This article covers what video formats are compatible with SpotCast
SpotCast can accept nearly every video format out there, Some video formats may take longer to upload and be processed by our system.
Formats recorded on Mobile phones
Most mobile devices capture H.264 8-bit 4:2:0 video by default and that is compatible with our systems.. Here are the main things to watch out for:
- Ensure that the total file bitrate is below 8 mbps.
- Ensure the output file uses SDR (standard dynamic range) imaging. Some newer devices capture video in HDR (High Dynamic Range), which requires 10-bit 422 color, and must be re-encoded by Mux Video to support most devices.
- Ensure the output file is smaller than 1080p (1920x1080) or 2K (2048x1152). Some cameras shoot 4K video, which is currently converted down to 1080p when using Mux Video.
- If possible, choose a keyframe interval of 5s or so, but certainly between 2 and 10 seconds, and enable closed-GOP encoding. (If you don't see these options in your app or camera, it's probably the default already.)
For users uploading videos
Again most video formats will work With SpotCast. Our optimal video format is as follows:
- 1080p/2K or smaller. Video up to 2048x2048 is considered standard, including 1080p (1920x1080) video. Video larger than this is considered non-standard.
- H.264 video CODEC. H.264 is the dominant video CODEC in use today and almost every device supports H.264. While Spotast accepts other CODECs as input, other CODECs must be normalized to H.264 and are considered non-standard.
- Max 20-second keyframe interval. To stream well using HTTP-based streaming methods like HLS, SpotCast requires all keyframes intervals to be less than 20 seconds.
- Closed GOP (group-of-pictures). (Warning: video jargon ahead. You can likely ignore this.) In closed-GOP video, all B frames reference other frames in the same GOP. Closed GOP always begins with an IDR (Instantaneous Decoder Refresh) frame. This means that every GOP can be played independently, without reference to another GOP. Standard input must be closed-GOP, which means that open-GOP video will be treated as non-standard and will be normalized to standard.
- 8Mbps or below. While SpotCast accepts higher bitrate inputs, bitrates higher than 8Mbps (and the bitrate should not exceed 16Mbps for any single GOP) are generally challenging for most viewer's connections and are considered non-standard.
- 8-bit 4:2:0 or below. This refers to the color depth and chroma subsampling. If you don't know what this is, you can probably ignore this, since most streaming video is 8-bit 4:2:0. This means that high dynamic range video (HDR) is currently considered non-standard, and will be normalized to SDR.
- Simple Edit Decision Lists. Edit Decision List (EDL) is typically added during post-production and defines how certain segments are used to build the track timeline for playback. A good example of a Simple Edit Decision List is to fix out of order frames in the video. Video with more complex uses of EDLs are considered non-standard.
- Frame rate between 5 and 120. Video with average frames per second (fps) less than 5 or greater than 120 is considered non-standard. Video frame rates within this range will be preserved. Video with less than 5 fps or greater than 120 fps will be normalized to 30 fps.
- AAC audio CODEC. AAC is the dominant audio CODEC in use today and almost every device supports this audio CODEC. While SpotCast accepts other CODECs as input, SpotCast only delivers AAC audio and non-AAC audio inputs are considered non-standard.