No audio in file that goes from DD5.1 <--> 2.0

Trey Waters wrote on 6/17/2013, 9:06 PM
I am having problems with importing videos that change from 5.1 channels to 2.0, or vice versa. VMS imports the videos fine, but there is no audio after the change, regardless of the import settings (ie., setting the project to 5.1 channels or 2.0 channels).

Here's what I'm doing:
1. Use Windows Media Center to record TV shows (starts 3 minutes before desired show, and ends 3 minutes after 35-36 minutes total).
2. MCE Buddy to convert to .ts (TS Unprocessed profile).
3. Attempt to load in VMS 12

I have no issues if the entire stream has the same audio format (usually 2 channels). However, if the show before the desired show is in 5.1 and the show I want is in 2.0, or the previous is 2.0 and the wanted show is 5.1, there is no audio in the VMS timeline after the audio switch.

If the 5.1 track is the first track, VMS does prompt me to change the audio profile to a 5.1 channel profile. Saying Yes or No here exhibits the same results - I have audio up until the change, and no audio after.

Also, probably related, when I click the filename in the Open File dialog, VMS becomes unresponsive for up to 3 hours. Then I can click Open and it loads the file. However, the "Finding Peaks" process can take another 1-3 hours. Again, this is only on files with the 5.1->2.0 or 2.0->5.1 transitions. Files that are fully 2.0 open "instantly" and take only a minute or two to analyze the audio track.

Any suggestions for getting my audio back? I 'could' have MCE Buddy process the video file and downmix to 2.0. However, I'd like to keep 5.1 if the show has it (sometimes does). And I'd rather keep the processing to a minimum (in other words, just delete the unwanted audio streams in VMS).

Comments

musicvid10 wrote on 6/17/2013, 9:13 PM
1. Set your project to whatever your audio is -- 5.1 or 2.0 before you import the media.
Don't change the project properties after that; you're trying to do too much.

2. Let's say you have 5.1 audio on the timeline and you want to render stereo. Set your Render Properties to stereo and render. The downmix will take care of itself.

3. Sorry, you won't be changing 2.0 source to 5.1 surround. You can't put in channels that aren't there to begin with.

4. The way Vegas works, you won't have 5.1 and 2.0 audio tracks in the same file. That means one show per project. You can probably mux them together later if you wish.
MSmart wrote on 6/17/2013, 11:01 PM
musicvid, I don't think you quite get what he's trying to do. He's basically trying to edit recorded TV shows to trim them.

Trey, why not use MCE Buddy to trim the leading and trailing events prior to importing into VMS so your files only contain one audio format?

What's the goal of importing into VMS? Some here, including myself, use VideoReDo to edit TV shows and convert to other formats (it does cost though).
GaryDZ wrote on 6/17/2013, 11:35 PM
"Also, probably related, when I click the filename in the Open File dialog, VMS becomes unresponsive for up to 3 hours."

I have the same problem loading some TS files. If I run them thru VideoReDo's Quickstream Fix function it solves that problem. It might also fix the audio problem.
musicvid10 wrote on 6/17/2013, 11:44 PM
MSmart, and GaryDZ,
You're both right wrt VideoRedo. For commercial cutting, joining, and re-indexing of flawed TS source, even with different media properties, there is none better I know of.

And if importing into Vegas for more advanced treatment, including sharpening, leveling, and color correction, the Quickstream Fix function is indispensable.

MSmart wrote on 6/18/2013, 1:53 AM
Going with the "you're both right" theme, QSF to fix time code issues is the most likely solution.

Trey, you can download and trial a fully functional version of VRD for 15-days. Just register it to be able to save more than 15 minutes worth of video.
Trey Waters wrote on 6/18/2013, 8:38 AM
Thank you all for your help.

The goal of importing into VMS is to edit and remove portions of the TV shows that are either extraneous (like the lead-in/lead-out sections) or just parts that my daughter doesn't like (like the paleontologist lessons from Dinosaur Train).

I had gotten VMS to play with editing home videos, but just haven't had much time to play with it in that respect. :-) I do like how easy it is to crop the videos, though, so I just used it for the TV shows.

I'll take a look at VideoReDo and see if that helps.
Trey Waters wrote on 7/6/2013, 8:01 AM
In case anyone comes across this thread with the same problems I have had, I just wanted to post a solution that I found, and which does not require purchasing another product: FFMpeg

Here is what I run:

onrop@tiger> ffmpeg -i <input file> -c:v copy -c:a ac3 -ab 384k -ac 6 <output file>

And a quick explanation of the options:
-i <input file>, <output file> - I hope these are obvious.
-c:v copy - copy the video stream - do not decode/re-encode
-c:a ac3 - convert audio stream to AC3
-ab 384k - bitrate for audio stream
-ac 6 - 6 channels

After doing the above, VMS loads the file just fine, and the DD5.1 track seems to be good. The options should be the same for Windows as it is for Linux (where I run ffmpeg). And I am by NO means an ffmpeg expert. So, if anyone has options they would like to suggest, please do so.