16_t*)p_out->p_buffer,
                            p_block->p_buffer );
            break;
        case ADPCM_DK3:
            DecodeAdpcmDk3( p_dec, (int16_t*)p_out->p_buffer,
                            p_block->p_buffer );
            break;
        case ADPCM_EA:
            DecodeAdpcmEA( p_dec, (int16_t*)p_out->p_buffer,
                           p_block->p_buffer );
        default:
            break;
        }

        p_block->p_buffer += p_sys->i_block;
        p_block->i_buffer -= p_sys->i_block;
        return p_out;
    }

    block_Release( p_block );
    return NULL;
}

/*****************************************************************************
 * CloseDecoder:
 *****************************************************************************/
static void CloseDecoder( vlc_object_t *p_this )
{
    decoder_t *p_dec = (decoder_t *)p_this;
    decoder_sys_t *p_sys = p_dec->p_sys;

    if( p_sys->codec == ADPCM_EA )
        free( p_dec->fmt_in.p_extra );
    free( p_sys );
}

/*****************************************************************************
 * Local functions
 *****************************************************************************/
#define CLAMP( v, min, max ) \
    if( (v) < (min) ) (v) = (min); \
    if( (v) > (max) ) (v) = (max)

#define GetByte( v ) \
    (v) = *p_buffer; p_buffer++;

#define GetWord( v ) \
    (v) = *p_buffer; p_buffer++; \
    (v) |= ( *p_buffer ) << 8; p_buffer++; \
    if( (v)&0x8000 ) (v) -= 0x010000;

/*
 * MS
 */
typedef struct adpcm_ms_channel_s
{
    int i_idelta;
    int i_sample1, i_sample2;
    int i_coeff1, i_coeff2;

} adpcm_ms_channel_t;


static int AdpcmMsExpandNibble(adpcm_ms_channel_t *p_channel,
                               int i_nibble )
{
    int i_predictor;
    int i_snibble;
    /* expand sign */

    i_snibble = i_nibble - ( i_nibble&0x08 ? 0x10 : 0 );

    i_predictor = ( p_channel->i_sample1 * p_channel->i_coeff1 +
                    p_channel->i_sample2 * p_channel->i_coeff2 ) / 256 +
                  i_snibble * p_channel->i_idelta;

    CLAMP( i_predictor, -32768, 32767 );

    p_channel->i_sample2 = p_channel->i_sample1;