Extension .mpeg or .m2t when, what, where? at DVinfo.net

Tyson Persall · March 6th, 2008, 01:55 AM

Im confused. When you capture from an HDV camera isnt the extension type usually .m2t?
How come my captures are extension type .mpeg?

Im using Canon XHA1 with premiere pro CS3.

Just wondering cause the client is asking for .M2T files... and well, did i do something wrong?

Graham Hickling · March 8th, 2008, 01:05 AM

An m2t file is a transport stream; an mpg file is (usually) a program stream. Transport streams carry extra error correction and are used when data is being transmitted e.g., by satellite or - in the case of HDV cameras - down firewire cables. Program streams are typically used for playback from physical media, like DVDs.

Visually transport streams are identical to program streams, and there is software (e.g. MpegStreamclip) that can losslessly mux from one to the other.

Some software (e.g Procoder and probably MpegStreamclip) will tell you which type of file you have. If your files have been captured directly from the camera, chances are they are transport streams and you can simply manually change their extensions to m2t.

Ervin Farkas · March 10th, 2008, 08:53 AM

This brings up another question: what exactly happens at the time of capture?

I suspect that capturing with HDVSplit is simply copying the content of the tape to the hard drive, but what is happening when capturing directly into an NLE?

Graham Hickling · March 10th, 2008, 09:24 AM

I just checked with what I have available here .... when I take the .mpeg file that CS3 generates by 'capturing' HDV from the camera and load that into Procoder, Procoder reports that it's a transport stream.

All the parameters that Procoder reports seem to be identical to those for a raw .m2t file imported from the same camera using Cineform's HDLink.

Hope that helps.

March 6th, 2008, 01:55 AM	#1
Tyson Persall Major Player Join Date: Sep 2004 Location: North Hollywood, Atlanta Posts: 437	Extension .mpeg or .m2t when, what, where? Im confused. When you capture from an HDV camera isnt the extension type usually .m2t? How come my captures are extension type .mpeg? Im using Canon XHA1 with premiere pro CS3. Just wondering cause the client is asking for .M2T files... and well, did i do something wrong? __________________ Tyson X

March 10th, 2008, 08:53 AM	#3
Ervin Farkas Inner Circle Join Date: Aug 2005 Location: Atlanta/USA Posts: 2,515	This brings up another question: what exactly happens at the time of capture? I suspect that capturing with HDVSplit is simply copying the content of the tape to the hard drive, but what is happening when capturing directly into an NLE? __________________ Ervin Farkas www.AtlantaLegalVideo.com

March 8th, 2008, 01:05 AM	#2
Graham Hickling Trustee Join Date: May 2004 Location: Knoxville, Tennessee Posts: 1,669	An m2t file is a transport stream; an mpg file is (usually) a program stream. Transport streams carry extra error correction and are used when data is being transmitted e.g., by satellite or - in the case of HDV cameras - down firewire cables. Program streams are typically used for playback from physical media, like DVDs. Visually transport streams are identical to program streams, and there is software (e.g. MpegStreamclip) that can losslessly mux from one to the other. Some software (e.g Procoder and probably MpegStreamclip) will tell you which type of file you have. If your files have been captured directly from the camera, chances are they are transport streams and you can simply manually change their extensions to m2t.

March 10th, 2008, 09:24 AM	#4
Graham Hickling Trustee Join Date: May 2004 Location: Knoxville, Tennessee Posts: 1,669	I just checked with what I have available here .... when I take the .mpeg file that CS3 generates by 'capturing' HDV from the camera and load that into Procoder, Procoder reports that it's a transport stream. All the parameters that Procoder reports seem to be identical to those for a raw .m2t file imported from the same camera using Cineform's HDLink. Hope that helps.