Preparing videos

Flowplayer encodering support most video formats and can handle them well, but to optimize your video quality there are some technical recommendations you should follow. If you don't want to bother with this we will still encode your uploads to the best possible result so don't worry too much about it.

We recommend using the MP4 container. MP4 video files using H.264 carry their metadata — duration, frame rate etc. — in the so called “moov atom”.

Most desktop encoding programs will insert the moov atom at the end of the video file which is suitable for playback of a local file in a desktop program. However, any kind of progressive download for online video requires the metadata to be available right away for immediate playback. Otherwise the player has to wait for the entire video to be downloaded before playback starts.

Make sure the Moov atom is at the begining of the file.

In case you already have a lot of MP4 videos with the moov atom at the end of the file, use a dedicated program such as QTIndexSwapper or MOOV Relocator to move it to the beginning. Please see our Wiki for details.

  • Progressive scan (no interlacing)
  • High Profile
  • 1080p source files: 10Mbps
  • 720p source files: 7Mbps
  • 480p source files: 4Mbps

Aspect ratio

Our default aspect ratio is 16:9 but we support other aspect ratios as well. These are the recommended video resolutions for 16:9 aspect ratio:

  • 2160p: 3840x2160
  • 1440p: 2560x1440
  • 1080p: 1920x1080
  • 720p: 1280x720
  • 480p: 854x480
  • 360p: 640x360
  • 240p: 426x240

We recommend to use one of the standard frame rates: 24, 25, 30, 48, 50, 60 frames per second (other frame rates are also acceptable).

Interlaced content should be deinterlaced before uploading. For example, 1080i60 content should be deinterlaced to 1080p30, going from 60 interlaced fields per second to 30 progressive frames per second.

  • Channels: Stereo
  • Sample rate 96khz or 48khz
  • Bitrate: 256kbps

Multiple audio tracks

We support multiple audio tracks in our encoding. To be able to use this feature your input file must contain all audio tracks that you want presented in the player, and they shoudl have valid language metadata.

Audio track language

To identify the language metadata for each audio track, we use the Language tag on the input audio tracks metadata. We accept tags using either ISO-639-1 or ISO-639-2 values.

The language metadata value can be set with the ffmpeg parameter -metadata:s:a:0 language=eng.

Audio files

We support uploading audio files with either aac or mp3 codecs, however we recommend the input to follow our recommended audio codec setup. For audio only files we encode the content to one HLS and one MP4 file.

We do not support Audio only files for DRM content.