AVCHD (Advanced Video Codec High Definition) is a high-definition and standard-definition recording format for use in digital tapeless camcorders. The format is comparable to other handheld video camera recording formats, particularly TOD, and HDV.

History

In 2003 Sony introduced XDCAM, one of the first professional tapeless video systems. The format used Professional Disc as recording media. The cost of media was comparable to other professional formats that existed at that time, and was prohibitively high for a consumer version of such a camera.

In April 2004 Sony mentioned the possibility of expanding XDCAM format or its variants into consumer market. Rick Clancy, Senior Vice President of Corporate Communications at Sony stated that XDCAM is more of a higher end professional HD product, and future consumer tapeless camcorders would be based on the less expensive Blu-ray format.^[1] Similar to Professional Disc, Blu-ray Disc format is based on blue-violet laser technology, but discs are single-sided, do not have protective cartridge, made of cheaper material and deliver lower data rates.^[2]

In September 2004 Sony augmented Blu-ray Disc specification with AVC and VC-1 video codecs in addition to existing MPEG-2 codec. New codecs provided more efficient compression and allowed using lower data rates, meaning longer movies could be stored on the same disc.^[3]

In May 2006 Panasonic and Sony jointly announced AVCHD as a tapeless high definition recording format. The format was based on existing Blu-ray Disc specification and allowed recording AVC-encoded video onto optical discs. 8 cm DVD discs were chosen as recording media instead of considerably more expensive Blu-ray discs.^[4]

In July 2006 the format was amended to include other types of random-access media, like SD/SDHC memory cards, "Memory Stick" cards and hard disk drives. Blu-ray discs were not included in the list of supported media.^[5]

The first AVCHD camcorder, Sony Handycam HDR-UX1, went on sale in September 2006 and recorded on 8 cm DVD media. Panasonic followed in spring 2007, releasing the HDC-SD1, the first AVCHD camcorder to record to SD/SDHC solid-state media, as well as a more conventional DVD-based model, the HDC-DX1. First Canon models included the HG10, with built-in hard disk drive storage, and the DVD-based HR10. JVC, which had been promoting its proprietary TOD video-format, finally introduced AVCHD-capable camcorders in April 2008.

Overview

File organization on Panasonic and Canon solid-state AVCHD camcorders

AVCHD (AVC-HD, AVC HD) video is recorded using the MPEG-4 AVC/H.264 video compression codec. Audio is stored in either compressed form (Dolby AC-3), or uncompressed form (multichannel PCM). Aside from recorded audio and video, AVCHD includes features to improve media presentation: menu navigation, slide shows and subtitles. The menu navigation system is similar to DVD-video, allowing access to individual videos from a common intro screen. Slide shows are prepared from a sequence of AVC still frames, and can be accompanied by a background audio track. Subtitles are used in some camcorders to timestamp the recordings.

Audio, video, subtitle, and ancillary streams are multiplexed together into an MPEG-2 Transport stream. The MPEG-2 transport stream is stored on random-access media as binary files. (In general, the FAT32 filesystem is used for memory cards and HDDs, ISO9660 is used on optical-disc.)

At the file system level, the structure of AVCHD is derived from the Blu-ray Disc specification, but is not identical to it. In particular, known Canon and Panasonic implementations use old-fashioned "8.3" file naming convention, while Blu-ray discs utilize long filenames. Another difference is location of the BDMV folder, which contains media files. On a DVD-based camcorder the BDMV folder is placed at the root level, just like on a Blu-ray disc. On the HDD-based Canon HG10 camcorder the BDMV folder is located in the AVCHD folder, which is placed at the root level.^[6] Solid-state Panasonic and Canon camcorders nest the AVCHD folder inside the PRIVATE folder.^[7] Following a standard agreed upon by many still camera manufacturers, solid-state camcorders have a root-level DCIM folder for still images.^[8]

AVCHD recordings can be transferred to a computer by connecting the camcorder via the USB connection. Many camcorders can record to removable media like SDHC and Memory Stick cards or DVD discs, which can be directly read on a computer. Copying files from an AVCHD camcorder can be performed much faster than from a tape-based camcorder, because it does not have to be done in realtime.

Just as HDV-editing once demanded an expensive high-end PC, the system requirements for AVCHD editing software currently limits it to powerful desktops. Compared to HDV, AVCHD video compression requires 2-4x the processing power, placing a greater burden on the computer memory and CPU. Older computers, even those that are capable of handling HDV, are often unacceptably slow for editing AVCHD, and can even struggle with smooth playback of AVCHD recordings. Improvements in multi-core computing and graphics processor acceleration is bringing AVCHD playback to mainstream desktops and laptops.

