After uploading your video to Carnival and receiving it in an In-App message, you may notice that the quality may not be as sharp or crisp as you expected. Below are a few potential reasons for what may be happening.
Carnival does create multiple versions of the transcoded video so the best quality video can be served based on the device's internet connection.
If the video was transcoded prior to upload to Carnival, it may lose some quality that way as well. It's possible the video is losing quality from the transcoding service being used, or being transcoded once more when uploaded to Carnival.
If the device connection is limited on the device the video is being tested, there could be loss of quality, due to the internet connection. The video is then cached by default. Best practice is to cache so video loads faster and reduces data usage. You can override cache only if you have your own custom UX for in-app messages.
Finally, it's also possible for some mobile plans to automatically transcode HD video into SD.
Check out the documentation, which does outline some best practices on videos here: https://marketing.carnival.io/docs/message-sizes