1. Register NOW and become part of this fantastic knowledge base forum! This message will go away once you have registered.

Finding signal in video/sound tracks?

Discussion in 'Recording' started by Winfried, Apr 17, 2012.

  1. Winfried

    Winfried Active Member


    I need to record lectures and conferences. As this is for personal use, I don't want to buy the semi-professional camcorders, which are the only ones that can use an external microphone.

    So I got a Tascam digital sound recorder that I'll just put next to a loudspeaker (the sound mixer is off-limit; I already tried this, and it works fine for this use) and will buy a more affordable camcorder to record the video before combining the two tracks using eg. Sony's Vegas or something similar.

    As an easy way to sync the two tracks, I'm thinking of starting the Tascam and the camcorder, do a clap or whistle or something in front of each device's integrated microphone, so that I know where both tracks start.

    Which free/affordable application for Windows would you recommend that can locate a signal within soundtracks, so I could just provide a WAV of the clap/whistle and the application will jump to it in both the WAV and the video file?

    Thank you.
  2. RemyRAD

    RemyRAD Well-Known Member

    With what you want to do, you are already discovering the most efficient and practical way in which to capture your lectures. One of the ways I've captured a PA board was not to put a microphone on the PA speaker. Instead, I utilized a simple suction cup telephone pickup coil costing about $2.00 from Radio Shaft. You then place the coil somewhere around the back of the PA speaker on the speaker and nearest to the voice coil you can get. This gives you a direct electrical feed without the acoustic aberrations & miserable sounding reverb/ambience of the room. Placing that coil around the speaker in different positions will create vastly different sonic signatures. So some experimentation is still needed. If you can't get access to the back of the speaker, your method of placing the recorder in front of the speaker is your only real option. And it will sound generally, crappy.

    As far as the video editing program to marry the video track to your soundtrack is a super easy thing to do with the lesser expensive programs such as Sony's Vegas home studio which is hundreds of dollars less than Vegas Pro. Since you're not going to be doing all sorts of effects and multi-camera shots, you can get by for around $150 US. Otherwise you are looking at over $600 US for something that has capabilities far beyond your needs. Your indication of utilizing a loud clapper to be utilized is also quite unnecessary. You only have to listen to synchronize your audio to your video track utilizing the audio of your video track to synchronize to your separate audio track. You simply match up the sentences, then zoom in to make sure you maintain proper lip sync. Then you can switch off the audio from the camcorder audio track. I do this all the time. Starting your recorder and your camcorder within one minute of each other should be more than adequate to obtain your synchronization.

    Inexpensive cameras in this application can be more than 100% adequate but I would also recommend that you have 2 of them. One for the head-on shot and one for a side profile shot. Perhaps even one for a projected image and/or a fourth to get a shot of the audience. This can make your editing a lot easier when you have a cutaway shot to utilize that will look more professional and broadcast oriented. Otherwise, you'll be dissolving over the same shot or cutting from the same shot to the same shot which looks more like amateur hour. And so to cameras I feel is a minimum necessity in this style of lecture capturing and production/presentation.

    Sony Vegas Pro user
    Mx. Remy Ann David
  3. dvdhawk

    dvdhawk Well-Known Member

    I don't know of any such locate a sound application. (I'd recommend a clap or similar with a distinct short spike in the waveform).

    You would very likely start both devices within a few seconds of each other and then clap as near as possible to half the distance between the camera and Tascam. (and do not stop the recording until the speech is over)

    Then you would put the video footage into your video editing software along with the Tascam's audio tracks side by side and visually zoom in on the audio waveforms of each and look for the large peak caused by the clap. They will have started within a few seconds of one another, so zoom in on the beginning. Then nudge the Tascam audio until it lines up with the camcorder's audio. As you keep zooming in closer and cloer to get it more precise, you will keep narrowing in to the nearest frame. You should be able to get the Tascam to within half a frame or less, which should be close enough for all practical purposes.

    The peaks of the two audio tracks lining up 100% perfectly in a video editor, are very slim - because video editors only have to be accurate to a single video frame. [ NTSC 1/29.97 of a second & PAL 1/25 of a second ] Although both audio recordings will be vastly higher sample rate (48k) the video editor is too coarse of a tool to cut it any finer than 1/25 of a second. In other words, for every second of video there are 48,000 audio samples compared to only 25 frames of PAL video.

