vorbis.c

uclinux 下的vlc播放器源代码

        p_dec->fmt_in.i_extra += oggpacket.bytes + 2;

        block_Release( *pp_block );
        p_sys->i_headers++;
        return NULL;
    }

    if( p_sys->i_headers == 3 )
    {
        if( ProcessHeaders( p_dec ) != VLC_SUCCESS )
        {
            p_sys->i_headers = 0;
            p_dec->fmt_in.i_extra = 0;
            block_Release( *pp_block );
            return NULL;
        }
        else p_sys->i_headers++;
    }

    return ProcessPacket( p_dec, &oggpacket, pp_block );
}

/*****************************************************************************
 * ProcessHeaders: process Vorbis headers.
 *****************************************************************************/
static int ProcessHeaders( decoder_t *p_dec )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    ogg_packet oggpacket;
    uint8_t *p_extra;
    int i_extra;

    if( !p_dec->fmt_in.i_extra ) return VLC_EGENERIC;

    oggpacket.granulepos = -1;
    oggpacket.b_o_s = 1; /* yes this actually is a b_o_s packet :) */
    oggpacket.e_o_s = 0;
    oggpacket.packetno = 0;
    p_extra = p_dec->fmt_in.p_extra;
    i_extra = p_dec->fmt_in.i_extra;

    /* Take care of the initial Vorbis header */
    oggpacket.bytes = *(p_extra++) << 8;
    oggpacket.bytes |= (*(p_extra++) & 0xFF);
    oggpacket.packet = p_extra;
    p_extra += oggpacket.bytes;
    i_extra -= (oggpacket.bytes + 2);
    if( i_extra < 0 )
    {
        msg_Err( p_dec, "header data corrupted");
        return VLC_EGENERIC;
    }

    if( vorbis_synthesis_headerin( &p_sys->vi, &p_sys->vc, &oggpacket ) < 0 )
    {
        msg_Err( p_dec, "this bitstream does not contain Vorbis audio data");
        return VLC_EGENERIC;
    }

    /* Setup the format */
    p_dec->fmt_out.audio.i_rate     = p_sys->vi.rate;
    p_dec->fmt_out.audio.i_channels = p_sys->vi.channels;

    if( p_dec->fmt_out.audio.i_channels < 0 ||
        p_dec->fmt_out.audio.i_channels > 6 )
    {
        msg_Err( p_dec, "invalid number of channels (not between 1 and 6): %i",
                 p_dec->fmt_out.audio.i_channels );
        return VLC_EGENERIC;
    }

    p_dec->fmt_out.audio.i_physical_channels =
        p_dec->fmt_out.audio.i_original_channels =
            pi_channels_maps[p_sys->vi.channels];
    p_dec->fmt_out.i_bitrate = p_sys->vi.bitrate_nominal;

    aout_DateInit( &p_sys->end_date, p_sys->vi.rate );
    aout_DateSet( &p_sys->end_date, 0 );

    msg_Dbg( p_dec, "channels:%d samplerate:%ld bitrate:%ld",
             p_sys->vi.channels, p_sys->vi.rate, p_sys->vi.bitrate_nominal );

    /* The next packet in order is the comments header */
    oggpacket.b_o_s = 0;
    oggpacket.bytes = *(p_extra++) << 8;
    oggpacket.bytes |= (*(p_extra++) & 0xFF);
    oggpacket.packet = p_extra;
    p_extra += oggpacket.bytes;
    i_extra -= (oggpacket.bytes + 2);
    if( i_extra < 0 )
    {
        msg_Err( p_dec, "header data corrupted");
        return VLC_EGENERIC;
    }

    if( vorbis_synthesis_headerin( &p_sys->vi, &p_sys->vc, &oggpacket ) < 0 )
    {
        msg_Err( p_dec, "2nd Vorbis header is corrupted" );
        return VLC_EGENERIC;
    }
    ParseVorbisComments( p_dec );

    /* The next packet in order is the codebooks header
     * We need to watch out that this packet is not missing as a
     * missing or corrupted header is fatal. */
    oggpacket.bytes = *(p_extra++) << 8;
    oggpacket.bytes |= (*(p_extra++) & 0xFF);
    oggpacket.packet = p_extra;
    i_extra -= (oggpacket.bytes + 2);
    if( i_extra < 0 )
    {
        msg_Err( p_dec, "header data corrupted");
        return VLC_EGENERIC;
    }

    if( vorbis_synthesis_headerin( &p_sys->vi, &p_sys->vc, &oggpacket ) < 0 )
    {
        msg_Err( p_dec, "3rd Vorbis header is corrupted" );
        return VLC_EGENERIC;
    }

    if( !p_sys->b_packetizer )
    {
        /* Initialize the Vorbis packet->PCM decoder */
        vorbis_synthesis_init( &p_sys->vd, &p_sys->vi );
        vorbis_block_init( &p_sys->vd, &p_sys->vb );
    }
    else
    {
        p_dec->fmt_out.i_extra = p_dec->fmt_in.i_extra;
        p_dec->fmt_out.p_extra =
            realloc( p_dec->fmt_out.p_extra, p_dec->fmt_out.i_extra );
        memcpy( p_dec->fmt_out.p_extra,
                p_dec->fmt_in.p_extra, p_dec->fmt_out.i_extra );
    }

    ConfigureChannelOrder(p_sys->pi_chan_table, p_sys->vi.channels,
            p_dec->fmt_out.audio.i_physical_channels, VLC_TRUE);

    return VLC_SUCCESS;
}

/*****************************************************************************
 * ProcessPacket: processes a Vorbis packet.
 *****************************************************************************/
static void *ProcessPacket( decoder_t *p_dec, ogg_packet *p_oggpacket,
                            block_t **pp_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    block_t *p_block = *pp_block;

