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Author Topic: combining 16 bit/44.1k audio with HD video  (Read 8713 times)

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Offline rsimms3

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Re: combining 16 bit/44.1k audio with HD video
« Reply #15 on: December 30, 2009, 09:46:29 AM »
In Audition 1.5 the way I use it, when you shrink or stretch the audio, you don't get to preview the change before the processing of the file.  In Vegas, you use the mouse and hold the Ctrl key to shrink or stretch the audio and can see the end result as you do it instead of having to wait for Audition to process the file and then show you the change you made.  I don't know how Audition is set up, if that is something meant to utilize less resources by processing the file, then changing it or what, but I much prefer Vegas for syncing.  Also, that shrink/stretch feature in Vegas isn't really advertised in the instructions or in general.  I think I did a web search on expanding audio and stumbled across it.
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Re: combining 16 bit/44.1k audio with HD video
« Reply #16 on: December 30, 2009, 11:39:31 AM »
^ OK, understand what you mean now.  FWIW, it's never really been an issue for me in Audition either because you key the stretch/shrink to the amount of time that the whole audio needs to be adjusted and then enter the stretch/shrink ratio...it's always dead nuts for me.  However, it sounds like you do this sorta visually with Vegas, so you don't have to mess with ratio's at all.  Just align the two files up and do a sort of drag and drop method...where the new audio file just kinda stretches and shrinks like slinky.  That would definitely be easier for sure.


Offline rsimms3

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Re: combining 16 bit/44.1k audio with HD video
« Reply #17 on: December 30, 2009, 08:06:18 PM »
Yep, exactly.  Math was never my strong suit....throw in ratios and I am toast.
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Offline boyacrobat

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Re: combining 16 bit/44.1k audio with HD video
« Reply #18 on: March 15, 2010, 10:44:10 PM »
if using vegas
go to your audio master track and click the plug inns/effects tab
by default sony inc the compessor and eq with a roll off in the chain.
remove all plug inns in the chain.

render an uncompressed audio track this way.

very important to your final mix.
the sony compressor is harsh in the chain when you compare the differance
do it for dynamics sake

g
« Last Edit: March 15, 2010, 10:46:32 PM by boyacrobat »

Offline Shadow_7

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Re: combining 16 bit/44.1k audio with HD video
« Reply #19 on: March 15, 2010, 11:25:46 PM »
I guess I'm the cheapskate of the bunch.  I do this exact thing also with a Korg MR-1000.  I record DSD audio, convert to 24/96 and do some other edits(EQ/Amp/HL/???).  I use audiogate (obviously), audacity, sox, faad and ffmpeg.  With a sanyo FH1 for now and plans for a more pro-ish cam someday.

# The workflow....

Capture audio - Korg MR-1000 - DSD 5.6MHz
Capture video - Sanyo FH1 - 1080p60

# extract camcorder audio from video...

ffmpeg -vn -sn -i video.ext -acodec copy -y audio_only.aac

# convert camcorder audio to wav...

faad -o audio_only.wav audio_only.aac

# convert korg audio to wav...

audiogate

# identify a sync point (a bit trial and error)...

audacity korg_audio_24_at_96.wav
--- File -> import -> audio --- audio_only.wav

# extract the needed audio segment from the korg audio...

sox korg_audio.wav extract_audio.wav speed 1.00011 trim 00:00:05.555 00:01:00.000

Check to see how close my guesses are and adjust to the 1/1000th (music video so it matters).  1/10th or so is probably good enough for most folks.  Repeat ID / Extract steps until perfect.  Usually about 3 tries, 1st to be on the right second alignment.  Zooming in on waveforms to align the right peak(s).  Highlight opposing peaks then zoom and minus one zoom and do the math, adjust repeat.  When matched the above sox command with the right offset and duration gives the desired segment of audio.  Edit in EQ and such and convert to resulting format/resolution.  In audacity and export selection new_audio.wav

Then join the new audio with the video element...

ffmpeg -an -i video.ext -sameq -r 30000/1001 -s hd720 -pix_fmt yuv420p -f yuv4mpegpipe - | ffmpeg -f yuv4mpegpipe -i - -qscale 1 -i new_audio.wav -y new_video_with_external_audio.mpg

A bit of a time suck and a round about way to do it, but it gets the job done.  For those of us with more time than money anyway.  A lot of this is from memory, so there might be errors in my syntax's.  And some of it simplified.  HD sources are a bit new, so you've got to run the latest versions of a few software parts, which might require compiling from source, so not for everyone. 

I've got most of my regular conversions scripted.  i.e. for DVD versions I run a script it generates audio only, video only, and the dvd video with camcorder audio.  I swap the audio only part and rerun the same script and out comes a DVD version with external audio.  No need to re-encode the video segment a second time and all that jazz.  Hopefully that's not too much to digest.

The speed option for sox is because there's about a 1/2 maybe 1/5th of a second difference (per hour) between the speed of the audio on the camcorder and the speed of the audio on the field recorder.  Negligible for clips < 5 minutes.  But drummers at 60p in excess of 10 minutes..... noticeable.  It also helps ID the sync point better if you're not using the exact same hand clap / drum hit / whatever each time.

A bit techy I know.  A major time suck.  But mostly functional for me anyway.

