VLC播放器调试经验总结
一、前言
二、时间戳日志打印具体方法
1、将live/liveMedia/include/RTPSource.hh中的fCurPacketRTPTimestamp变量修改为pubilc类型
class RTPSource: public FramedSource {
public:
u_int32_t fCurPacketRTPTimestamp;
static Boolean lookupByName(UsageEnvironment& env, char const* sourceName,
RTPSource*& resultSource);void FramedSource::afterGetting(FramedSource* source) {
source->fIsCurrentlyAwaitingData = False;
// indicates that we can be read again
// Note that this needs to be done here, in case the "fAfterFunc"
// called below tries to read another frame (which it usually will)
// m by yagerfgcs begin 用时间戳fCurPacketRTPTimestamp替换fDurationInMicroseconds，传递到live555::StreamRead函数中
if (source->fAfterGettingFunc != NULL) {
(*(source->fAfterGettingFunc))(source->fAfterGettingClientData,
source->fFrameSize, source->fNumTruncatedBytes,
source->fPresentationTime,
((RTPSource*)source)->fCurPacketRTPTimestamp);
}
/*if (source->fAfterGettingFunc != NULL) {
(*(source->fAfterGettingFunc))(source->fAfterGettingClientData,
source->fFrameSize, source->fNumTruncatedBytes,
source->fPresentationTime,
source->fDurationInMicroseconds);
}*/
// end
} /* Update our global npt value */
if( tk->f_npt > 0 &&
( tk->f_npt < p_sys->f_npt_length || p_sys->f_npt_length <= 0 ) )
p_sys->f_npt = tk->f_npt;
if( p_block )
{
if( !tk->b_muxed && !tk->b_asf )
{
if( i_pts != tk->i_pts )
p_block->i_pts = VLC_TS_0 + i_pts;
/*FIXME: for h264 you should check that packetization-mode=1 in sdp-file */
p_block->i_dts = ( tk->fmt.i_codec == VLC_CODEC_MPGV ) ? VLC_TS_INVALID : (VLC_TS_0 + i_pts);
// yagerfgcs for 借dts值赋值给timestamp;
p_block->i_dts = duration;
}
if( tk->b_muxed )
stream_DemuxSend( tk->p_out_muxed, p_block );
else if( tk->b_asf )
stream_DemuxSend( p_sys->p_out_asf, p_block );
else
es_out_Send(p_demux->out, tk->p_es, p_block);
}
4、在src\input\es_out.c中EsOutSend函数中可以分别打印音视频码流时间戳timestamp、显示时间戳pts。也可以在此处屏蔽音频或视频的输入，避免送入到解码模块。
static int EsOutSend( es_out_t *out, es_out_id_t *es, block_t *p_block )
{
es_out_sys_t *p_sys = out->p_sys;
input_thread_t *p_input = p_sys->p_input;
if( libvlc_stats( p_input ) )
{
uint64_t i_total;
vlc_mutex_lock( &p_input->p->counters.counters_lock );
stats_Update( p_input->p->counters.p_demux_read,
p_block->i_buffer, &i_total );
stats_Update( p_input->p->counters.p_demux_bitrate, i_total, NULL );
/* Update number of corrupted data packats */
if( p_block->i_flags & BLOCK_FLAG_CORRUPTED )
{
stats_Update( p_input->p->counters.p_demux_corrupted, 1, NULL );
}
/* Update number of discontinuities */
if( p_block->i_flags & BLOCK_FLAG_DISCONTINUITY )
{
stats_Update( p_input->p->counters.p_demux_discontinuity, 1, NULL );
}
vlc_mutex_unlock( &p_input->p->counters.counters_lock );
}
vlc_mutex_lock( &p_sys->lock );
/* Mark preroll blocks */
if( p_sys->i_preroll_end >= 0 )
{
int64_t i_date = p_block->i_pts;
if( p_block->i_pts <= VLC_TS_INVALID )
i_date = p_block->i_dts;
if( i_date < p_sys->i_preroll_end )
p_block->i_flags |= BLOCK_FLAG_PREROLL;
}
if( !es->p_dec )
{
block_Release( p_block );
vlc_mutex_unlock( &p_sys->lock );
return VLC_SUCCESS;
}
/* Check for sout mode */
if( p_input->p->p_sout )
{
/* FIXME review this, proper lock may be missing */
if( p_input->p->p_sout->i_out_pace_nocontrol > 0 &&
p_input->p->b_out_pace_control )
{
msg_Dbg( p_input, "switching to sync mode" );
p_input->p->b_out_pace_control = false;
}
else if( p_input->p->p_sout->i_out_pace_nocontrol <= 0 &&
!p_input->p->b_out_pace_control )
{
msg_Dbg( p_input, "switching to async mode" );
