m4a file format - what is this?, page 3

crocodile pwr on June 27th, 2007 / post 19884

About format m4a , i have easy decision .

For fast listening , play file with VLC player .

For cuting , mixing , editing , you first encode file with Nero , very easy and fast way and then edit file with Sound Forge or Adobe Audition , the quality of the file is depending of first download source and of course your "Save as" format . M4a is not file with bad quality .

TomMix 3daywarning on July 2nd, 2007 / post 20008

hello spasv, it is me again :-D

im sorry but i have to post some things in here regarding ur xmradio mp4 stream propaganda

first a very little introduction to business:
xm is business
business wants to make profit=money by delivering as little as possible so its a good business
satellite bandwidth is limited and expensive
scientists develop new technologies to increase the efficiency
business uses the new technologies to make more money
C.R.E.A.M. got it?!

back to topic:
xm uses a proprietary aacplus from coding technologies
some facts of that codec are

"facts" wrote:
Features
• True Superset architecture
• Multi-channel support for 5.1, 7.1 and beyond (48 channels total)
• Built-in error concealment for mobile applications
• CD-quality stereo down to 48 kbps
• Near CD-quality stereo at 32 kbps
• Excellent quality stereo down to 24 kbps
• Widest available audio bandwidth
• Optimized speech, mixed speech/music down to 8 kbps mono
• Compliant with ISO/IEC 14496-3, incl. Amd.1:2003, Amd.2:2004, and all corrigenda

so xm broadcasts with sound quality remarkably close to Compact Disc
this means 32 kbps to 48kbps to give some extra bits maybe 64 kbs
are u with me so far?

so now please tell me how it happens that a approx ~50 kbs xmradio stream bloats up to a
>200 kbs m4a audio file?! :-O

post scriptum: peeps can read on here

scorpio06 user on July 6th, 2007 / post 20068

id like to have my mp3 format then cue it on nero into audio cd. with m4a, majority of us dont like the hassle converting it back with some software. so m4a :thumbsdown:

TomMix 3daywarning on July 7th, 2007 / post 20091

SpasV wrote:
I would continue showing m4a encoder advantages:
• I tried to recode 01_armin_van_buuren_-_a_state_of_trance_302_05-31-2007.mp3 preserving its 192 kbps quality (preserving almost the same signal spectrum). The result I have is an m4a @ 172 kbps with the (almost) same spectrum.
• When I encoded John Digweed at Transitions on XM80 31May-2007.m4a I had to go to a little bit higher bit rate. Then, it turned out the VBR avg 260 kbps m4a preserved the recorded signal spectrum better than an mp3@320 kbps.

so lets sum this up:
xmradio has a ~50kbit stream and ur spectra shows u full cd-quality that has to be encoded
at a 260kbit vbr aac. :'-(

please use the web

"hydrogenaudio.com" wrote:
Using VBR mode (-q) will give the best quality. The default setting is -q 0.5, which will give about 160-170kbps on average.

some more setting values:
Recommended Nero AAC Presets

"hydrogenaudio.com" wrote:
High Quality - VBR/Stereo - Streaming, 100-120 Kb/s (LC AAC) / Actual bitrate ~150kbps

Portable - VBR/Stereo - Internet, 90-100 Kb/s (LC AAC) / Actual bitrate ~128kbps

Small Filesize - VBR/Stereo - Portable, 50-70 Kb/s (HE AAC) / Actual bitrate ~90kbps

get the needed infos here! and i hope ur also realizing there that u can drop ur funny spectra...
there they do talk about the best aac encoding results from real audio cds with some weird complex content like classical music. not a ridiculous xmradio stream!
what are u trying to sell here?!

SpasV wrote:
Note: I use “almost” because I cannot avoid it. Without it I have to proof strictly the spectra are the same. But for a listener the music should be the same because the spectra, and accordingly the sound signals are very close.

man please please with sugar on top: DROP UR SPECTRA IN UR TRASHBIN!
YOU CANT' SAY SOMETHING SOUNDS BETTER BASED ON A PICTURE.
the only thing u can see most is the audiorange of the file and in case of mp3, the lowpass.

TomMix 3daywarning on July 7th, 2007 / post 20092

i also want to say that i dont have any problems with any codec.
only with some ways the codecs are used to compress audiofiles.
and some strange teqniques or validations to proove quality like using pictures
to rate audioquality ...

:cool: