Save740

Even years after its release and though there is no more official entry in the product list on the Siemens homepage today, the Gigaset M740 AV is still one of the most interesting receivers available for digital, terrestrial television using DVB-T: twin receiver, two USB ports for connecting external hard disk drives for recording, a 100 MBit fast ethernet port and support for recording to Windows network shares using the SMB protocol. Personally, I use a Network Attached Storage (NAS), namely a 250 GB Buffalo LinkStation. Even though this might sound like a dream team, the box suffers from sluggish behaviour, rare visual glitches due to unsteady reception and, sometimes, aborted recordings. Features like the Electronic Program Guide (EPG) and Timeshifting save the M740 from being used as a ballistic object and keep the WAF at a decent level.

DVB-T uses a special kind of MPEG transmission format: a «transport stream», which is made for broadcasting through a lossy medium such as the atmosphere. Unfortunately, this format is less practical when it comes to post processing and DVD authoring. Additionally, the M740 saves recordings not as a single file each, but creates a number of smaller files. A special file called CRID is used to store meta information for a recording, such as the broadcast’s title, date/time and so on. The typical way from the M740 to a DVD looks as follows:

  1. Make sure, data from your recording share is transferred to the computer used for post processing.
  2. Append all chunks to a new, huge file (and I mean huge).
  3. Possibly evaluate data contained in the CRID file for creating a DVD menu or the like.
  4. Transform the MPEG file from a «transport stream» to a «program stream», which is the kind of MPEG you probably know and which is supported by media players, DVDs and much more. Under certain conditions, MPEG data has to be de-multiplexed (create separate data streams for audio, video etc. out of the single knotty stream) and multiplexed again during this process.
  5. Cut the MPEG to the film’s boundings, and get rid of commercial breaks.
  6. Run a DVD authoring program and create a DVD.
Steps 1 to 3 are done by Save740 for me, the rest is done by using different third-party tools. At least until I’ve read, understood, and implemented all what’s said in several MPEG standard documents consisting of several hundred pages each …

Features

Licence

Save740 is available for free under the GNU General Public Licence. This means that source code is available and may be altered. It also means that any new software incorporating even parts of the source automatically has to be published under this licence, too.

Credits

Download & run

There are three versions available: an executable JAR file (download, save, double-click), a Java Web Start application (just click the link below), and a ZIP archive containing the source files.

Executable JAR Java Web Start Sources
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