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TwinVQ

Is this encoder related to AAC?  Winamp can rip down to 16 kbps .aac.  Is TwinVQ theoretically strictly for 8kbps?
Daniel L Newhouse


Re: TwinVQ

Reply #2
The Fraunhoffer mpeg4 AAC encoder with Winamp does

He-AAC v2 12 -40 kbps
HE-AAC 44-84 kbps
LC-AAC  88-448 kbps

with the encoder on automatic

TwinVQ does speech encoding at 8 kbps. 

How about some optional features that are needed, parametric volume normalization. 

Also, nano-parametric EQ.  Every album is put through an EQ curve, and to get the right sound out, you need to compensate with an EQ curve.

Honestly, I understand parametric EQ and volume normalization.  But parametric volume?
Daniel L Newhouse

Re: TwinVQ

Reply #3
Parametric volume does make sense, as all you need to provide, is parameters to an envelope function. Those coefficients then get multiplied with the sample and you get the un-attenuated sample back (which can be bit-depth limited). I'd assume a volume function isn't computed for the entire track, but on some sort of per-frame, or per-number-of-frames.

Re: TwinVQ

Reply #4
534 kpbs per channel is the rate at which you can get lyrics to scroll with the song, is it not?  I'm wondering if HD radio could have met that broadcast rate.

Daniel L Newhouse

Re: TwinVQ

Reply #5
108 kbps is minimum for synchronized lyrics.  534 kbps would include cover art and rear art with each song in addition to the scrolling lyrics.  For .aac broadcast.
Daniel L Newhouse

Re: TwinVQ

Reply #6
The bitrate for one cover art and synchronized lyrics is 434 kbps. 

After Appetite for Destruction, nobody is going to want to broadcast the rear cover art.

I'm looking at mp3Tag Pro which is the only software that lists multiple artwork for each file and Tag & Rename which has a separate listing for folder art. 
Daniel L Newhouse

Re: TwinVQ

Reply #7
K, the mpeg2 ADTS -AAC Franhoffer encoder encodes .aac.  The mpeg4 encodes .m4a and is much more powerful.  However, I don't know if .m4a was ever intended for streamed music.  

Also, when going from 32 kbps to 28 kbps with the mpeg2 encoder, the sampling rate is cut from 441000 to 220500.  Also, SBR is cut off, and so is PS - at 28 kbps the sound is just mono. 

This is using the shareware version of Winamp Pro.


The lowest bit rate version of Vorbis I can do is 48kbps.
Daniel L Newhouse

Re: TwinVQ

Reply #8
In Winamp, parametric stereo works down to the lowest bitrate if the profile is set to Automatic or HE-AAC v2. To output AAC, you use the "SHOUTcast MPEG-2 ADTS-AAC" encoder, not the old one from Coding Technologies. The effective bitrate is less in ADTS because of bigger overhead esp. at lower quality. In the binned thread you already admitted that 28 kbit/s has SBR. MediaInfo can usually report the He-AAC mode for ADTS, but players may only do so during playback, as this format is poorly supported and there isn't a "Xing frame" with metadata. Also I believe the SBR/PS format extensions are only defined for "MPEG-4".

It does not make sense to say that artwork has a bitrate, as it doesn't last any time, unless you are talking about a specific system where certain amout of data is allocated for it, the image has a particular dimensions and retransmission interval. A black artwork ("Apetite") is smaller than colorful "Life in Cartoon Motion".

I wish broadcast radio worked at 500 kbit today when a single listener can stream at this rate only for himself.

Re: TwinVQ

Reply #9
Streaming MP4s doesn't really work, it is a program stream afterall.

MPEG-TS is used for digital broadcasting, if that's what you mean. A never version of that was defined in MPEG-H called MPEG Media Transport (MMT).

For audio-only broadcasting of AAC, ADTS is the MPEG-4 Audio standard format.

In DAB+ has some sort of extra frame limitation, I remember running into it, when I tried making my DAB+ decoder with an SDR. It was something about the frame size limit or something, and the way the subchannels are multiplexed.

Re: TwinVQ

Reply #10
In the binned thread you already admitted that 28 kbit/s has SBR.

