encode to m4a (aac) with correct tags & 192k bitrate

[piedro]

Hello!

I tried all kinds of different programs to convert flac files to m4a oe aac files. I tried to get a bitrate of 192k. It won't work correctly!

- sound-converter converts the files and tags but the resulting files show no bitrate at all!
- using ffmpeg on hte commandline with -ab 192k results in files also not showing any bitrate in any musicplayer. (same with nautilus file information!). Using media info on any resulting file shows no bitrate at all.

The files will play still but I need to compare some files so I need the bitrate. I used ffmpeg -i on the files and voila: they show a bitrate but with 152k instead of 192k!!!

How to encode these files correctly transfering the metatags and getting a correct bitrate of 192k which is also shown when looking at the audio file info?

plz help,
thx for reading,
piedro

[ron999]

Hi
I think that the faac encoder is variable bitrate. That's why you don't see accurate readings.
From faac --long-help it says:-

-b <bitrate> Set average bitrate (ABR) to approximately <bitrate> kbps.

This is the command that I'd use with ffmpeg

ffmpeg -i filename.flac -acodec libfaac -b 192k -map_meta_data 0:0 output.m4a

It transfers the meta-data OK.
But mediainfo and ffmpeg -i both show the result as 64kbps, so I think it's the VBR thing that's confusing them.

Complete name : output.m4a
Format : MPEG-4
Format profile : Apple AAC audio with iTunes info
Codec ID : M4A
File size : 3.02 MiB
Duration : 6mn 18s
Overall bit rate : 66.8 Kbps
Album : Live Rust
Track name : Cortez the Killer
Track name/Position : 12
Track name/Total : 0
Performer : Neil Young and Crazy Horse
Genre : Rock
Encoded date : 1979
Writing application : Lavf52.84.0

Audio
ID : 1
Format : AAC
Format/Info : Advanced Audio Codec
Format version : Version 4
Format profile : LC
Format settings, SBR : No
Codec ID : 40
Duration : 6mn 18s
Bit rate mode : Variable
Bit rate : 64.0 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 44.1 KHz
Stream size : 2.89 MiB (96%)

[ron999]

EDIT
There's an error in my command above.
It should be -ab instead of -b.

Like this:-

ffmpeg -i filename.flac -acodec libfaac -ab 192k -map_meta_data 0:0 output.m4a

mediainfo then shows 152Kbps.
So I still think that the VBR confuses it.

Complete name : /home/ron/output.m4a
Format : MPEG-4
Format profile : Apple AAC audio with iTunes info
Codec ID : M4A
File size : 6.99 MiB
Duration : 6mn 18s
Overall bit rate : 155 Kbps
Album : Live Rust
Track name : Cortez the Killer
Track name/Position : 12
Track name/Total : 0
Performer : Neil Young and Crazy Horse
Genre : Rock
Encoded date : 1979
Writing application : Lavf52.84.0

Audio
ID : 1
Format : AAC
Format/Info : Advanced Audio Codec
Format version : Version 4
Format profile : LC
Format settings, SBR : No
Codec ID : 40
Duration : 6mn 18s
Bit rate mode : Variable
Bit rate : 152 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 44.1 KHz
Stream size : 6.87 MiB (98%)

[shantiq]

well using neroAacEnc (enclosed) will give a constant bitrate

flac * -d &&
for f in *.wav; do neroAacEnc -cbr 192000  -if "$f"  -of "${f%.wav}.m4a"; done

but one had to encode from wav so no tags not sure this is better


to install neroAacEnc


place in home folder

then

sudo cp neroAacEnc /usr/bin

and then

cd /usr/bin

then

 sudo chmod +x neroAacEnc

there has to be a way to do it all 192 constant +tags let us think

[FakeOutdoorsman]

You can verify the bitrate of the output file: bitrate = filesize / duration. For example, a 7 MB file that is 378 seconds long: (7*1024)8 / 378 = ~152 kilobits per second.

This doesn't mean that the file was encoded at a constant bitrate of 152 Kbps.

[piedro]

Wow, that's alot of great advice.

