Working with AVCHD on the Mac

I do nearly all of my video editing now on a Mac so this post is about processing AVCHD files on the Mac.

Easiest Import

The easiest way to deal with AVCHD is to let iMovie (latest version) import and transcode to the Apple Intermediate Codec (AIC). If you want, you can then edit in iMovie. If you wish to edit in older versions of Final Cut Express or Final Cut Pro, you can import the Quicktime .mov files created by iMovie. Set your timeline sequence encoding to the Apple Intermediate Codec. You can now edit copy your clips direct to the time line, edit as much as you want.

Converting AVCHD to HDV Format

If you must edit both original AVCHD video and HDV video into a single time line and do not want to spend lots of time rendering video clips from AIC into your HDV timeline, then it may be useful to convert AVCHD direct to HDV. If you do not need to merge with HDV footage, then you will not want to do this at all!

Toast 10 from Roxio is the only product that has successfully done the transcoding from AVCHD to HDV (for me). Toast can import your AVCHD files directly from the camera and then re-encode into HDV file format. You do lose some quality (but not very much that most people would actually notice) by re-encoding into HDV.

UPDATE 2009: The Toast 10 product has been riddled with bugs (defects). The company  came out with a 10.0.2 fix release five months later but much is still broken. Worse, the AVCHD conversion feature in Toast 10 DOES NOT WORK. Their decoder gets the video and audio out of synchronization. It does not matter whether you convert from AVCHD to AIC or to HDV. The synchronization will be off. Roxio knows about the problem but after many months has not yet produced a fix. I recommend that you do not purchase Roxio Toast 10 at this time. (Its now 2012 as I revise this text Рpresumably this has been fixed but I have not gone back to check.)

24p

If you have a consumer camera with 24p capability, you probably cannot directly edit the 24p video without first doing a conversion. But before you consider shooting in 24p, ask yourself if you’d be better off shooting 30p progressive? If you have sort of last year’s Canon camera (HV20, HG10, HG20), you can, in fact, shoot 30p progressive using a simple trick:¬† Use the Program mode and the Tv selection to set your shutter speed. Set the shutter to 1/30th of second. Your camera now records in 30p mode! This is because the camera actually contains a progressive imaging system-with a 1/30th second shutter speed, both “fields” of the 60i video are recorded without any field shifts. You get perfect 30p, as long as the 1/30th of a second shutter speed is acceptable. (Most 24p is shot at 1/48th or 1/24th of a second. Many people like the blurred motion effect of the slow shutter speeds. Your choice). This trick actually works on a wide variety of older cameras too. If you have a newer camera with true 30p, you may wish to use 30p for all your shooting since it can be directly processed for online or Apple TV/XBox360/PS3 viewing without having to de-interlace.

If you do use the 30p trick, just import your video as 60i and edit as usual. That’s all there is too it.

But if you choose to use 24p, then you must do a “reverse telecine” (or sometimes called “de-telecine” or “inverse telecine”) step to convert the recorded 24p to a true 24p that can be edited in Final Cut Pro. (Final Cut Express and iMovie do not edit 24p video).

VoltaicHD ($35) claims to do the conversion but the demo version did not do so successfully for me. However, if it works, you can use VoltaicHD to import and do telecine removal in one step, producing the AIC files for editing. If it worked, this would be my preferred solution.

HandBrake (see next section) also claims to do reverse telecine conversion but it failed to do so properly on my HG10 video stream. However, its output format is MP4 which is not ideal for video editing.

JES De-Interlacer does do reverse telecine and does it properly and very well (and also does excellent de-interlacing as well as several other features). And its FREE! To use, first import the 24p AVCHD files in iMovie. Then, find the converted files (.mov) in your Movies Events folder. Run JES-Deinterlacer, select all of your input files, and the options page, select the “inverse telecine” option. On the output page, specify a folder to store the converted files – and set your output file format to AIC (Photo JPEG is also very good). Then let it run to convert the input files, producing a new set of output files.

You can then import the output files to Final Cut and begin editing.

You can also see why editing 24p is viewed as somewhat difficult!

Update Fall 2012

Since this post was originally written, another popular solution has emerged called Neo Scene which converts videos to the Cineform codec (now owned by GoPro). Neo Scene converts your AVCHD into the Cineform codec – files do become much larger but editing becomes much quicker and smoother. The Cineform codec is better suited for editing than is AVCHD and many editing programs can play Cineform coded video in real time, smoothly.

