Wednesday, January 31, 2007

using the histogram function to turn on the light

Wow. I used the histogram function to lighten up a dark video. It really did wonders. I simply changed the Value parameter as in the graphic below:

Here are the results. Before applying histogram:

After applying histogram:

Test videos:

Here are two articles on histograms and their purpose. The second taught me a great deal:

Wednesday, January 03, 2007

MediaGate MG-350HD review

Happy New Year folks! I thought I'd take a break from the usual Cinelerra-HDV talk to discuss a new toy I got for Christmas: the MediaGate MG-350HD.

Since I am in a band and am its archivist, I have a lot of audio and video files that I've created over the years. So I wanted to get a device that would playback the high-definition videos and audio I've recorded on my home theater. The MediaGate MG-350HD seemed to fit the bill as an all-in-one media player: it plays video and audio files of almost any type (no Quicktimes, though) streamed from one or more network shares via wired or wireless ethernet connection. It also plays files from an attached USB drive or hard drive you supply and can act as a network storage device. In practice, the device works well enough with its bare bones setup and media selection/playback interfaces, but needs more setup and careful installation than the shiny brochure would have you believe.

I will tailor the following discussion to technically inclined individuals who will read the MGs' manual or search google for reviews and information that has already been discussed. You can get the manual and firmware upgrades online from in the Support section. I will highlight the time consuming points for me or information about the device that is lacking in the online resources. It is best if one reads the manual first. Though the supplied manual has enough information to get the device setup and working, it is poorly written by a non-native english speaker.

For those who don't like reading manuals, my suggestion would be to simply hook it up to your TV using any of the provided composite, svideo, component or DVI connections, turn it on and press "setup" on the remote. If you don't have a picture on the TV immediately, select an alternate video mode by pressing the "TV out" button multiple times to cycle through the different options. With the remote, you control all the device configuration and media playback functions of the MediaGate.

After opening the box, I decided to configure the device in logical fashion by trying out the simpler functions and then advance to the more complicated setups:
- attach a USB drive and play files from it
* USB setup was easy and playback worked using my Corsair Voyager 2GB USB drive, though you cannot copy files to the USB drive.
- install a hard drive into the unit and play files from it
* Drive setup was also easy using an 80GB drive I had lying around and playback worked using the provided USB cable.
- connect it to my network via wired LAN connection
* Wired setup worked using DHCP after some fiddling.
- copy files to the internal hard drive using its network attached storage drivers
* works over a proprietary network protocol (NDAS) from Ximeta (
* NDAS drivers only work on Windows 98/2000/XP, but there are experimental Linux drivers on their website that I haven't yet tried.
- connect it to my wireless network
* Wireless setup worked using DHCP and access point scan (ad hoc access point attachment is also available)
* laborious WEP key input using the remote
- stream files from my main server to the MediaGate
* tricky Windows share setup was the source of a couple hours of frustration
* streaming high def content only worked using internal disk or wired connection
* dvd and lower resolution content can be streamed using wireless

Speaking of playback, here are the file formats that the MG 350HD played for me:
- DVD format MPEGs (720x480 MPEG2s with 16 bit, 48Khz stereo or MPEG1 audio) and their individual, demuxed audio/video streams
- VOB files
- MPEG2 TS (transport stream) HD files (720p)
- AVIs
- MPEG4s created by iTunes

It doesn't play:
- Quicktime videos
- WMVs (I need to test this more)
- Ogg/Theora videos

This is not an exhaustive list, but at least will give you an idea of file compatibility. Playlists of videos and music can be created from any of the attached devices and played back in order or shuffled. The interface to sort through your media and create playlists is basic at best and no where near as slick or as easy as an iPod. Since the interface is where you will be spending quite a bit of time, it is also unfortunate to note that it is not customizable or skinnable. Firmware updates come once per quarter or less frequently, so there will be a long wait for any enhancements to the interface.

SMB shares from Windows 2000 were easily recognized. For XP, you need an account named "guest", "media" or "administrator" with a blank password. This obviously creates a security hole. Also, I needed to assign Read privileges to the XP Guest account for the directories I wanted to share.

The most pain I experienced in the share setup was getting the device to recognize the SMB share I created on my Fedora Linux box. Lots of issues with this one:
- proper user authentication
* you need to use either an account named "guest", "media" or "administrator" with a blank password. Security hole on the systems with the shares
- lowering SELinux lockdowns for SAMBA
* select all options under SAMBA in the SELinux config utility
- appropriate file privileges
* chmod 755 on any files you want to play
- change the default SMB security level
* use a security level of "share" in the /etc/samba/smb.conf file

I had no trouble streaming high definition content from a network share using a wired connection. Using wireless I was only able to stream DVD resolution files (including MPGs and DIVx) as well as any music files without dropouts. Over wireless, strong signal strength is a must for playing back DVD resolution files without dropouts. If you're not playing back any files, the "info" button on the remote will show you the wireless signal strength. While playing back files, "info" will show you the specifications of the file being played back. Many of the buttons on the remote serve double duty depending on if you are in setup versus playback mode.

In sum, the MediaGate MG-350HD met my expectations and can playback an impressive array of video and audio files. The interface needs a -face lift, but the unit does a yeoman's job of serving up content. Definetly, you will need a wired connection or copy any high def media you have to an internal hard drive in order to view those on your HDTV via the MediaGate. Nice product.