FranceBB
2nd April 2021, 13:54
Hi there,
although I'm very familiar with normal audio codecs like AAC, AC3, AC4, Opus, PCM, Vorbis etc, I'm not really familiar with bluetooth codecs.
Here is the thing, when I connect my bluetooth headsets, the computer is asking me which codec to use among the following using the A2DP Sink:
- SBC
- AAC
- aptX
- aptX HD
- LDAC
It doesn't specify anything like bitrate, sample rate, bit depth etc, so I have no idea about the specs, which annoys me... a lot.
Doing a bit of research, it looks like all of the support the output of my sound card setting, so 48'000Hz passthrough (with 44100Hz resampled automatically to 48kHz), however not all of them support 32bit (which is my output).
If I got that right, it should be:
SBC: 16bit 48'000Hz 345kbit/s CBR 2ch Stereo
aptx: 16bit 48'000Hz 384kbit/s CBR 2ch Stereo
aptX HD: 24bit 48'000Hz 576kbit/s CBR 2ch Stereo
LDAC: 32bit 48'000Hz 990kbit/s CBR 2ch Stereo
So, although I don't know the codec implementation, what's their psycho-acoustic, which transform they use etc, it looks like LDAC is the clear winner here as it's the only one that can actually output a 32bit precision stream. I also gladly noticed that it uses a modified version of the classic DCT, so it looks good. I actually tried to listen to those codecs myself and although I wasn't able to hear any difference between aptX HD and LDAC while playing AAC radio stations like BBC Radio 1 or Capital London or YouTube Music, but I was able to hear the difference while playing commercially available PCM files from CDs. So... should I just pick LDAC and go ahead with it?
I'm sorry for all those questions but I'm really not familiar with bluetooth codecs...
although I'm very familiar with normal audio codecs like AAC, AC3, AC4, Opus, PCM, Vorbis etc, I'm not really familiar with bluetooth codecs.
Here is the thing, when I connect my bluetooth headsets, the computer is asking me which codec to use among the following using the A2DP Sink:
- SBC
- AAC
- aptX
- aptX HD
- LDAC
It doesn't specify anything like bitrate, sample rate, bit depth etc, so I have no idea about the specs, which annoys me... a lot.
Doing a bit of research, it looks like all of the support the output of my sound card setting, so 48'000Hz passthrough (with 44100Hz resampled automatically to 48kHz), however not all of them support 32bit (which is my output).
If I got that right, it should be:
SBC: 16bit 48'000Hz 345kbit/s CBR 2ch Stereo
aptx: 16bit 48'000Hz 384kbit/s CBR 2ch Stereo
aptX HD: 24bit 48'000Hz 576kbit/s CBR 2ch Stereo
LDAC: 32bit 48'000Hz 990kbit/s CBR 2ch Stereo
So, although I don't know the codec implementation, what's their psycho-acoustic, which transform they use etc, it looks like LDAC is the clear winner here as it's the only one that can actually output a 32bit precision stream. I also gladly noticed that it uses a modified version of the classic DCT, so it looks good. I actually tried to listen to those codecs myself and although I wasn't able to hear any difference between aptX HD and LDAC while playing AAC radio stations like BBC Radio 1 or Capital London or YouTube Music, but I was able to hear the difference while playing commercially available PCM files from CDs. So... should I just pick LDAC and go ahead with it?
I'm sorry for all those questions but I'm really not familiar with bluetooth codecs...