Partial audio recorded

[SteveTyrakowski]

Is there any clue about why my recording would have audio that only works during the commercials but not the show itself?

The problem was in a late night recording of Wendy Williams on the local Fox station in Chicago. There is sound for the commercials, but not the show. I looked in the database to see if that particular tuner had a different setting for that station than the other 3 ATSC tuners but all 4 have the same settings. The next day, Glee and the following 2 Fox shows all recorded just fine on the same tuner and channel.

In the past with GBPVR I had sound issues once in awhile if I chose the wrong channel if there were more than one audio option. In those cases I was able to easily see in the database where I had one tuner set differently than the others for that channel.

I didn't notice multiple options for that particular channel when I looked at the mapping.

I am attaching the recording log just in case there might be some clue in there as to what is different about the 2 recordings. If you search for "Wendy" you will find the "Wendy Williams" show that has the problem and if you continue from there to search for "Glee" you will find that recording on the same tuner and channel at 7PM on Sept 20 which recorded the audio just fine.

Is there anything I can do to try and prevent the problem, or am I just at the mercy of the whims of how WFLD decides to broadcast the audio?

Thanks,
Steve Tyrakowski

[sub]

If you the play the file with VLC, is the audio present?

[SteveTyrakowski]

If you the play the file with VLC, is the audio present?

Same results with VLC. Actually, not all the commercials have audio. After looking a little more, one commercial near the beginning has audio and another one near the middle of the file had audio. Several other commercials were silent just like the show. I didn't try lookiing thru the entire hourlong recording.

Note that I no longer have the original .TS file. I have a program that runs and monitors the database for recordings over 6 hours old and copies the oldest one to another computer so MCEBuddy can convert it to MP4 format using about 1/10th the space, and when done it copies the MP4 back, updates the filename in the database, then deletes the original .TS file. It greatly increases the number of hours I can keep on my system and the transcoding is offloaded to a different computer with a Core2Quad cpu. Also it seems to work better on that XP computer than when I tried to run the Windows 7 version on the NPVR computer.

I probably didn't get a chance to watch this one until after it was converted by MCEBuddy. I can try to record the show again tonight to see if it happens again and I can turn off the conversion program until I check it. But I really do not thing MCEBuddy is the culprit. I have been converting hundreds of hours of ATSC recordings this way with GBPVR's dvr-ms format and a pretty good start with the NPVR TS format without any problems.

Thanks for the quick reply,
Steve Tyrakowski

[mvallevand]

I'd guess it is an issue with conversion or playback of AC3 5:1 files, commercials are often 2:0

Martin

[sub]

Yep, that'd be my suspicion too - conversion problem, probably due to switches of audio standard in commercials.

If you had the original .ts file then we could look into it closer.

[SteveTyrakowski]

Yep, that'd be my suspicion too - conversion problem, probably due to switches of audio standard in commercials.

If you had the original .ts file then we could look into it closer.

OK I set it to record that show again and turned off my conversion program. I'll make a backup of the original .TS tomorrow and then let it convert and compare to see if the original works differently from the conversion.

So you think it might have occurred in the conversion process and that it is not an issue with the original recording?

SO I am recording the entire show, but I also set a manual record of just 4 minutes of the show on another tuner which I might be able to make available for you to look at with a smaller file. I'll let you know tomorrow what I find.

Thanks Again,
Steve

[sub]

So you think it might have occurred in the conversion process and that it is not an issue with the original recording?

Yes. It might have changed audio standards during the adverts or something similar and the conversion utility didnt cope with it.

[SteveTyrakowski]

Yes. It might have changed audio standards during the adverts or something similar and the conversion utility didnt cope with it.

OK I have the results of my 4 minute test recording. The original TS fille has all the audio, but the MP4 file only has some of the commercials with audio and the rest of the recoding is silent.

The TS file is about 509mb and the MP4 is about 38mb. A ZIP file with both is about 520mb. Is this something you would care to look at? I know the conversion program is not your issue.

I guess what I'd be looking for:
1. Is there some way I'd be able to detect that something like this would happen and not convert those files?
or
2. Is there a more reliable solution for converting the video.

This compressed more than usual, but for example my 1 hour recording of "The Middle" went from 3629mb to 610mb which makes a dramatic difference in my recording capacity. MCEBuddy under XP has been the most reliable method I found for good automated conversions. I think I tried using ffmpeg to process in a batch file and a few others but often got poor audio sync or other issues.

Any suggestions? If you want to get the file, please let me know how to get it to you since it is too big to email. If you have an FTP site I could upload it, otherwise I have a place I can make it available for you to download, but I would want to send you those details privately.

Thanks,
Steve Tyrakowski

[sub]

I'm glad to hear the original TS is fine. Sorry, but I dont really have any suggestions for you about your MP4 conversion. I just leave my files as .ts files so I'm no expert in that area.