OTS uses the following settings for your VOD videos.
MP4 with H.264/AAC is an ubiquitous format these days. All widely used editing, compositing, screencasting and transcoding tools support it. If your tools do not, take a look at Handbrake, a free but powerful desktop transcoder.
Dimensions and Bitrates
In terms of dimensions, bigger is better. Video in 720p is today's standard and a great option. We also see an increase in 1080p uploads. If your original video is full HD, we suggest you upload 1080p too. If your source footage is standard definition (NTSC, PAL), we suggest 360p as the dimension to use. Anything smaller than 360p is not recommended.
Since H.264 and AAC are excellent codecs, the upload bitrates do not have to be extremely high. They should be sufficiently high to not introduce any data loss though. Remember that JW Platform creates the final encodes to be streamed. If the input format already has compression artifacts, the final transcodes may look quite bad.
Here is an overview that includes the preferred format, dimensions and audio/video bitrates to use. If you upload video in these formats, JW Platform will be able to build high quality transcodes and deliver smooth playback across devices.
RESOLUTION | DIMENSIONS | VIDEO BITRATE | AUDIO BITRATE |
1080p | 1920x1080 | 15,000 kbps | 256 kbps |
720p | 1280x720 | 10,000 kbps | 256 kbps |
360p | 640x360 | 5,000 kbps | 256 kbps |
Note that our built-in transcoding will generate smaller versions of your uploaded video. If you upload video in 1080p, only viewers whose device and connection support 1080p playback will see that resolution. Other viewers (e.g. on older computers or phones) will see lower resolution transcodes (e.g. 360p or 180p).
Note also that if your upload contains 5.1 audio tracks, we will retain the 5.1 audio for 720p, 1080p and higher. At lower resolutions, the 5.1 audio will be down-mixed to stereo. This provides a better playback experience for your audiences on networks where bandwidth is limited.
WARNING
It is highly recommended that you prepare your uploads using a constant, non-fractional frame rate. This will avoid timing issues and other glitches during transcoding. For example, instead of encoding your videos at a variable 29.97 frames-per-second (fps), use a constant 30 fps.
ADDITIONAL SETTINGS
There are many more settings associated with video encoding. Here are some additional suggestions to follow when exporting your video for upload:
Use progressive frames (e.g. 720p) instead of interlacing (e.g. 720i). Interlacing does not apply to online video
Use a screen aspect ratio of 16:9. This will fill the screen of many monitors, laptops, tablets and phones with your footage. More rectangular (4:3) or cinematic (2.39:1) ratios will result in black borders on many screens.
Use a pixel aspect ratio of 1:1. Older broadcast formats (like PAL or NTSC) use non-square pixels, but online video pixels are always square. JW Platform may have troubles converting non-square pixel aspect ratios, resulting in a stretched image.
Export the to-be-uploaded videos in MP4 format and not in MOV. The latter contains additional features like Edit Lists that often result in audio-video sync issues.
If available, select the Main or High profile for the H.264 video. These profiles support features like B-frames and CABAC, resulting in higher quality at the same bitrate.