Why transcoding is necessary
Source videos come in many formats — from smartphones recording in HEVC to cameras producing ProRes or RAW files. These formats are not suitable for direct streaming: they may be too large, use unsupported codecs, or exist as a single quality level. Transcoding solves all of these problems.
- Format compatibility: convert any input format to web-ready codecs (H.264, VP9, AV1)
- Multi-quality output: create multiple renditions for adaptive bitrate streaming
- File size optimization: reduce storage and bandwidth costs through efficient encoding
- Device support: ensure playback on mobile, desktop, smart TVs, and streaming devices
Transcoding vs transmuxing
Transcoding and transmuxing are often confused but are fundamentally different operations.
| Operation | What changes | Speed | Use case |
|---|
| Transcoding | Codec, resolution, bitrate | Slow (minutes to hours) | Upload processing, quality optimization |
| Transmuxing | Container format only | Fast (seconds) | MP4 to HLS segmentation, format conversion |
Key transcoding settings
The quality and efficiency of transcoded output depends on several encoding parameters. Professional platforms optimize these settings automatically based on the source content.
- Resolution: the output frame size (e.g., 1920x1080 for Full HD)
- Bitrate: the target data rate, which directly affects quality and file size
- Codec: the compression algorithm (H.264, H.265, VP9, AV1)
- Profile: complexity level within a codec (Baseline, Main, High for H.264)
- Preset: speed vs quality trade-off (slower presets produce better quality at the same bitrate)
- Keyframe interval: frequency of full reference frames (affects seeking and ABR switching)
How Videas transcodes your videos
On upload, Videas analyses the source file and produces a set of HLS renditions: four levels at most — 1080p, 720p, 480p, 360p — each in H.264 and VP9, capped by the source resolution. The ladder is therefore cut to your file: a 720p upload wastes nothing on 1080p, and a 4K source adds no level beyond 1080p. Processing is progressive: the audio track and the lowest level go first, so the video is playable before encoding finishes.
Frequently asked questions
What is video transcoding?+
Video transcoding is the process of converting a video from one format to another: changing codec, resolution, bitrate or container so the video can be delivered across different devices and networks.
Transcoding or transmuxing?+
Transmuxing only changes the wrapper — from an MP4 to HLS segments, for instance — without touching the image. It is near-instant, but it creates no additional quality level: adaptive streaming requires real transcoding.
How long does transcoding take?+
The video becomes playable one to two minutes after upload for a short file, because Videas produces the audio track and the lowest level first. Higher qualities follow; for a long video the full encode naturally takes longer, but playback is possible well before that.
Does transcoding reduce video quality?+
Any re-encode introduces a slight loss, known as generational loss. Videas encodes once, from your master: it is the number of generations that damages a video, not transcoding itself. So upload the master rather than a version already compressed for another use.
Which formats can I upload?+
MP4, MOV, AVI, MKV, WebM, FLV, WMV, MPEG and others. On the codec side, H.265 (HEVC), VP9, AV1 and ProRes are accepted and converted automatically, with nothing to do on your part.
Should I compress a video before uploading it?+
In most cases no: Videas re-encodes anyway, and uploading a heavy master degrades nothing. Compress only if the file exceeds 100 GB, the maximum size per file, or if your storage is tight.
What happens if my connection drops during upload?+
The upload resumes where it stopped rather than starting over. The one constraint is the browser: an upload started in Chrome does not resume in Firefox, nor on another machine.
Does a vertical video stay vertical?+
Yes. The source orientation is preserved: the levels of a vertical video are produced vertically, not cropped to landscape.
Why does my video not reach 1080p?+
Because the source is not 1080p. Videas never manufactures a resolution higher than the original; re-uploading from a better master gains you a level.
Is transcoding billed?+
No, it has no line on the invoice. What is counted is storage — EUR 0.20 per hour of video per month — and delivery, EUR 0.02 per gigabyte with the first terabyte free each month.