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View Full Version : TekSoft: "the MS BT stack can not be hacked to enable flawless call recording"


Menneisyys
06-10-2007, 07:53 PM
TekSoft, one of the most excellent newcomers to the Windows Mobile developer scene but already being Bluetooth experts (see for example their excellent BlueMouse and BlueMusic applications), have just announced in THIS (http://www.teksoftco.com/forum/viewtopic.php?p=2950) thread that it's, unfortunately, not possible to "hack" the Microsoft Bluetooth implementation of Windows Mobile to "capture" speech packets and record them:

"We had another attempt of making PhoneREC possible - by intercepting the voice flowing through the BT driver when a Bluetooth headset is connected:

1) when a call is established, the software would have enabled voice routing to Bluetooth headset
2) if a headset was not present, it would have been emulated (to be able to use the device without headsets with phonerec too)
3) voice data over Bluetooth would have been in the form of SCO packets
4) our software would have intercepted the SCO packets, extract the voice data, record it to a file, and play it on the device's speaker (so no need of using the headset to hear the other party in the call)

Unfortunately this failed too, as the SCO packets are handled in the hardware, so we found no way of capturing those from a software program.

The only remaining option is to use a custom made wired headset with PhoneREC. This works and assures high fidelity sound for both parties, but the phoneREC user can only record the phone call by using the special wired headset."

This is certainly very bad news for anyone not having a call recording-capable model.

For the time being, you have only few choices if you want to record your phone conversations. These are as follows:

If you want to stay with Pocket PC's, go for either the Gigabyte gSmart (http://www.pocketpcthoughts.com/forums/viewtopic.php?p=391825). According to the user comments HERE (http://www.pocketpcmag.com/blogs/index.php?blog=3&p=1931&more=1&c=1&tb=1&pb=1), the O2 Atom Exec and, HERE (http://www.pocketpcthoughts.com/forums/viewtopic.php?t=55116&postdays=0&postorder=asc&start=10), the Asus P525 and P535 are also call recording-enabled. Unfortunately, the availability of (some of) these models can be restricted (for example, it's pretty hard to get the gSmart in the non-Asian / Australian region and when it's available at all - through, for example, ordering via Expansys (http://www.expansys.com/p.aspx?i=133620) -, it is pretty expensive.)
If you prefer MS Smartphones (in the Windows Mobile 6 parlance, WM6 Standard devices) or, are ready for returning to the two-device approach (one for phone calls and basic stuff like, say, playing emulated games via SmartGear (http://www.pocketpcmag.com/blogs/index.php?s=SmartGear&sentence=AND) / MasterAll's emulators (http://www.pocketpcmag.com/blogs/index.php?s=MasterAll&sentence=AND) or quickly browsing the Web via Opera Mobile or Opera Mini, another for anything other requiring a decent Pocket PC or Smartphone), with the HTC Oxygen (HTC s310). I'm absolutely sure it DOES support call recording - it makes excellent recordings, even when a BT headset is used. Note that I have an Orange rebranded Oxygen localized to Central-Eastern Europe (I've bought mine from a Slovakian guy to keep the costs down and it has Polish / Slovakian / Hungarian localization), SPV C100. However, I don't think the original HTC Oxygen wouldn't support call recording and it's just because the given countries' allowing for call recording that my Oxygen supports it. (To make sure HTC supports it in the "basic", non-localized models, I couldn't reflash it to a generic HTC ROM discussed HERE (http://forum.xda-developers.com/showthread.php?t=282538) because there are no CID unlocking solutions (http://forum.xda-developers.com/showthread.php?t=307966) for the model.)

Note that some? many? other Smartphone models do NOT support call recording. One of them, unfortunately, is the HTC Vox (s710), which is by far the best Smartphone available today. It does not, I repeat, NOT support recording the other party and yes, I've tested this VERY thoroughly.
If you don't want to get the above-listed PPC / Smartphone models but is ready to keep a non-Windows Mobile phone with you, you may want to read for example THIS (http://www.pocketpcmag.com/blogs/index.php?blog=3&p=1931&more=1&c=1&tb=1&pb=1) article on the Symbian alternatives and what call recorder applications the platform has. Note that UIQ-based Sony-Ericsson phones, according to this thread (http://www.pocketpcthoughts.com/forums/viewtopic.php?t=55116&postdays=0&postorder=asc&start=10), aren't capable of recording calls, only Nokia models. Also note that it's not with ALL Nokia models that you can get rid of the constant beeping.

If Symbian isn't your favorite, you may want to stick to "dumb" phones like the (Sony-)Ericsson t610/t618 (and, probably, later models). If you assign the call recording functionality to be started by quickly pushing the joystick to the left, you can easily emulate the (missing) auto-recording functionality. Unfortunately, the t610 doesn't support saving the other party's number / name along with the recording, unlike the call recording-capable predecessors of the t610. An example of the latter are the t68(i) and the, now, seven-year-old r520m. Note that the latter only supports recording one party and the former, while it stores both the timestamp and the other party's identity, doesn't let for transferring these recordings to anything via a cabled / IR / BT connection - that is, the recordings must be played back on the t68(i). Furthermore, on the t68(i), it takes slightly more button presses to start recording (there are no auto-recording capabilities either), unlike on the successor, the t610.

Siemens' old "dumb" models (for example, the SL-45) are also stated to be able to make flawless recordings. I don't know whether it's easy to make them automatic, whether the recordings are correctly timestamped or whether the other party's number / name is also stored along with the recording.
Finally, if always switching your phone to speakerphone mode is OK with you (and your environment: co-workers / family members etc.) and you never use wired / Bluetooth headsets (which would make recordings entirely impossible), make sure you always do so. It'll deliver definitely worse recording quality than recording with a phone that does support recording, but is still better than in the non-speakerphone mode. Note that if you need automatic speakerphone activation (as opposed to the manual one), you'll want to take a closer look at VITO AudioNotes (http://www.pocketpcmag.com/blogs/index.php?blog=3&p=1998&more=1&c=1&tb=1&pb=1) - currently, it's the only audio / call recorder application to support auto speakerphone activation (and is, in general, an excellent call recorder for both the Pocket PC and the Smartphone).

Please DO read my related articles for more information on all these questions; they may answer all your questions.

Windows Mobile device manufacturers & Microsoft, we DO need phone recording capabilities! (http://www.pocketpcmag.com/blogs/index.php?blog=3&p=1931&more=1&c=1&tb=1&pb=1)

Review: decent phone call (!) / note / MP3 recorder VITO AudioNotes 1.3 out! (http://www.pocketpcmag.com/blogs/index.php?blog=3&p=1998&more=1&c=1&tb=1&pb=1)

How can I record phone conversations on my Pocket PC Phone Edition device? (http://www.pocketpcmag.com/blogs/index.php?blog=3&p=513&more=1&c=1&tb=1&pb=1)