Offline digitallive

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Re: combining 16 bit/44.1k audio with HD video
« Reply #20 on: March 23, 2010, 02:24:47 AM »
I posted the same question in the computer forum but have not gotten any answers in the last two days, so I thought this might be a better place.


My friend and I have been recording live music using stereo mics into a Korg MR-1000 DSD recorder.  Now we are video taping as well using one of the new Sony HD AVC-HD camcorders.  The problem is how to most efficiently and easily put the high res audio together with the HD video.

Is anybody doing the same thing?  I would like to do it two ways.

1. combining and synching the HD video with our audio at 24bit/96k or even 16bit/44.1.
2. dumbing down the HD video to something like DVD quality and combining and synching the audio

We were thinking of buying Sony Vegas Platinum pro.  Any thoughts?

kinda like what the other guy was saying, you can just dump both your V/A from cam and your HD audio into vegas, then synch the audio to your video (making sure you keep the video starting at 00:00:00:00) and then render the new audio as a WAV file (either delete the A/V file from cam or mute the audio from it). check various spots in the video to make sure it synchs up fine all the way to the end.

Offline Shadow_7

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Re: combining 16 bit/44.1k audio with HD video
« Reply #21 on: March 23, 2010, 07:08:23 AM »
Basically you want your audio segment to start before and end after the video segment.  Extract a segment of said audio at the right offset of equal length to the video segment.  And either add it to the video with the existing audio, or swap out the video's audio for the external one.  You may or may not need to compensate for clock drift since you're syncing two independent devices without worldclock / timecode / ???.  For segments less than five minutes it's close enough with my setup.  But most of my recordings are in that ten to twenty minute lengths, so I compensate.  It also makes it easier to use any sync point as the sync point doesn't change (much) if you choose a different one with each trial and error attempt.  There are software packages out there that will do this guessing for you to find the offset that matches.  In the absense of a hand clap or drum hit it might be the only sane way to handle that guess work.  Fortunately what I record has claps and drums.

http://www.youtube.com/watch?v=6bV4RRTJRRU

One I did a couple of weekends ago for a friend.  You can see the Korg and mics in the video.

Offline Matt Quinn

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Re: combining 16 bit/44.1k audio with HD video
« Reply #22 on: March 23, 2010, 02:53:52 PM »
I'm not sure about the DSD part, but I've developed a way to do this with a Flip Ultra HD cam that basically could not be any easier. Zero stretching etc required. The only software required is a multitrack audio editor of your choice, and a program called DVD Flick.

In my case, I use Ableton Live as my editor. Simply drag & drop the video file to a track, then drag the hi-res audio to the next track. Find a sync point (easiest way IMO is to pick the drummer counting off the tune, or banter between tunes). I will pan one source hard left, and one hard right, then move the 2 clips around until they are dead in sync. Live is particularly awesome for this as you can turn on a very narrow grid & slide your clips along it until you find the right spot.

Once your audio is lined up, select the portion that acompanys the video, and export the AUDIO ONLY as a wav - 16/44.1 or 16/48. You should have a wav that is the exact same length as the video.


Open up DVD Flick. Drag your video into the main window, and it will add it to the project. The program is pretty self explanatory, but the 2 things that may be a bit tricky:

Go into the 'audio' tab, remove the audio track that is listed (it is the camera's native audio track). Then add the new audio file you exported from your editor. After you add the new audio, you have to go right back into it, click 'Edit' ,then there's a little box at the bottom that says 'Ignore audio delay'. CHECK THIS BOX. Repat these steps for each video file. Hit 'Create DVD' in DVD Flick, and you are done.

That's it. I have done this flawlessly 4 times now. There is no drift between audio & video even with ~ 1 hour files.
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Offline BayTaynt3d

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Re: combining 16 bit/44.1k audio with HD video
« Reply #23 on: April 16, 2010, 07:04:49 PM »
Vegas has virtually unlimited tracks, so that's never an issue. I regularly drop loads of video and full multitrack audio on the timeline no problem.

As for the real-time thing, Vegas is insane for that, some people familiar with other editors can't believe their eyes when they see that. Basically, you can be playing the audio (hearing it real time off the timeline), WHILE you drag or expand/contract audio or video events/tracks. So, basically, you can zoom way into the timeline, and move the video event a frame forward or backward (or move the audio for that matter), and literally listen to how the changes affect the sound as you do it. It can be helpful to just loop on a small region as you're doing things like that. It makes it SOOOO much easier to manually sync.

Also, I use Plural Eyes to great success in Vegas, that tool ROCKS, especially for someone like myself shooting on a 12-minute-limited Canon 5D2 where I end up with loads of clips to be synced. There are a few options you can use to help it make sync if it struggles, and I have yet to not be able to sync something with those tweaks.

Finally, I find all versions of Vegas 9x to be somewhat unstable (at least in my workflow, including the new 9d), but Vegas 8c is rock solid stable for me on a Win 7 i7 box. Another thing is that it's helpful to have your audio at 48hz to sync to hopefully the ambient track of your video (which will undoubtedly be at 48). As far as "replacing" the video's audio, no need in Vegas, just mute that track once you have sync and leave it right there in case you need it later.
« Last Edit: April 16, 2010, 07:07:46 PM by BayTaynt3d »
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