Audio-Video synchronization error in Quicktime .mov file
严望
using Mov Recorder 1.3. The audio is ahead of video in the recorded
file. The amount of advanced time is negligible at the beginning of
the file, but increases gradually as we go forward, and reaches the
maximum at the tail of the file. I also observe the fps (Frames Per
Second) of the file by Quicktime 7.2. When playing the rtsp stream
directly on the Internet, the fps is 25.00. While the fps becomes 24
in the recorded file. Moreover, compared to the rtsp stream, the last
part of the video in the recorded file is lost, while the audio is
complete. I guess the change of the fps is the causation.
Is there any possible solution to this? Maybe modifying the fps of the
recorded file is one, but I don't know how to. Thank you.
Pat Horridge
video is too high for the data connection to sustain the video and audio
will start to drift out of sync. Lowering the video to half the fps would
probably solve the problem.
You would have to re-encode the video at a lower fps rate to achieve that.
"СПНы" <bobb...@msn.com> wrote in message
news:1192621803.9...@v29g2000prd.googlegroups.com...
bobb...@msn.com
> I think Quicktime isn't too hot on Audio video sync. If the FPS for the
> video is too high for the data connection to sustain the video and audio
> will start to drift out of sync. Lowering the video to half the fps would
> probably solve the problem.
> You would have to re-encode the video at a lower fps rate to achieve that.
>
>
> news:1192621803.9...@v29g2000prd.googlegroups.com...
>
>
>
> >I have recorded .mov file form rtsp://202.38.70.248/2003sjh/20030901.mov
> > using Mov Recorder 1.3. The audio is ahead of video in the recorded
> > file. The amount of advanced time is negligible at the beginning of
> > the file, but increases gradually as we go forward, and reaches the
> > maximum at the tail of the file. I also observe the fps (Frames Per
> > Second) of the file by Quicktime 7.2. When playing the rtsp stream
> > directly on the Internet, the fps is 25.00. While the fps becomes 24
> > in the recorded file. Moreover, compared to the rtsp stream, the last
> > part of the video in the recorded file is lost, while the audio is
> > complete. I guess the change of the fps is the causation.
> > Is there any possible solution to this? Maybe modifying the fps of the
>
> - -
But the Audio-Video sync is perfect when I playing the rtsp stream on
the Internet, and I think the network is good enought to sustain the
playback. The loss of synchronization only occurs in the recorded
file. You mean re-encode the recorded file may solve problem? Would
you please explain the reason? Thank you.
Pat Horridge
How did you record it?
If the file came in in sync but plays back wrong after being recorded I'd
have to suspect soemthig wrong either with the lcal palyback of that file or
it was recorded wrong in the first place.
<bobb...@msn.com> wrote in message
news:1193539368....@q5g2000prf.googlegroups.com...
On 10 24 , 5 17 , "Pat Horridge" <p...@remove-spam.vet.co.uk> wrote:
> I think Quicktime isn't too hot on Audio video sync. If the FPS for the
> video is too high for the data connection to sustain the video and audio
> will start to drift out of sync. Lowering the video to half the fps would
> probably solve the problem.
> You would have to re-encode the video at a lower fps rate to achieve that.
>
> "СПНы" <bobby_...@msn.com> wrote in message
bobb...@msn.com
http://www.streamingstar.com/movrecorder.htm
It's the only program which can record rtsp based .mov stream.
The stream on the internet has no sync error, for I can play it
properly. But the recorded file has. The player used is Quicktime
downloaded from apple, which is unlikely to have any problem. So I
agree with you that the recorded file must have some problem. I jsut
want to fix it, but yet has no idea of how.
Some guesses were presented in the beginning of this topic thread.
Would you kindly give some hint? Thanks.
On 10 30 , 12 54 , "Pat Horridge" <p...@remove-spam.vet.co.uk>
wrote:
> Soory I hadn't realised you had the issue with the recorded file.
> How did you record it?
> If the file came in in sync but plays back wrong after being recorded I'd
> have to suspect soemthig wrong either with the lcal palyback of that file or
> it was recorded wrong in the first place.
>
> <bobby_...@msn.com> wrote in message
>
> news:1193539368....@q5g2000prf.googlegroups.com...
> On 10 24 , 5 17 , "Pat Horridge" <p...@remove-spam.vet.co.uk> wrote:
>
>
>
>
>
> > I think Quicktime isn't too hot on Audio video sync. If the FPS for the
> > video is too high for the data connection to sustain the video and audio
> > will start to drift out of sync. Lowering the video to half the fps would
> > probably solve the problem.
