Encoding questions, CBR LC issues Options

[derekja]

Hi,

I've got a rather specific problem I'm trying to solve. LiveScribe, a recording pen, does not currently provide any way to edit the audio files. I've got the files out in an AAC format (specifics from mediainfo below) and I'm trying to edit and put it back into the same format to get it back into the livescribe application.

The problem I have is that any change to the bitrate seems to have the application convinced that the length of the recording changes, and then all of my annotations are at the wrong place. So I think I need to figure out how to encode my post-edit files EXACTLY the way that livescribe does so originally.

I'm getting close by using faac with a constant bitrate (hah! or what passes for constant to faac's deluded mind) but it still puts me out by several minutes on a couple hour recording, which makes my annotations pretty close to useless.

Thanks for any insight!

--Derek

Here is the original format:


General
Complete name : C:\Users\derekja\AppData\Local\Livescribe\Desktop\Library\Recordings\Pen_0\PRS-a997ddd3d\audio-0_orig.aac
Format : ADTS
Format/Info : Audio Data Transport Stream
File size : 26.0 MiB

Audio
Format : AAC
Format/Info : Advanced Audio Codec
Format version : Version 2
Format profile : LC
Bit rate mode : Constant / Variable
Bit rate : 26.9 Kbps
Minimum bit rate : 72.0 Kbps
Maximum bit rate : 111 Kbps
Channel(s) : 1 channel
Channel positions : Front: C
Sampling rate : 16.0 KHz
Compression mode : Lossy
Stream size : 26.0 MiB (100%)


And here is the closest that I can get to with faac:


General
Complete name : C:\Users\derekja\AppData\Local\Livescribe\Desktop\Library\Recordings\Pen_0\PRS-a997ddd3d\audio-0_throughpipe.aac
Format : ADTS
Format/Info : Audio Data Transport Stream
File size : 26.3 MiB

Audio
Format : AAC
Format/Info : Advanced Audio Codec
Format version : Version 2
Format profile : LC
Bit rate mode : Variable / Variable
Minimum bit rate : 67.5 Kbps
Maximum bit rate : 129 Kbps
Channel(s) : 1 channel
Channel positions : Front: C
Sampling rate : 16.0 KHz
Compression mode : Lossy
Stream size : 26.3 MiB (100%)

This post has been edited by derekja: Feb 1 2012, 04:45