All about AVCHD

Introduction

AVCHD is a high definition video format for video cameras. AVCHD stands for Advanced Video Codec, High Definition and is owned and managed by Sony and Panasonic. The following manufacturers are now using AVCHD for their high definition consumer level video cameras:
  • Sony
  • Panasonic
  • Canon
  • JVC
AVCHD has become the de-facto standard for high definition camcorders.

The Format

AVCHD is a 'proprietary' standard which means that it is not publicly available. Having said that, anyone can obtain a full copy of the specification for development purposes from Sony by signing up to the AVCHD Certification program. The most common usage of the format is in the following way:
  • Video stream (always H.264):
    • 1440x1080 interlaced
    • 1920x1080 interlaced
    • 1920x1080 progressive
    • NTSC and PAL variations of the above
  • Dolby Digital stereo or 5.1 surround sound
An overview of the supported video resolutions and audio formats can be found on the AVCHD Co-producers web site. AVCHD files are stored with a .MTS or .m2ts file extension, depending on the camera brand and whether you are copying to a Mac or PC. There is no difference in the contents of the video files with the different extensions.

AVCHD Lite

As of January 2009, there is now a new AVCHD variant called "AVCHD Lite". This format supports a maximum resolution of 1280x720 progressive and uses a less intensive video compression algorithm than full strength AVCHD. The simplified compression makes AVCHD Lite easier to implement on lower-end hardware. Panasonic have been the first company to implement this spec, adding AVCHD Lite video recording to their high-end point and shoot digital cameras.

There is one anomaly with AVCHD Lite. The format is 50p, which means the video which is recorded by the camera can be played back as a 50p signal - 50 updates per second, progressive scan. The thing is that they only capture at 25 frames per second (I'm using PAL for this example). When we convert the files using VoltaicHD, we create a 25 fps movie. We don't simulate the 50p setting in our output, as this would just mean repeating every frame twice, doubling the size of the video.

In the manual for our DMC-FT1 it states:
"50p recording" and below that
"CCD output is 25fps"

Working with AVCHD

There are a few editors out there that support 'native' editing of AVCHD. This means that they require no conversion in order to start editing the files. Due to the fact that AVCHD is a very highly compressed format, you will normally need a very high end PC to edit AVCHD directly. For this reason many editors require the conversion (which is really decompression) of AVCHD before they can work with it.

Apple

Apple has decided not to support AVCHD natively, which means that it has to be converted to another video format before you can edit it. This approach means that older, low powered computers can edit high definition content, but there is a delay in converting from AVCHD.

Apple uses the Apple Intermediate Codec (iMovie and Final Cut) and ProRes 442 (Final Cut Pro only) as its editing formats.

Under Final Cut Pro X, Apple has introduced support AVCHD in a new way. This new way requires 're-wrapping' of video from AVCHD to Quicktime, but without converting the H.264 video stream. This results in very fast conversions and does away with the need for decompression to ProRes. The resulting Quicktime files are the same size as the original AVCHD movie, so a lot of space can be saved.

To help people manage their own AVCHD files, we have a Quick Look plug-in available called HD Quick Look which gives you AVCHD preview capabilities within Finder. This is very useful if you have a library of AVCHD clips that you are keeping as an archive. You can quickly see the first frame of the clip without any conversion.

PC

Your options on the PC vary according to the editing package that you decide to use. Starting on the simple end of the scale, Microsoft Movie Maker does not support AVCHD, so needs it converted beforehand. Some editors, such as Sony Vegas, support native AVCHD editing, so you don't need to convert your footage. Note that native AVCHD editing takes a lot of processor power, so only high-end PCs are capable of this.

Managing

ShedWorx has released Cosmos for Mac, which is a digital asset manager supporting AVCHD (and many other file types). Cosmos for Mac helps you manage your digital movie library but without requiring you to convert the footage in order to view/manage it.

Converting

Converting AVCHD clips to a more editable format is a fairly common practice. VoltaicHD converts from AVCHD to the most common formats on the relative computer types. That is Apple Intemediate Codec (AIC) on the Mac and Windows Media Video (WMV) on the PC. Almost every video editor will be able to work with these formats.

Mac

The Apple editing suites all contain an AVCHD to AIC converter for the capture of video direct from an AVCHD camera. If you don't like leaving this process to Apple (and losing your original AVCHD clips), you can convert your AVCHD clips to AIC when you need them using a third-party converter. You have the following stand-alone conversion options on the Mac:
  • VoltaicHD for Mac - an AVCHD to AIC converter from ShedWorx
  • Toast - this is a full-featured disk burning application from Roxio which also includes an AVCHD to AIC converter

PC

You have the following stand-alone conversion options on the PC:
  • VoltaicHD for PC - our AVCHD to WMV (and AVI) converter
  • AVCHD Converter - an AVCHD to MPEG2 converter from Elecard

Editing

For new HD users, we recommend starting out with the in-built (and free) movie editor that comes with your computer, then moving up to a more advanced editing suite if you need it.

The advanced editing suites that are available now are very good, but require considerable time and effort to get up to speed on. The in-built applications on the Mac and PC are very good (in our opinion) and may be all you need.

Mac

On the Mac, you have the option of iMovie (which comes with every new Mac), Final Cut Pro and Adobe Premiere Pro. Note that Premiere Pro does support Native AVCHD but is pitched more at the professional user (who won't be using AVCHD). Our recommendation is to start with iMovie, then move up to Final Cut Pro if and when you need to.

PC

You have many editing options available on the PC. While not widely publicized by Microsoft, all Windows machines come with Microsoft Movie Maker built in. Movie Maker is HD-capable, but does not support AVCHD. We recommend VoltaicHD for PC to convert AVCHD into WMV. VoltaicHD also comes with HD profiles for Movie Maker which make HD editing and exporting a breeze.

Please see our article on Making HD movies with Movie Maker if you are going to give this a go.

Burning

Why would you want to know about burning AVCHD files to disk? Well, AVCHD is one of the two video formats supported by the Blu-ray specification. The AVCHD video file format also comes with a disk format which is playable on almost every Blu-ray player. The good news is that AVCHD disks are DVDs, not Blu-ray disks.

This means that you can burn AVCHD DVDs using your current DVD burner, and they will play on Blu-ray players!

There are a number of options for burning AVCHD DVDs or Blu-ray disks. Note that Blu-ray disk burning does require a Blu-ray burner.

Since this is an article on AVCHD, we will only cover the AVCHD DVD burning options.

Mac

You have the following AVCHD DVD burning options on the Mac:

PC

Most AVCHD cameras come with basic AVCHD DVD burning software.