dts.c

VLC Player Source Code

    p_dec->fmt_out.audio.i_physical_channels =
        p_sys->i_channels_conf & AOUT_CHAN_PHYSMASK;

    p_dec->fmt_out.i_bitrate = p_sys->i_bit_rate;

    if( p_sys->b_packetizer )
    {
        block_t *p_sout_buffer = GetSoutBuffer( p_dec );
        p_buf = p_sout_buffer ? p_sout_buffer->p_buffer : NULL;
        *pp_out_buffer = p_sout_buffer;
    }
    else
    {
        aout_buffer_t *p_aout_buffer = GetAoutBuffer( p_dec );
        p_buf = p_aout_buffer ? p_aout_buffer->p_buffer : NULL;
        *pp_out_buffer = p_aout_buffer;
    }

    return p_buf;
}

/*****************************************************************************
 * GetAoutBuffer:
 *****************************************************************************/
static aout_buffer_t *GetAoutBuffer( decoder_t *p_dec )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    aout_buffer_t *p_buf;

    /* Hack for DTS S/PDIF filter which needs to send 3 frames at a time
     * (plus a few header bytes) */
    p_buf = p_dec->pf_aout_buffer_new( p_dec, p_sys->i_frame_length * 4 );
    if( p_buf == NULL ) return NULL;
    p_buf->i_nb_samples = p_sys->i_frame_length;
    p_buf->i_nb_bytes = p_sys->i_frame_size;

    p_buf->start_date = aout_DateGet( &p_sys->end_date );
    p_buf->end_date =
        aout_DateIncrement( &p_sys->end_date, p_sys->i_frame_length );

    return p_buf;
}

/*****************************************************************************
 * GetSoutBuffer:
 *****************************************************************************/
static block_t *GetSoutBuffer( decoder_t *p_dec )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    block_t *p_block;

    p_block = block_New( p_dec, p_sys->i_frame_size );
    if( p_block == NULL ) return NULL;

    p_block->i_pts = p_block->i_dts = aout_DateGet( &p_sys->end_date );

    p_block->i_length = aout_DateIncrement( &p_sys->end_date,
        p_sys->i_frame_length ) - p_block->i_pts;

    return p_block;
}

/*****************************************************************************
 * SyncInfo: parse DTS sync info
 *****************************************************************************/
static const unsigned int ppi_dts_samplerate[] =
{
    0, 8000, 16000, 32000, 0, 0, 11025, 22050, 44100, 0, 0,
    12000, 24000, 48000, 96000, 192000
};

static const unsigned int ppi_dts_bitrate[] =
{
    32000, 56000, 64000, 96000, 112000, 128000,
    192000, 224000, 256000, 320000, 384000,
    448000, 512000, 576000, 640000, 768000,
    896000, 1024000, 1152000, 1280000, 1344000,
    1408000, 1411200, 1472000, 1536000, 1920000,
    2048000, 3072000, 3840000, 1/*open*/, 2/*variable*/, 3/*lossless*/
};

static int SyncInfo16be( const uint8_t *p_buf,
                         unsigned int *pi_audio_mode,
                         unsigned int *pi_sample_rate,
                         unsigned int *pi_bit_rate,
                         unsigned int *pi_frame_length )
{
    unsigned int i_frame_size;
    unsigned int i_lfe;

    *pi_frame_length = (p_buf[4] & 0x01) << 6 | (p_buf[5] >> 2);
    i_frame_size = (p_buf[5] & 0x03) << 12 | (p_buf[6] << 4) |
                   (p_buf[7] >> 4);

    *pi_audio_mode = (p_buf[7] & 0x0f) << 2 | (p_buf[8] >> 6);
    *pi_sample_rate = (p_buf[8] >> 2) & 0x0f;
    *pi_bit_rate = (p_buf[8] & 0x03) << 3 | ((p_buf[9] >> 5) & 0x07);

    i_lfe = (p_buf[10] >> 1) & 0x03;
    if( i_lfe ) *pi_audio_mode |= 0x10000;

    return i_frame_size + 1;
}

static void BufLeToBe( uint8_t *p_out, const uint8_t *p_in, int i_in )
{
    int i;

    for( i = 0; i < i_in/2; i++  )
    {
        p_out[i*2] = p_in[i*2+1];
        p_out[i*2+1] = p_in[i*2];
    }
}

