IPB

Welcome Guest ( Log In | Register )

Ultra Low Bitrates (REALLY!), 22khz Mono at 16kbps
Freya
post Mar 15 2012, 10:55
Post #1





Group: Members
Posts: 7
Joined: 15-March 12
Member No.: 97816



I'm encoding at around 16kbps/24kbps in Mono at 22khz. I'm trying to achieve something like FM radio quality.
Sometimes I get close...

I've tried lame VBR with maxbitrate and more recently have tried ABR but I'm not sure the VBR wasn't better?

Does anyone have any tips on how I can improve my encodes in Lame? Should I add a highpass filter? What do others think of ABR vs VBR? I know ABR is recommended for low bitrates...

I know this is really far away from the usual Lame stuff but I hope people might be able to help a bit anyway!

love

Freya
Go to the top of the page
+Quote Post
 
Start new topic
Replies
Fedot L
post Mar 15 2012, 11:36
Post #2





Group: Members
Posts: 109
Joined: 2-January 10
Member No.: 76586



QUOTE (Freya @ Mar 15 2012, 10:55) *
I'm trying to achieve something like FM radio quality.
…Does anyone have any tips on how I can improve my encodes in Lame?

To achieve something like FM radio quality, you can code in “mp3 CBR-128 kbps”. Listened to and verified on spectrum analyzer display on music and white noise samples. FM radio frequency band is 30…15000 Hz, “mp3 CBR-128 kbps” frequency band is 30…16000 Hz. If you want to simulate FM radio sound/noise ratio for the best reception conditions too, add hiss at “minus 60 dB” relative to the 0 dB (peak) level of a program listened to.
Go to the top of the page
+Quote Post
Freya
post Mar 15 2012, 11:52
Post #3





Group: Members
Posts: 7
Joined: 15-March 12
Member No.: 97816



QUOTE (Fedot L @ Mar 15 2012, 10:36) *
QUOTE (Freya @ Mar 15 2012, 10:55) *
I'm trying to achieve something like FM radio quality.
…Does anyone have any tips on how I can improve my encodes in Lame?

To achieve something like FM radio quality, you can code in “mp3 CBR-128 kbps”. Listened to and verified on spectrum analyzer display on music and white noise samples. FM radio frequency band is 30…15000 Hz, “mp3 CBR-128 kbps” frequency band is 30…16000 Hz. If you want to simulate FM radio sound/noise ratio for the best reception conditions too, add hiss at “minus 60 dB” relative to the 0 dB (peak) level of a program listened to.


Heh heh! Love your reply Fedot! Really made me smile, especially the stuff about adding hiss! It's very tempting! You've given me all manner of ideas now!

Anyway I should be more careful about what I'm saying. The low bitrate stuff is the important bit more than emulating Fm radio, I was trying to get across some kind of abstract quality idea but now I'm actually starting to wonder about emulating short wave!

Anyway, I'm looking to improve my low bitrate encodings by quite a bit, so they can be less swirly!

Also would love to hear from anyone with experience with encoding speech content at low bitrates too but thats a bit of an aside as well!

Come on, there's got to be at least a few low bitraters out there!

love

Freya
Go to the top of the page
+Quote Post

Posts in this topic
- Freya   Ultra Low Bitrates (REALLY!)   Mar 15 2012, 10:55
- - Fedot L   QUOTE (Freya @ Mar 15 2012, 10:55) I...   Mar 15 2012, 11:36
|- - Freya   QUOTE (Fedot L @ Mar 15 2012, 10:36) QUOT...   Mar 15 2012, 11:52
|- - Porcus   For really low bitrates, you might want to check o...   Mar 15 2012, 12:07
- - KMD   If you just want to reduce the quality dont use an...   Mar 15 2012, 12:30
|- - Freya   QUOTE (KMD @ Mar 15 2012, 11:30) If you j...   Mar 15 2012, 12:47
- - forart.eu   You have to consider Stereo Tool too for mono down...   Mar 15 2012, 14:18
|- - Freya   QUOTE (forart.eu @ Mar 15 2012, 13:18) Yo...   Mar 15 2012, 15:47
- - onkl   If it doesn't need to be MP3, you should give ...   Mar 15 2012, 15:16
- - DonP   QUOTE (Freya @ Mar 15 2012, 05:55) I...   Mar 15 2012, 15:36
|- - Freya   QUOTE (DonP @ Mar 15 2012, 14:36) QUOTE (...   Mar 15 2012, 16:00
|- - DonP   QUOTE (Freya @ Mar 15 2012, 11:00) [ I...   Mar 15 2012, 16:07
- - LithosZA   QUOTE In fact it also needs to be linux and gstrea...   Mar 15 2012, 15:43
- - LithosZA   A few speech codecs that you could try: speex amrn...   Mar 15 2012, 16:01
- - Remedial Sound   Have you tried "--abr 16 -mm." with the ...   Mar 15 2012, 16:01
|- - IgorC   QUOTE (Remedial Sound @ Mar 15 2012, 12:0...   Mar 15 2012, 16:18
- - AndyH-ha   I've done many audiobooks with this. It isn...   Mar 15 2012, 20:54
- - birdie   I'd also suggest HE-AAC or even Skype's SI...   Mar 15 2012, 23:26
|- - NullC   QUOTE (birdie @ Mar 15 2012, 15:26) I...   Mar 16 2012, 04:04
- - Fedot L   QUOTE (Freya @ Mar 15 2012, 11:52) QUOTE ...   Mar 16 2012, 14:28


Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



RSS Lo-Fi Version Time is now: 30th September 2014 - 16:30