demux.c

uclinux 下的vlc播放器源代码

    int64_t     i_pos;

    /* Demuxer */
    char        *psz_name;
    es_out_t    *out;
    demux_t     *p_demux;

} d_stream_sys_t;

static int DStreamRead   ( stream_t *, void *p_read, int i_read );
static int DStreamPeek   ( stream_t *, uint8_t **pp_peek, int i_peek );
static int DStreamControl( stream_t *, int i_query, va_list );
static int DStreamThread ( stream_t * );


stream_t *__stream_DemuxNew( vlc_object_t *p_obj, char *psz_demux,
                             es_out_t *out )
{
    /* We create a stream reader, and launch a thread */
    stream_t       *s;
    d_stream_sys_t *p_sys;

    if( psz_demux == NULL || *psz_demux == '\0' ) return NULL;

    s = vlc_object_create( p_obj, VLC_OBJECT_STREAM );
    s->pf_block  = NULL;
    s->pf_read   = DStreamRead;
    s->pf_peek   = DStreamPeek;
    s->pf_control= DStreamControl;

    s->i_char_width = 1;
    s->b_little_endian = VLC_FALSE;

    s->p_sys = malloc( sizeof( d_stream_sys_t) );
    p_sys = (d_stream_sys_t*)s->p_sys;

    p_sys->i_pos = 0;
    p_sys->out = out;
    p_sys->p_demux = NULL;
    p_sys->p_block = NULL;
    p_sys->psz_name = strdup( psz_demux );

    /* decoder fifo */
    if( ( p_sys->p_fifo = block_FifoNew( s ) ) == NULL )
    {
        msg_Err( s, "out of memory" );
        vlc_object_destroy( s );
        free( p_sys );
        return NULL;
    }

    if( vlc_thread_create( s, "stream out", DStreamThread,
                           VLC_THREAD_PRIORITY_INPUT, VLC_FALSE ) )
    {
        vlc_object_destroy( s );
        free( p_sys );
        return NULL;
    }

    return s;
}

void stream_DemuxSend( stream_t *s, block_t *p_block )
{
    d_stream_sys_t *p_sys = (d_stream_sys_t*)s->p_sys;
    if( p_block ) block_FifoPut( p_sys->p_fifo, p_block );
}

void stream_DemuxDelete( stream_t *s )
{
    d_stream_sys_t *p_sys = (d_stream_sys_t*)s->p_sys;
    block_t *p_empty;

    s->b_die = VLC_TRUE;
    if( p_sys->p_demux ) p_sys->p_demux->b_die = VLC_TRUE;
    p_empty = block_New( s, 1 ); p_empty->i_buffer = 0;
    block_FifoPut( p_sys->p_fifo, p_empty );
    vlc_thread_join( s );

    if( p_sys->p_demux ) demux2_Delete( p_sys->p_demux );
    if( p_sys->p_block ) block_Release( p_sys->p_block );

    block_FifoRelease( p_sys->p_fifo );
    free( p_sys->psz_name );
    free( p_sys );

    vlc_object_destroy( s );
}


static int DStreamRead( stream_t *s, void *p_read, int i_read )
{
    d_stream_sys_t *p_sys = (d_stream_sys_t*)s->p_sys;
    uint8_t *p_out = p_read;
    int i_out = 0;

    //msg_Dbg( s, "DStreamRead: wanted %d bytes", i_read );

    while( !s->b_die && !s->b_error && i_read )
    {
        block_t *p_block = p_sys->p_block;
        int i_copy;

        if( !p_block )
        {
            p_block = block_FifoGet( p_sys->p_fifo );
            if( !p_block ) s->b_error = 1;
            p_sys->p_block = p_block;
        }

        if( p_block && i_read )
        {
            i_copy = __MIN( i_read, p_block->i_buffer );
            if( p_out && i_copy ) memcpy( p_out, p_block->p_buffer, i_copy );
            i_read -= i_copy;
            i_out += i_copy;
            p_block->i_buffer -= i_copy;
            p_block->p_buffer += i_copy;

            if( !p_block->i_buffer )
            {
                block_Release( p_block );
                p_sys->p_block = NULL;
            }
        }
    }

    p_sys->i_pos += i_out;
    return i_out;
}

static int DStreamPeek( stream_t *s, uint8_t **pp_peek, int i_peek )
{
    d_stream_sys_t *p_sys = (d_stream_sys_t*)s->p_sys;
    block_t **pp_block = &p_sys->p_block;
    int i_out = 0;
    *pp_peek = 0;

