Audio Channel Mapping

[Keith Elliott]

I have questions about audio channel mapping. I am editing a dance performance that was recorded with two cameras. Each has a stereo audio track. The audio tracks were laid on the timeline as A1 and A2 and were mixed together at varying levels.

The channel map is set to
1A (1) ch 1
1A (2) ch 2
2A (1) ch 1
2A (2) ch 2
I assume this setting is standard?

I see the options for Monaural and Stereo channels. I assumed that since the audio was recorded in "stereo" it would be better to switch the timeline settings to Stereo 1/2 and Stereo 3/4. BUT, when it was ouput to DVD, the audio only played on SOME DVD players... on other DVD players there is no audio at all. Why?

Is this because there are now four channels of audio and some players can't process this? Should I have set 1A and 2A to Monaural settings?

Please tell me when to use the Stereo or Monaural audio settings, and what are the results of setting them incorrectly (as I apparently did).

I have watched the online tutorials and Mike's Edius DVD and read the documents and it still isn't clear to me. Thank you for providing as much detail as possible!

Keith

[antonsvideo]

first of all, what software did you use for DVD authoring?

if DVD creator, make sure you use dolby digital audio, by default it is set to mpeg audio, and mpeg audio is not supported by over 50% of NTSC DVD players

[Keith Elliott]

The DVD software used is Sonic Scenarist. The DVDs are created by a professional outsourcing company and they say they have never run into this audio problem before.

Does anyone else have any other suggestions?

I'm still looking for an explanation of what circumstances the Monaural or the Stereo settings should be changed on the audio tracks.... vs the option of "Clear All Tracks"

Thanks for any input!

[antonsvideo]

Monaural simply means that say the left channel will be duplicated to the right channel, or vice versa

very handy if the left channel is the good sound from boom or lapel and the right channel is the camera microphone

how did you provide the video to the authoring company, as a file? what kind of file? DV, HQ, lossless, uncompressed?

if you hear all sounds while playing timeline, then the exported file will contain the same sound

I would say your authoring company stuffed up, unless you did not listen to timeline sound prior to export

personally, I don't use mapping at all

[Keith Elliott]

In this situation I am using two cameras/ two stereo microphones that are recording that same show... one in the back with a shotgun mic and one close to the stage with the camera mic. I want to mix both audio tracks together. The shotgun is the main track, the other camera picks up stage sounds (voices, taps).

If I use Monaural 1 and 2 for the two tracks will I get an even mix of both together? Will it be stereo or totally mono?

When would you use the Stereo settings?

The file was printed to DVCAM tape before it went to the DVD printer. The tape plays fine. The audio on the DVD plays in most DVD players, but on some the audio is gone. The problem is related to the audio connection from DVD player to TV (the audio problem does not exist on computer DVD players.)

[antonsvideo]

if the sound was there on the DVCAM tape, then the people who capturted from it to make the DVD stuffed up

since you are using stereo microphones, you leave the whole show in strereo, so when you right click the clips, leave on stereo

you can place the stereo sound from camera1 on A1
you can place the stereo sound from camera2 on A2

remember to lower the volume of A2 clip or track and you may have to offset A2 by a frame to compensate for the delay that would be expected from a camera close to the stage and away from the stage

compare waveforms while zoomed to 1 frame level and while waveform is displayed in linear and not log (I always use linear)

[Keith Elliott]

I am editing a dance performance that was recorded with two cameras. Each has a stereo audio track. The audio tracks were laid on the timeline as A1 and A2 and were mixed together at varying levels.

I assumed that since the audio was recorded in "stereo" it would be better to switch the timeline settings to Stereo 1/2 and Stereo 3/4. BUT, when it was ouput to DVD, the audio only played on SOME DVD players... on other DVD players there is no audio at all. Why?

Keith

Problem apparently solved.

As I said earlier, when I exported the project to DVCAM the tape played back fine. When the tape was converted to DVD, the DVD audio played fine on most players, but not all. Sometimes there was no audio.

The Sony DSR-11 DVCAM player was set to 48k Hz audio. Edius is also set to 48k. But when I changed the DSR-11 setting to 32k audio the problem no longer occurs. The DVD now seems to play audio on all players.

[Khoi Pham]

Problem apparently solved.

As I said earlier, when I exported the project to DVCAM the tape played back fine. When the tape was converted to DVD, the DVD audio played fine on most players, but not all. Sometimes there was no audio.

The Sony DSR-11 DVCAM player was set to 48k Hz audio. Edius is also set to 48k. But when I changed the DSR-11 setting to 32k audio the problem no longer occurs. The DVD now seems to play audio on all players.

That don't make any sense, the problem is what Anton mentioned earlier, whoever author the dvd screw up and use mpeg audio instead of AC3, and now they redo it and you think the problem was solve on your end but actually it was not.

[Keith Elliott]

I have tested DVDs and the audio problem is apparently resolved as I described. I burned several test DVDs myself, getting the same (bad audio) results as the DVD authoring service... so it couldn't be strictly an error made by them. The problem was in the tape, which lead me to the DSR-11 player setting. After the setting change, the audio problem disappeared on further burned DVDs. (using my external DVD burner)

But I will pass your comments to the authoring service for their additional consideration.

[tuyle]

Problem apparently solved.

As I said earlier, when I exported the project to DVCAM the tape played back fine. When the tape was converted to DVD, the DVD audio played fine on most players, but not all. Sometimes there was no audio.

The Sony DSR-11 DVCAM player was set to 48k Hz audio. Edius is also set to 48k. But when I changed the DSR-11 setting to 32k audio the problem no longer occurs. The DVD now seems to play audio on all players.

When audio is good at 32K playback on DSR-11 => You set the recorder (DSR-11) at 32K audio for 4 channels during export to tape. So depending on the playback deck setup, it could give you good or bad sound. Can you change the audio input setup of DSR-11 to 2 chan. @48K before exporting to DVCAM ?

[Keith Elliott]

Quote: "When audio is good at 32K playback on DSR-11 => You set the recorder (DSR-11) at 32K audio for 4 channels during export to tape. So depending on the playback deck setup, it could give you good or bad sound. Can you change the audio input setup of DSR-11 to 2 chan. @48K before exporting to DVCAM ?"

The DSR-11 has been set to 48K and that seemed to cause the problems. Setting it to 32K seems to have eliminated the audio issue. Yes, I know that 32K is for four channels, which may be appropriate because the show was taped with two stereo soundtracks mixed together. Does that sound right?