Beispiel #1
0
static block_t *PacketizeParse( void *p_private, bool *pb_ts_used, block_t *p_block )
{
    decoder_t *p_dec = p_private;

    /* Check if we have a picture start code */
    *pb_ts_used = p_block->p_buffer[3] == 0x00;

    return ParseMPEGBlock( p_dec, p_block );
}
Beispiel #2
0
static block_t *PacketizeParse( void *p_private, bool *pb_ts_used, block_t *p_block )
{
    decoder_t *p_dec = p_private;
    const mtime_t i_dts = p_block->i_dts;
    const mtime_t i_pts = p_block->i_pts;

    block_t *p_au = ParseMPEGBlock( p_dec, p_block );

    *pb_ts_used = p_au &&  p_au->i_dts == i_dts && p_au->i_pts == i_pts;

    return p_au;
}
Beispiel #3
0
/*****************************************************************************
 * Packetize:
 *****************************************************************************/
static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    block_t       *p_pic;

    if( pp_block == NULL || *pp_block == NULL )
    {
        return NULL;
    }

    if( (*pp_block)->i_flags & BLOCK_FLAG_DISCONTINUITY )
    {
        p_sys->i_state = STATE_NOSYNC;
        if( p_sys->p_frame ) block_ChainRelease( p_sys->p_frame );
        p_sys->p_frame = NULL;
        p_sys->pp_last = &p_sys->p_frame;
        p_sys->b_frame_slice = VLC_FALSE;
        block_Release( *pp_block );
        return NULL;
    }

    block_BytestreamPush( &p_sys->bytestream, *pp_block );

    while( 1 )
    {
        switch( p_sys->i_state )
        {

        case STATE_NOSYNC:
            if( block_FindStartcodeFromOffset( &p_sys->bytestream,
                    &p_sys->i_offset, p_sys->p_startcode, 3 ) == VLC_SUCCESS )
            {
                p_sys->i_state = STATE_NEXT_SYNC;
            }

            if( p_sys->i_offset )
            {
                block_SkipBytes( &p_sys->bytestream, p_sys->i_offset );
                p_sys->i_offset = 0;
                block_BytestreamFlush( &p_sys->bytestream );
            }

            if( p_sys->i_state != STATE_NEXT_SYNC )
            {
                /* Need more data */
                return NULL;
            }

            p_sys->i_offset = 1; /* To find next startcode */

        case STATE_NEXT_SYNC:
            /* TODO: If p_block == NULL, flush the buffer without checking the
             * next sync word */

            /* Find the next startcode */
            if( block_FindStartcodeFromOffset( &p_sys->bytestream,
                    &p_sys->i_offset, p_sys->p_startcode, 3 ) != VLC_SUCCESS )
            {
                /* Need more data */
                return NULL;
            }

            /* Get the new fragment and set the pts/dts */
            p_pic = block_New( p_dec, p_sys->i_offset );
            block_BytestreamFlush( &p_sys->bytestream );
            p_pic->i_pts = p_sys->bytestream.p_block->i_pts;
            p_pic->i_dts = p_sys->bytestream.p_block->i_dts;

            block_GetBytes( &p_sys->bytestream, p_pic->p_buffer,
                            p_pic->i_buffer );

            /* don't reuse the same timestamps several times */
            if( p_pic->i_buffer >= 4 && p_pic->p_buffer[3] == 0x00 )
            {
                /* We have a picture start code */
                p_sys->bytestream.p_block->i_pts = 0;
                p_sys->bytestream.p_block->i_dts = 0;
            }

            p_sys->i_offset = 0;

            /* Get picture if any */
            if( !( p_pic = ParseMPEGBlock( p_dec, p_pic ) ) )
            {
                p_sys->i_state = STATE_NOSYNC;
                break;
            }

            /* We've just started the stream, wait for the first PTS.
             * We discard here so we can still get the sequence header. */
            if( p_sys->i_dts <= 0 && p_sys->i_pts <= 0 &&
                p_sys->i_interpolated_dts <= 0 )
            {
                msg_Dbg( p_dec, "need a starting pts/dts" );
                p_sys->i_state = STATE_NOSYNC;
                block_Release( p_pic );
                break;
            }

            /* When starting the stream we can have the first frame with
             * a null DTS (i_interpolated_pts is initialized to 0) */
            if( !p_pic->i_dts ) p_pic->i_dts = p_pic->i_pts;

            /* So p_block doesn't get re-added several times */
            *pp_block = block_BytestreamPop( &p_sys->bytestream );

            p_sys->i_state = STATE_NOSYNC;

            return p_pic;
        }
    }
}