Supported Formats
Full list of supported video file formats, codecs, and recommended specifications.
YouCast accepts a wide range of video file formats and codecs. For the best streaming results, we recommend using modern, widely-supported formats. This page lists every supported format and provides guidance on optimal encoding settings for your source videos.
Supported Container Formats
| Format | Extension | Notes |
|---|---|---|
| MPEG-4 | .mp4 | Recommended — best compatibility and performance |
| QuickTime Movie | .mov | Common on macOS and iOS devices |
| Matroska | .mkv | Popular for high-quality video storage |
| AVI | .avi | Legacy Windows format, fully supported |
| WebM | .webm | Web-optimized format, great for smaller files |
| FLV | .flv | Legacy Flash format, supported for compatibility |
| Windows Media Video | .wmv | Windows native format |
| Transport Stream | .ts, .mts | Common for broadcast and camera recordings |
Supported Video Codecs
- H.264 (AVC) — most common, excellent compatibility, recommended for most users
- H.265 (HEVC) — better compression at high resolutions, ideal for 4K source files
- VP8 / VP9 — used in WebM files
- MPEG-2 / MPEG-4 — legacy codecs, fully supported
- ProRes — macOS professional format, supported
- DNxHD / DNxHR — Avid professional codecs, supported
Supported Audio Codecs
- AAC — recommended, universally compatible
- MP3 — standard audio format
- AC3 (Dolby Digital) — downmixed to stereo AAC for streaming
- PCM / WAV — lossless audio, re-encoded for streaming
- Opus — supported in WebM containers
- FLAC — lossless, re-encoded for streaming
Recommended Encoding Settings
For the best streaming experience, we recommend encoding your source videos with these specifications before uploading. While YouCast can handle virtually any format, pre-optimized files process faster and result in better stream quality.
| Setting | Recommended Value |
|---|---|
| Container | MP4 |
| Video Codec | H.264 (High Profile) |
| Audio Codec | AAC-LC |
| Audio Channels | Stereo (2.0) |
| Audio Sample Rate | 44.1 kHz or 48 kHz |
| Keyframe Interval | 2 seconds (every 2s or every 60 frames at 30fps) |
| Frame Rate | 24, 25, 30, 50, or 60 fps (constant frame rate) |
| Bit Depth | 8-bit |
| Color Space | YUV 4:2:0 |
Variable frame rate (VFR) files
Videos recorded on smartphones or screen recorders often use variable frame rate. VFR files can cause sync issues during streaming. We recommend converting VFR files to constant frame rate (CFR) before uploading using a tool like HandBrake or FFmpeg.
Converting Videos with FFmpeg
If your video is in an unsupported format or you want to optimize it for streaming, here is a universal FFmpeg command to convert any video to the recommended format:
ffmpeg -i input.mov -c:v libx264 -profile:v high -crf 18 -c:a aac -b:a 192k -movflags +faststart output.mp4
This command re-encodes the video using H.264 with AAC audio and the faststart flag, which is optimal for streaming and uploading to YouCast.