And yes: this is exactly the same phenomena I experienced: got the tags, but bitrate showing 152k (which I also figured probalbly to be a variable one ...).
So by applying -ab 192k I get an average vbr of 152k - that's at least unexpected, isn't it?

Most of my music collection was encoded by apples itunes on an old apple machine. All those files are constant bitrate 192k. So for good measure it would be nice to get some consistency by encoding my flacs ripped by my new linux box to the same format.

I like your nero encoder solution also but retagging is a bit of a nuisance. BTW: I never realized that you can't get the tags from wav ...

I also tried "Mobile Media Converter" but I gave up at creating a profile for that one to do the job.

[shantiq]

piedro 192k is really quite a "thin" pared down version of a piece of music why do you not rip to flac/alac/wavpack/ape/alac etc from now on on your linux machine the sound quality of your music files becomes much higher 192 m4a is really like fatfree slimline audio

but of course it is your choice if you want to rip directly to aac 192k you can use rubyripper for that with tags and constant bitrate

you will need to do with neroAacTag the same install process you have to do with neroAacEnc




once rubyripper is installed settings are
preferences/codecs/other
the other command line is

neroAacEnc -cbr 192000 -if %i -of %o.m4a && neroAacTag %o.m4a -meta:artist=%a -meta:album=%b -meta:genre=%g -meta:year=%y -meta:track=%n -meta:title=%t

There you have aac 192 tagged and you can tick flac at the same time and compare the quality of both files

ps rubyripper often handles better starting with the command line

rrip_gui

for the settings and

rrip_cli

for the rip


Anyway thought i would add this

[cascade9]

piedro 192k is really quite a "thin" pared down version of a piece of music why do you not rip to flac/alac/wavpack/ape/alac etc from now on on your linux machine the sound quality of your music files becomes much higher 192 m4a is really like fatfree slimline audio

+1....well, +1 on flac, +0.5 on wavapck and -losts and lots on ALAC (why go to a closed source codec with crap support?) and .ape (ape is a joke.....read the licence if you dont believe me)

In these days of super cheap 1TB+ sized drives, lossless makes great sense.

[shantiq]

+1....well, +1 on flac, +0.5 on wavapck and -losts and lots on ALAC (why go to a closed source codec with crap support?) and .ape (ape is a joke.....read the licence if you dont believe me)

In these days of super cheap 1TB+ sized drives, lossless makes great sense.

well Cascade we from time to time have these chats about codecs i personally do not care for ape and agree with you there


only mentioned as it is popular with many and people have heard about it

you know my favourite ...

as regards alac i love it i know it is mac's baby but i adore it and it is very well handled on linux all players play it

Players which handle alac

VLC plays them
QMMP (right-click on player/settings/plugins/FFmpeg plugin/highlight/Preferences/Tick alac )
deadbeef
aqualung
audacious
xine

and rubyripper will rip it for you in style with help from ffmpeg

ffmpeg  -i %i -acodec alac  "%o".m4a && neroAacTag %o.m4a -meta:artist=%a -meta:album=%b -meta:genre=%g -meta:year=%y -meta:track="%n" -meta:title="%t"

wavpack is really cool no beef there


again rubyripper

wavpack -w "Artist=%a" -w "Title=%t" -w "Album=%b" -w "Year=%y" -w "Track=%n" -w "Genre=%g" -hhm %i -o "%o.wv"

[cascade9]

as regards alac i love it i know it is mac's baby but i adore it and it is very well handled on linux all players play it

wavpack is really cool no beef there

You know what I've said before.......if its lossless, there should be no difference in output quality (depending on decoder).

ALAC is playable under linux, but the decoders were all written from scratch (by reverse engineering of quicktime .dlls), since apple didnt release ANY specifications on the format. Sod apple.

wavpack isnt bad, but hybrid ripping (one of the main points of wavpack) is pretty much useless, it takes more CPU time to decode compared to flac, and flac has far more support in portable media players, etc. (mainly thanks to the extra CPU time needed by wavpack). So IMO flac is better.

IMO there are too many open source lossless codecs. Division will just make things easier for microsoft (with WMA lossless) and apple (with ALAC) to tie up the market.