MOD and TOD
MOD and TOD are recording formats for use in digital
.Overview
![MOD/TOD directory structure](http://upload.wikimedia.org/wikipedia/commons/a/a3/Mod_tod_file_format.gif)
MOD and TOD are informal names of tapeless video formats used by JVC (MOD and TOD), Panasonic (MOD only) and Canon (MOD only) in some models of digital camcorders. Format names correspond to extensions of video files. Neither JVC nor Panasonic, who pioneered the format, explained the meaning of the file extensions, and the formats were never given an official name. Some think that TOD stands for "Transport stream on disk". MOD is used exclusively for standard definition video files, while TOD is used for high definition files.
The first camcorders that used MOD format appeared in 2003. JVC introduced the Everio GZ-MG30, which recorded directly to an internal hard disk drive. Panasonic unveiled the SDR-S100, which recorded to SD cards. The encoding scheme, data rate, frame rate and frame size closely matched parameters of
In January 2007 JVC announced its first high definition tapeless consumer camcorder, the Everio
In January 2008 Canon unveiled a family of tapeless standard definition consumer camcorders: the FS100, FS10 and FS11. All these camcorders record in MOD format.
Both MOD and TOD are file-based formats that are stored on a random-access media. Directory structure and naming convention are identical except for extensions of media files. Each file has a sequential name with last three characters comprising a hexadecimal number,[2] which allows for 4096 unique file names.
Standard definition video is stored in
Despite the file structure being unique to this video recording format, the location for still images follows the standard agreed upon by many still camera manufacturers.[4]
Standard definition video can be recorded in 4:3 and 16:9 formats. Some video decoders do not interpret the aspect ratio information in the media file header correctly, so 16:9 video may appear squeezed horizontally when viewed.[5] Software that is shipped with camcorders is capable of processing the aspect ratio information correctly, aided perhaps by the metadata stored in MOI files. There are also third-party tools for modifying the wide-screen aspect ratio information in the media file header so that it satisfies decoders which would otherwise fail to interpret this information correctly in an unmodified MOD file.[6][7][8] Some tools such as MediaInfo can correctly report the aspect ratio of widescreen MOD files, but media players may or may not display them correctly depending on the capabilities of the video decoder that they are utilizing at the time.
Conversion to widely accepted formats
MOD video can be viewed on a computer with a player that is capable of reproducing MPEG-2 video. This video can be easily authored for watching on a DVD player without recompression, because it is fully compliant with DVD-video standard.
TOD format is comparable with AVCHD, but cannot be directly played on consumer video equipment. Media files must be packaged into distribution formats like
While many camcorders that produce the MOD and TOD formats also include Windows and/or Mac conversion software to run on your computer, there are other tools available for free to do the same work. Transport stream files can be converted into program stream files without recompressing the video itself. For example, FFmpeg, a free program, performs the conversion on Windows, Mac and Linux systems with the following command
$ ffmpeg -i myClip.TOD -vcodec copy -acodec copy myClip.mpg
A similar command is used for MOD files:
$ ffmpeg -f mpeg -i myClip.MOD -vcodec copy -acodec mp2 -ab 192k myClip.mpg
This is no longer necessary if the
Specifications
Name of format | MOD | TOD |
---|---|---|
Media | Hard disk drive, solid-state memory cards | |
Video | ||
Video signal | 480i, 576i | 1080/60i, 1080/50i |
Frame size in pixels | 720 x 480, 720 x 576, 704 x 480, 352 x 480 | 1440 x 1080, 1920 x 1080 |
Frame aspect ratio | 4:3, 16:9 | 16:9 |
Video Compression | MPEG2 Video (profile & level: MP@ML) | MPEG2 Video (profile & level: MP@HL) |
Chroma sampling format
|
4:2:0
| |
Compressed video bitstream rate | ~3 - 10 Mbit/s depending on quality mode | ~17 - 30 Mbit/s depending on quality mode |
Audio | ||
Compression | MPEG-1 Audio Layer II or Dolby Digital | |
System | ||
Stream type | Program stream | Transport stream |
Media file extension | MOD (on camcorder),
MPG or MPEG (on computer) |
TOD (on camcorder),
M2T (on computer) |
See also
- H.262/MPEG-2 Part 2: digital video compression scheme
- HDV: tape-based high definition format that uses MPEG-2 Part 2 video compression
- XDCAM: a family of tapeless high definition formats that use MPEG-2 Part 2 video compression
References
- ^ "JVC GZ-HD7: World's First 1920x1080 MPEG-2 Camcorder".
- ^ "JVC Everio/High Definition FAQ". Archived from the original on 2012-05-29.
- ^ "Working with JVC Everio MOD and TOD files". Archived from the original on 2008-10-23. Retrieved 2008-08-25.
- ^ "KODAK Digital Camera: Navigating to Your Pictures".
- ^ "The MOD Video File Format".
- ^ "New version of SDcopy.exe available".
- ^ "Linux python script to work with mod files". Archived from the original on March 4, 2009.
- ^ "Python script copying mod files to mpg with automatic aspect ratio correction".