Verify whether headset supports aptX?

[yubimusubi]

I purchased a headset that claims to support aptX, but I can't verify it's working. I've enabled it in OP5 settings, and also tried restarting the phone for good measure. The manual for the headset specifies that it supports aptX, and it doesn't list any special steps to enable.

Looking at logcat and btsnoop output it seems to be negotiating SBC. I've tried playing FLAC and MP3 files with VLC, and streaming over Google Play music and it does not negotiate aptX. Has anyone else been able to confirm that aptX is working on their OP5?

I followed this answer on stackexchange and got the btsnoop logs, analyzed with WireShark. This is what I came up with:

AVDTP   25      Rcvd ResponseAccept - GetCapabilities - Audio SBC (16000 32000 44100 48000 | Mono DualChannel Stereo JointStereo | block: 4 8 12 16 | subbands: 4 8 | allocation: SNR Loudness | bitpool: 2..53)

The headset is obviously responding with SBC, but does this definitively mean the headset is refusing to support aptX, or could it be an issue with the OP5?

I can post more of the btsnoop logs or logcat if necessary.

 

[Chahk]

How would I confirm it? I see the "aptX HD" logo briefly flash on the screen whenever I start playing video or music after connecting to my LG HBS-730, but how would I know for sure? I mean it does sound better than the same media on my wife's Moto X Play.

 

[yubimusubi]

How would I confirm it? I see the "aptX HD" logo briefly flash on the screen whenever I start playing video or music after connecting to my LG HBS-730, but how would I know for sure? I mean it does sound better than the same media on my wife's Moto X Play.

If you run a logcat over adb while either connecting or playing the media (I'm not sure which) you should see some output about codec negotiation. That's probably the quickest and easiest way. The btsnoop method in the stackexchange I linked is more low level, but I was hoping to see conclusively if the device supports aptX

I've never seen an aptX logo you up on screen. Hopefully that's a reliable indicator, but I would think that would get annoying!

One more thing, my understanding is that aptX and aptX HD are two different things (someone correct me if I'm wrong), even if one is working I don't think that necessarily means the other is.

I'm probably going to return this headset if I can't prove that aptX is working for it...

 

[Chahk]

Here is the screenshot.

And here's an exert from logcat while trying to play some tune via Google Play Music app:

08-17 17:39:43.734  2880 20308 D bt_btif : btif_snd_ctrl_cmd : A2DP_CTRL_CMD_START DONE
08-17 17:39:43.734  2880  2900 D bt_btif : btif_av_state_opened_handler event:BTIF_AV_START_STREAM_REQ_EVT flags 0 and index = 0
08-17 17:39:43.734  2880  2900 I bt_btif_media: btif_a2dp_encoder_init SCMS_T DISABLED
08-17 17:39:43.734  2880  2900 E bt_btif : bta_av_select_codec hdl = 65
08-17 17:39:43.734  2880  2900 I bt_btif_media: btif_a2dp_encoder_init Selected Codec aptX
08-17 17:39:43.734  2880 20306 D bt_btif : btif_media_thread_handle_cmd : 5 BTIF_MEDIA_SBC_ENC_INIT
08-17 17:39:43.734  2880  2912 D bt_btif : AV Sevent(0x41)=0x120b(AP_START) state=3(OPEN)
08-17 17:39:43.734  2880 20306 D bt_btif : btif_media_thread_handle_cmd: BTIF_MEDIA_SBC_ENC_INIT DONE

The "Selected Codec aptX" bit makes me think it's working. There are a lot of crappy knock-off headsets that boast aptX "support" that isn't working right because they omit the profiles necessary for it to actually work. I remember reading an article a while back about this very problem, but can't seem to find the link anymore.

 

[yubimusubi]

The "Selected Codec aptX" bit makes me think it's working. There are a lot of crappy knock-off headsets that boast aptX "support" that isn't working right because they omit the profiles necessary for it to actually work. I remember reading an article a while back about this very problem, but can't seem to find the link anymore.

Ok, that logcat looks like what I was expecting to see. I agree that yours is working. Thanks!

For the record, this one *is* some cheap Chinese one I found on Amazon. The sound quality is not awful for the price, but the false advertising is unforgivable.

 

[Vlad_z]

I see aptX logo flashed on a screen after my Sennheiser HD1 got connected via Bluetooth. And I don't see that logo when using other BT headsets.