Issues with Large Files

[RS]

>From: iz

>Sent: Friday, January 13, 2017 20:19

>In this case, you only need arithmetic. AAC uses a fixed number of samples 
>per frame (the "1024 spf" you see in the frame rate in MediaInfo output), 
>so the >total number of frames is basically a function of sample rate and 
>programme duration. 400k+ would be expected for a 48kHz 9200 sec AAC LC 
>file.

If that's the case there is no point in making the suggestion I was about to 
make, but I'll make it anyway.

The problem I had with AGPtEK was that they had done their testing with 
files about 7 years old, so they could not take account of recent changes 
such as the M4A Minor Version 512, and clips of only 3 or 4min.  If Linn's 
problem had been similar I was going to suggest re-encoding with the Nero 
AAC encoder, which I understand is highly regarded, but is of a similar age. 
It means using the decoder to convert from .M4A/.AAC to .WAV and then 
re-encoding with the encoder.  That is not as daunting as it sounds.  The 
decoder is very fast.  The encoder is much faster than the AAC codec built 
in to ffmpeg.  It encodes a 24min 128kbit/s file in 20s, which compares with 
about 10min for the ffmpeg aac codec.

It is no longer available on nero.com, but it is here
http://www.softpedia.com/get/Multimedia/Audio/Audio-CD-Rippers-Encoders/Nero-Digital-Audio.shtml

I have looked at some files ranging from 12kbit/s with an 8kHz sample rate 
to 320kbit/s with a 48kHz sample rate.  They all have 1024 samples per 
frame.  Is that part of the AAC standard?  If it is, it is inevitable that 
with a sampling rate of 48kHz there are going to be just under 47 frames per 
second.  What is surprising that Linn were surprised by it, although I am 
always suspicious of people who refer to "chunks" when there is a recognised 
technical term.

Does the Linn play all the files in a directory in turn?  It it does, would 
it help to split the file into separate files for each act of the opera?