In BDAV's M2TS there are .clpi files, in AVCHD the same files are labeled as .CPI. As i understand, some sort of metadata is written into these files. The question is twofold:

  1. What metadata exists in these files? (both 'by the standard' and 'de facto', if there are differences)
  2. Are there any free/libre/open-source software tools that are able to extract this metadata from them?

An example of such a file is here.

  • @BartArondson, Interesting link, but that is talking about something that is within the m2ts file itself, some sort of switch in a stream, for me CPI files are getting generated by my camcoder, i have definitely set no copyright protection on anything.
    – v010dya
    Dec 10, 2013 at 19:23

2 Answers 2


As Professor Sparkles has correctly pointed out (I've just checked and confirm) — the MediaInfo tool can extract some metadata from these files. Here is a sample output from one of mine:

Complete name                            : /Volumes/CAM_SD/PRIVATE/AVCHD/BDMV/CLIPINF/00119.CPI
Format                                   : Blu-ray Clip info
File size                                : 502 Bytes

ID                                       : 4113 (0x1011)
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Width                                    : 1 920 pixels
Height                                   : 1 080 pixels
Display aspect ratio                     : 16:9
Frame rate                               : 50.000 fps

ID                                       : 4352 (0x1100)
Format                                   : AC-3
Format/Info                              : Audio Coding 3
Channel(s)                               : 2 channels
Sampling rate                            : 48.0 KHz
Compression mode                         : Lossy
Language                                 : English

ID                                       : 4608 (0x1200)
Format                                   : PGS
Language                                 : English

(But note that it can output more details in the --full mode.)

Also, it may be helpful to note that the AVCHD standard is proprietary and its spec is not publicly available. Attempts to reverse-engineer its components exist, and one of them is in this forum thread (from 2008): http://forum.doom9.org/showthread.php?t=141361


Did some quick research on the Internet and found this:

File extension CPI is AVCHD Video Clip Information File. The AVCHD directory contains a folder for clipinfo which contains one .cpi file for each .mts file in the stream folder. cpi (clip info) contains various contains metadata describing an AVCHD video stream, such as the frame rate, frames per second, and aspect ratio. The video and audio is stored in the mts/m2ts (Transport Stream) files.

It would appear that basic metadata about the camera (frame rate, aspect ratio, etc.) is saved in this format. You might be able to use ffdshow (open source) or similar to extract the metadata.

  • Ffdshow, as i understand it, is a Windows only package. I could try it out under wine of course, but can somebody with Windows confirm that it does actually report something like that from the file i've added as an example.
    – v010dya
    Jan 8, 2014 at 6:40
  • MediaInfo should be able to handle these files aswell.
    – timonsku
    Jun 3, 2014 at 23:41
  • Pavtube is a GPL violator.
    – llogan
    Jan 10, 2015 at 1:46

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