Media

AVCHD specification allows using several kinds of recording media, in particular recordable DVD discs, memory cards and hard disk drives.

DVD discs

Conventional 12 cm disc (left) compared to 8 cm disc (right)

DVD discs are the original media specified in the AVCHD standard. To reduce camcorder size, only smaller 8 cm discs, sometimes called miniDVDs, are allowed. Recording capacity ranges from 1.4 GB for a single-sided single layer disc to 5.2 GB for a double-sided double layer disc.

Pros:

• DVDs are familiar to most consumers, thus considered user-friendly
• Recordable DVDs are relatively cheap
• Recorded disc can be played back in a Blu-ray player
• Discs can be used as immediate backup media, can be stored separately from a camcorder

Cons:

• The longevity of recordable DVDs is argued to be much shorter than expected^[9]
• Rewritable DVDs cost more than write-once discs
• DVDs have to be "finalized" to be played back on set-top players
• AVCHD DVDs cannot be played back on regular DVD players
• Recording data rate for DVD-based AVCHD camcorders is limited to 18 Mbit/s
• A single-sided single-layer 8 cm DVD can fit only 15 minutes of video at 12 Mbit/s data rate, 10 minutes at 18 Mbit/s data rate

Hard disk drives

Canon HG10 HDD-based AVCHD camcorder

HDD was added as a possible media to AVCHD specification shortly after the new video standard had been announced. Capacity ranges from 30 GB to 120 GB.

Pros:

• Higher capacity than other media types, which allows for longer continuous recording.
• Faster recording data rate than DVDs and memory cards.

Cons:

• Sensitive to atmospheric pressure. Most HDD-based camcorders cannot be operated at altitudes above 10,000 feet (3,000 m).
• Vulnerable to mechanical shock or fast movement.
• A built-in HDD is non-removable. To transfer video to a computer the camcorder must be connected with a USB cable. Usage of an AC power adapter is often needed as well.

Memory cards

Canon HF100 camcorder using a 4 GB SDHC card

Many tapeless camcorders record to memory cards, such as SD/SDHC cards or "Memory Stick" cards. Utilizing solid-state flash technology, memory cards offer rewritable storage in a compact form-factor with no moving parts.

Historically, flash memory capacity and pricing have improved steadily since introduction to the consumer market.

Pros:

• Most computers and many TV sets and Blu-ray Disc players accept memory cards directly
• Compact and lightweight
• Not vulnerable to magnetic fields.^{citation needed}
• Can be easily backed up to DVD discs for viewing on various format video players and for long-term archiving.^[7]
• Some TVs, video players, personal portable media players, printers, etc. have built-in card readers and can play AVCHD video directly off a card.
• Can simultaneously store mixed media content, including still images (snapshot photos or still-frame captures).

Cons:

• per minute of recording, more expensive than a built-in HDD or DVD media
• Compatibility issues: not all card-readers can read high-capacity Memory Stick or SDHC cards
• Vulnerable to electrical damage, such as static discharge
• Not yet proven for archival purposes
• easier to misplace due to small form-factor

Playing back AVCHD video

Recorded AVCHD video can be played back in variety of ways:

• directly from a camcorder on a HDTV, through HDMI or component-video cable;
• burned onto writable Blu-ray disc, then played on a Blu-ray Disc player or on a PLAYSTATION 3 gaming console;
• recorded on a solid-state memory card (SDHC, Memory Stick), then played from many Blu-ray Disc players, on select Panasonic HDTV sets and on a PLAYSTATION 3 gaming console;
• burned onto DVD disc, then played from most Blu-ray Disc players;^[7]
• on a computer, playing from the camcorder connected via USB as an external storage device (with requisite software such as media player with AVC decoder installed);
• on a computer, playing directly from recorded media using a DVD drive or a memory card reader (with requisite software such as media player with AVC decoder installed);

Compatibility between brands

The implementation of H.264/AVC codec varies from manufacturer to manufacturer. In particular, Canon camcorders use High-Profile@Level-4.1, achieving 24 Mbit/s data rate. Known implementations of AVCHD in Sony camcorders are restricted to Main-Profile@Level-4.0, at a maximum data rate of 17 Mbit/s.

Consequently, a video recorded on one vendor's camcorder may not necessary be playable on another vendor's hardware. Same is true in regards to editing systems. Some editing tools may accept video from one brand but not from another. As time goes by and the standard matures, the compatibility improves.

