How does the audio / video transcoder work?
The audio and video transcoder in FotoWeb will convert audio and video files in FotoWeb archives to a format that is playable on most devices.
The transcoding is non-destructive - i.e. we use your original files to create proxies and then use those proxies for playback. The originals are safe and unmodified in the storage repositories.
The ffmpeg library required to decode video formats is not included with the FotoWare installers. It can be installed manually on the FotoWare server by following the directions in this article.
Video Proxy file specifications and bandwidth requirements
The video proxy file is an H.264 encoded MPEG using CRF mode (constant quality and variable bitrate), and will play back on practically all modern browsers and devices. Giving an exact bandwidth requirement is difficult because the compression will depend largely on the resolution and activity in the video feed, since these factors affect the level of compression that can be applied.
Supported video resolutions
Video formats are simply interpreted as X x Y, i.e. width x height. The transcoder consequently supports mostly all video formats, from small web to 4K.
The proxy files that FotoWeb creates are resized to HD720 for optimal playback on most device types and web. Large formats require more storage and processing power than smaller formats.
MPTS (Multiple Program Transport Stream)
FotoWare currently does not support MPTS. Only SPTS files are supported. In practise, this means that if the transcoder is served a MPTS file with multiple programs, only the first program will be available in the transcoded preview.
Features only available with the optional Audio-Video license
All versions of FotoWeb since Feature Release 5 (build 730) have audio/video transcoding built-in. Some advanced features, however, are only available with the optionally-licensed Audio-Video module. They are:
- Adjustment of transcoding performance
- All versions of FotoWeb since Feature Release 5 (build 730) have audio/video transcoding built-in. The built-in transcoder runs in one thread and only transcodes one file at a time. With an additional audio/video license for FotoWeb, you can utilize up to 8 cores for transcoding, transcoding one video at a time divided between the number of cores.
- Navigation by key frames
- Allows users to jump to a certain part of the video using extracted key frames
- Playback speed adjustment
- Playback of AV content on thumbnails in FotoWeb Pro
A separate topic lists the formats supported by the audio-video transcoding engine.