A mistake, at exactly 28 kbps the mpeg-2AAC encoder engages a sampling rate of 22050 Hz and cuts off any frequencies above 11025 Hz.

The Shoutcast software lets you use anything you want as an archival file.  I use dbpoweramp for genuine flac archival of my collection. 

Also, given that it's either car radio or internet radio now, it should be noted that the car radio version is guaranteed better than the internet radio version, therefore the internet radio version of XM won't sound better than 24 kbps mpeg-2 AAC. 

I think the internet radio is broadcast in WMA.  I tried 32 kbps WMA 10.  On Metallica.  Grotesquely affected sound.  I wouldn't use it lower than 48 kbps based on what I heard.

Does this standard not come from V.35?
Daniel L Newhouse

Re: TwinVQ

Reply #11
The way to get the gist of how XM internet radio works is to run Shoutcast into SAM Broadcaster, hypothetically.  That doesn't work.  You'd have to archive your files at 24 kbps and then use SAM Broadcaster Pro to broadcast a stream.  The SAM Broadcaster Pro software available for trial, I had to open a separate tab to see the link.  But it requires either SQL Server or MS SQL already installed to operate.    
Daniel L Newhouse

Re: TwinVQ

Reply #12
The way to get the gist of how XM internet radio works is to run Shoutcast into SAM Broadcaster, hypothetically.  That doesn't work.  You'd have to archive your files at 24 kbps and then use SAM Broadcaster Pro to broadcast a stream.  The SAM Broadcaster Pro software available for trial, I had to open a separate tab to see the link.  But it requires either SQL Server or MS SQL already installed to operate.    
K, just use the first option Firebird and a shareware version installs just fine.  The minimum bitrate for WMA is 20 kbps.  But, the WMA robust encoder only reveals its settings with the activated shareware version. 
Daniel L Newhouse

Re: TwinVQ

Reply #13
The way to get the gist of how XM internet radio works is to run Shoutcast into SAM Broadcaster, hypothetically.  That doesn't work.  You'd have to archive your files at 24 kbps and then use SAM Broadcaster Pro to broadcast a stream.  The SAM Broadcaster Pro software available for trial, I had to open a separate tab to see the link.  But it requires either SQL Server or MS SQL already installed to operate.    
K, just use the first option Firebird and a shareware version installs just fine.  The minimum bitrate for WMA is 20 kbps.  But, the WMA robust encoder only reveals its settings with the activated shareware version. 
With the encoder set at "aacPlusv1" you can set the output to 24, 20, or 16 kbps at a reduced sampling rate. 

With the encoder set at "aaPlusv2" you can set the output with 44.1 kHz sampling rate down to 16 kbps.
Daniel L Newhouse

Re: TwinVQ

Reply #14
Also, given that it's either car radio or internet radio now, it should be noted that the car radio version is guaranteed better than the internet radio version, therefore the internet radio version of XM won't sound better than 24 kbps mpeg-2 AAC. 

I'm making a big assumption here!  Some of the channels get bit rate bonus points past 32kbps on the satellite broadcast and may sound better over internet radio.  All they have to do is re-encode a channel with lossy audio and you are stuck with worse sound on the internet radio for those channels no matter what the bit rate.  There are 2 satellite channels at 28 kbps.  XM41 by satellite was 32kbps, btw.
Daniel L Newhouse

Re: TwinVQ

Reply #15
Also, given that it's either car radio or internet radio now, it should be noted that the car radio version is guaranteed better than the internet radio version, therefore the internet radio version of XM won't sound better than 24 kbps mpeg-2 AAC. 

I'm making a big assumption here!  Some of the channels get bit rate bonus points past 32kbps on the satellite broadcast and may sound better over internet radio.  All they have to do is re-encode a channel with lossy audio and you are stuck with worse sound on the internet radio for those channels no matter what the bit rate.  There are 2 satellite channels at 28 kbps.  XM41 by satellite was 32kbps, btw.
The mpeg4 AAC encoder adds SBR at 80  kbps and not at 84 kbps.
Daniel L Newhouse


 
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