Compatibility with Blu-ray Disc players

Before the AVCHD standard has been finalized, end users could master high definition content in Blu-ray format (BDMV) on either BD-R/BD-RE discs or regular DVD discs. At one point, the Blu-ray Disc Association was considering separating studio content and home-made content using different folders, namely BDMV for studios and HDMV or BDAV for home use. This idea did not seem to get a lot of traction.^[10] Instead, AVCHD is being offered as the means of distributing amateur video in high definition.

Being creators of AVCHD, Sony and Panasonic are keen to support AVCHD discs in their Blu-ray players. In particular, Sony BDP-S1, Sony BDP-S300, Panasonic DMP-BD10, Panasonic DMP-BD30, and the PLAYSTATION 3 can play AVCHD video recorded onto a DVD disc. The PLAYSTATION 3 can also play AVCHD content from connected USB storage devices. Select Panasonic players and television sets are capable of playing AVCHD content off of SDHC memory cards.

Other manufacturers do not provide reliable AVCHD support in their products. For example, Samsung removed support for both "BDMV on DVD" and "AVCHD on DVD" in a recent firmware release 2.3 for the BD-P1200 player.^[11] The removed features were not added back in the subsequent 2.4 firmware release.

AVCHD 1080i

An example of interlace combing

Most AVCHD camcorders released to date record 1080i interlaced video. This creates issues when such video is watched on a computer or when it is rescaled. Computer monitors as well as plasma and LCD televisions are inherently progressive. Watching interlaced video on a progressive display device may produce horizontal ripples known as combing artifacts.

Deinterlacing allows getting rid of combing artifacts, but may reduce vertical resolution. Interlaced video can be deinterlaced in post-production and delivered as progressive, or it can be deinterlaced on playback. All modern flat-panel televisions have a built-in deinterlacing engine, so deinterlacing is not required if video is distributed on DVD or Blu-ray Disc. Watching interlaced video on a computer can be more complicated, but some codecs provide different deinerlacing schemes that can be manually chosen by a viewer.^[12]

Some 1080i AVCHD camcorders offer capturing and recording of progressive video, borrowing techniques from television industry. There are two major methods of packaging progressive video into interlaced carrier signal depending on whether a particular video system utilizes 50 Hz or 60 Hz scanning.

50 Hz systems commonly use Progressive segmented frame (PsF) recording scheme, which originates from 2-2 pulldown technique. This scheme is utilized in Canon camcorders for 50 Hz market ("PF25" mode, 25 frame/s) and in some newer Canon camcorders for 60 Hz market ("PF30" mode, 30 frame/s). Such a video can be processed with standard interlaced hardware and software. When handled properly, it retains full vertical resolution.

Another approach has been borrowed from the 60 Hz television system, which uses 2-3 pulldown to broadcast movies. This recording scheme was originally meant to add cinematic feel to interlaced video, but newer editing systems are capable of recognizing the pulldown pattern and recover the original frames. This process is known as inverse telecine or film-mode deinterlacing. Select camcorders from Canon and Panasonic are capable of recording 24 frame/s progressive video using this scheme.

The major downside of recording progressive video within an interlaced stream is that technically video remains interlaced and is detected as interlaced by most editing tools. A videographer has to remember how a particular video was shot, or has to visually check video frames and make a correct decision.

Another disadvantage is that frame rate cannot be higher than half of field rate, this means that shooting 1080p50 or 1080p60 video is not possible with this technique.

AVCHD 720p

AVCHD specification supports 720p progressive, but this mode has not been widely used.

As of September 2008, the Panasonic AG-HMC150 is the first and only AVCHD camcorder to support recording in 720p. All other AVCHD camcorders record HD at 1080-line resolution. The AG-HMC150 is notable in that it supports both 720p and 1080i/1080p recording-modes, and that progressive-recordings are stored using true progressive-frames (as opposed to the more common technique of storing frames as paired-fields, flagged for pulldown or PsF.)

The use of the native progressive recording simplifies the editing process by eliminating the time-consuming inverse-telecine step for 24p source material.

