Anything listed in RED is to be removed
from the guide and is only there for a reference.
Encode DivX Videos for the PocketPC
Guide by Dan “BetaBoy” Marlin
Revision v2.0
With this guide we hope to help you learn how to encode DivX videos for use
with the Pocket DivX Player on all PocketPC (PPC) devices.
Please note: When encoding you must take into consideration the
specific PPC device that you are encoding too for playback. A DivX Video that
is encoded for one PocketPC device may not play properly on another PPC device.
|
What you will need: |
|
· Compatible PocketPC Device · Pocket
DivX Player http://www.projectmayo.com/projects/detail.php?projectId=9 · DivX
Codec http://www.divx.com/download/downloadlist.php?typeid=1 · VirtualDub http://www.virtualdub.org · MPEG Layer-3
Codec |
Let’s Begin:
Start VirtualDub. Choose File | Open video file and open the video you
want to encode.
images/vdub1.gif
Next, set audio to full Processing by choosing:
Audio | Full Processing Mode
images/audiofull.gif
Also make sure video is set to full Processing
as well by choosing:
Video | Full Processing Mode
images/videofull.gif
Audio:
Before we
encode… The Pocket DivX Player will play either stereo or mono audio and is
using the MAD MP3 decoder library. The Play list editor is very handy in
creating a series of songs and videos to play at once.
Now we want to configure how the audio is compressed in the video.
So next go to Audio | Compression. If the MP3 codec is
installed, Select 'MPEG Layer-3'.
images/acompression.gif
* For the profiles
listed in the video section below. We suggest audio at 32kbps at 22khz Mono. Though you can try to encode at higher
bitrates or try a stereo setting and work your way back down if audio begins to
skip during playback after encoding. But we have done the testing already for
you and found that the settings above have been a perfect match for almost all
PPC devices.
Video:
Next
we are going to go to Video | Compression
images/vcompression.gif
Select the video Compression menu and select 'DivX Codec’. Press Configure to setup the codec options. But, hold on…
Here is where you have to STOP…. And truly think
about what PPC platform you are going to encode to and possibly any other
potential people on other PPC platforms that will see the video as well.
Note: You
must also think about possibly encoding your video pre-rotated (90˚)
without using the "rotate" mode within the Pocket DivX Player, which
is slower and takes up resources. Fortunately for those you have an IPAQ this
is not and issue but for almost all other PPCs, encoding a video pre-rotated
will perform better than using the rotate option. To pre-rotate a video in
virtualdub you must use a filter. This is discussed further on down in the
guide.
Here are the three different profiles we
suggest you encode too.
Low
Quality
Devices: All PPC platforms
Settings: 160X120 15fps 100 kbps
Audio*
(see Below)
Medium
Quality
Devices: IPAQ, E100, E10x, E125, EM500, HP720, ARM devices
Settings: 320x(176/240) 10 fps 100-150 kbps
or
160X120 24fps full screen cleaned 100-150 kbps
Audio*
(see Below)
High Quality
Devices: IPAQ, E125, EM500, HP720, ARM devices
Settings: 320X(176/240) 24fps 250 kbps
or
160X120 24fps full screen cleaned 200-250 kbps
Audio*
(see Below)
Though it is NOT mandated that you use one of
the profiles listed above. Remember that if you are going to use a different
resolution, that you’re cropping and aspect ratios are divisible by multiples
of 16x. For example: 320x176 for 16x9 (1.78:1). 320x128 videos crop from 2.35:1
to 2.5:1
Once you choose the profile you want to use,
let’s configure the codec settings.
Encoding:
2-Pass Explained
In
the codec parameters box, we have several encoding methods in which to choose
from. We suggest for optimal quality and file size that you use 2-Pass
encoding. This encoding process is done just like it suggests, in 2 parts. The
first pass analyzes the video and creates a log file. Then you do the second
pass that actually will do the encoding from the log file that was created from
the first pass.
Note: Don’t mess with
quantizers in 2-pass mode as the codec will use quantizers of its own,
according to complexity of the frame, average complexity, average quantizer,
set bitrate, etc Changing the parameters to anything else than defaults (shown
below) will have an effect on
the 2nd pass. So as a result your frame
complexity values are not precise.
