How to resynch audio, QSF did not resolve

RickN

New member
I have a mpeg clip that was obtained by capturing a streaming video from the web. The video plays fine in all video players but the audio is off slightly. When I load into VRD TVS4, the audio is more out of synch. QSF does not resolve the issue. Any thoughts on other procedures for resynching the audio? Thanks.
 

Dan203

Senior Developer
Staff member
Is it uniformly out of sync? What I mean i... Is it the same distance out of sync over the entire length of the program? Or does it start out OK and then get out of sync as the program goes on?

If it is uniformly out of sync then you can adjust the sync in VideoReDo using Tools->Adjust Audio

If it goes out of sync over time then there is nothing we can do. This usually happens when the file is muxed using the incorrect sampling rate for the audio or incorrect frame rate for the video.

Dan
 

RickN

New member
Thanks Dan203. A constant adjustment appears to help but for some reason, the audio is much worse in VRD than an original copy in a video player. When running QSF, 4 video resync frames were removed but there were 27,842 audio resync frames removed. The video is just over an hour in length. Audio is very jumbled in the QSF file in both VRD and other video players.
 

Dan203

Senior Developer
Staff member
Open the file in MediaInfo, switch to text view and then copy/paste the info here. I want to see if there is anything that stands out that might cause a problem. (like variable frame rate)

Dan
 

RickN

New member
Here you go:


General : C:\Users\Rick\Videos\WMC Recordings\Lesson 1 part 1.mpg
Format : MPEG-PS at 21.7 Mbps
Length : 1.95 GiB for 12mn 52s 295ms

Video #0 : MPEG Video at 21.2 Mbps
Aspect : 792 x 592 (1.338) at 25.000 fps

Audio #0 : MPEG Audio at 128 Kbps
Infos : 2 channels, 44.1 KHz
 

Dan203

Senior Developer
Staff member
When you open the file in VideoReDo and go to Tools->Show Program Info does it match?

Dan
 

RickN

New member
File sizes are different but the other parameters are the same. Output from VRD is shown below. Are Mpeg-PS files a problem for VRD? I did find a program (AVIdemux) that will convert the Mpeg-PS files to Mpeg-TS files. Is this worth doing?


File: Name : C:\Users\Rick\Videos\WMC Recordings\Lesson 1 part 1.mpg
Size : 2.097 GB
Duration : 01:02:37.09
Mux type : PS - MPEG2
Video: Encoding : MPEG2
VideoStreamID : xE0
Frame rate : 25.00 fps
Encoding size : 792 x 592
Aspect ratio : 1:1
Header bit rate : 18.000 Mbps
VBV buffer : 916 KBytes
Profile : High @High
Progressive : Prog or Int
Chroma : 4:2:0
Bit rate : 4.287 Mbps
Audio Stream: 1 (Primary) Codec : MPEG
MPEGLayer : Layer 2
Channels : 2.0
PES Stream Id : xC0
Bit rate : 128 Kbps
Sampling rate : 44100
Sample size : 16 bits
 

Dan203

Senior Developer
Staff member
No, MPEG-PS files are the first file type VRD ever supported. They should be the most solid format we support.

Try this... Use the audio tool to get the sync as close as you can. Then when saving click the Options button, change the audio type to MPEG Layer 2 and the sample rate to 48KHz. See if recoding the audio makes it sync up any better.

Dan
 

RickN

New member
Good Morning, Dan! I tried your suggestion but am still having problems. I think the original file just has too many issues and when I try to download the stream, it is giving me problems. I have been recording a 1 hour 20 minute stream. The capture program has a max file size of 2 GB so I needed to do it with two files. The beginning video has problems but not the second one. There does appear to be some slight audio issue with the original stream on-line which is probably causing all the errors with my capture. VRD really does not like this file and works hard to fix it yet it plays fine on my computer but has appearance of audio out of synch:

-Video output packets: 1006187
-Audio output packets: 47590
-Padding output packets: 0
Video output frames: 75126
Audio output frames: 125168
Processing time (secs): 44
Processed frames/sec: 1679.66
Actual Video Bitrate: 5.41 Mbps
* Video resync frames removed: 4
* Audio resync frames removed: 28825
* Audio resync frames added: 17

I tried recapturing and still have the same problem therefore it got to be in the original and I will need accept the capture as is. Thanks for taking a look and offering suggestions!