Hardware Products

Sony

• September 2006: HDR-UX1 (DVD), HDR-UX3/UX5 (DVD), HDR-UX7 (DVD)
• October 2006: HDR-SR1 (30 GB HDD)
• June 2007: HDR-SR5 (40 GB HDD), HDR-SR7 (60 GB HDD)
• July 2007: HDR-SR5C (100 GB HDD), HDR-SR8 (100 GB HDD)
• Summer 2007: HDR-CX7 (Memory Stick Duo)
• March 2008: HDR-SR10 (40GB HDD, Memory Stick), HDR-SR11 (60 GB HDD, Memory Stick), HDR-SR12 (120 GB HDD, Memory Stick)
• HDR-TG1/TG3 (Memory Stick Duo)
• August 2008: HDR-CX12 (Memory Stick Duo)

Panasonic

• HDC-DX1 (MiniDVD), HDC-SD1 (SDHC)
• HDC-SD3 (SDHC, available in Japan only)
• HDC-SD9
• AG-HSC1U (SDHC, comes with portable 40 GB HDD storage)
• July 2007: HDC-SD5 (SDHC), HDC-SX5 (MiniDVD, SDHC)^{citation needed}
• HDC-SD7 (SDHC)
• January 2008: HDC-SD9 (SDHC), HDC-HS9 (60 GB HDD, SDHC)^[13]
• April 2008: AG-HMC70 (SDHC)^[14]
• June 2008: HDC-SD100 (SDHC), HDC-HS100 (60 GB HDD, SDHC)^[15]
• September 2008: AG-HMC150 (SDHC)^[16]

Canon

• HR10 (MiniDVD)
• 2007: HG10 (40 GB HDD)
• April 2008: HF10 (SDHC, build-in flash memory), HF100 (SDHC)
• September 2008: HF11 (SDHC), HG20 (HDD, SDHC), HG21 (HDD, SDHC)

JVC

• June 2008: GZ-HD10 (HDD, MicroSDHC), GZ-HD30/GZ-HD40 (HDD, MicroSDHC card, dual AVCHD and TOD recording)

Software

Converting

• FFDshow is a free, Open Source collection of codecs, including AVCHD.^[17] To convert, it then requires a video editor/compressor like VirtualDubMod.^[18]
• Canopus's AVCHD Converter can convert AVCHD clips into a format which can be edited using Canopus' EDIUS 3/4.
• A related tool, Canopus' ProCoder, can perform conversions that produce files which are usable by other video editing applications that do not support AVCHD natively.
• Cineform also offers the Neo HDV product that allows AVCHD clips to be converted into I-frame wavelet .avi files designed for editing and post-production. These .avi files can be accepted by many popular consumer non-linear video editors, including those from Sony, Adobe and Corel, which has acquired Ulead.
• Another useful product is CoreAVC, a reasonably cheap and quick h.264 decoder for Windows, which can decode AVCHD as well as a variety of other h.264 formats.
• MainConcept sells a codec that is recommended for Adobe Premiere users.
• Nero Vision can convert AVCHD files to other formats such as MPEG-2 or AVI and can import them for use in video editing projects. Nero Vision can also export Sony's M2TS format to MPEG-4 files that can be viewed by Quicktime 7.
• PowerDVD Ultra comes with an AVCHD codec that can be used with AVISynth and VirtualDubMod.^[18]
• There is a transcoder to convert AVCHD into P2, which is a format you can import into Avid's MXF file format. The transcoder was created by Main Concept and is distributed free of charge by Panasonic. Version 1.1 and earlier will convert AVCHD media from any camera, while version 1.2 and higher is locked to only work with AVCHD media created with Panasonic cameras. You can download the file from Panasonic.
• Latest version VAIO Editing Components that pre-loaded with Sony VAIO PCs can serve as a plug-in for Adobe Premiere Pro 2 to support AVC-HD import/export and editing.
• VoltaicHD is a simple yet useful tool to allow you to convert AVCHD files into other useful formats. The PC version allows output to WMV and AVI files. A Mac version is also available. HD Quick Look from ShedWorx lets you view the first frame of your AVCHD files (mts or m2ts) without even opening them. View multiple files as a slide show, as an index sheet or full screen - all with a single click.
• Badaboom from Elemental Technologies uses the NVIDIA card in your computer to drastically accelerate conversion of AVCHD to various H264 formats including iPod, AppleTV, PSP.

