I need predictable compression settings for web and mobile playback

For predictable playback on web and mobile, aim for widely supported codecs + fixed encoding settings + consistent container choices.

Recommended baseline

Video

• Codec: H.264 / AVC
• Profile: High or Main
• Level: choose based on resolution/frame rate
• Container: MP4
• Pixel format: yuv420p
  • This is important for broad device compatibility.

Audio

• Codec: AAC-LC
• Sample rate: 48 kHz or 44.1 kHz
• Channels: stereo
• Bitrate: 128–192 kbps

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Suggested encoding settings

For general web/mobile playback

• Resolution: keep source or scale to a standard size like:
  • 1920x1080
  • 1280x720
  • 854x480
• Frame rate: keep constant, usually 30 fps or 24 fps
• Bitrate control: use CRF for quality consistency, or CBR/target bitrate for predictability
  • CRF 18–23 is common
  • Lower = better quality, larger files
• GOP/keyframe interval: 2 seconds is a good default
  • Example: 60 frames at 30 fps

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If you need very predictable file sizes

Use CBR or constrained VBR instead of CRF.

Example targets:

• 1080p: 5–8 Mbps
• 720p: 2.5–5 Mbps
• 480p: 1–2 Mbps

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Example FFmpeg settings

Web/mobile compatible MP4

ffmpeg -i input.mov \
  -c:v libx264 -profile:v high -pix_fmt yuv420p \
  -preset medium -crf 20 \
  -c:a aac -b:a 128k \
  -movflags +faststart \
  output.mp4

More predictable bitrate

ffmpeg -i input.mov \
  -c:v libx264 -profile:v high -pix_fmt yuv420p \
  -preset medium -b:v 5M -maxrate 5M -bufsize 10M \
  -c:a aac -b:a 128k \
  -movflags +faststart \
  output.mp4

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If you want adaptive web delivery

Create multiple renditions:

• 1080p
• 720p
• 480p

Then package as:

• HLS for broad web/mobile support
• Codec still usually H.264 + AAC

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Avoid if you want maximum compatibility

• H.265/HEVC for general web unless you know target device support
• VP9/AV1 if you need guaranteed mobile playback across older devices
• Variable frame rate, unusual audio sample rates, or non-yuv420p pixel formats

If you want, I can give you:

1. best settings for FFmpeg,
2. settings for Premiere/HandBrake, or
3. a web + iPhone + Android compatibility preset.