Every conversion of a video can be downloaded from the Content Server. Conversions are transcoded, optimized versions of the original video, usually much smaller and much more widely supported by playback devices. The original video itself cannot be downloaded by default, but this can be circumvented by creating a Passthrough conversion.
Videos are requested with the unique key of the video and an optional transcoding template key or width. The extension of the video depends upon the provided conversion template.
If no template or width is provided, the mobile MP4 video is returned. Here is an example of a video without and two videos with a template:
If a width is provided, the MP4 conversion with the width that is closest to the requested width is returned. Here is an example of a video with a width:
The key is an 8 character code (e.g. 9ke9KW4b) you can request through the /videos/ API Class. Alternatively, it can be copy/pasted from the video details pages in the Dashboard. It uniquely identifies the video.
The template key is an 8 character code that uniquely identifies the transcoding template used to build this conversion. The template contains settings for dimensions, codecs and quality. Templates can be requested through the /accounts/templates/ API Class. You can also find them in the Dashboard account page. Note that templates will be the same across all your videos.
The width is the requested width in pixels of the conversion. If a width is provided, the returned video will always be an MP4 conversion. If multiple MP4 conversions of a video exist, the conversion with the width closest to this value is chosen. Note that only values in the range 120 to 4096 (inclusive) are supported.
The extension is the file extension of the specific video. It should be matched to the template format (mp4 for MP4, webm for WebM, mp3 for MP3, etc), but in reality our Content Server ignores the extension in determining which file to return.
When no template or width is provided, the Content Server will return the mobile MP4 conversion. This video is always available within the system, since it is also used as both preview and mobile phone fallback. It cannot be deleted. It has the extension .mp4.
The format (codecs and container), dimensions and quality of a conversion depends upon the used template. Bits on the Run contains a variety of conversion templates. These templates are available to new accounts:
- MP4 320
320px wide, about 400kbps, MP4 with AAC audio and H264 Baseline video
- MP4 480
480px wide, about 800kbps, MP4 with AAC audio and H264 Baseline video
- MP4 720
720px wide (SD), about 1200kbps, MP4 with AAC audio and H264 Baseline video
- MP4 1280
1280px wide (HD), about 2000kbps, MP4 with AAC audio and H264 Baseline video
This template does not transcode, but copy your original to the CDN for streaming.