    Given your scenario, available equipment, low-budget, non-professional expectations - this is the best & cheapest method. And again if it 'drifts', you will need to look for pauses where you can cut the Tascam footage and nudge the tracks visually to match distinctive waveforms. If there's a time before the event to shoot a few minutes of footage of the audience attentively looking toward the stage - you can use snippets of that any time you need a cutaway to hide out-of-sync audio.
  4. RemyRAD

    RemyRAD Well-Known Member

    To be honest, I utilize heavy consonants as my clapper. It works just as well and marvelously to boot. Especially since you have the ability to zoom in with most applications down to the sample at one 48,000th of a single second.

    So that's another thing to consider. You actually want to be recording your audio track at 48 kHz, not at 44.1 kHz as you would for a CD. And 48 kHz can be down converted to 44.1 kHz without much worry of any audio artifacts since the math really doesn't work from 48 kHz to 44.1 kHz. And vice versa. So when trying to maintain lip-synch, you should be recording your wild soundtrack at 48 kHz, 16 bit. Screw the 24-bit blah blah nonsense. It's simply not necessary. 24-bit only really matters if you're recording level is too stupidly low. And it won't prevent overloads at all if your gain is not properly set to begin with. 16-bit provides for a 96 DB dynamic range. If you can't get it right within 96 DB, you have no right doing this in the first place. And you really don't get 140 DB of dynamic range from 24-bit. That's because, most all audio equipment, even the finest stuff made, doesn't have much more than 100 DB of usable dynamic range. So it's a flaky bit of information to tell people they should be recording a 24-bit. That does not improve the resolution. Sample rate improves the resolution. So a 16-bit recording at 88.2/96 kHz is higher in resolution than a 24-bit recording at 44.1/48 kHz. It's not like connecting the numbers in a drawing we used to do as kids. It requires a little bit of technical understanding as to why this is so. You only need 24-bit if your level setting is really sloppy. Coming from the land of broadcast, you knew and learned better. Coming from the land of analog audio tape recording, you would utilize the nonlinear overload characteristics of analog tape to provide some natural limiting along with a certain kind of distortion that was deemed more musical for certain instruments such as drums. But you're not recording drums. They're not recording attires nor keyboards nor screaming vocalists. You are recording mumbling talking heads and all that is important is intelligibility not fidelity. So when recording talking heads, you'll want to roll off most everything below 100 Hz and virtually anything above 15 kHz anyhow. So hi fidelity condenser microphones can actually be more of a hindrance than a more frequency restricted dynamic microphone would be. So plug a SHURE SM57/58 into your TASCAM/TEAC audio gizmo instead of utilizing its onboard condenser microphone thingies. You can still utilize those condenser microphone thingies and simply roll off the highest and lowest of the frequencies in the software of your video editing software. It's already got provisions for that. All that's needed to accurately understand human speech is the same frequency response as telephones which is between 300 to 4000 Hz. Anything beyond that is just icing on the cake until the cake gets too hot and the icing turns back into melted butter and Crisco.

    Intelligibility is my game and I always win
    Mx. Remy Ann David
  5. dvdhawk

    dvdhawk Well-Known Member

    What Non-Linear Video Editing program are you using that allows you to do sample accurate 48k editing in the video realm? - rather than frame accurate 25 / 29.97 / 30 fps editing, as the case may be?

    Maybe the concern I've expressed in the previous post is outdated, although it is based on years of experience with two of the most widely used professional NLE programs. [Final Cut Pro HD and Premiere]

    I am not the type of person who upgrades, just for the sake of upgrading - so, neither of these is the latest/greatest/bleeding edge version. They work so perfectly, so I haven't felt the need to replace, or upgrade either of these for a number of years. So if Vegas, or similar, can manipulate audio that well, I may have to look into buying that as well.
  6. Winfried

    Winfried Active Member

    Thanks guys for the input. After I get the camcorder, I'll play with Vegas Home Studio and see how it goes.

    Even though the audio test recording I did recently sounded pretty good, out of curiosity, would you have a link (web page or picture) for the "simple suction cup telephone pickup coil costing about $2.00 from Radio Shaft" whose coil I should try to hook to the PA speaker, so that I know what it looks like?
  7. dvdhawk

    dvdhawk Well-Known Member

    I believe this is what Remy is referring to: Recorder Telephone Pickup

    This would be the Maplin equivalent: Telephone Pickup Coil
  8. Winfried

    Winfried Active Member

    Thanks for the links. I'll check where I can get one of those things over here and experiment when I get the chance.
  9. RemyRAD

    RemyRAD Well-Known Member

    That is exactly the device I am speaking of. It is essentially one half of a transformer basically, a single flat wound guitar pickup coil. So any electromagnetic energy it comes near it will pick up. So if you can get it close to the back of the speaker near the voice coil, you will pick up the feed directly. You will also in all likelihood need to equalize it to sound appropriate. Other nearby electromagnetic interference could interfere with it. But it can work better than a microphone in many situations. Turning it and placing it differently around the back of the speaker has a broad range on its tonality. It can go from thin and tinny to huge and fat depending upon the placement. Generally, I don't rely on the suction cup but a piece of duct tape instead.