I do not – yet – own this product but have used the trial version and have used the free GoPro Studio (which also uses Cineform but does not support so many cameras). Cineform really works.

Cineform can also handled 24p files embedded in a 60i video stream. Versions are available for both Windows and Mac, and based on my experiments on Windows – Cineform coded files work fine in Sony Vegas Movie Studio 11 and in Magix Movie Edit Pro latest versions.

Converting Camera Video Files Direct to MP4 Format

Plug in your camera and copy the files from the camera to your hard disk. (You can also use iMovie’s Archive feature to do this for you).

Then, run the HandBrake program. It can read AVCHD files and convert directly to MP4 files. HandBrake is quite fast and can be configured to re-size your images to 1280×720, as well as de-interlacing (if you did not shoot in progressive). HandBrake is probably the fastest (and FREE!) utility for converting your camera files direct to MP4 files for viewing XBox360’s, Apple TV etc.

Toast 10 can also do the AVCHD to MP4 conversion in one step.

4 thoughts on “Working with AVCHD on the Mac”

  1. You didn’t mention that once imported to iMovie, an AVCHD file becomes an AIC file and there is loss. If going at 60i, there will be a lot of loss as it will be converted and split scan by scan to half the original resolution. The only real solution is to use another program (as much as I like using iMovie as well).

    1. Yes, there is going to be some small amount of loss – while AIC is not a lossless codec, it is pretty good. That is, in part, because it throws a lot of bits at the transcoding and why AIC files are typically 3 to 5x larger than the original input files.

      The only other “best” alternatives that I know of are to buy the newest versions of Final Cut Pro (pricey) which includes their ProRes 422 codec, which is supposedly one of the best. The new versions of FCP can import the AVCHD file and transcode to ProRes.

      The other is to edit on Windows and use Sony Vegas – either the consumer version or the professional version. Sony Vegas edits AVCHD files directly and does not transcode, I believe, except for where it does transitions you add during editing.

      I get very good results going from AVCHD to either AIC or Photo JPEG compression. The 24p inverse telecine operation does add a 2nd transcode operation, however. Still, I am very pleased with my results when compared to an XH A1 shot and edited in native HDV/24p and both output to a large screen HDTV. If pause and examine the frames very carefully I can detect a tiny bit more sharpness in the XH A1 images – I can’t say, though, whether that is due to the sharper, larger lens of the XH A1 or because of the AVCHD transcoding process.

      There are two ways to avoid interlaced video with the HG10 – and this may work for other cameras too. The HG10 has only one progressive mode – 24p. It lacks 30p. However, if your subject is appropriate, you can manually set the shutter speed to 1/30th of a second and you will get real 30p due to how the camera operates.

      I virtually never shoot 60i anymore. Either 30p or 24p. I like using 24p especially for indoor, night and any other low light situation as we can lengthen the shutter to 1/24th of a second.

      Ed

    2. Yes, there is going to be some small amount of loss – while AIC is not a lossless codec, it is pretty good. That is, in part, because it throws a lot of bits at the transcoding and why AIC files are typically 3 to 5x larger than the original input files.

      The only other “best” alternatives that I know of are to buy the newest versions of Final Cut Pro (pricey) which includes their ProRes 422 codec, which is supposedly one of the best. The new versions of FCP can import the AVCHD file and transcode to ProRes.

      The other is to edit on Windows and use Sony Vegas – either the consumer version or the professional version. Sony Vegas edits AVCHD files directly and does not transcode, I believe, except for where it does transitions you add during editing.

      I get very good results going from AVCHD to either AIC or Photo JPEG compression. The 24p inverse telecine operation does add a 2nd transcode operation, however. Still, I am very pleased with my results when compared to an XH A1 shot and edited in native HDV/24p and both output to a large screen HDTV. If pause and examine the frames very carefully I can detect a tiny bit more sharpness in the XH A1 images – I can’t say, though, whether that is due to the sharper, larger lens of the XH A1 or because of the AVCHD transcoding process.

      There are two ways to avoid interlaced video with the HG10 – and this may work for other cameras too. The HG10 has only one progressive mode – 24p. It lacks 30p. However, if your subject is appropriate, you can manually set the shutter speed to 1/30th of a second and you will get real 30p due to how the camera operates.

      I virtually never shoot 60i anymore. Either 30p or 24p. I like using 24p especially for indoor, night and any other low light situation as we can lengthen the shutter to 1/24th of a second.

Leave a Reply to ipad cover Cancel reply

Your email address will not be published. Required fields are marked *