Formats including Blu-Ray, and whatever computer files they use for HD content.
We’ve had selectable audio tracks since the DVD, but only one track could be played at a time, even though a track might have data for several channels. I was just wondering if there are any formats designed with multiple simultaneous audio tracks in mind.
The reason for this is: many people complain about dialog in movies being too soft, but explosions being too loud. I bet there are people who want it that way, making use of the full dynamic range etc. So you can’t satisfy both. If we could have a “dialog” track and “effects” track, we could set the dialog volume independently. I don’t think this is very difficult, right?
Videos aren’t recorded that way, so there’s no way to split out the audio from existing movies into things like a dialog track and an effects track (even though they were initially created using different tracks).
There’s a much simpler solution called dynamic range compression (often abbreviated DRC). This makes the quiet parts louder and the louder parts quieter, so that when you crank up the volume to hear the dialog the explosions don’t break your windows. This feature is built into a lot of DVD and Blue Ray players but you do have to go into the settings and enable it.
The audio in a Dolby multi-channel setup usually carries dialog on the center channel unless it’s shifted to front-left or front-right for audio tracking. The simplest thing you could do is use a programmable remote with a button that independently controls the center-channel volume; back when I used a Philips Pronto Pro I did just that, for exactly the reason you’re asking. It was sufficient to allow me to adjust dialogue audio independently of fx audio, especially when we wanted to keep the volume down but still hear the dialogue.
ETA: as engineer_ says, you can also get amps with dynamic control - often called “Night Mode” or something like that. I’ve had a couple; it’s kind of iffy and does semi-automatically what I am suggesting you take manual control of.
Wait, you mean they record audio with the video in movies? I thought they were recorded separately. Wasn’t there a profession for making sound effects? I remember a SD article on it.
When they make a movie, sound from the live action is recorded. This is often processed and is mixed with overdubs, special effects, etc. At some point all of this is mixed down onto the final tracks for the movie (left, right, center, bass, etc). This final mixed track is put into the video, and from there you can’t easily get back to the original dialog tracks, effect tracks, etc. that all went into it.
So you can’t do what you want with existing video formats.
The profession for making sound effects is called “Foley” and a person who does this for a living is called a Foley Artist.
ETA: This is probably the Straight Dope article you were thinking of:
No matter when or how the audio is recorded (and some scenes in some movies might have a dozen master tracks - wild audio, fx, ADR, foley, overdubs, VO) it is is combined into the 5+1 channels of the standard Dolby mix on nearly all movies. To pull out the dialogue only would be equivalent to reengineering cars so the engine was a plug-in module - it’s just not going to happen.
But nearly all 5.1 mixes concentrate the dialogue on the center speaker and put the fx on the surrounds, so if you are looking for an easy method to control dialogue volume independently of the overall volume, the technique above will work. When I do theater-room audio balance, I always end by cranking the center channel up a couple of notches to enhance dialogue. It almost never sounds unbalanced except on very quiet, well-engineered movies… and keeping a dedicated remote button handy fixes that and the need for “night mode” audio.
AVI and MKV files support multiple audio streams, so if the player and splitter supports multiple output streams, then you’re good to go. I’ve linked to some interesting threads that suggest what you’re looking for is possible.
Many video containers support multiple types of video and audio streams, along with embedded data (think subtitles and fonts). MKV is generally regarded to be the most flexible, last I checked.
Yes, just mux an AVI file with two or more audio tracks and play it back with the default media player or media center. You will hear all the tracks at once (whether you want to or not)!
This is as close as you can get. The center channel acts as the dialogue channel, so just boost it (or better yet, reduce the volume of the other channels) if you want to hear conversations better.
DV cassettes had two 16 bit or four 12 bit channels. I used to record to both when I would shoot with a Canon XL-1 camcorder, recording the stereo feed from the mixing board on channels 3 and 4 and a pair of room microphones on channels 1 and 2.
I was annoyed that they got rid of this feature on the HDV canon XH-A1. Now I record room mics on the XH-A1 and board on a different camera, syncing them up later.
Not the majority of the time. People talking on screen are directly in front of you, the viewer, so they use center channel. Stereo and surround channels are used when you have a character talking from off-screen in whatever direction.
Use Audacity to look at a 5.1 audio track. One thing you will notice is that the center channel is the most used channel of any 5.1 mix. Another thing is that with the center channel muted, very little of the on-screen dialogue is heard.
Dialog is not in stereo except in very unusual circumstances.
In real life if you are listening to Robert and Lenny, Robert is to your right and Lenny is to your left. Robert’s dialog comes from the right and Lenny’s comes from the left. No confusion.
In the movies, Lenny is on the left and Robert is on the right. They start to talk. Now the camera switches so we can hear Lenny reply. Now Lenny is on the right and Robert is on the left of the screen. Do you really want Lenny and Robert’s voice to suddenly switch from side to side?
It’s been tried and is very confusing for the audience.
Most 5.1 dialogue uses some audio positioning, but for all practical purposes (such as achieving the OP’s aim) you can ignore dialogue on the surround channels. In those rare cases where a director wants a shout or line to come from one side, a substantial amount of the audio remains on the center channel, with varying amounts up to almost full level on the front-side (and sometimes rear-side) channel.
Where two characters have an extended conversation across the screen, side audio is often used to enhance the separation but center audio is not reduced.
But you’re right that putting one speaker on each channel is not done except as a gimmick. It sounds sensible but just doesn’t work.
