Exporting and Codecs

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"Exporting" or "Encoding" is the process of converting information from one form into another. In most cases this is taking raw information from a project file and converting it into a image or movie file that can be read on another device.

When "encoding", you use a codec. The word "Codec" is a combination of the two words: Encode & Decode. A codec is a formula, or a recipe for compressing your project file into a common playback file (like an .mov).

When you export your file from a program, you are "encoding" your file into a compressed format. Later, when you watch your file, the playback device is "decoding" from its compressed format, back into a sequence of images for you to view.

When you are first exporting your project to a movie file you should first ask yourself:

  • What will this file be used for? Where will this movie file be seen, and on what device?
  • How important is quality?
  • How important is file size?

Generally speaking, there are a few variables you can adjust that influence quality and size:

  • -Quality - the higher the quality, and the larger the file size.
  • -Keyframe distance - Distance between each "image". This is better left unadjusted.
  • -Bitrate* - the higher the bitrate the higher the quality, and the larger the file size.

*Bitrate will be your primary tool in reducing the size of your exported files.

Contents

Export Presets

Adobe Media Encoder User Presets

In Adobe Media Encoder under "User Presets" you'll find a collection of presets created for the most common export scenarios:

  • Archive and Final Output
  • Editing and Sound Design
  • Production and Compositing
  • Web and Preview

Each preset uses "Match Source", which matches the output resolution and frame-rate to the your sequence.

Bitrate Guidelines

Trailer and Final Film Delivery

(Apple Prores 422)

Sharing over email, sending to an instructor for feedback.

(H.264)
-3-5 Mbps

Posting online for streaming

(H.264)
-Youtube (1080p) 8 Mbps
-Youtube (720p) 5 Mbps
-Vimeo (1080p) 10-20 Mbps
-Vimeo (720p) 5-10 Mbps

Screening

(ProRes)(DNxHD)
-1080p 

Editing and Assembly

(Animation)(ProRes)(DNxHD)
-Lossless
-1080p 25Mbps


Youtube Compression Guidelines https://support.google.com/youtube/answer/1722171?hl=en

Vimeo Compression Guidelines https://vimeo.com/help/compression

Containers

  • Quicktime MOV - A ubiquitous media container. Mostly used to house loseless, animation, h.264, and prores codecs. Right click>properties to view the compression information.
  • Microsoft AVI - A legacy (outdated format). Does not support files over 4 gb.
  • MP4 - MPEG’s MP4 container is an industry standardized format based on Apple Quicktime MOV with some additional extending features. It is commonly an acquisition and delivery format. Although it can contain different codecs, the most commonly used codecs in the MP4 container like h.264 aren’t totally suitable in an editing environment.

Compression Schemes

  • Animation - Large file sizes. Supports transparency. It uses run-length compression meaning that it compresses video more efficiently the longer pixels stay the same from frame to frame. Common as an intermediate codec for storing footage before it’s used in an edit and delivered.
  • Apple Pro Res - Unavailable on most PCs. Designed specifically for editing. Common for editing and delivery. Designed to balance size, playback quality, and CPU usage.
  • Avid DNxHD - PC equivalent to Pro Res. Supports transparency. Designed editing and delivery.
  • H.264 - Extremely common compression for delivery, streaming and playback. Used by streaming sites like YouTube, Vimeo etc. Not suitable for editing.
  • MPEG2 - Known as H.262. Similar to H.264. Compression used by DVD, Blu-ray, HDV, XDCAM and others.
  • PNG - An alternative to Animation. A lossless codec that supports transparency.
  • JPG - Lossy compression. Videos are compressed frame by frame using JPG compression.
  • JPG2000 - Similar to JPG compression, but can be made lossless. Can be used for digital cinema and digital archiving.

Terminology

  • Codec - A codec is a computer program capable of encoding or decoding a digital data stream or signal.
  • Variable Bit Rate (VBR) - As opposed to constant bitrate (CBR), VBR files vary the amount of output data per time segment.
    • 1-pass: Faster, but lower quality
    • 2-pass: Slower, higher quality and sometimes smaller file-size
  • Constant Bit Rate (CBR) - When referring to codecs, constant bit rate encoding means that the rate at which a codec's output data should be consumed is constant

Workflow

You can easily export from each program using the built in export dialogue. (After Effects, Tv.Paint, Harmony). But, theres a better way:

Export using "animation" codec from your primary program.

Drag and drop your uncompressed .mov into Adobe Media Encoder and re-encode using one of the presets.

For Editing Codecs like H.264 save space by only inserting keyframes periodically, then using a mathematical calculation to interpolate (blend) between those keyframes. This blending calculation makes playback in Premiere or Final Cut slow and buggy. For this reason, use a codec that has a keyframe on every frame (prores,animation,dnxhd etc) when you are editing footage in a program like Premiere Pro.

Common Bitrates

  • 16 kbit/s – videophone quality (minimum necessary for a consumer-acceptable "talking head" picture using various video compression schemes)
  • 128–384 kbit/s – business-oriented videoconferencing quality using video compression
  • 400 kbit/s YouTube 240p videos (using H.264)[21]
  • 750 kbit/s YouTube 360p videos (using H.264)[21]
  • 1 Mbit/s YouTube 480p videos (using H.264)[21]
  • 1.15 Mbit/s max – VCD quality (using MPEG1 compression)[22]
  • 2.5 Mbit/s YouTube 720p videos (using H.264)[21]
  • 3.5 Mbit/s typ – Standard-definition television quality (with bit-rate reduction from MPEG-2 compression)
  • 3.8 Mbit/s YouTube 720p (at 60fps mode) videos (using H.264)[21]
  • 4.5 Mbit/s YouTube 1080p videos (using H.264)[21]
  • 6.8 Mbit/s YouTube 1080p (at 60 fps mode) videos (using H.264)[21]
  • 9.8 Mbit/s max – DVD (using MPEG2 compression)[23]
  • 8 to 15 Mbit/s typ – HDTV quality (with bit-rate reduction from MPEG-4 AVC compression)
  • 19 Mbit/s approximate – HDV 720p (using MPEG2 compression)[24]
  • 24 Mbit/s max – AVCHD (using MPEG4 AVC compression)[25]
  • 25 Mbit/s approximate – HDV 1080i (using MPEG2 compression)[24]
  • 29.4 Mbit/s max – HD DVD
  • 40 Mbit/s max – 1080p Blu-ray Disc (using MPEG2, MPEG4 AVC or VC-1 compression)[26]

References & Additional Resources

http://www.fallenempiredigital.com/blog/2013/02/08/a-guide-to-common-video-formats-containers-compression-and-codecs/