I have some videos (H264/AAC in a .mp4 container) with an audio track that I'd like to make louder without having to re-encode the whole thing. I was thinking that I'd need to extract the AAC audio, bring it into Audacity (or something like that app), make it louder, save it back to an AAC audio file, and substitute this new track for the old audio track in the video. Finally I'd save the re-assembled video as a QT movie so what I'd end up with is H264/AAC in a .mov container.
Is there a way to shortcut this or do I have the process pretty much as short as it's going to get?
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A-ha! Thanks. I'll give it a shot and report back with the results.
Avidemux did the trick but when I tried to drop the file into my iPod (through iTunes), iTunes reported the file couldn't be transferred. I checked both files (old and new) with VideoSpec but the only differences were the encoding library (Handbrake vs Lavf) and some trivial differences in audio and video bitrate. I wonder what iTunes is seeing?
I then tried my solution (but I used Amadeus). Amadeus was able to open the AAC file (in a .mov container as that's how I exported it from QT Player). I then normailzed it with a boost in volume, saved the file (it saved without forcing me to change format), switched back over to QT Player, deleted the old audio track from the video, added the new video track, and saved. QT Player automatically saves as a .mov but the H264 and AAC were preserved (albeit with the new, louder audio). I then dropped that file into my iPod through iTunes and it works.
I've found a number of tools don't seem to work perfectly with the "legacy" iPod (5G). This is probably not a problem with the tools but a problem with this old iPod and how Apple wants to treat it.
I'll add that Apple changed iTunes' ability to transfer videos into iPods at some older iTunes release. It used to be possible to bring almost any width of video (800pixels, for example) as long as the total pixel size was no more than 307,200 (640x480). Since that "update", however, they are enforcing the 640 pixel max width. I'm sure this was a marketing decision to push people to the AppleTV.
Okay, now I'm totally confused. I tried using avidemux again with a few other files and it seems to be working quite well with those files being happily accepted by iTunes when I ask to have them sync'd to my 5G iPod.
I examined the files with VideoSpec and can't find anything that would, all of a sudden, make a difference.
Consistency may be the hobgoblin of little minds but I'd be happy with some of that right now.
Is the "AVC Level" the same for the files that were accepted as those that were not?
Yes; in all cases the avc level is "1" regardless of whether iTunes approves of it for the iPod or not.
I refined my Amadeus method a bit. I simply open the video with Amadeus. Of course, it only sees the audio. I modify it accordingly (normalize with a 2dB boost) then save as a .mov (which only saves the audio). I then open both the original video and the altered audio in QT Player Pro, delete the original audio from the video, copy and paste in the altered audio, and save as a self-contained ".mov". It does this with no re-encoding necessary and drops into my iPod with no trouble.
If anyone would like me to upload two short clips (a good one and a "bad" one), let me know and I'll post the links here.
Thanks for any suggestions.
The files are a number of different resolutions from 320x up to 640x (and some even larger but those are for my AppleTV). The "avc1" is what comes out of Handbrake, Turbo264, ViddyUp and even QT Player Pro. (I'm referring to the "FourCC" code. This is the same whether I use VideoSpec or MediaInfo.)
I should mention that any file that I export (using the "iPod" setting) out of QT Player Pro works perfectly; it drops into the 5G iPod without complaint. Also, the other apps I mentioned work fine (re: iPod & iTunes)
The method of generating the .mp4 files was the same? or varied sources?
Did they all work with ipod before touching avidemux?
I think it's a container issue, but it doesn't make sense that some would work where some would not (unless you had different spec video, in which case the original .mp4 should have had the same problems)
By different spec video, I mean things like CABAC, b-frames, I8x8, all these things will prevent ipod compatibilty
When I use avidemux, the resulting file doesn't drop into the iPod (and I've also noticed that, in some cases, the audio is muted with no way of turning it up - the audio track is there).
All of the other apps I mentioned work fine and, yes, the files all dropped into the iPod correctly (when run through those apps).
I have found that Video Monkey has stopped producing files that can be dropped into the 5G iPod. It used to work (some previous version) but now no longer does. Again, I can't see any difference in the files otherwise. (This last paragraph is a bit OT as my original post was simply about boosting the volume.)
I wasn't clear; sorry.
The original files -all- transferred to the iPod properly.
When I ran them through avidemux for the audio boost, -some- transferred to the iPod and at least one was muted with no way to get any volume out of it at all (and it was one that did transfer to the iPod).
When I open an H264 file with avidemux, it gives me a warning about an alternate mode that "loses frame accuracy". However, since I'm not actually editing anything, I figured it didn't matter which mode I used. I tried them both; same results (they either work or they don't).
I'm thinking I may need to disable Perian just so I'm sure it's not jumping in to do things where, perhaps, it shouldn't. (Although it looks like avidemux - and I'm using the qt version- , being a *nix app, probably doesn't even see QuickTime or Perian, right?)
I'm going to clean up my Macbook Pro and try some of these file mods there without Perian installed. I'll report back once I mess around and have some results.
Thanks again to all for your concern.
Well that's just weird... They should either all fail or all transfer properly
I know some older versions of avidemux didn't work at all with ipod, it had to do with the .mp4 wrapper spec, and when you re-wrapped it with another application it would work fine. But something else is happening if some tranfer to ipod, but some don't
(Although it looks like avidemux - and I'm using the qt version- , being a *nix app, probably doesn't even see QuickTime or Perian, right?)
If you want to pursue this farther, you can open a thread in the mac avidemux forum
Originally Posted by rumplestiltskin
The profile (Baseline/Extended/Main/High/etc.) and level (1.0 to 5.1) of AVC video can break compatibility with iPod/iPhone/AppleTV. (QuickTime Pro's iPod preset encodes with Baseline Profile Level 3.0, possibly because some important/current playback device can't decode level 3.1 or higher.)
Baseline is 3.0 and VideoSpec does, indeed, list it. All the files are Baseline 3.0. The original files are Baseline 3.0 as are the reworked ones (either through avidemux or QT Pro).
When I use Handbrake to transcode to iPod, I have to use the "Legacy iPod" setting; anything else results in a file that won't drop into my 5G iPod (which, of course, -is- a legacy device).
The files from my Samsung MX20 are all Baseline 3.0 but they won't transfer to my iPod unless I run them through Handbrake (or MPEG Streamclip, etc.). In this case, though, I know their bitrate is way too high for an iPod.
I have checked everything that I can see in VideoSpec and MediaInfo looking for what might be the difference between a good file and a bad one. Can't seem to find anything yet.
I'll post again once I have that chance to do this on a clean system without 3rd party codecs.
For Windows users, if you're just looking to play H264/AAC movies louder, you can play them in a player like MPC HomeCinema.
Play Menu -> Audio -> Options -> tick Normalize.
Default boost is +1.0 dB which should do the trick or you can boost further.
Last edited by MavDVDR; 29th Jun 2011 at 21:23.