brettf wrote:
Found it!
Out of the box QT X has issues with M4V and AC3. Google 'quicktime x ac3' for pointers to various discussions on the subject. Seems that some folks are having luck installing Perian, which is a collection of codecs for QT but may require you to run QT in 32 bit mode. I didn't install it since success is not guaranteed.
Instead, I started playing around with the arguments to ffmpeg and discovered that this minimal command line will work (using Alan's syntax from his workflow):
ffmpeg -i "$1" -vcodec copy "$1.m4v"
What this does is re-encode the AC3 track into an AAC track. I couldn't exactly tell if the audio quality was affected. You can also opt to keep the original AC3 track and add a new AAC track with the following command line:
ffmpeg -i "$1" -acodec copy -vcodec copy "$1.m4v" -newaudio
Do either of those and you'll get your sound.
I leave updating your copy of Alan's workflow as an exercise to the reader 🙂
I was so excited when I saw this as I have been trying to get the AVHCD .mts files from my Windows PC over to my new MacBook Air to iMovie to create some videos from my wedding. I've read tons of posts and tried so many different pieces of conversion software and all are insanely slow and the videos look terrible. Horizontal lines all over the place whenever someone moves in the video, garbled sound, etc. This is the first solution that provides decent video quality and since it doesn't actually convert formats, its instantaneous.
I say decent video quality because the horizontal lines aren't there, but it does seem a bit blurry and jerky as the camera moves around.
However, both of these above suggestions for dealing with the sound do produce sound, but the quality is poor. There is a squeeky sounding background noise that interferes with the real sounds in the video. Its as if any background noise is being amplified. i.e. its mildly irritating when there isn't much background noise, but videos from say a hockey game are terrible.
We are so close here I don't want to give up. Can anyone provide a couple more suggestions of audio commands that might produce clear sound?
Here are the details of the video from the Inspector in QuickTime when I used the original automator script (didn't mess with the audio at all):
Format: H.264, 1920 x 1080, Millions
AC3, Stereo (L R), 48.000 kHz
FPS: 59.94
Current Size: 1384 x 780 pixels
That of course won't play audio at all (haven't tried Perian, but VLC will play it but in VLC the video is terrible with the horizontal lines).
Then with the two alternate command line arguments above, Quicktime shows the AAC track and it plays, but the sound is poor:
AAC, Stereo (L R), 48.000 kHz
The fate of my wedding videos lies in the hands of you good people :-D