Editing

The following video-editing software features support for the AVCHD format:

• Adobe Premiere Elements 7
• Apple's Final Cut Express 4, Final Cut 6.0.1, and iMovie '08 (Bundled with all new macs) do not support editing of AVCHD clips directly. Imported AVCHD clips are auto-converted into the Apple Intermediate Codec format, .^[19]
• ArcSoft's TotalMedia Extreme
• Avid Xpress Pro, Avid Media Composer
• Corel's Ulead DVD MovieFactory 6
• CyberLink's PowerDirector 6
• Grass Valley's Edius 5.0
• Nero 7 Ultra Edition Enhanced and Nero 8 Ultra Edition are software suites which contains the AVCHD editor, found in Nero Vision. Also included in this suite is Nero Showtime, which plays AVCHD files natively. Edited video can also be burned to DVD discs in AVCHD format for playback on hardware players or in Blu-ray format.
• Pinnacle's Studio Plus 11 & 12
• Sony Vegas 7.0e
• Vegas Pro 8
• Vegas Movie Studio Platinum 8
• Vegas Movie Studio Platinum 9
• TMPGEnc 4.0 XPress.

• Other developers have pledged their support but it may still take some time for the implementation.

See the comparison of video editing software for more information on these products.

Authoring

• Production Premium CS4 supports AVCHD for Premiere Pro, AfterEffects, and Encore.

• (Mac) Roxio Toast Titanium 9 is a converting and authoring tool with rudimentary editing functions. It is capable of importing AVCHD video and authoring a DVD, AVCHD or Blu-ray disc. Standard definition authoring is included, high definition authoring requires HD/BD Plug-in, which costs extra.

Open Source Codecs

The following open source codecs can decode AVCHD files:

• ffdshow tryouts, revision 1971 May 23 2008, will decode AVC (H.264) format video.^[20]

Specifications

See also

• AVCREC: a standard to allow recording AVC encoded, Blu-ray Disc compatible HD content on ordinary DVD discs.
• Comparison of video editing software

References

1. ^ Liss, Robin (2004-04-18). "Sony plans to eventually release Blu-ray HD camcorder". Camcorderinfo.com.
2. ^ "Will Blu-ray discs require a cartridge?". Blu-ray FAQ. Blu-ray Disc Association.
3. ^ Kallender, Paul (2004-09-21). "Sony is developing 200GB Blu-ray storage". Macworld, Mac Publishing, LLC.
4. ^ AVCHD Format Co-promoters (2006-05-11). "Panasonic and Sony jointly developed new HD Digital video camera recorder format for recording on disc". Press release.
5. ^ AVCHD Format Co-promoters (2006-07-12). "Panasonic and Sony expand AVCHD recorder format". Press release.
6. ^ "Steve" (2008-05-18). "Canon HG10 AVCHD camcorder video sample".
7. ^ ^{a b c} "Backing up AVCHD video onto DVDs and playing them on a Blu-ray player". avchduser.com.
8. ^ "KODAK Digital Camera: Navigating to Your Pictures". KODAK (1999).
9. ^ Dixon, Douglas (September 2003). "DVD "rot": DVD Longevity and Reliability".
10. ^ "AVCHD compatibility testing". Doom9.com (November 2006).
11. ^ "02fx4dude" (2008-04-28). "Samsung BDP1200 discussion". avsforum.com.
12. ^ "Watching interlaced video on a computer".
13. ^ Panasonic Consumer Electronics Company (2008-01-06). "Panasonic unveils two new AVCHD camcorders with new face detection and intelligent shooting guide". Press release.
14. ^ Panasonic Consumer Electronics Company (2008-02-13). "Panasonic ships industry's first professional AVCHD shoulder-mount camcorder". Press release.
15. ^ Panasonic Consumer Electronics Company (2008-06-18). "Panasonic introduces two first AVCHD camcorders with a 3MOS system". Press release.
16. ^ Panasonic Consumer Electronics Company (2008-07-31). "Panasonic unveils pricing and ship date for the AG-HMC150 camcorder". Press release.
17. ^ "FFDshow". AfterDawn Ltd..
18. ^ ^{a b} Ludington, Jake (2007-01-18). "How to edit AVCHD M2TS files from Sony HDR-SR1 camcorders". Jake Ludington's MediaBlab.
19. ^ "Final Cut Express 4 User Manual" (PDF). Cupertino, CA, USA: Apple Inc. (2007). Search for "AVCHD".
20. ^ "ffdshow tryouts: The Official Website".

External links

• AVCHD Official Consortium Web site
• How to Edit AVCHD Files with VirtualDub
• Panasonic DMP-BD10 AVCHD firmware update
• Sony BDP-S1E AVCHD firmware update (for European players with firmware below v3.20)
• Elecard AVCHD batch folder converter
• Voltaic HD Converter for Mac OS X
• RevolverHD for Mac
• HD Quick Look for Mac
• Voltaic HD Converter for PC
• Canopus AVCHD Converter Download
• MainConcept AVC codec
• Oxygen AVCHD Player
• Intro to cs4 and avchd editing