p_input->p->b_out_pace_control = true;
}
}
// add by yagerfgcs for log 音视频打印不同日志，便于定位
if (es->p_dec->fmt_out.i_cat == VIDEO_ES)
{
msg_Dbg(p_input, "[TS es_out::EsOutSend] video pts[%llu] timestamp[%llu]", p_block->i_pts, p_block->i_dts);
}
else if (es->p_dec->fmt_out.i_cat == AUDIO_ES)
{
msg_Dbg(p_input, "[TS es_out::EsOutSend] audio pts[%llu] timestamp[%llu]", p_block->i_pts, p_block->i_dts);
}
// end by add
/* Decode */
if( es->p_dec_record )
{
block_t *p_dup = block_Duplicate( p_block );
if( p_dup )
input_DecoderDecode( es->p_dec_record, p_dup,
p_input->p->b_out_pace_control );
}
input_DecoderDecode(es->p_dec, p_block,
p_input->p->b_out_pace_control);
// yagerfgcs test for:有时在定位视频问题时，为了排查干扰，可以屏蔽音频。反之亦然。需要的同仁，可以放开这段代码。
/*if (es->p_dec->fmt_out.i_cat == VIDEO_ES)
{
input_DecoderDecode(es->p_dec, p_block,
p_input->p->b_out_pace_control);
}
else
{
block_Release(p_block);
}*/
es_format_t fmt_dsc;
vlc_meta_t *p_meta_dsc;
if( input_DecoderHasFormatChanged( es->p_dec, &fmt_dsc, &p_meta_dsc ) )
{
EsOutUpdateInfo( out, es, &fmt_dsc, p_meta_dsc );
es_format_Clean( &fmt_dsc );
if( p_meta_dsc )
vlc_meta_Delete( p_meta_dsc );
}
/* Check CC status */
bool pb_cc[4];
input_DecoderIsCcPresent( es->p_dec, pb_cc );
for( int i = 0; i < 4; i++ )
{
es_format_t fmt;
if( es->pb_cc_present[i] || !pb_cc[i] )
continue;
msg_Dbg( p_input, "Adding CC track %d for es[%d]", 1+i, es->i_id );
es_format_Init( &fmt, SPU_ES, EsOutFourccClosedCaptions[i] );
fmt.i_group = es->fmt.i_group;
if( asprintf( &fmt.psz_description,
_("Closed captions %u"), 1 + i ) == -1 )
fmt.psz_description = NULL;
es->pp_cc_es[i] = EsOutAdd( out, &fmt );
es->pp_cc_es[i]->p_master = es;
es_format_Clean( &fmt );
/* */
es->pb_cc_present[i] = true;
}
vlc_mutex_unlock( &p_sys->lock );
return VLC_SUCCESS;
}5、在src\input\decoder.c中DecoderProcess函数中打印音视频时间戳
static void DecoderProcess( decoder_t *p_dec, block_t *p_block )
{
decoder_owner_sys_t *p_owner = (decoder_owner_sys_t *)p_dec->p_owner;
const bool b_flush_request = p_block && (p_block->i_flags & BLOCK_FLAG_CORE_FLUSH);
if( p_dec->b_error )
{
if( p_block )
block_Release( p_block );
goto flush;
}
if( p_block && p_block->i_buffer <= 0 )
{
assert( !b_flush_request );
block_Release( p_block );
return;
}
#ifdef ENABLE_SOUT
if( p_owner->b_packetizer )
{
if( p_block )
p_block->i_flags &= ~BLOCK_FLAG_CORE_PRIVATE_MASK;
DecoderProcessSout( p_dec, p_block );
}
else
#endif
{
bool b_flush = false;
if( p_block )
{
const bool b_flushing = p_owner->i_preroll_end == INT64_MAX;
DecoderUpdatePreroll( &p_owner->i_preroll_end, p_block );
b_flush = !b_flushing && b_flush_request;
p_block->i_flags &= ~BLOCK_FLAG_CORE_PRIVATE_MASK;
}
if( p_dec->fmt_out.i_cat == AUDIO_ES )
{
//add by yagerfgcs for log
if (p_block)
{
msg_Dbg(p_dec, "[DS 01 decoder::DecoderProcess] audio pts[%llu]", p_block->i_pts);
}
//end
DecoderProcessAudio( p_dec, p_block, b_flush );
}
else if( p_dec->fmt_out.i_cat == VIDEO_ES )
{
//add by yagerfgcs for log
if (p_block)
{
msg_Dbg(p_dec, "[DS 01 decoder::DecoderProcess] video pts[%llu]", p_block->i_pts);
}
//end
DecoderProcessVideo( p_dec, p_block, b_flush );
}
else if( p_dec->fmt_out.i_cat == SPU_ES )
{
DecoderProcessSpu( p_dec, p_block, b_flush );
}
else
{
msg_Err( p_dec, "unknown ES format" );
p_dec->b_error = true;
}
}
/* */
flush:
if( b_flush_request )
DecoderProcessOnFlush( p_dec );
}6、在modules\codec\avcodec\video.c中DecodeVideo函数增加日志
picture_t *DecodeVideo( decoder_t *p_dec, block_t **pp_block )
{
.................