static int Buf14To16( uint8_t *p_out, const uint8_t *p_in, int i_in, int i_le )
{
    unsigned char tmp, cur = 0;
    int bits_in, bits_out = 0;
    int i, i_out = 0;

    for( i = 0; i < i_in; i++  )
    {
        if( i%2 )
        {
            tmp = p_in[i-i_le];
            bits_in = 8;
        }
        else
        {
            tmp = p_in[i+i_le] & 0x3F;
            bits_in = 8 - 2;
        }

        if( bits_out < 8 )
        {
            int need = __MIN( 8 - bits_out, bits_in );
            cur <<= need;
            cur |= ( tmp >> (bits_in - need) );
            tmp <<= (8 - bits_in + need);
            tmp >>= (8 - bits_in + need);
            bits_in -= need;
            bits_out += need;
        }

        if( bits_out == 8 )
        {
            p_out[i_out] = cur;
            cur = 0;
            bits_out = 0;
            i_out++;
        }

        bits_out += bits_in;
        cur <<= bits_in;
        cur |= tmp;
    }

    return i_out;
}

static inline int SyncCode( const uint8_t *p_buf )
{
    /* 14 bits, little endian version of the bitstream */
    if( p_buf[0] == 0xff && p_buf[1] == 0x1f &&
        p_buf[2] == 0x00 && p_buf[3] == 0xe8 &&
        (p_buf[4] & 0xf0) == 0xf0 && p_buf[5] == 0x07 )
    {
        return VLC_SUCCESS;
    }
    /* 14 bits, big endian version of the bitstream */
    else if( p_buf[0] == 0x1f && p_buf[1] == 0xff &&
             p_buf[2] == 0xe8 && p_buf[3] == 0x00 &&
             p_buf[4] == 0x07 && (p_buf[5] & 0xf0) == 0xf0 )
    {
        return VLC_SUCCESS;
    }
    /* 16 bits, big endian version of the bitstream */
    else if( p_buf[0] == 0x7f && p_buf[1] == 0xfe &&
             p_buf[2] == 0x80 && p_buf[3] == 0x01 )
    {
        return VLC_SUCCESS;
    }
    /* 16 bits, little endian version of the bitstream */
    else if( p_buf[0] == 0xfe && p_buf[1] == 0x7f &&
             p_buf[2] == 0x01 && p_buf[3] == 0x80 )
    {
        return VLC_SUCCESS;
    }
    else return VLC_EGENERIC;
}

static int SyncInfo( const uint8_t *p_buf,
                     unsigned int *pi_channels,
                     unsigned int *pi_channels_conf,
                     unsigned int *pi_sample_rate,
                     unsigned int *pi_bit_rate,
                     unsigned int *pi_frame_length )
{
    unsigned int i_audio_mode;
    unsigned int i_frame_size;

    /* 14 bits, little endian version of the bitstream */
    if( p_buf[0] == 0xff && p_buf[1] == 0x1f &&
        p_buf[2] == 0x00 && p_buf[3] == 0xe8 &&
        (p_buf[4] & 0xf0) == 0xf0 && p_buf[5] == 0x07 )
    {
        uint8_t conv_buf[DTS_HEADER_SIZE];
        Buf14To16( conv_buf, p_buf, DTS_HEADER_SIZE, 1 );
        i_frame_size = SyncInfo16be( conv_buf, &i_audio_mode, pi_sample_rate,
                                     pi_bit_rate, pi_frame_length );
        i_frame_size = i_frame_size * 8 / 14 * 2;
    }
    /* 14 bits, big endian version of the bitstream */
    else if( p_buf[0] == 0x1f && p_buf[1] == 0xff &&
             p_buf[2] == 0xe8 && p_buf[3] == 0x00 &&
             p_buf[4] == 0x07 && (p_buf[5] & 0xf0) == 0xf0 )
    {
        uint8_t conv_buf[DTS_HEADER_SIZE];
        Buf14To16( conv_buf, p_buf, DTS_HEADER_SIZE, 0 );
        i_frame_size = SyncInfo16be( conv_buf, &i_audio_mode, pi_sample_rate,
                                     pi_bit_rate, pi_frame_length );
        i_frame_size = i_frame_size * 8 / 14 * 2;
    }
    /* 16 bits, big endian version of the bitstream */
    else if( p_buf[0] == 0x7f && p_buf[1] == 0xfe &&
             p_buf[2] == 0x80 && p_buf[3] == 0x01 )
    {
        i_frame_size = SyncInfo16be( p_buf, &i_audio_mode, pi_sample_rate,
                                     pi_bit_rate, pi_frame_length );
    }
    /* 16 bits, little endian version of the bitstream */
    else if( p_buf[0] == 0xfe && p_buf[1] == 0x7f &&
             p_buf[2] == 0x01 && p_buf[3] == 0x80 )
    {
        uint8_t conv_buf[DTS_HEADER_SIZE];
        BufLeToBe( conv_buf, p_buf, DTS_HEADER_SIZE );
        i_frame_size = SyncInfo16be( p_buf, &i_audio_mode, pi_sample_rate,
                                     pi_bit_rate, pi_frame_length );
    }
    else return 0;