Add in: The WM capture says the following:

"The Universal Audio Driver should be used if your sound card does not allow recording (mostly XP computers purchased in 2007 and thereafter). We strongly recommend to use the Firefox web browser when recording audio from a web page. Internet Explorer may not work well on Vista and Windows 7. If you're using Internet Explorer click the "Open iExplore" button from Settings to open the browser.

Before enabling this option close the browser or any media players. Open WM Capture first, then open your browser or media player.
Universal Audio Driver has limited use and may require some manual tweeking when capturing the computer screen."

Is this the issue? My computer is a Win 7 64 bit machine with an ATI 5850 video card.
Best,

Rick
 
Last edited:

RickN

New member
I tried capturing a new video from the same web site this afternoon. Video plays fine in all my video players plus appears to be in synch inside VRD. Unfortunately, if I simply save the file, VRD really trashes the audio by making a ton of changes. It appears that I will not be able to edit these captures in VRD. Here is the log and video info for the last capture:

Input file: C:\Users\Rick\Videos\WMC Recordings\WMCap[7].mpg
Output file: D:\Work area VR\WMCap[7] test save.mpg
Mode: Frame Accurate
-Video output packets: 422668
-Audio output packets: 25544
-Padding output packets: 0
Video output frames: 40311
Audio output frames: 61727
Processing time (secs): 11
Processed frames/sec: 3628.68
Actual Video Bitrate: 4.23 Mbps
* Video resync frames removed: 1
* Audio resync frames removed: 15449


File: Name : C:\Users\Rick\Videos\WMC Recordings\WMCap[7].mpg
Size : 0.888 GB
Duration : 00:33:36.08
Mux type : PS - MPEG2
Video: Encoding : MPEG2
VideoStreamID : xE0
Frame rate : 25.00 fps
Encoding size : 800 x 600
Aspect ratio : 1:1
Header bit rate : 18.000 Mbps
VBV buffer : 916 KBytes
Profile : High @High
Progressive : Prog or Int
Chroma : 4:2:0
Bit rate : 3.382 Mbps
Audio Stream: 1 (Primary) Codec : MPEG
MPEGLayer : Layer 2
Channels : 2.0
PES Stream Id : xC0
Bit rate : 128 Kbps
Sampling rate : 44100
Sample size : 16 bits
 

Dan203

Senior Developer
Staff member
Do me a favor, use the Trim & Copy tool to grab the first 50-100MB of the file and then upload it our FTP.... (verify it has the same problem first)

http://www.videoredo.net/msgBoard/showthread.php?t=15807

Also can you tell me what program you're using to "capture" these clips? I'd like to take a look at it to see if there are any options which might help it produce a better clip. (if you'd rather not say in public you can send me a PM)

Dan
 

RickN

New member
Dan,

I uploaded three files and sent an email to support. The software used to capture the video stream was WM capture.

Thanks for your help!
 

Dan203

Senior Developer
Staff member
I took a look at your file. Even though MediaInfo and VRD both list it as 25fps it's actually just 20fps. That is not a valid MPEG-2 frame rate, which is why VRD is having so much trouble handling it. I verified the bad frame rate by remuxing the file in mkvmerge. If I manually set the frame rate in there to 20fps the resulting file played correctly. But if I left it alone, which picked 25fps like VRD, the file was way out of sync.

Looking at the screen shot you sent of the program options there appears to be a drop down list of frame rates. Here is a list of valid MPEG-2 frame rates...

23.976
25
29.97
50
59.94

See if one of those are available and if so select it instead. That should create a valid recording that VRD can handle properly.

