static?void?EsOutDecodersStopBuffering( es_out_t *out, bool b_forced )

{

????es_out_sys_t *p_sys = out->p_sys;

????mtime_t i_stream_start;

????mtime_t i_system_start;

????mtime_t i_stream_duration;

????mtime_t i_system_duration;

????//获取已经缓存的数据量

????if?(input_clock_GetState( p_sys->p_pgrm->p_clock,

??????????????????????????????????&i_stream_start, &i_system_start,

??????????????????????????????????&i_stream_duration, &i_system_duration ))

????????return;

????mtime_t i_preroll_duration =?0;

????if( p_sys->i_preroll_end >=?0?)

????????i_preroll_duration = __MAX( p_sys->i_preroll_end - i_stream_start,?0?);

????//缓存上限，主要由i_pts_delay控制，可以通过options设置

????const?mtime_t i_buffering_duration = p_sys->i_pts_delay +

?????????????????????????????????????????i_preroll_duration +

?????????????????????????????????????????p_sys->i_buffering_extra_stream - p_sys->i_buffering_extra_initial;

????if( i_stream_duration <= i_buffering_duration && !b_forced )

????{

????????//计算缓冲进度并上报

????????double?f_level;

????????if?(i_buffering_duration ==?0)

????????????f_level =?0;

????????else

????????????f_level = __MAX( (double)i_stream_duration / i_buffering_duration,?0?);

????????input_SendEventCache( p_sys->p_input, f_level );

????????int?i_level = (int)(100?* f_level);

????????if( p_sys->i_prev_stream_level != i_level )

????????{

????????????msg_Dbg( p_sys->p_input,?"Buffering %d%%", i_level );

????????????p_sys->i_prev_stream_level = i_level;

????????}

????????return;

????}

????//缓冲完成并上报

????input_SendEventCache( p_sys->p_input,?1.0?);

????msg_Dbg( p_sys->p_input,?"Stream buffering done (%d ms in %d ms)",

??????????????(int)(i_stream_duration/1000), (int)(i_system_duration/1000) );

????p_sys->b_buffering =?false;

????p_sys->i_preroll_end = -1;

????p_sys->i_prev_stream_level = -1;

????if( p_sys->i_buffering_extra_initial >?0?)

????{

????????/* FIXME wrong ? */

????????return;

????}

????//等待解码器解出首帧

????const?mtime_t i_decoder_buffering_start = mdate();

????for(?int?i =?0; i < p_sys->i_es; i++ )

????{

????????es_out_id_t *p_es = p_sys->es[i];

????????if( !p_es->p_dec || p_es->fmt.i_cat == SPU_ES )

????????????continue;

????????input_DecoderWait( p_es->p_dec );

????????if( p_es->p_dec_record )

????????????input_DecoderWait( p_es->p_dec_record );

????}

????msg_Dbg( p_sys->p_input,?"Decoder wait done in %d ms",

??????????????(int)(mdate() - i_decoder_buffering_start)/1000?);

????/* Here is a good place to destroy unused vout with every demuxer */

????input_resource_TerminateVout( input_priv(p_sys->p_input)->p_resource );

????/* */

????const?mtime_t i_wakeup_delay =?10*1000;?/* FIXME CLEANUP thread wake up time*/

????const?mtime_t i_current_date = p_sys->b_paused ? p_sys->i_pause_date : mdate();

????//更新clock_point

????input_clock_ChangeSystemOrigin( p_sys->p_pgrm->p_clock,?true,

????????????????????????????????????i_current_date + i_wakeup_delay - i_buffering_duration );

????//解码器停止等待

????for(?int?i =?0; i < p_sys->i_es; i++ )

????{

????????es_out_id_t *p_es = p_sys->es[i];

????????if( !p_es->p_dec )

????????????continue;

????????input_DecoderStopWait( p_es->p_dec );

????????if( p_es->p_dec_record )

????????????input_DecoderStopWait( p_es->p_dec_record );

????}

}

//正常

libvlc input: Decoder wait done in?77?ms

//异常

libvlc input: Decoder wait done in?0?ms

void?input_DecoderWait( decoder_t *p_dec )

{

????decoder_owner_sys_t *p_owner = p_dec->p_owner;

????assert( p_owner->b_waiting );

????vlc_mutex_lock( &p_owner->lock );

????//如果b_has_data为false，就一直循环；b_has_data只有在DecoderPlayXxx函数中才会被置为true，此时代表解码器解出了首帧

????while( !p_owner->b_has_data )

????{

????????/* Don't need to lock p_owner->paused since it's only modified by the

?????????* owner */

????????//第一个提前break的条件，paused变量为true，即解码器在pause状态下，此时不会解码数据，如果不break会发生死锁

????????if( p_owner->paused )

????????????break;

????????vlc_fifo_Lock( p_owner->p_fifo );

????????//第二个提前break的条件，解码器fifo为空，此时没有要解码的数据，同样不会解码数据，如果不break也会发生死锁

????????if( p_owner->b_idle && vlc_fifo_IsEmpty( p_owner->p_fifo ) )

????????{

????????????msg_Err( p_dec,?"buffer deadlock prevented"?);

????????????vlc_fifo_Unlock( p_owner->p_fifo );

????????????break;

????????}

????????vlc_fifo_Unlock( p_owner->p_fifo );

????????vlc_cond_wait( &p_owner->wait_acknowledge, &p_owner->lock );

????}

????vlc_mutex_unlock( &p_owner->lock );

}

/**

?* MainLoop

?* The main input loop.

?*/

static?void?MainLoop( input_thread_t *p_input, bool b_interactive )

{

????mtime_t i_intf_update =?0;

????mtime_t i_last_seek_mdate =?0;

????//这里在起播前将player pause住了

????if( b_interactive && var_InheritBool( p_input,?"start-paused"?) )

????????ControlPause( p_input, mdate() );

????......

}