> > You would have to re-encode the video at a lower fps rate to achieve that.
>
> > "ÑÏÍû" <bobby_...@msn.com> wrote in message
>
> >news:1192621803.9...@v29g2000prd.googlegroups.com...
>
> > >I have recorded .mov file form rtsp://202.38.70.248/2003sjh/20030901.mov
> > > using Mov Recorder 1.3. The audio is ahead of video in the recorded
> > > file. The amount of advanced time is negligible at the beginning of
> > > the file, but increases gradually as we go forward, and reaches the
> > > maximum at the tail of the file. I also observe the fps (Frames Per
> > > Second) of the file by Quicktime 7.2. When playing the rtsp stream
> > > directly on the Internet, the fps is 25.00. While the fps becomes 24
> > > in the recorded file. Moreover, compared to the rtsp stream, the last
> > > part of the video in the recorded file is lost, while the audio is
> > > complete. I guess the change of the fps is the causation.
> > > Is there any possible solution to this? Maybe modifying the fps of the
> > > recorded file is one, but I don't know how to. Thank you.- -
>
> > - -
>
> But the Audio-Video sync is perfect when I playing the rtsp stream on
> the Internet, and I think the network is good enought to sustain the
> playback. The loss of synchronization only occurs in the recorded
> file. You mean re-encode the recorded file may solve problem? Would
> you please explain the reason? Thank you.- -
>
> - -
Pat Horridge
level before.
My solution would probably be import the QT into a non linear system and see
what I end up with.
If it looks good then export and see if that produces the right result.
If it's wrong on import do what needs to be done to fix it there.
<bobb...@msn.com> wrote in message
news:1193887955....@e9g2000prf.googlegroups.com...
> > "СПНы" <bobby_...@msn.com> wrote in message
bobb...@msn.com
> Sorry haven't had to try and modify the properties of a QT file at that
> level before.
> My solution would probably be import the QT into a non linear system and see
> what I end up with.
> If it looks good then export and see if that produces the right result.
> If it's wrong on import do what needs to be done to fix it there.
>
>
> news:1193887955....@e9g2000prf.googlegroups.com...
> I used mov recorder to recorded it, which could be downloaded here.http://www.streamingstar.com/movrecorder.htm
>
> > >news:1192621803.9...@v29g2000prd.googlegroups.com...
>
> > > >I have recorded .mov file form
> > > >rtsp://202.38.70.248/2003sjh/20030901.mov
> > > > using Mov Recorder 1.3. The audio is ahead of video in the recorded
> > > > file. The amount of advanced time is negligible at the beginning of
> > > > the file, but increases gradually as we go forward, and reaches the
> > > > maximum at the tail of the file. I also observe the fps (Frames Per
> > > > Second) of the file by Quicktime 7.2. When playing the rtsp stream
> > > > directly on the Internet, the fps is 25.00. While the fps becomes 24
> > > > in the recorded file. Moreover, compared to the rtsp stream, the last
> > > > part of the video in the recorded file is lost, while the audio is
> > > > complete. I guess the change of the fps is the causation.
> > > > Is there any possible solution to this? Maybe modifying the fps of the
> > > > recorded file is one, but I don't know how to. Thank you.- -
>
> > > - -
>
> > But the Audio-Video sync is perfect when I playing the rtsp stream on
> > the Internet, and I think the network is good enought to sustain the
> > playback. The loss of synchronization only occurs in the recorded
> > file. You mean re-encode the recorded file may solve problem? Would
> > you please explain the reason? Thank you.- -
>
>
> - -
Is Adobe Premiere Pro CS3 a nonlinear editing system? I have tried to
import the QT file into it. No error occured during the import, but
the imported video had the same sync problem. Is there any other
system? Thanks.
Pat Horridge
<bobb...@msn.com> wrote in message
news:1194313316....@e9g2000prf.googlegroups.com...
Loads of other systems but I suspetc they'd all show the same issue.
Clearly indicates the captured file has the problem.
So failing a method to actually capture without the error your only solution
is to re-establish the sync in Premiere.
Either the sound needs to be shortened (which may need a pitch shift to
compensate) or the video needs to be extended by applying a motion effect
and decreasingt he playback speed slightly.
Not sure how good Premiere is at any of those.
bobb...@msn.com
>
> - -
Wow, it's really a hard job. Thank you.