FORUMS: list search recent posts

Audio codecs and video bitrates in Compressor 4

COW Forums : Compression Techniques

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
Jake Shepherd
Audio codecs and video bitrates in Compressor 4
on Jun 10, 2013 at 3:43:54 pm

Hello.

I have edited a short film using FCPX and have just bought Compressor 4 to export the video file.
One of the festivals that I am submitting the film to requires very precise export settings.
Can anyone suggest how I can export the audio as a Mpeg-4 AAC LC codec and select a bitrate of 821kbps for the video? I can see that there is a 'restrict to' datarate option for the video. Can this be treated as a way of selecting bitrate? I have also searched online to download a low complexity audio codec with no success.
Any help would be much appreciated.

Many thanks.

Jake


Return to posts index

Craig Seeman
Re: Audio codecs and video bitrates in Compressor 4
on Jun 10, 2013 at 4:40:53 pm

I believe Compressor gives you a choice between HE-AAC and AAC. I think the latter is AAC-LC but, like much of Apple's documentation and UI, they keep this information hidden.

In Compressor 4 I see:
AAC
MPEG-4 AAC Enhanced Low Delay
MPEG-4 AAC Low Delay
MPEG-4 HE AAC
MPEG-4 HE AAC V2

It's difficult to hit a precise data rate. You can target (or restrict) to it but there's some degree of over/under depending on the content. CBR encodes tend to hit a target more closely more often but they also are often lower quality.



Return to posts index

Jake Shepherd
Re: Audio codecs and video bitrates in Compressor 4
on Jun 10, 2013 at 4:51:15 pm

Is that a general rule that it's hard to hit a precise data rate? Or just for Compressor? If I used a different program in conjunction with FCPX could I get precisely that bitrate?
The audio codec requested is MPEG-4 AAC LC. Would you say that MPEG-4 AAC Low Delay is an equivalent?

Many thanks Craig.


Return to posts index


Craig Seeman
Re: Audio codecs and video bitrates in Compressor 4
on Jun 10, 2013 at 5:02:54 pm

[Jake Shepherd] "Is that a general rule that it's hard to hit a precise data rate?"

Yes, it's the nature of encoders IMHO. Some are more accurate than others depending on the underlying analysis.

[Jake Shepherd] "The audio codec requested is MPEG-4 AAC LC. Would you say that MPEG-4 AAC Low Delay is an equivalent?"

No.



Return to posts index

Jake Shepherd
Re: Audio codecs and video bitrates in Compressor 4
on Jun 10, 2013 at 5:20:14 pm

Thanks.

Do you happen to know if low complexity audio codecs are available to download and use in Compressor 4?


Return to posts index

Craig Seeman
Re: Audio codecs and video bitrates in Compressor 4
on Jun 10, 2013 at 5:48:40 pm

As per my previous post I believe AAC is AAC-LC. It's not documented though in my checking.



Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]