Dan
 

RickN

New member
Interesting, I ran mediainfo and VRD on this particular file (results are shown earlier in this thread). Both programs report that fps is 25. The screen shot sent to support was an image of the settings screen for WM capture. I manually set the fps to 25 before recording and both the above programs confirm that I had. WM capture resets to default upon startup (that's why the image shows an incorrect fps because I captured the image days after the recording).

I have made a couple more captures earlier this week, again setting the fps to 25. Both mediainfo and vrd confirm that they are 25 fps files. Unfortunately, they blow up (ie thousands of audio frames deleted) when saving in VRD (even with no editing). I had hoped to burn files to dvd but looks like I will need a different dvd burning program...
 

Dan203

Senior Developer
Staff member
It says 25fps in VRD and MediaInfo because that is how the MPEG headers are marked. However there are only 1267 video frames in the whole file you sent. That clip is 1:03 long. (plus a few odd frames) If it were really 25fps then there would be 1575+ frames of video, since 63 seconds * 25fps = 1575. However there are only 1267, so the math suggests that it's 20fps. (63 seconds * 20fps = 1260) In fact if you open the file in the main VRD UI and look at the thumbnail view you can see that it skips a few timecode values as you move along in an attempt to fit the clip into the suggested 25fps. However if you click on the first frame and actually count the number of frames between 0.00 and 1.00 you'll see that there are actually only 20.

The program you're using to capture is manipulating the timecodes in the file to make it play as if it's 25fps. However since there are really only 20fps VRD gets confused and ends up throwing out a few frames of audio every second in an attempt to keep everything in sync. In fact if you play the QSFed file you'll notice that it's only ~50 seconds long. This is because 1267 frames / 25fps = 50.68 seconds.

Unfortunately, since 20fps is not a valid MPEG-2 frame rate, it's impossible for VRD to recognize the trick that capture program is using and remux the file correctly. In fact I think you'll be hard pressed to find any program that creates MPEG-2 PS or TS streams that will allow a setting of 20fps. However you can use alternative containers, such and MKV or MP4, to remux the file at 20fps and adjust the sync. It'll be more of a manual trial and error process, but it should work if you're desperate.

Dan
 

RickN

New member
Well, that's disappointing... When I bought the program, I saw that I could alter the fps with settings control and assumed everything would work fine. There is a back up plan though. If I want to share a file, I can simply save the video to a jump drive. Of course it's limited to playing only a computer but that's fine. A video stream from the internet will probably look terrible on large widescreen tv anyways... Thanks for taking a look and apologies for my newbyness in that I didn't know that VRD only reports fps in the headers rather than full video.
 

Dan203

Senior Developer
Staff member
If you want to put in some work to do some conversion you can probably make these files compatible. You just need to use a program with a frame rate converter (VRD doesn't have one) to convert the file to true 25fps. While you're at it I'd suggest resizing the recording to a more normal resolution as well. If you're in a PAL country then 720x576 would work well.

Dan
 

RickN

New member
Dan,

I greatly appreciate all your efforts to resolve my issue. You've given a potential solution but I'm too inexperienced and lack the knowledge on how to proceed. I have contacted support at wm capture and hopefully there are changes that can be made at their end. If not, I'm still in the 30 day refundable period and will probably return the software to get my money back.

Thanks again for your time!
 

RickN

New member
Good news, received the following e-mail from WM capture support:

"I am sorry to hear you are having this problem. Actually, it's not the first time I've come accross this. As your DVD burning software has noticed WM Capture does not prepare videos properly for DVD burning at all at this time. However, I am happy to say that in our newest version of WM Capture (which will be coming out in about 2-3 weeks) we have incorporated a powerful DVD burning feature, which not only has WM Capture recording at the proper framerate, and resolution for DVD burning, but also includes a "Direct-to-DVD" feature where as soon as a video is finished recording it can be burned to DVD without any additional modification."

Sorry Dan, I should have contacted WM capture first... If it doesn't work in VRD, chances are the other software is the one that's at fault... :)
 

Dan203

Senior Developer
Staff member
I'm glad to hear they've got something coming up that should work for what you want. If you have any trouble with the captures from the new version just let me know.

Dan
 
Top Bottom