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nagyist / vidnik

Automatically exported from code.google.com/p/vidnik
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Audio not synced #4

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago 
What steps will reproduce the problem?
1. Create video
2. Upload to YouTube
3. Watch

What is the expected output? What do you see instead?
Video with audio in sync. Instead, audio is delayed ~1 second.

What version of the product are you using? On what operating system?
0.12.0

Please provide any additional information below.
See http://www.youtube.com/watch?v=BV_jpPhwK30 for a demo.

Original issue reported on code.google.com by chris.br...@gtempaccount.com on 12 May 2008 at 5:46

GoogleCodeExporter commented 9 years ago 
Hi, I've previously been informed by YouTube that audio sync can be affected by 
the
sample rate that the audio is in, before YouTube converts the file.

Could this be the issue?

According to YouTube, the audio sample rate has to be 44.1kHz and 16bit.

Original comment by erik.hau...@gmail.com on 14 May 2008 at 9:38

GoogleCodeExporter commented 9 years ago

Original comment by DavidPhi...@gmail.com on 21 May 2008 at 11:55

GoogleCodeExporter commented 9 years ago 
Im having the same problem!!

Original comment by faustori...@gmail.com on 5 Feb 2009 at 8:14

GoogleCodeExporter commented 9 years ago 
the movie contains p-frames and i-frames, and there appears to be a bug between 
YouTube and Quicktime that 
Quicktime can generate movies with p-frames that are in the cropped-off, 
invisible prefix, and YouTube doesn't 
correctly handle movies where the first sequence of frames are i-frames. I may 
be able to work around the 
problem by (a) detecting that Quicktime wrote a movie like this and (b) 
re-writing the movie to get it to start 
with a p-frame.

However, when I've tried this in the past, Quicktime just blindly copies the 
original move, so the rewritten movie 
has the same problem as the original. The real fix is for YouTube to encode 
movies like this correctly.

Original comment by DavidPhi...@gmail.com on 5 Feb 2009 at 6:29

GoogleCodeExporter commented 9 years ago 
The audio still is out of sync.  I recorded the video with Vidnik (0.12) and 
when
played back on Vidnik the audio sync was fine.  Once I uploaded it to youtube 
the
audio sync was off when played online 
(http://www.youtube.com/watch?v=OtaAfFMBQxc). 
This is a great app.  Are there any workarounds for me to avoid this problem?  
Will
this be fixed?

Original comment by zeetw...@gmail.com on 19 May 2009 at 1:16

GoogleCodeExporter commented 9 years ago 
The bug is still open on the YouTube side.

Original comment by DavidPhi...@gmail.com on 19 May 2009 at 5:07

GoogleCodeExporter commented 9 years ago 
Could you provide more information on the YouTube bug? Maybe end users could 
file reports with Google to 
speed things along. Vidnik is the best recorder-uploader to YouTube I've come 
across for Macs - it's a shame 
this bug continues for over a year.

Original comment by mace...@gmail.com on 4 Aug 2009 at 4:42

GoogleCodeExporter commented 9 years ago 
See comment 4 on this issue.

The quicktime movie consists of an audio track, a video track, and an edit 
list. The audio track is a sequence 
of compressed samples, tens of thousands per second. The video track is a 
sequence of video frames, "p" 
frames which completely and "i" frames, or interpolation frames, that just 
concisely describe the difference to 
an adjacent "p" frame (either the previous "p" frame, or the next one, that 
will be shown.)

The edit list is a sequence of ranges: trimming off the prefix, for example.

The bug is that YouTube's re-encoder is not correctly handling trims that point 
at an i-frame: it silently 
rounds to a p-frame, on the video, but not the audio, causing the two to be out 
of sync.

From the Mac point of view, I haven't been able see the i-frames and p-frames 
at the Quicktime level, the 
level the app is written at. Further, telling the app to re-copy the movie as a 
self-contained movie doesn't 
change the i-frame and edit-list structure: the result is still a problematic 
movie.

There is a bug filed on this inside Google. It has more than a dozen other bugs 
labelled as duplicate filings of 
this same bug

Original comment by DavidPhi...@gmail.com on 7 Aug 2009 at 9:04

GoogleCodeExporter commented 9 years ago 
YES, THIS IS STILL GOING ON.  It is SO frustrating.  I wish there was a way to 
get
around it.  Any ideas out there?  I thought there was a way you could put it 
through
another vid application afterward and then upload it from there. ??

Original comment by allegr...@gmail.com on 26 Nov 2009 at 5:21