How do you edit AVCHD?What is AVCHD?It is a highly compressed form of video stored in MPEG4 format. The sound can either be stereo or 5.1 surround sound depending on the camera. The picture is excellent given the amount of space it takes up but the heavy compression leads to problems when editing. The footage is recorded in the camera to memory cards or a hard drive or in some cases onto a DVD-style disc. Once recorded you need to transfer the footage form the memory card etc onto your computer for editing. This is generally done by simply plugging in a USB cable and copying the footage across. There are two main formats of AVCHD - Panasonic and Sony. Both are the same basic format but are slightly different. AVCHD can be recorded in various sizes and at various data rates - The two main sizes would be 1440 x 1080 and 1920 x 1080. 1440 x 1080 is exactly the same number of pixels as used in HDV cameras and you should get an equivalent picture. HDV cameras record in MPEG2, which is less advanced compression than MPEG4 as used by AVCHD, and so is easier edit. 1920 x 1080, or "full HD" means that you will be filming at the top quality of HD and theoretically better than HDV. Having said that other considerations mean that an AVCHD camera's picture may not be as good as HDV. AVCHD cameras are designed for the domestic user and so are normally cheaper than good quality HDV camera. A good quality HDV camera with a good lens and decent controls will probably produce a better picture than a domestic AVCHD camera . There are some professional AVCHD cameras available from Panasonic, however. Another main difference between HDV and AVCHD is that HDV is recorded to tape, and AVCHD to memory cards - although you can choose to record to a disc based format with HDV by using a FireStore, and some new HDV cameras are arriving with card recorders attached. Which programs support it directly?Thompson Edius 5, Sony Vegas 8and Adobe Premiere Pro CS4 let you put AVCHD footage directly on the timeline. Initially Vegas would only deal with Sony AVCHD footage but it will now also load Panasonic. With all the programs the playback is fairly similar - they can barely playback the footage off the timeline and cannot manage any realtime effects with either. This is true with even our most powerful Xeon systems. This is because as AVCHD is heavily compressed it is very hard for the computer to deal with so a lot of processing power is needed. Premiere Pro 4 does the best job of editing native AVCHD and it is actually usable, although it does add significantly to the rendering time of the final movie, DVD or Blu-ray. To get decent performance it is best to convert the footage to something more usable. Sony Vegas has the CineForm codec built in which makes a good intermediate format. The only problem is that you cannot select a series of clips and get Vegas to transcode them all, it will only transcode what is on the timeline. You could put all the clips on the timeline and then convert them en-masse into one new file which you would then have to split into your individual scenes. Once converted editing the footage is like editing any other normal footage. How do I get the footage into a program that does not support it?Avid Media Composer and Avid Liquid do not support AVCHD directly. To get the footage into these programs you need to convert it before using the program or capture the footage directly off your camera using the HDMI or component out of your camera. Convert to DVC Pro HDIf you have a Panasonic camera then there is a utility from Panasonic to convert AVCHD to DVC Pro HD. The latter is a much less compress format which is easier for the computer to edit. All programs these days support DVC Pro HD. There are various sizes of DVC Pro HD although none are 1920 x 1080. If using PAL footage then this program will convert it to 1440 x 1080 - fine if you are using that as your filming size, but not so good if filming at 1920 x 1080 as the picture is bound to be slightly inferior to the original. However the quality drop will not be huge and if you have a program that does not directly support AVCHD this may be your best option. This utility only produces stereo sound and does not work with footage taken from a Sony AVCHD camera. Convert to MPEGYou could convert the footage to MPEG using an editing program. For a customer using Avid Liquid we did just this using a copy of Pinnacle's home user editing program, Studio. We copied the files onto the computer, loaded them to Studio to convert and then once done loaded them into Liquid. This is not the best way of editing this footage but the only practical one for the customer concerned since he had Sony AVCHD footage and a copy of Avid Liquid. Capture through HDMI or componentThe other way would be to play the footage off the camera and record via component orHDMI. HDMI would be preferable as the signal is digital ,where as component video is analogue, although in practice we have seen very little difference between the two. When you capture the computer will convert it to something that the computer can use easily, which could be totally uncompressed, Motion JPEG compression, if using a Black Magic card,Matrox MPEG I-frame if using a Matrox card, orCanopus HQ if using an EDIUS card. All would be good formats and work well. What potential problems are there?None really - although if copying files off a hard drive or memory card will be as fast as the connection you have, with my own system I can copy 1 hour from a card in about 15 minutes. If capturing through HDMI or component then 1 hour footage would take 1 hour to capture. All the different cards we use, from Black Magic (an Intensity with HDMI is just £129 +VAT), Canopus, who also have HDMI input using the Pegasus, or HDSTORM cards, and Matrox which could capture through component support full HD, 1920 x 1080, except the Matrox RT.X2 family, which only support 1440 x 1080 capture. Once captured in this way the footage is no longer AVCHD but something a lot more usable, and should look practically the same, if not indistinguishable, from the original. So which is the best program to choose?Based purely on which one has the best support for AVCHD then Canopus Edius would be our choice. However, that should not be your only consideration when deciding which program to use as there are many reasons why you should choose one program over another. Please read the various documents on our website for more information on why you would chose Edius, Media Composer, Vegas or Premiere as your preferred editing program. | 