    //msg_Dbg( s, "DStreamPeek: wanted %d bytes", i_peek );

    while( !s->b_die && !s->b_error && i_peek )
    {
        int i_copy;

        if( !*pp_block )
        {
            *pp_block = block_FifoGet( p_sys->p_fifo );
            if( !*pp_block ) s->b_error = 1;
        }

        if( *pp_block && i_peek )
        {
            i_copy = __MIN( i_peek, (*pp_block)->i_buffer );
            i_peek -= i_copy;
            i_out += i_copy;

            if( i_peek ) pp_block = &(*pp_block)->p_next;
        }
    }

    if( p_sys->p_block )
    {
        p_sys->p_block = block_ChainGather( p_sys->p_block );
        *pp_peek = p_sys->p_block->p_buffer;
    }

    return i_out;
}

static int DStreamControl( stream_t *s, int i_query, va_list args )
{
    d_stream_sys_t *p_sys = (d_stream_sys_t*)s->p_sys;
    int64_t    *p_i64;
    vlc_bool_t *p_b;
    int        *p_int;

    switch( i_query )
    {
        case STREAM_GET_SIZE:
            p_i64 = (int64_t*) va_arg( args, int64_t * );
            *p_i64 = 0;
            return VLC_SUCCESS;

        case STREAM_CAN_SEEK:
            p_b = (vlc_bool_t*) va_arg( args, vlc_bool_t * );
            *p_b = VLC_FALSE;
            return VLC_SUCCESS;

        case STREAM_CAN_FASTSEEK:
            p_b = (vlc_bool_t*) va_arg( args, vlc_bool_t * );
            *p_b = VLC_FALSE;
            return VLC_SUCCESS;

        case STREAM_GET_POSITION:
            p_i64 = (int64_t*) va_arg( args, int64_t * );
            *p_i64 = p_sys->i_pos;
            return VLC_SUCCESS;

        case STREAM_SET_POSITION:
        {
            int64_t i64 = (int64_t)va_arg( args, int64_t );
            int i_skip;
            if( i64 < p_sys->i_pos ) return VLC_EGENERIC;
            i_skip = i64 - p_sys->i_pos;

            while( i_skip > 0 )
            {
                int i_read = DStreamRead( s, NULL, i_skip );
                if( i_read <= 0 ) return VLC_EGENERIC;
                i_skip -= i_read;
            }
            return VLC_SUCCESS;
        }

        case STREAM_GET_MTU:
            p_int = (int*) va_arg( args, int * );
            *p_int = 0;
            return VLC_SUCCESS;

        case STREAM_CONTROL_ACCESS:
            return VLC_EGENERIC;

        default:
            msg_Err( s, "invalid DStreamControl query=0x%x", i_query );
            return VLC_EGENERIC;
    }
}

static int DStreamThread( stream_t *s )
{
    d_stream_sys_t *p_sys = (d_stream_sys_t*)s->p_sys;
    demux_t *p_demux;

    /* Create the demuxer */
    if( !(p_demux = demux2_New( s, "", p_sys->psz_name, "", s, p_sys->out,
                               VLC_FALSE )) )
    {
        return VLC_EGENERIC;
    }

    p_sys->p_demux = p_demux;

    /* Main loop */
    while( !s->b_die && !p_demux->b_die )
    {
        if( p_demux->pf_demux( p_demux ) <= 0 ) break;
    }

    p_demux->b_die = VLC_TRUE;
    return VLC_SUCCESS;
}

/****************************************************************************
 * Utility functions
 ****************************************************************************/
static void SkipID3Tag( demux_t *p_demux )
{
    uint8_t *p_peek;
    uint8_t version, revision;
    int i_size;
    int b_footer;

    if( !p_demux->s ) return;

    /* Get 10 byte id3 header */
    if( stream_Peek( p_demux->s, &p_peek, 10 ) < 10 ) return;

    if( p_peek[0] != 'I' || p_peek[1] != 'D' || p_peek[2] != '3' ) return;

    version = p_peek[3];
    revision = p_peek[4];
    b_footer = p_peek[5] & 0x10;
    i_size = (p_peek[6]<<21) + (p_peek[7]<<14) + (p_peek[8]<<7) + p_peek[9];

    if( b_footer ) i_size += 10;
    i_size += 10;

    /* Skip the entire tag */
    stream_Read( p_demux->s, NULL, i_size );

    msg_Dbg( p_demux, "ID3v2.%d revision %d tag found, skipping %d bytes",
             version, revision, i_size );

    return;
}