mike wrote:

Random Step Forward/skip/fast forward delays win7 VLC .wtv files

Win7 Ultimate
WMC
VLC
K-Lite Codec Pack
I've been using Media Center to record/time-shift 4 TV channels.
I play them back with VLC because it allows me to increase
the playback speed to 2X.
It's been working flawlessly for several years.

Recently, Avira AV went rogue and resisted all attempts
to uninstall it. I gave up and reinstalled the OS.

Now, I have a random symptom that I can't track down.
Playing the .wtv files with VLC.
If I try to skip forward, the first skip always works.
Subsequent skips may or may not have a 10 second or
more delay. The screen is frozen and nothing happens until
the delay expires. It's similar to a buffering problem, but the CPU
activity stays low and there's no obvious increased disk
activity.
This is file related. If the .wtv has the skip delay, it always
has the skip delay. If it skips correctly, it always skips correctly.
I initially suspected a codec issue, but that shouldn't be random.
Other recordings from that session may or may not have the
symptom. The symptom is unrelated to the selected
playback speed as long as I keep it below where the hardware
can't keep up.
There's a VLC setting "fast skip" that was not enabled.
I enabled it and the problem went away...until sometime
later when it started happening again.

.wtv files recorded before the system reload have never exhibited
the symptom.
Recorded files that exhibit the symptom continue to exhibit
the system when played at a later date. All files always play/skip
without delay when played with WMC.
I've copied the files to a different partition and the problem persists,
although it's somewhat random.
Rebooting doesn't help.
Defragmenting doesn't help.
Registry cleaners and unnecessary file deleters don't help.

The files play fine and skip fine using Media Center for playback,
but I haven't found a way to increase the playback speed with WMC.
That functionality is essential.

It sounds like it's mostly related to recording, so...
I picked a TV channel and restricted recording to one tuner.
Playback skip works fine.
I cycled thru all 4 tuners and all worked fine.
Since it's random, I still can't be sure that it's not a tuner driver or
configuration issue.

I copied a bad file to a different computer and it plays/skips
correctly in VLC. Same file played across the network with VLC
doesn't seem to have the problem, but the network speed limitations
to introduce a lesser delay in the skips.

If there were a way to increase the playback speed of WMC,
that would solve my problem. That's the only reason I
use VLC for playback.

I've reloaded WMC. I've reinstalled VLC. Nothing helps.
I've not found any log issues showing an error, but maybe
I'm not looking in the right place.

Any suggestions on what I might try to diagnose this random
symptom?

WTV (Windows Recorded TV Show) is a Microsoft proprietary file format.
It is a container using MPEG-2 compression and audio uses either MPEG-1
Layer 2 or Dolby Digital AC-3 compression. It may contain metadata
along with DRM (Digital Rights Management) control. If the show
contained ads, they might use DRM to make sure you see them when you
play the show so you cannot simply skip past them. If you are recording
shows using Windows Media Center, it uses the SBE (Stream Buffer Engine)
to create the .wtv file. Because you are capturing streamed media from
a server, quality can vary wildly and what the server delivers can
change if you re-stream later. WMC can be converted back to the older
..dvr-ms proprietary format but I don't know that will progressing
forward or backward regarding quality of content or resolve your
problem. Note: Microsoft abandoned the WTV media file format which
irritated many users encouraged by WMC to create WTV files. Since WMC
was intended as the only player for WTV files, and since WMC got dropped
by Microsoft in Windows 10, it's an orphaned media format. I went to
wiki.videolan.org and search on "wtv". Looks like it hasn't even been
mentioned since 2015 (and that was only to propose a mentor, or
proponent, of the media format to add support for it).

Aside: For capturing streaming media, the best that I've found, so far,
is Jaksta or Applian Replay Media Catcher (RMC, which is just a
rebranded Jaksta) but it is payware. They still have to frequently
update it to accomdate changes at sites regarding how they are
delivering streamed content. They do take user reports about capture
problems at sites (and forward them to Jaksta who actually develops the
program). I found WMC to be lots of glitz with lacking depth. So I
also went to VLC as a player and RMC for stream capture.

Also, the granularity of sync points (where you can skip forward/back)
might be greater than you had originally if the media is being retrieved
from a server rather than downloaded and stored locally, and granularity
might change between what you downloaded before and what you download
now for the same video. I see this all the time in VLC where I set it
to loop from A to B and repeat but a large granularity means I cannot
get the loop to start and stop exactly where I want.

