How-Tos

How To Use Amped DVRConv To Quickly Convert And Make Playable Proprietary CCTV Video

by Blake Sawyer, Amped Software

When I worked for the police department, I was constantly pulled in a lot of different directions. To keep a good turnaround time for the nearly 200 requests we had each month, I was constantly looking for tools to automate or ease the load. Amped FIVE was a great resource for most of my daily tasks and managed the entire video evidence workflow. With it I could create lossless playable versions of a proprietary CCTV video, generate stills for a bulletin, clarify details such as logos or license plates, and conduct comparative analysis.

But a lot of the time, the detective or light duty officer just wanted to review the video to see if the event matched the witness testimony. With over 300,000 residents there was no lack of new CCTV or proprietary formats that would come in. To keep our forensic computers free to conduct the more intensive work, we found and implemented a few dedicated machines for conversions using Amped DVRConv.

Using DVRConv, we could prevent ourselves from having to install dangerous proprietary players, in a way that was easy to play back in VLC or SMPlayer. Most critically, DVRConv can create playable files that retain all the original pixel information, which is critical for future work, should it be needed. Below is the quick and easy way to set it up to get great, quick results.

One of the first things you’ll notice is how simplified the DVRConv interface is. Once installed, DVRConv’s default settings will cover maybe 80% of your needs. You can simply drag and drop files into the big white box, and DVRConv will be off and running.

For those who are wondering what is happening in the background, unlike some other tools, there is no mystery. Simply going to the Console Log allows you to see exactly what tools and processes were employed.

In addition, there is a lot of customization that can be done from within the settings. Here are some of the options available.

The very first thing I wanted to point out is in the second tab: Folders.

In addition to dragging and dropping the files into DVRConv, you can also add them to the Input Folder. Often, I will leave the DVRConv Input Folder on the desktop, and then put the Output Folder in another location or on a storage drive. This way I can easily add files to DVRConv, and don’t keep a lot of excess on my desktop. I like to keep things organized, and DVRConv does a great job keeping things in order. Not only can I keep all my Output Files contained in one folder, but I can also add folders to the Input Folder and have the folder structure be retained in the Output Folder.

All of that is great, and super helpful to get the day-to-day files in and out, but the real power of DVRConv is in the Video Options.

The first thing to notice is the preset options. These set the conversion type, output format, and video codec automatically. By default, DVRConv is set to AVI – Copy Stream if Possible. This option carves the video stream out of a proprietary filetype and puts it into an AVI container. I tend to move this option to MKV – Copy Stream if Possible for a couple reasons. 

  1. It allows me to quickly find the converted video, as many proprietary videos claim to use an AVI container, but few use MKV.
  2. MKV is a more forgiving format for these stripped video streams. It is recognized by Windows Media Player, VLC and most video players.

Copy Stream if Possible, or else Transcode is the conversion type I tend to keep as much as possible. It breaks the process down into two sections.  Copy Stream if Possible allows the video to just be put in a new container whenever that is an option. This will not change the pixel information in the video for those who may have to testify about a video or send it to be analyzed later.

The “or else Transcode” part of the option comes into play if you run into a truly proprietary video codec that cannot be converted. This uses the information we have learned from hundreds of codecs to convert the video into a playable codec, that is decided by you and can be changed based on the terminal and intention. If you are looking to convert the video into something that just needs to be reviewed and played everywhere, the default H264 should suffice. For videos that will need to be analyzed later, or where you need to make sure every pixel is exactly copied, Raw (Uncompressed) is your friend. This takes a full picture of every frame and saves it for you to review. The downside is that these files can be VERY large, and multiple GB per file is not uncommon.

One other piece of media I commonly deal with is audio. DVRConv also is set up to deal with audio. You can set the audio the same way you do with video. It can copy an audio channel, or convert the audio channel if you need it in a more playable codec. There is also an option in Audio Codec to ignore audio, but for evidentiary review, I wouldn’t recommend ignoring evidence. 

The other Audio option is Separate Audio Stream, to separate audio from the video. I know some departments use this extensively when they need to redact audio from the video, or if they need to work on the audio separately from the video (possibly for clarifications).

Two new settings I wanted to mention are Change Output Frame Rate and Generate Input File Info, which have been added in the latest release.

Because most proprietary videos do not encode their frame rate the way it is done in a standard container, there are times when DVRConv cannot parse the frame rate from the container or video stream. When that happens, it places a default frame rate that is usually generated by FFmpeg, one of the conversion engines within DVRConv. DVRConv has added a way to account for that by making an optional Output Frame Rate. If DVRConv doesn’t find a valid frame rate, DVRConv can replace it with one you choose.

The other new setting is Generate Input File Info. This will give you the container and stream information from the video, so you can have a log of what was received. This is a great tool for discovery or to help add some data for file validation.

As you can see, DVRConv is a really powerful program, hidden inside a clean, simplified interface. DVRConv is like the goalie for a water polo team. A lot happening below the water, but everything seems calm from the surface. So many times, I had a person shocked when they came into my office after struggling with a video for hours only for me to have it ready for them after about five minutes. It meant that the next time, they would just bring it straight to me, and eventually to the other two people we had to hire to help. 

Find out more about Amped DVRConv.

About Scar de Courcier

Scar de Courcier is Senior Editor at Forensic Focus.

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