    Regarding the sample accuracy of video editing NLE programs. None of them are sample accurate. They are frame accurate which is 1/30 to 1/25 of a second which is all you need for lip-synch. And it generally comes close enough for music as well to maintain synchronization with the picture and sound. On very few occasions have I had the need to take my soundtrack then remove a few samples for extremely tight synchronization with video. That rarely happens. You can also get 1 to 2 retarded frames of audio to video before it becomes noticeable. It becomes much more noticeable if you're audio leads the video by as little as one frame. I've done this with programs all the way back to Adobe Premier 6.0.

    I think you'll enjoy the Sony program
    Mx. Remy Ann David
  10. bouldersound

    bouldersound Real guitars are for old people. Well-Known Member

    Vegas (6 is what I use) is like having pretty much all the functionality I'd use from FCP plus Pro Tools, all in one program. You can even have two instances open at once, which I've done for manually triggering samples while recording a live performance to multitrack. There are a couple of things Pro Tools does better but Vegas does other things better and I prefer the workflow, even for audio-only projects.
  11. Winfried

    Winfried Active Member

    Thanks for the feedback. What codecs are recommended in the camcorder and Vegas that offer minimum headaches to non-pros like me?
  12. RemyRAD

    RemyRAD Well-Known Member

    I think you'll find that strangely enough, the highest quality settings can be the least problematic to work with. Utilizing what they refer to as " uncompressed " .AVI file format is the way to go. It's actually not uncompressed but very lightly compressed data that has very few artifacts to it. So a one-hour lecture will create something on the order of a 30 GB file of video. Uncompressed audio will create around 600 MB of audio data utilizing uncompressed ".wav " file format. The more highly compressed formats such as MPEG 2, MPEG 4, Quick Time makes the computer actually work harder. And that's because it has less to work with. Given the size of current hard disc drives today, one does not have to rely upon these heavily data compressed and smaller file formats. Less is lost and more can be processed with less data compressed material along with less artifacting to contend with. Picture quality is better maintained. Sound quality is also better maintained.

    All the codecs you need are actually included in the Sony software. It's really powerful software. Other third-party codecs might be required for certain other applications. But that's to be dealt with later. Sony has been fundamental in creating much of what we use today. Even though Vegas was created by Sonic Foundry and sold to Sony Corp.. It can actually do things that Avid/Digi Design, Media Composer-Pro Tools is now only getting to years later. But all have their place depending upon the kind of production you are doing. You are not doing network television production and nobody is handing you a $30,000 contract to make a rock 'n roll recording. And to be able to get away with a piece of software costing between $150 US-$600 US is a heck of a lot less than that other stuff. And is actually equally as powerful in the right hands or left.

    My hearing & Video productions, are ambidextrous
    Mx. Remy Ann David
  13. bouldersound

    bouldersound Real guitars are for old people. Well-Known Member

    What Remy said.

    I found that Vegas 6, which is now very old, has more trouble with MOV (Quicktime) files than AVI or MPEG.
  14. RemyRAD

    RemyRAD Well-Known Member

    I guess Sony doesn't like Apple? Avid sure does.
  15. Winfried

    Winfried Active Member

    So I'm still stuck with the MOV file since Vegas Movie Studio HD 11.0 can't open it, altough I installed the latest QuickTime application (
    • Is there a good application to convert it to something Vegas is happy with?
    • If not, which other good, affordable video editing application for Windows would you recommend for basic tasks like replacing the soundtrack with a WAV file or removing parts of the file?
    Should I check Avid's Studio for PC or Pinnacle Studio?

    Thank you.
  16. dvdhawk

    dvdhawk Well-Known Member

    Vegas works with Quicktime (.mov) files. As I've said before in one of your other threads, this may be a configuration issue, because Sony should "play nice" with just about any common source.