    /* Date management */
    if( p_block && 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 );
    }

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

    *pp_block = NULL; /* To avoid being fed the same packet again */

    if( p_sys->b_packetizer )
    {
        return SendPacket( p_dec, p_oggpacket, p_block );
    }
    else
    {
        aout_buffer_t *p_aout_buffer;

        if( p_sys->i_headers >= 3 )
            p_aout_buffer = DecodePacket( p_dec, p_oggpacket );
        else
            p_aout_buffer = NULL;

        if( p_block ) block_Release( p_block );
        return p_aout_buffer;
    }
}

/*****************************************************************************
 * DecodePacket: decodes a Vorbis packet.
 *****************************************************************************/
static aout_buffer_t *DecodePacket( decoder_t *p_dec, ogg_packet *p_oggpacket )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    int           i_samples;

#ifdef MODULE_NAME_IS_tremor
    int32_t       **pp_pcm;
#else
    float         **pp_pcm;
#endif

    if( p_oggpacket->bytes &&
#ifdef MODULE_NAME_IS_tremor
        vorbis_synthesis( &p_sys->vb, p_oggpacket, 1 ) == 0 )
#else
        vorbis_synthesis( &p_sys->vb, p_oggpacket ) == 0 )
#endif
        vorbis_synthesis_blockin( &p_sys->vd, &p_sys->vb );

    /* **pp_pcm is a multichannel float vector. In stereo, for
     * example, pp_pcm[0] is left, and pp_pcm[1] is right. i_samples is
     * the size of each channel. Convert the float values
     * (-1.<=range<=1.) to whatever PCM format and write it out */

    if( ( i_samples = vorbis_synthesis_pcmout( &p_sys->vd, &pp_pcm ) ) > 0 )
    {

        aout_buffer_t *p_aout_buffer;

        p_aout_buffer =
            p_dec->pf_aout_buffer_new( p_dec, i_samples );

        if( p_aout_buffer == NULL ) return NULL;

        /* Interleave the samples */
#ifdef MODULE_NAME_IS_tremor
        Interleave( (int32_t *)p_aout_buffer->p_buffer,
                    (const int32_t **)pp_pcm, p_sys->vi.channels, i_samples, p_sys->pi_chan_table);
#else
        Interleave( (float *)p_aout_buffer->p_buffer,
                    (const float **)pp_pcm, p_sys->vi.channels, i_samples, p_sys->pi_chan_table);
#endif

        /* Tell libvorbis how many samples we actually consumed */
        vorbis_synthesis_read( &p_sys->vd, i_samples );

        /* Date management */
        p_aout_buffer->start_date = aout_DateGet( &p_sys->end_date );
        p_aout_buffer->end_date = aout_DateIncrement( &p_sys->end_date,
                                                      i_samples );
        return p_aout_buffer;
    }
    else
    {
        return NULL;
    }
}

/*****************************************************************************
 * SendPacket: send an ogg dated packet to the stream output.
 *****************************************************************************/
static block_t *SendPacket( decoder_t *p_dec, ogg_packet *p_oggpacket,
                            block_t *p_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    int i_block_size, i_samples;

    i_block_size = vorbis_packet_blocksize( &p_sys->vi, p_oggpacket );
    if( i_block_size < 0 ) i_block_size = 0; /* non audio packet */
    i_samples = ( p_sys->i_last_block_size + i_block_size ) >> 2;
    p_sys->i_last_block_size = i_block_size;

    /* Date management */
    p_block->i_dts = p_block->i_pts = aout_DateGet( &p_sys->end_date );

    if( p_sys->i_headers >= 3 )
        p_block->i_length = aout_DateIncrement( &p_sys->end_date, i_samples ) -
            p_block->i_pts;
    else
        p_block->i_length = 0;

    return p_block;
}

/*****************************************************************************
 * ParseVorbisComments: FIXME should be done in demuxer
 *****************************************************************************/
static void ParseVorbisComments( decoder_t *p_dec )
{
    input_thread_t *p_input = (input_thread_t *)p_dec->p_parent;
    char *psz_name, *psz_value, *psz_comment;
    int i = 0;

    if( p_input->i_object_type != VLC_OBJECT_INPUT ) return;

    while( i < p_dec->p_sys->vc.comments )
    {
        psz_comment = strdup( p_dec->p_sys->vc.user_comments[i] );
        if( !psz_comment )
        {
            msg_Warn( p_dec, "out of memory" );
            break;
        }
        psz_name = psz_comment;
        psz_value = strchr( psz_comment, '=' );
        if( psz_value )
        {
            *psz_value = '\0';
            psz_value++;
            input_Control( p_input, INPUT_ADD_INFO, _("Vorbis comment"),
                           psz_name, psz_value );
            if( strcasestr( psz_name, "artist" ) )
            {
                vlc_input_item_AddInfo( p_input->input.p_item,
                                        _(VLC_META_INFO_CAT), _(VLC_META_ARTIST),
                                        "%s", psz_value );
            }
            else if( strcasestr( psz_name, "title" ) )
            {
                p_input->input.p_item->psz_name = strdup( psz_value );
            }
        }
        /* FIXME */
        var_SetInteger( p_input, "item-change", p_input->input.p_item->i_id );
        free( psz_comment );
        i++;
    }
}

/*****************************************************************************
 * Interleave: helper function to interleave channels
 *****************************************************************************/
static void ConfigureChannelOrder(int *pi_chan_table, int i_channels, uint32_t i_channel_mask, vlc_bool_t b_decode)
{
    const uint32_t *pi_channels_in;
    switch( i_channels )
    {
        case 6:
        case 5: