[HD2 General] curiousGeorge:
For the lazy reader:

Your HD2 probably suffers from an audio lag using the default media players. This is evident in the transformers movies and many other videos. You just may not have noticed it for a variety of reasons. There is no fix yet.

Coreplayer/TCPMP are not solutions, since they defeat the purpose of proper HW scaling and decoding for battery life/processor utilization. They also render the video improperly (bad scaling, colorspaces, etc), and Coreplayer doesn't even support AAC+ (HE-AAC) audio.

BACKSTORY

The first day I got my HD2 from TMOUS, I noticed that the included Transformers videos suffered from what appeared to be close to a 250ms audio delay. Sure enough, the problem was universal to all video files unless an artificial delay is introduced into the transcoding process. This means that every video file placed on the device will play back with the audio playing up to 250ms (about 1/4 second) late. This turned out to be a very common problem with the HTC HD2 and many devices seem to suffer from it (including some other HTC devices mentioned in this thread), particularly in video playback. This is a not a placebo effect and is very noticeable--in some videos/scenes more than others due to video pacing.

Before you post to say "Mine doesn't seem to do it," read the following and check again just in case--you'll be surprised. As I mention below, to some people with untrained eyes, even a 250ms delay (about 1/4 second) isn't very noticeable, and without careful attention, the mind can sometimes be tricked into thinking the delay somehow "isn't real." The proof? Testimony of many members (read this thread), and of course: Here's a video of me playing the new test clip below.

This problem is well known and is often referred to as a "video sync" or "lip sync" problem. All seem to describe this problem in which the audio ends up getting significantly delayed.

STATUS

A list summarizing the current understanding of the situation.

1. The audio lag is up to 250ms (100-250ms) for ANY a/v stream. Please understand that the duration of 250ms is 1/4 of a single second; in some slow scenes (or even slow speech), this problem is very difficult to detect. However, in any very fast scenes or speech, it should become strikingly and painfully apparent to even the most callous of observers.

2. It does appear that a minority of HD2 users insist they are completely unaffected by the problem, and they are very vocal about it. This does introduce the possibility that, in fact, contrary to all common sense, there may be differences in HD2 hardware that are quite elusive. Alternatively, there is some yet-undiscovered combination of settings, roms, and drivers in which this problem disappears. More likely in many cases is the possibility that the issue is simply difficult to spot in some people's chosen sample footage.

3. HTC has acknowledged the problem in some form but is doing nothing about it, either because of development cost (software issue) or hardware issues. Again, there is also the possibility that there are other factors tying the company's hands.

4. In theoretical terms, the class 2 SD card read speed is more than sufficient to maintain sustained data flow of, for instance, a 300kbps audio/video stream. However, the delay issue persists even with the smallest of encodes, and even when the files are placed in the phone's built-in memory.

5. The Snapdragon chipset itself has been repeatedly implicated as being the culprit behind the A/V delay. Other potential candidates include driver issues, ROM issues, and/or general software issues on the part of HTC.

6. It is absolutely not a codec issue. This is not speculation or conjecture, but certainty. There is an overwhelming amount of evidence to support this, including the use of different players and encoders that produce valid streams--which play back perfectly in sync on any other computer or device. If there is any software you are using that you claim "doesn't get lag," you either do not experience lag/delay issues on your device, or the software is introducing opposite audio delay to compensate, which isn't a solution at all. The latter is known to occur with some community-produced frontends specifically for the HD2 as a crude workaround for this issue. However, it is hardly necessary to stress that the dilemma of not only re-encoding every existing media file for the HD2, but also the obvious lunacy of producing invalid files specifically so this device can read them.

7. The issue is ROM-independent. Cooked and stocked ROMs produce identical results. However, some users report a slight decrease in delay when they disable processor scaling (i.e. lock the device near 1ghz).

WHAT YOU CAN DO

First, decisively determine whether or not your device has this problem, which a large number of HD2 units seem to have. To test this, play this video (or others mentioned in this thread) on your HD2 in Windows Media Player or the HTC Video Player. Also try the included Transformers movie if you have a TMOUS unit. If you have any other media players on the device, you may also play these clips in those players with default settings. Note that all of these files are properly encoded and exhibit no audio lag when played using a computer or other device (including the original HTC HD). Report your findings, along with your OS version, ROM version, radio version, and model of HD2 (i.e. TMOUS or "European"). Also indicate your purchase date or, if known, the date of manufacture.

Secondly, once you've confirmed you have the issue, contact HTC and issue a report/complaint (in other words, request that they fix the problem). To support your complaint, you may refer to some of the ticket numbers at the bottom of this post, which are relevant to this issue. Once your complaint is filed, post the complaint ticket number here. It is crucial that HTC understands the prevalence of this problem or they will not fix it.

Finally, propose a solution (optional). If you manage to change device settings or install software/drivers/tweaks to eliminate the issue device-wide without destroying the file's actual synchronization (i.e. it remains in sync on the computer, other devices, etc), please post what you did! Please, no touting random 3rd party "converters" unless you understand the approach used by these to escape this sync/lag issue.

Ticket numbers (HTC Support)

10GBCW02ENA001052

10GBCW12ENA000301

10USCW13ENA001524

10GBCW12ENA000421

10AUCW15ENA000117

10GBCW13ENA000299

10ZACW16ENA000014 (HTC's acknowledgment)

Further Reading

http://xdaforums.com/showthread.php?t=612935

http://xdaforums.com/showthread.php?t=617163

Another test video. This was the default test clip until I replaced it with my own above.