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Topic: Results from two encoders seem to differ -- could someone tell me in what way? (Read 1460 times) previous topic - next topic
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Results from two encoders seem to differ -- could someone tell me in what way?

Hello,
I have two different AAC encoders on my hard drive. I've tried to take the same sound file and run it through each of the two encoders. I used the same target bitrate in both cases.
For whatever reason, there are a few programs that are only able to recognize the format of the first file but not that of the second one, even though most players or sound editors seem to load both files successfully. This indicates that one encoder does something differently from the other, even though in theory both encoders should give the same results.
I'm attaching a link to a folder containing two M4A files and my request is this:
Could someone please tell me in what way do the contents of the two files differ? I thought they were the same data. But apparently they're not when the first file can be loaded by every program I've tried while the second file is recognized by most but not all of them.
The link is here:
https://1drv.ms/u/s!Ap_EgwEX00SDgiOznKS343Oieb37?e=icxmpF
Thanks in advance.
- Petr

Re: Results from two encoders seem to differ -- could someone tell me in what way?

Reply #1 –
swclorm1.m4a
Code: [Select]
Format profile                           : Base Media / Version 2
Codec ID                                 : mp42 (mp42/isom)
Overall bit rate mode                    : Variable
Writing application                      : fhgaac v03.02.16;CBR=256000

swclorm2.m4a
Code: [Select]
Format profile                           : Apple audio with iTunes info
Codec ID                                 : M4A  (M4A /mp42/isom)
Overall bit rate mode                    : Constant
Writing application                      : fdkaac 1.0.4, libfdk-aac 4.0.1, CBR 256kbps
Files have a different header and 1 has a variable bitrate while 2 has a constant bitrate.
 

Re: Results from two encoders seem to differ -- could someone tell me in what way?

Reply #2 –
Thanks. This is indeed good to know. That's exactly the kind of information that I was looking for.
Trouble is, when I'm running Windows, FHG AAC is only available in the older versions of Winamp but not in the latest one.
So, if I didn't have a local copy of the older version of Winamp, I would not have the possibility to run FHG AAC on Windows (I have no idea why they dropped FHG AAC in the newer Winamp release).
This means that if I wanted to make M4A files in the style of the first file, I would have to either find FHG AAC somewhere outside of Winamp (which I'm not sure where), or find a different piece of software that would be able to make such files (which I'm not sure what that is).
But I'll definitely have to seriously think about this issue, just because I'm currently unable to figure out which other software I might replace FHG AAC with.