Has the CCTV video evidence been converted to DVD-VIDEO?

DVDinawindow-analoguematerial

Video tape recording converted to DVD-Video

It appears to have become common practice to convert CCTV video evidence to the DVD-Video format.

Why should Solicitors and courts care?

Our CCTV Analysis has shown that there can be issues with the quality of the conversion of the original material to DVD-Video in respect of image quality and it not always being a faithful representation of all the originally  recorded images.

Apart from the quality and veracity of the content it is unlikely that the Compilation DVD will  contain all of the material seized and you may possess information that requires additional images to be viewed.

See my previous article on the problems with using the DVD-Video format for evidential material. Click here

What to look for.

Here are some indicators to help you tell if the CCTV evidence has been re-formatted to the DVD-Video format;

  • The disc may be identified with an easy to see DVD-R or DVD+R text or logo, not a definitive test but enough to suggest that the material needs further examination.

    DVD+R disc

    Look for disc markings

  • When you insert the DVD into your computer either a window opens with options to play the DVD using one of your installed software players or one of those players automatically opens.
    pop up window when disc inserted

    Pop up window

     

  • Once the software player is open you may see a menu which might provide some information about the content of the video and who created it. The menu will also contain text or small thumbnails which act as buttons that allow you to select which video to play. Some DVD-videos do not have a menu and the video images play straightaway. – See more at: https://demux.co.uk/blog/category/dvd/#sthash.VhNJQScG.dpuf

    DVD Menu Screens

    Selection of DVD menu screens

  • With the video playing there are likely to be visual clues such as;
    • There might be a wide border, typically black, around the video.
    • The images may show the video playing in another player that you are unable to control.
    • The camera view may change suddenly indicating that the video may have been created as a compilation of views to show the images that best support the editors point.
    • Some of the text around the image such as the date and time may be blurred, imagine what the conversion has done to the image detail.
  • Using your computer explore the contents of the disc in the same way you would folders on your hard drive, if you find a folder entitled VIDEO_TS and it contains files with the extensions .IFO, .BUP & .VOB you have a DVD-Video.

What to do next?

If you want to ensure that you have all of the recorded images at the best possible quality and the CCTV system uses a Digital Video Recorder (DVR) you should request a bit for bit copy of the original material or if the system is tape based you will require access to the original master video tape recording.

Or if you prefer you can send the material to us together with copies of relevant case papers and we will carry out an Initial Assessment and provide a report on its suitability for analysis or as a format for presenting the evidence.

CCTV DVR

Comments

  1. If CCTV footage is Mastered onto DVD, for the purpose of distributing to prosecution and defence teams, would there be any reason to then reformat it into an alternative file format – such as .avi, .mpeg-4, etc. – or would all copies be DVD also? It seems unlikely and unnecessary for this to be done, as DVD is pretty universal.
    If it were to be done, surely one would have to go back txt orogfl filet CCTV to “remaster it”. Is this so?

    • Hello Simon, by “Mastered” I assume you mean the CCTV video is converted to the DVD-Video format. Apart from the legal professionals and the court probably having having access to a DVD player so can therefore play a DVD there is no technical reason or benefit to use that format. In fact it is a backward step which will change the images. The DVD format uses lossy compression and has a fixed frame rate and frame size none of which are useful when presenting evidence. The aim should always be to provide the material in its native form or in a lossless format. These files could be copied to a Data-DVD for distribution but they wouldn’t probably play in the vast majority of DVD Players hence this article.

      There could be an argument to use the DVD-Video format strictly for presentation of material from multiple sources or when DVD authoring features such as Menus are required but this would specifically be for an overview of the evidence and with the proviso that the images have been altered. The original CCTV recordings should always be available to the prosecution, defence and the court.

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