Problems rendering 5.1 Audio

magillagorilla wrote on 1/6/2011, 8:09 AM

I having a problem with rendering 5.1 Audio in VMS. When I choose this option, in any codec that offers it, I get no sound or sound rendered at the wrong sample rate. My goal is to render AVC with 5.1 surround so I can author AVCHD DVDs to play on my BR player. When I render AVC with 5.1 the video looks fine but the audio runs at double speed and the audio track is finished playing half way through the video footage. If I render the same project in AVC with identical settings, except I choose stereo instead of 5.1, the sound renders fine.

Here is my setup
PC: Windows 7 64bit pro
PROC: Core 2 Quad Q8300
RAM: 4GB
SW: Sony Vegas Movie Studio 10 Platinum

Video track 1
Canon HF100
17mbps AVCHD (M2TS) 1080 24p

Video track 2
Nikon D7000
?mbps h.264 (in a MOV container) 1080 24p

Audio
Zoom H2
4 Channel 16bit 48k WAV
Stereo Front pair
Stereo Rear pair

Any suggestions?

Comments

Markk655 wrote on 1/6/2011, 9:42 AM

Have you tried playing back on another computer (is the issue with the playback or the actual render of the file?). For example, if you bring the file back into Vegas after render, what does the audio sound like?

magillagorilla wrote on 1/6/2011, 10:30 AM

Good idea. In theory Vegas should demux (virtually) to display my original 4 channels of sound. If my rendered filed looks and plays OK in vegas then my player is the problem. I don't doubt this because I used WMP to play back the render. I don't really like WMP, I just haven't gotten around to installing VLC since reimageing my PC.

I'll give it a go. Thanks.

magillagorilla wrote on 1/6/2011, 7:01 PM

Results

I rendered a test MP4 using 5.1 audio and opened it in VMS. The audio track was a single stereo track and was about 60% the length of the video file and plays fast. VLC media player plays no audio with normal video.

In VMS the properties of the rendered file show an AAC audio track attributes of 48Khz Stereo 04;12 seconds. The whole clip length is 06;20.

I also noticed another thread going about issues with rendering 5.1 audio in AVC. Does anyone have any suggestions?

Markk655 wrote on 1/7/2011, 5:57 AM

What happens if you render only the audio? Can you convert the wav file (just to check) to something else and drop that file to the timeline? It might be the way VMS is seeing your audio file (or perhaps there is an issue with the wav file). Not sure why that would be the case, but worth a check.

I haven't had issues with the Sony AVC 1440x1080, AC3 5.1 template. You can try that to see if it works.

magillagorilla wrote on 1/7/2011, 7:01 AM

I haven't tried rendering only audio. But It renders fine when I choose stereo. The problem is specific to choosing 5.1 for sound.

I rendered a DVD with the same project in 5.1, video looks good and there is no sound. I have to be doing something wrong.

I have 1 stereo wave file assigned to the "Front" layer and one stereo WAV file assigned to the "Rear" layer of the project. Both wav files are 16bit 48khz, same as the audio sample rate on both camera sources.

I rendered an M2TS file in surround. Same results, good video and no audio.

Sony devlopment team are you out there?

Markk655 wrote on 1/7/2011, 9:26 AM

for the m2ts file...No audio or fast audio?

If no audio, that would seem to point towards an issue with one or both .wav files. Since that is a different result. Can you try to convert the audio to a different format, adding it back to the timeline and then try rendering again?