    Straight from the Vegas Movie Studio HD 11 Technical Specs

    [h=1]Capture and Import[/h]
    • New! Support for 24p, 50p, and 60p files
    • New! Improved QuickTime AVC decoding for DSLR cameras
    • Import support for LPEC files
    • Import support for MJPEG-encoded files
    • Sony AVCHD import and edit support
    • Import support for ATRAC3™, ATRAC3plus™, and ATRAC Advanced Lossless™ files
    • Gracenote[SUP]®[/SUP] MusicID[SUP]®[/SUP] CD album recognition
    • Import media from Sony[SUP]®[/SUP] DVD Handycam[SUP]®[/SUP] camcorders
    • Batch capture and automatic DV scene detection
    • PC connection via FireWire[SUP]®[/SUP] or IEEE-1394 devices
    • Import pictures in BMP, GIF, JPG, and PSD formats
    • Import AVI, DV, SWF, and MPEG 1 & MPEG 2 files
    • Import audio files in WAV, MP3, AIF, CD Audio and PCA formats
    Supported Formats

    Import: AAC, AA3, AIFF, AVI, BMP, CDA, FLAC, GIF, JPEG, MP3, MPEG-1, MPEG-2, MPEG-4, OGG, PCA, PNG, RealMedia[SUP]®[/SUP], QuickTime[SUP]®[/SUP], SND, SFA, W64, WAV, WDP, WMA, WMV
    Export: AAC, AIFF, AVC, AVI, BMP, FLAC, JPEG, LPEC, MP3, MPEG-2, MPEG-4, OGG, PCA, PNG, RealMedia[SUP]®[/SUP], TIFF, QuickTime, W64, WAV, WDP, WMA, WMV

    [h=1]Vegas Movie Studio HD system requirements[/h]
    • Microsoft[SUP]®[/SUP] Windows[SUP]®[/SUP] XP SP3, Windows Vista[SUP]®[/SUP] SP2, or Windows[SUP]®[/SUP] 7
    • 2 GHz processor (multicore or multiprocessor CPU recommended for HD)
    • 400 MB hard-disk space for program installation
    • 1 GB RAM (2 GB recommended)
    • IEEE-1394DV card (for DV capture and print-to-tape)
    • USB 2.0 connection (for importing from AVCHD or DVD camcorders)
    • Windows-compatible sound card
    • DVD-ROM drive (for installation from a DVD only)
    • Microsoft .NET Framework 3.51 (included on application disc)
    • Apple[SUP]®[/SUP] QuickTime[SUP]®[/SUP] 7.1.6 or later
    • Internet Connection (for Gracenote[SUP]®[/SUP] MusicID[SUP]®[/SUP] Service)
  17. Winfried

    Winfried Active Member

    On a brand new Windows7 laptop, I installed the latest QuickTime application, then Vegas, then opened the MOV file and I get the error.

    Is there a way to investigate what the problem is?
  18. RemyRAD

    RemyRAD Well-Known Member

    I'm not sure what's going on there? I'm working on a documentary that was all imported as QuickTime files and I'm having no problems with that. I believe it wasn't even necessary to have the latest QuickTime application? Perhaps there is a conflict in codecs that you have loaded? Sony works with QuickTime files. What is the error you are getting? Have you utilize the Sony drop down menu to " import "? Have you tried dragging and dropping? And when you started your Vegas software what kind of file format did you choose to work in? I'm only asking this because I don't tell my Sony software to create a QuickTime project even though I am importing QuickTime files. I generally choose the mostly uncompressed, lightly compressed, .AVI as my project. Then I import the QuickTime files. If your QuickTime files have .AC 3 files for the audio, that's where there may be the issue? So it may require a workaround? Let us know?

    Vegas 9 user with DVD Architect
    Mx. Remy Ann David
  19. Winfried

    Winfried Active Member

    I click on Project > Import Media to open the MOV file from the camcorder, and Vegas says:
    FWIW, the MOV file opens OK in VLC and AviDemux.

    If you want to give it a try, I extracted a 5MB sample (crappy video, but it was just for testing purposes):

    Also, to sync the camcorder and the Tascam, I figured I could use Audacity to generate 2s of 440Hz and play the file with my smartphone in front of them. Here's what it sounds like on the two devices (soundtrack from the camcorder extracted using VLC):

    Hopefully, Vegas or whichever video editor I end up using will be able to easily locate this 2s sound byte within the two tracks.

    Thank you.
  20. Winfried

    Winfried Active Member

    Someone found what it was: The JVC camcorder seems to format files using the Mac version of QuickTime, and it's different enough from the PC version that some applications cannot open such MPEG2 files directly.

    AviDemux (video=>copy, audio=>copy, format=>mpeg-ps) or ffmpeg can convert the file, and I could import the file in Vegas successfully.

    That's definitely a feature I'll check when buying my own camcorder.

    Thanks everyone for the help.

Share This Page