After doing a fresh install of Windows, did you also proceed through all
the updates for Windows and other MS programs from Microsoft's Windows
Update site? Did you update all your hardware drivers, including for
the mobo's chipset? You might've done a lot of updating in all those
years of using VLC to play WTV files that you neglected in your fresh
Windows install.

After the fresh install of Windows 7, did you test before installing the
KLite Codec Pack to retest for the problem or did you install KLite
before testing? You did not say which KLite package you installed --
Basic, Standard, Full, or Mega -- or that you installed KLite after the
fresh Windows install. Hopefully you did not install their Beta package
if you installed KLite. In the past, I had installed the Mega pack but
since backed off the Full pack (plus I do a custom install since I don't
need all products in either, like the media players). Did you let the
KLite installer use the defaults for codecs on filetype or content type
or did you change the defaults?

Oops, just remember VLC won't use any codecs installed by KLite. When
using VLC, it doesn't use *any* codec in the OS, including those you
installed by KLite. VLC uses its own private repository of codecs that
it stores under its install path rolled into one, or more, DLL files.
Did you install the latest version of VLC to make sure you got its
latest private codec libraries? Don't use an old saved download of VLC.
Get the newest version, download it, and install that version. A lot of
functionality in VLC and other free players is the use of the ffmpeg
library. At one time, ffmpeg didn't work with WTV as it was Microsoft
proprietary. ffmepg is used for playback. The codecs are snippets of
code for the algorithms needed to decode a particular media file format.

You did not mention the bitwidth of your Windows 7. There is 32- and
64-bit. You also did not mention the bitwidth of the installed VLC
program. If it doesn't say, load VLC and check in Task Manager's
Processes tab. In x64 Windows, if the process name is followed by "*32"
then it is a 32-bit program. If "*32" is missing (no bitwidth appended)
then it is a 64-bit program. I use Windows 7 x64 and VLC x64 so the
process name is just "vlc.exe" (no *32 appended qualifier) in Task
Manager's Processes tab. I only see a single "Windows" download of VLC
so they might've rolled both 32- and 64-bit versions of VLC into the
same installer but you might get a choice during the install. If so,
pick VLC x64 if you are using Windows x64.

VLC comes with some plug-ins (aka extensions). Did you install all the
default ones during its installation?

Are these copyrighted WTV files? I don't know if VLC was setup to play
copyrighted (DRM'ed) content.

WTV format's popularity is pretty low. You might want to pick a
standard media coding when saving files, if permitted, or use a
converter to get away from WTV. WMC creates some obscenely huge WTV
files so you might save a lot of space by recording the stream into a
more efficient container.

Since the problem is with playback in VLC (you never mentioned WMC had
any problems playing the WTV files), you might want to inquire over at
VLC forums about problems with that program.

https://forum.videolan.org/

Searched there on "wtv" and "dvr-ms" (do an advanced search and group by
topic so you don't end up with a long list of posts which are each one
in each thread). Looks like support was added to VLC for those formats
but the reverse engineering did not produce a wholly compatible player
for WTV. It is unclear if you are trying to stream the same or
different WTV containered media streams or trying to play downloaded and
saved .wtv files (which are the entire media content and not some
pointer to a server). Since Microsoft abandoned the WTV container
format, not likely VideoLAN will invest much, if any, resources to fix
bugs with their code to support WTV.

For example, someone noted there the delay when trying to jump forward
or backward that you noted. See:

https://forum.videolan.org/viewtopic...6626&hilit=wtv

That "sometimes" the low granularity in choosing a play position is not
clear if the behavior is evident within the same WTV file (i.e.,
sometimes there is a lag and sometimes not) or one WTV has no lag while
a different WTV file does have lag (which could be due to granularity in
sync points).

Are you doing something non-typical that you did not mention, like using
an application to watch your video card's/chip's output across multiple
monitors? I've see one user, for example, that used The Maxifier
(http://www.mods.com.au/Maxifier/) who found that setting it to "fit to
screen" worked but "full screen" caused playback problems. Apparently
WMC itself can have performance problems with multiple monitors, like
those using the Aero theme and noticing disabling transparency removed
the problems.

I'd say dump the WTV format. It's abandoned. VLC's reversed engineered
implementation doesn't look complete or bug-free. If you are trying to
capture new streamed shows, use something better for stream capture (and
NOT screen capture tools which will record any window you accidentally
open over the playback window, your mouse crossing over the video, any
jerkiness due to buffering, and hiccups in playback due to network
hiccups, etc). If you have lots of .wtv files on your computer then
look at converting them to a non-Microsoft (aka standard) format.