MX Telecom Video Gateway Technical Information
The MX Telecom Video Gateway Service allows both recorded and live video content to be delivered straight to an end user's 3G handset.
Contents
- List of Compatible Video Formats
- Content Preparation Guidelines
- Recording User-Generated Video Content
- Technical Setup
- Live Streaming of Video Content
- TV to Phones
List of Compatible Video Formats
The MX Telecom Video Gateway can accept virtually all video file formats. The following file types are the most common and are supported by the MX Telecom Video Gateway:
| File formats supported |
|---|
| MPG |
| AVI |
| Windows Media (WMV, ASF) |
| RealMedia |
| QuickTime/MOV/3gp |
| JPEG and PNG images |
MX Telecom recommends that high quality originals are uploaded to the Video Gateway (i.e. content that has not been resized etc). The MX Telecom Video Gateway resizes and reformats (transcodes) the video, ensuring the best picture quality possible on each handset type.
The recommended format is MPEG-4 encoded video with MP3 or AAC audio, packaged in a .avi or .mpg file. The aspect ratio for a 3G handset is 1.22:1, with square pixels; ideally, the resolution should lie between 352x288 and 720x576, and most efficient results will be achieved with a framerate of 10fps. The video should be progressive (not interlaced).
In addition to video, JPEG and PNG still image files can be uploaded to the video gateway. When uploaded the images are automatically converted into video. This provides a way of quickly producing menu prompts and test content for use with a video IVR service.
The image dimensions should be 352x288 pixels. Where adjustment of the images is possible during production the highest quality setting should be used to ensure the best results. The resulting video files are a few seconds in length.
Content Preparation Guidelines
Production guidelines for video content can be found on the Video Short Code page.
When preparing menus and other text-based prompts for video IVR services care should be taken to achieve the best results on the handset. Following some simple guidelines will normally give good results, but it is always best to test your proposed style on a handset before finalising the service.
- The amount of text on each screen should be kept to a minimum, aiming for around 5-8 lines of text each with around 5 words. A menu can comfortably have a title and 5 options.
- Many handsets will obscure the edges and corners of the video when it is displayed, often with items such as the outgoing video or call timers and battery meters. It is wise to avoid putting important information near the edges or corners of the screen.
- Backgrounds and graphics should be as plain and simple as possible to enable better compression and improve text readability.
- Font choice is important to ensure text is easily readable. Use plain sans-serif fonts such as Arial and avoid complex italic, serif, or script-like typefaces.
- Consideration should be given to the colours used to ensure that any text stands out against the background. Use contrasting colours for the background and foreground and avoid the use of similar colours, such as orange and yellow, as they will be hard to distinguish on a phone screen.
- Wherever possible test your proposed style on a handset before use; this can normally be done using a test Short Code. Your account manager can provide you with details of how this can be set up.
Recording User-Generated Video Content
As the video call channel is two way, video data is constantly being sent from a user's 3G handset into the MX Telecom Video Gateway. This content can be recorded and saved for future use, or playback.
Video recordings (as downloaded from our IVR Web application) are the following:
- The file format is AVI
- The audio is 8kHz mono A-Law
- The video is H.263, typically around 50kbps (as it is recorded directly from the phone).
Please note that by default the file format is supported by QuickTime, but not Windows Media Player. We recommend simply using QuickTime to view these video files, but if Windows Media Player must be used, then please contact us for details on how to obtain the codec, as this is not a straightforward process.
Technical Setup
The following diagram shows the technical setup involved in using the MX Telecom Video Gateway:
Live Streaming of Video Content
There are two possibilities for a provider streaming video through the MX Telecom Video Gateway: one-to-one, and one-to-many streaming.
One-to-one streaming allows the provider to interface two-way live content via the Internet using the MX Telecom Video Gateway. Each end user receives a separate video stream, and the end user's video is streamed back to the provider. The MX Telecom Video Gateway supports the industry standard H.323 (as used by Microsoft NetMeeting) and SIP protocols (as used by recent IP videophones) for one-to-one video streaming. The outbound content must be encoded by the provider as baseline H.263 video (46kbps peak data rate, with a picture-size limit of 4096 bytes, ~1:45 I:P keyframe ratio), and the incoming video from the handset will be received similarly encoded. Audio must be encoded as PCM A-law.
Details on H.323 can be found at http://www.packetizer.com/voip/h323/, and SIP information at http://www.packetizer.com/voip/sip/.
In one-to-many broadcasting, every call is connected to the same video stream, so that all end users see the same content. For one-to-many services, in addition to H.323 and SIP, the MX Telecom Video Gateway supports RTSP streams. If H.323 is used, the content must be H.263 video with PCM A-law audio as described above; for SIP or RTSP streams, the Video Gateway can also transcode from the common standard video and audio formats. The video formats supported include MPEG-1, MPEG-2, MPEG-4, H.263 and H.264.
The recommended format for a one-to-many SIP or RTSP video stream is progressive MPEG-4 video with AAC or MP3 audio. The aspect ratio, as with uploaded video, should be 1.22:1 with square pixels; a resolution of 352x288 is recommended. A stream providing a data rate of approximately 256kbps will provide good quality video to the end user's handset after transcoding.
When setting up an RTSP video stream, three components are involved: a video capture device, an RTSP-capable streaming server, and a broadcaster to transmit the video from the device to the streaming server. A variety of solutions, both in software and hardware, are available to implement this. To discuss the most appropriate solution for your requirements, please contact us.
TV to Phones
MX Telecom can stream a television channel direct to end users' 3G handsets. The channel must be available on Sky. Setup involves providing MX Telecom with a working Sky card and an EPG number for the channel. The Sky card will be hosted by MX Telecom and can provide live video from the channel to the end users.
