Is there a way to differentiate between aptx and aptx hd codec

asked 2018-06-26 17:41:36 +0000

updated 2018-06-26 17:42:53 +0000

I was trying to figure out which codec my lg g5 phone and anker soundbuds slim+ bluetooth earphones were using while transmitting audio. Both of them support aptx hd.

I captured bluetooth hci packets to a log file using my phone and opened the log file in wireshark. The earphones responded to GetCapabilities request with both sbc and aptx and the phone sent a setConfiguration to aptx which the earphone accepted and aptx audio packets started being sent henceforth.

This confirmed that aptx was being used but how would one differentiate between normal aptx and aptx hd using wireshark, even though in my case its most likely aptx hd. Couldnt find any helpul info on the wireshark aptx codec page.

Another question, roughly 60-70 aptx packets were being sent while listening to both "It's All Well Above Wonder Anyway - Grace Cathedral Park" flac(775kbps) and mp3 (233 kbps). Each aptx packet data payload was 672 bytes or 5376 bits. That would roughly equate to 5376 bits x 65 packets/sec = 349kbps. Is that estimate of bitrate correct? but that also makes me wonder why a lower bitrate mp3 was being transmitted at a higher bitrate. Although this is probably not wireshark's domain. Thanks

Screenshots

https://www.mediafire.com/view/vj9nxr...

https://www.mediafire.com/view/rvomgg...

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