    switch( i_audio_mode & 0xFFFF )
    {
        case 0x0:
            /* Mono */
            *pi_channels_conf = AOUT_CHAN_CENTER;
            break;
        case 0x1:
            /* Dual-mono = stereo + dual-mono */
            *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
                           AOUT_CHAN_DUALMONO;
            break;
        case 0x2:
        case 0x3:
        case 0x4:
            /* Stereo */
            *pi_channels = 2;
            *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
            break;
        case 0x5:
            /* 3F */
            *pi_channels = 3;
            *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
                                AOUT_CHAN_CENTER;
            break;
        case 0x6:
            /* 2F/1R */
            *pi_channels = 3;
            *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
                                AOUT_CHAN_REARCENTER;
            break;
        case 0x7:
            /* 3F/1R */
            *pi_channels = 4;
            *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
                                AOUT_CHAN_CENTER | AOUT_CHAN_REARCENTER;
            break;
        case 0x8:
            /* 2F2R */
            *pi_channels = 4;
            *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
                                AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT;
            break;
        case 0x9:
            /* 3F2R */
            *pi_channels = 5;
            *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
                                AOUT_CHAN_CENTER | AOUT_CHAN_REARLEFT |
                                AOUT_CHAN_REARRIGHT;
            break;
        case 0xA:
        case 0xB:
            /* 2F2M2R */
            *pi_channels = 6;
            *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
                                AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT |
                                AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT;
            break;
        case 0xC:
            /* 3F2M2R */
            *pi_channels = 7;
            *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
                                AOUT_CHAN_CENTER | AOUT_CHAN_MIDDLELEFT |
                                AOUT_CHAN_MIDDLERIGHT | AOUT_CHAN_REARLEFT |
                                AOUT_CHAN_REARRIGHT;
            break;
        case 0xD:
        case 0xE:
            /* 3F2M2R/LFE */
            *pi_channels = 8;
            *pi_channels_conf = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
                                AOUT_CHAN_CENTER | AOUT_CHAN_MIDDLELEFT |
                                AOUT_CHAN_MIDDLERIGHT | AOUT_CHAN_REARLEFT |
                                AOUT_CHAN_REARRIGHT | AOUT_CHAN_LFE;
            break;

        default:
            if( i_audio_mode <= 63 )
            {
                /* User defined */
                *pi_channels = 0;
                *pi_channels_conf = 0;
            }
            else return 0;
            break;
    }

    if( i_audio_mode & 0x10000 )
    {
        (*pi_channels)++;
        *pi_channels_conf |= AOUT_CHAN_LFE;
    }

    if( *pi_sample_rate >= sizeof( ppi_dts_samplerate ) /
                           sizeof( ppi_dts_samplerate[0] ) )
    {
        return 0;
    }
    *pi_sample_rate = ppi_dts_samplerate[ *pi_sample_rate ];
    if( !*pi_sample_rate ) return 0;

    if( *pi_bit_rate >= sizeof( ppi_dts_bitrate ) /
                        sizeof( ppi_dts_bitrate[0] ) )
    {
        return 0;
    }
    *pi_bit_rate = ppi_dts_bitrate[ *pi_bit_rate ];
    if( !*pi_bit_rate ) return 0;

    *pi_frame_length = (*pi_frame_length + 1) * 32;

    return i_frame_size;
}