Skip to content

Commit

Permalink
avoid out of sync after seek
Browse files Browse the repository at this point in the history 
before pakcet queue.clear(), a/v thread may takes 1 packet and
later compares to new packets after seek. the diff will be large. just
ignore once
when seeking, can not contunue without decoding video.
  • Loading branch information
@wang-bin
wang-bin committed Dec 9, 2014
1 parent 9422c46 commit fbd94ee
Show file tree
Hide file tree
Showing 2 changed files with 47 additions and 19 deletions.
8 changes: 5 additions & 3 deletions src/AudioThread.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,7 @@
#include "output/OutputSet.h"
#include "QtAV/private/AVCompat.h"
#include <QtCore/QCoreApplication>
#include <QtCore/QDateTime>
#include "utils/Logger.h"

namespace QtAV {
Expand Down Expand Up @@ -106,12 +107,13 @@ void AudioThread::run()
* a frame is about 20ms. sleep time must be << frame time
*/
qreal a_v = pkt.pts - d.clock->videoPts();

//qDebug("skip audio decode at %f/%f v=%f a-v=%fms", pkt.pts, d.render_pts0, d.clock->videoPts(), a_v*1000.0);
if (a_v > 0)
if (a_v > 0) {
msleep(qMin((ulong)20, ulong(a_v*1000.0)));
else
} else {
// audio maybe too late compared with video packet before seeking backword. so just ignore
msleep(1);
}
pkt = Packet(); //mark invalid to take next
continue;
}
Expand Down
58 changes: 42 additions & 16 deletions src/VideoThread.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -175,6 +175,8 @@ void VideoThread::run()
bool wait_key_frame = false;
int nb_dec_slow = 0;

bool is_pkt_bf_seek = true;
qint32 seek_count = 0;
while (!d.stop) {
processNextTask();
//TODO: why put it at the end of loop then playNextFrame() not work?
Expand Down Expand Up @@ -211,10 +213,11 @@ void VideoThread::run()
// skip decoding
// TODO: force fit min fps
if (nb_dec_slow > 10 && !pkt.hasKeyFrame) {
nb_dec_slow = 0;
wait_key_frame = true;
pkt = Packet();
continue;
//nb_dec_slow = 0;
//wait_key_frame = true;
//pkt = Packet();
// TODO: use discard flag
//continue;
} else {
nb_dec_slow++;
}
Expand All @@ -224,34 +227,36 @@ void VideoThread::run()
/*
*after seeking forward, a packet may be the old, v packet may be
*the new packet, then the d.delay is very large, omit it.
*TODO: 1. how to choose the value
* 2. use last delay when seeking
* 3. compute average decode time
*/
bool skip_render = pts < d.render_pts0;
const bool seeking = d.render_pts0 != 0.0;
// TODO: check frame type(after decode) and skip decoding some frames to speed up
if (skip_render) {
d.clock->updateVideoPts(pts); //here?
//qDebug("skip video render at %f/%f", pkt.pts, d.render_pts0);
}
if (qAbs(pts < d.render_pts0) < 1.0) { // not seeking
if (!seeking) { // not seeking
if (dec_opt_state == kFrameDrop) {
dec_opt_state = kNoFrameDrop;
dec->setOptions(d.dec_opt_normal);
}
} else { // seeking
if (dec_opt_state == kNoFrameDrop) {
dec_opt_state = kFrameDrop;
//dec_opt_old = dec->options();
dec->setOptions(d.dec_opt_framedrop);
if (seek_count > 0) {
if (dec_opt_state == kNoFrameDrop) {
dec_opt_state = kFrameDrop;
//dec_opt_old = dec->options();
dec->setOptions(d.dec_opt_framedrop);
}
} else {
seek_count = -1;
}
}
if (qAbs(d.delay) < 0.5) {
if (d.delay < -kSyncThreshold) { //Speed up. drop frame?
//continue;
}
} else if (qFuzzyIsNull(d.render_pts0)){ //when to drop off?
qDebug("delay %f/%f", d.delay, d.clock->value());
} else if (!seeking){ //when to drop off?
qDebug("delay %fs @%fs", d.delay, d.clock->value());
if (d.delay < 0) {
if (!pkt.hasKeyFrame) {
// if continue without decoding, we must wait to the next key frame, then we may skip to many frames
Expand All @@ -260,10 +265,24 @@ void VideoThread::run()
//continue;
}
skip_render = !pkt.hasKeyFrame;
} else {
// video too fast if old packet before seek backward compared with new audio packet after seek backward
// what about video too late?
if (is_pkt_bf_seek && d.delay > 2.0) {
// if seeking, we can not continue without decoding
is_pkt_bf_seek = false;
pkt = Packet();
continue; // seeking and this v packet is before seeking
}
const double s = qMin<double>(d.delay/2.0, 0.1);
qWarning("video too fast!!! sleep %.2f s", s);
d.clock->updateVideoPts(pts); //here?
usleep(s * 1000000UL);
d.delay = qMax<qreal>(0.0, qMin(d.delay, qreal(pts - d.clock->value())));
}
}
//audio packet not cleaned up?
if (d.delay < 2.0 && qFuzzyIsNull(d.render_pts0)) {
if (d.delay < 1.0 && !seeking) {
while (d.delay > kSyncThreshold) { //Slow down
//d.delay_cond.wait(&d.mutex, d.delay*1000); //replay may fail. why?
//qDebug("~~~~~wating for %f msecs", d.delay*1000);
Expand All @@ -274,6 +293,7 @@ void VideoThread::run()
d.delay -= kSyncThreshold;
d.delay = qMax<qreal>(0.0, qMin(d.delay, qreal(pts - d.clock->value())));
processNextTask();
//check seeking?
}
if (d.delay > 0)
usleep(d.delay * 1000000UL);
Expand All @@ -282,7 +302,7 @@ void VideoThread::run()
qDebug("video thread stop before decode()");
break;
}
} else if (qFuzzyIsNull(d.render_pts0)) {
} else if (!seeking) {
if (d.delay > 0)
msleep(40);
}
Expand All @@ -301,6 +321,7 @@ void VideoThread::run()
} else {
int undecoded = dec->undecodedSize();
if (undecoded > 0) {
qDebug("undecoded size: %d", undecoded);
pkt.data.remove(0, pkt.data.size() - undecoded);
} else {
pkt = Packet();
Expand All @@ -312,11 +333,16 @@ void VideoThread::run()
qWarning("invalid video frame");
continue;
}
is_pkt_bf_seek = true;
if (skip_render) {
pkt = Packet(); //mark invalid to take next
continue;
}
d.render_pts0 = 0;
if (seek_count == -1)
seek_count = 1;
else if (seek_count > 0)
seek_count++;
frame.setTimestamp(pts);
frame.setImageConverter(d.conv);
Q_ASSERT(d.statistics);
Expand Down

0 comments on commit fbd94ee

Please sign in to comment.