PART THREE - Audio Playback
For most of the files you will download at the moment you will be able
to play the audio. However, with some of the more advanced containers,
new audio codecs and other developments you may find you have a file in
which you have video but no audio. If this happens you should find out
what the audio stream is and see if you can download a codec for it.
Common examples are listed below.
AVIcodec can detect what
audio stream the file has so load your file into that and find the
audio type. If it doesn't match any of the types listed below then try
searching for it on
google and
see if that helps.
FFDShow
can decode a lot of audio types as well as video types so run the Audio
Configuration link in the start menu to configure any audio codecs you
may be missing. Remember too that
VLC media player does all its
own decoding so it may support the audio and save you the trouble of
finding a DirectShow filter for it.
AAC - This can be played with FFDShow but CoreAAC and 3ivx are also aac
decoders.
AC3 - This can be played with FFDShow. AC3Filter is also a very
good option for Direct Show players. Commercial DVD players can also
play AC3 audio.
DTS - FFDShow can decode DTS audio.
OGG - This needs the Ogg Vorbis direct show filters
installed.
FLAC - The Free Lossless Audio Codec. FFDShow
contains FLAC decoding support as do these filters that support
FLAC and OGG.
WMA - Windows Media Audio - requires the same support as
Windows Media Video above.
PART FOUR - Troubleshooting
Even with all this help, things can go wrong. This troubleshooting
section is going to be written as a Q&A. I'll post as many things
now as I can think of and add to them later if people still have
problems after reading this page. Remember folks, use
AVIcodec to find out information
about your file. If for some reason it doesn't work, try
GSpot which does the same
thing.
1)
"I found out the
format and codec, followed the instructions but my media player still
wont play it"
Did you configure the filter or codec correctly? With codecs like 3vix,
FFDShow, DivX and so on you can configure these codecs either using a
link in the Start Menu or via the decoder properties list in your media
player.
2)
"OK something I
don't want is doing the decoding instead of my preferred filter - how
do I change this?"
Even though you have something installed, a different filter could have
been configured to play this content instead of the one you want.
Generally the way to handle this is to uninstall the things that you
don't want to play your content and then install the things you do.
However, sometimes it's not as easy as this so instead you need to
change the DirectShow Filter Priority.
Many different filters can be listed as things that can decode certain
content so if you want to make sure that a certain thing does the
decoding you have to make sure that it has the highest merit. To do
this, download the
DirectShow
Filter Manager and run it. Click and sort the merit section and you
will see the filters in order of priority, Find the offending filter,
note its merit, find the filter you prefer and make its merit a number
higher than the one currently doing the decoding.
Not a very neat interface, I know, but it's the only suitable free
program that I know about at the
moment. If anyone else knows of a more user-friendly system please get
in touch.
3)
"The video plays but really
lags a lot."
This could be all sorts of things. It might be lagging
because the media player you use takes up a lot of system resources
(such as Windows Media Player 9/10). It might also be lagging because
the
filter that is being used isn't actually very good at decoding that
content. See the questions 1 and 2 for more information about what
decodes what.
However, the most common reason for this is that the filter being used
needs more processor power than your computer can give it. This is
sometimes because the video is high bitrate with a large frame size or
because the video has a lot of complicated encoding options like
b-frames, qpel, gmc and so on and all of this makes it harder to
decode. This sounds like there's nothing you can do to help but
actually that's not always true. Not all decoder filters are created
equal. FFDShow is much faster at decoding divx content than the DivX
decoder is. - especially if you select the option "use overlay mixer"
in the Output part of the FFDShow configuration. Also, you may have
Post Processing options enabled so you
should configure your filter to disable those if you are having
problems with lag.
There are also some codecs that you may never be able to play real-time
as they are not designed for it. Lossless storage formats, for example,
are not designed for quick playback and you shouldn't expect it when
playing these files.
4)
"I have and avi
file that I can play in Media Player Classic but I cannot seek with it"
This sounds like a file that has not completed
downloading fully and hence does not have its keyframe index. AVI files
store their index at the end of the file which means that sometimes it
can be difficult to play the file without it. However, all is not lost.
You can use
VirtualDub to
re-index an avi file. There are instructions on how to perform this
operation in the program's help file.
5)
"I have a file
that says it is a certain codec but I know that it's not, can I change
this?"
I won't ask how you know that it's labelled as the wrong codec but it's
not impossible. The thing that identifies a codec is it's FourCC (Four
Character
Codec). Typical FourCCs are things like DIV5 (DivX 5). FourCCs are easy
to change, you can download a FourCC changer on the download page on
the
Doom9 website.
6)
"Every time I
select a file in windows, explorer crashes!!"
Some codecs do not co-exist happily with the media preview options in
newer
Windows operating systems. The only solution to this is to turn off the
preview feature in your folder options. Do you really need that things
slowing down your file browsing anyway?
7)
"Every time I
click a file to download it, a media player wants to play it instead"
This is to do with MIME settings. Websites often say
what kind of content a file is and many web browsers are configured to
do certain things when they receive certain content types. Sometimes
you can configure this, sometimes you can't - it depends on many
factors. If you can, always "right-click to save as..." instead of
left-clicking.
1) Is it something you can configure in the
browser?
In Firefox, each content type is listed as a plugin
in the Tools > Options > Downloads > File Types >
Plug-Ins... menu. You can disable these MIME plug-ins as you see fit.
You can also specify the default action for specific file types around
here too.
In Internet Explorer things aren't so easy. One trick is to click the
Media button to bring up the media side menu. Now click the Media
Options and deselect Settings > Play web media in the bar. That
sometimes fixes things.
2) Is it the media player being intrusive?
Some media players try and force MIME settings,
such
as Quicktime. Go into the player settings and see if you can disable
anything to do with playing this kind of content from the web.
8)
"Every time I play a DivX file I get the DivX logo - what's up with
that?"
If you are using the DivX decoder for your divx content instead of
FFDShow then this will happen by default. You can stop this by going to
your
start menu > DivX > DivX Codec > DivX Decoder Configuration
Utility. On the Quality Settings check "Disable Logo". This will need
to be done after each time you install the DivX codec.
9)
"Is there any way I can get things to look less blocky during playback?"
Yes, this is called Post-processing and many decoders have these
options
in their configuration settings. FFDShow has a number of
post-processor options - choosing the "mplayer" option will give the
best results IHMO. If
there is an option for automatic quality control in your decoder then
select it as it
will turn off the post-processor if it would take up too much cpu power
to use it for a certain scene.
Credits
Thanks to all those who have offered feedback on this guide. As with
all technologies, things are constantly changing so if any of this
information becomes out of date be sure to let me know. Likewise as we
are all human any corrections, problems, comments, additions or
whatever are appreciated so please email them to me:
ian at
absolutedestiny dot org.