if( p_block)
{
//yagerfgcs for log
msg_Dbg(p_dec, "[DS 02 video::DecodeVideo] video pts[%llu]", p_block->i_pts);
if( p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
{
p_sys->i_pts = VLC_TS_INVALID; /* To make sure we recover properly */
p_sys->i_late_frames = 0;
post_mt( p_sys );
if( p_block->i_flags & BLOCK_FLAG_DISCONTINUITY )
avcodec_flush_buffers( p_context );
wait_mt( p_sys );
block_Release( p_block );
return NULL;
}
if( p_block->i_flags & BLOCK_FLAG_PREROLL )
{
/* Do not care about late frames when prerolling
* TODO avoid decoding of non reference frame
* (ie all B except for H264 where it depends only on nal_ref_idc) */
p_sys->i_late_frames = 0;
//yagerfgcs for log
msg_Dbg(p_dec, "[DS video::DecodeVideo] p_block->i_flags == BLOCK_FLAG_PREROLL");
}
}
....................
}
7、src\input\decoder.c中DecoderProcess函数
static void DecoderDecodeVideo( decoder_t *p_dec, block_t *p_block )
{
decoder_owner_sys_t *p_owner = p_dec->p_owner;
picture_t *p_pic;
int i_lost = 0;
int i_decoded = 0;
int i_displayed = 0;
while( (p_pic = p_dec->pf_decode_video( p_dec, &p_block )) )
{
//yagerfgcs for log
msg_Dbg(p_dec, "[DS 03 decoder::DecoderDecodeVideo] video pts[%llu]", p_pic->date);
vout_thread_t *p_vout = p_owner->p_vout;
if( DecoderIsExitRequested( p_dec ) )
{
/* It prevent freezing VLC in case of broken decoder */
vout_ReleasePicture( p_vout, p_pic );
if( p_block )
block_Release( p_block );
break;
}
.....................
}
......................
}
8、src\input\decoder.c中DecoderProcess函数
static void DecoderPlayVideo( decoder_t *p_dec, picture_t *p_picture,
int *pi_played_sum, int *pi_lost_sum )
{
...........................
const bool b_dated = p_picture->date > VLC_TS_INVALID;
int i_rate = INPUT_RATE_DEFAULT;
mtime_t dateBefore = p_picture->date;
DecoderFixTs( p_dec, &p_picture->date, NULL, NULL,
&i_rate, DECODER_BOGUS_VIDEO_DELAY );
//yagerfgcs for log
msg_Dbg(p_dec, "[DS 04 decoder::DecoderPlayVideo] video date before[%llu] after DecoderFixTs[%llu]",
dateBefore, p_picture->date);
vlc_mutex_unlock( &p_owner->lock );
/* */
if( !p_picture->b_force && p_picture->date <= VLC_TS_INVALID ) // FIXME --VLC_TS_INVALID verify video_output/*
b_reject = true;
............................
}
三、让VLC默认打印debug日志，方便保存的方法
1、通过VLC菜单->工具->消息，可以将日志级别改为“2（调试）”，这样就可以打印出所有的调试日志，点击“另存为”可保存到文件中
2、也可以通过修改代码，让vlc默认打印debug日志
在modules\gui\qt4\dialogs\messages.cpp中MessagesDialog::MessagesDialog函数，修改默认级别
MessagesDialog::MessagesDialog( intf_thread_t *_p_intf)
: QVLCFrame( _p_intf )
{
setWindowTitle( qtr( "Messages" ) );
setWindowRole( "vlc-messages" );
/* Build Ui */
ui.setupUi( this );
ui.bottomButtonsBox->addButton( new QPushButton( qtr("&Close"), this ),
QDialogButtonBox::RejectRole );
/* Modules tree */
ui.modulesTree->setHeaderHidden( true );
/* Buttons and general layout */
ui.saveLogButton->setToolTip( qtr( "Saves all the displayed logs to a file" ) );
int i_verbosity = 2;// var_InheritInteger(p_intf, "verbose");
changeVerbosity( i_verbosity );
ui.verbosityBox->setValue( qMin( i_verbosity, 2 ) );
................
}