Also… For
those that are going to ask… “How do I do 2 passes at once in VirtualDub?”. We
have already created a guide just for you called ”How to Encode 2pass VBR with DivX™ 4.0 Using VirtualDub's
Job Control http://www.divx.com/support/guides/2pass_vbr.php?cid=2&gid=4”. It’s easy enough so
that you can incorporate the ‘job control’ into this guide too.
Encoding: 2-Pass,
first pass:
To begin we choose from the General Parameters |
Variable bitrate mode pulldown menu, choose 2-Pass, first pass
images/2pass1.gif
Next you put “performance/quality” to Slowest.
The next setting is your ‘Output video bitstream’. This
will be the bitrate setting you have chosen from the VIDEO PROFILE above.
Either:
Low
Quality: 100 kbps
Medium Quality: 100-150 kbps
High Quality: 250 kbps
Need more
help with these settings? Is your video not coming out like you would like?
Then try looking at what others have suggested works best for them here in our
forums:
http://www.divx.com/forums/viewtopic.php?topic=17455&forum=5
Once you have set you Codec settings for the first pass, choose OK to close the configuration box.
Encoding:
Filters
Next we have to set a resize filter and the FPS (frames per
second) via decimating for the PPC device you are encoding to based upon the
profile you have chosen.
Note: Why decimate the framerate? Because it is
the best way to lower the file size. Also note that though it’s not shown in
the guide that if your video has top and bottom black bars you must add
additional cropping and resizing filters. As the bars compress poorly. Plus it
simply looks better ;-)
To resize the video, go to Video | Filters | Add and select Resize and hit OK:
images/addfilter.gif
Next in the width and height fields choose from your
profile. Either:
Low Quality: 160X120
Medium Quality: 320x(176/240) or 160X120
High Quality: 320X(176/240)
images/resize.gif
After you have added your dimensions, from the ‘filter mode’ pull
down menu choose the Bicubic filter for the best video
quality. If you want to see a preview of what the video is going to look like and
to make sure the dimensions are correct, press the 'Show Preview' button. Make
any changes to the width and height if necessary. Press Ok to close the ‘resize’ box.
Now it’s decision time. Do you want to pre-rotate the video? If so
you need to add a filter to do this. Scroll down the ‘add filter’ menu and
highlight ‘rotate’ and press OK.
images/rotate.gif
When the ‘filter: rotate box’ comes up. Choose the appropriate
rotation that you want to use and press OK to add the filter.
Now press OK again to close the ‘Filters’ box which will now list the
filter(s) you have just added.
Next we have to adjust the frame rate (FPS) by decimating. So go to Video | Frame Rate.
images/framerate_menu.gif
In the middle of the frame rate control box is the “frame rate
decimation’ area. Choose Process every other frame (decimate by 2) and press OK
images/framerate.gif
That’s it for the ‘2-pass first pass’ so go to File |
Save as AVI select a filename and a location to store the ‘dummy’ video. This may
take several minutes to hours depending on the video to be analyzed.
images/saveas.gif
Encoding: 2-Pass, second pass:
Remember we still have to do a ‘Save as Avi’ one more time before
our video is complete. Once the first pass is completed it’s time to do the
second pass so go to:
Video | Compression | Choose DivX Codec | Press
Configure
From the General Parameters | Variable bitrate
mode pulldown menu,
choose 2-Pass,
second pass and make sure that the bitrate that you chose for use in
the first pass is in the ‘Output Video bitstream box’ for the second pass as
well. Meaning either:
Low
Quality: 100 kbps
Medium Quality: 100-150 kbps
High Quality: 250 kbps
images/2pass2.gif
Now finally all
you have to do is press OK to close the ‘Codec
Configuration’ box and go to File | Save AVI for the second time
select a filename and where to store the video to begin the final encoding
process.
This may take several minutes to several hours
depending on the content that is being encoded and the settings used. After it
is completed check the quality of the video on your device and see if it plays
as you would like.
Now put together a play list and enjoy the
show!