QT converting AVI to MOV at DVinfo.net

Andrew Clark · July 9th, 2014, 12:35 AM

Hello -

When converting an AVI file into a MOV file using QuickTime, is there any image quality loss in doing this?

Les Wilson · July 9th, 2014, 03:03 AM

It's impossible to say without more information about your files.

There are ways to convert from AVI to MOV and lose IQ. AVI and MOV are file formats not video compression formats (CODECS). An AVI or a MOV file can contain various types of video and audio data each stored in a variety of CODEC formats. For example, you can have a MOV file with DV CODEC video or H.264. SO when converting file types, it depends on if you transcode the video data as to whether you will have a generation of loss due to recompression.

Clipwrap is a utility that can "re-wrap" the data from one file format to another. It can optionally transcode the video from one CODEC to another. If your AVI file has video in a Windows only CODEC, it will have to be transcoded into one of the CODEC formats common between the Windows and Macintosh world.

I'd think this is only an issue with old files or old equipment. Anymore these days there are great CODECS and software that supports them common in both worlds.

Andrew Clark · July 9th, 2014, 10:58 AM

@ Les -

Thanks and appreciate your reply!!!

What I did was, (on the MAC) opened up an AVI file (it was miniDV footage shot from either a VX1000 or XL1) in QTX and it automatically started converting the file to a MOV file. When it was finished, it played just fine ... in the QTX player.

I then opened the AVI file with the VLC player.

I played the the two files side by side on the same monitor and noticed that the VLC player (playing the AVI file) looked a bit more saturated than the QTX player (playing the "converted" MOV file).

Don't know if it is just a player issue/setting (haven't changed any settings on either player since installation) or if it's the QTX conversion process or ???

Not a huge issue for me; more curious than anything.

Les Wilson · July 10th, 2014, 10:07 AM

QTX player is doing the file format conversion only....not a transcode of the data. I believe the difference you are seeing is player dependent. Each interprets the display gamma differently. VLC will open MOV files too so open the avi and mov files side by side in VLC to compare.

Andrew Clark · July 10th, 2014, 05:48 PM

@ Les -

Agreed that it appears to be a "player" thing.

I've played both files (AVI and MOV) on both the Mac and Windows OS's and find that the footage on:

- Windows Media and the VLC players look the same (colors appear more saturated compared to the QT players)

- QT X and QT 7 (Windows) look the same as well (colors appear more neutral compared to Windows Media and VLC players)

Neither appears bad by any means; just different.

Using a film analogy ... this sort of reminds me of Provia vs. Velvia ... (both Fuji brand slide/transparency/reversal film stocks) ... where the QT players would be Provia and the WM/VLC players would be Velvia ... at least to my eyes.

July 9th, 2014, 12:35 AM	#1
Andrew Clark Major Player Join Date: Nov 2003 Location: Bay Area, CA Posts: 477	QT converting AVI to MOV Hello - When converting an AVI file into a MOV file using QuickTime, is there any image quality loss in doing this?

July 9th, 2014, 03:03 AM	#2
Les Wilson Inner Circle Join Date: Jan 2004 Location: Boca Raton, FL Posts: 3,014	Re: QT converting AVI to MOV It's impossible to say without more information about your files. There are ways to convert from AVI to MOV and lose IQ. AVI and MOV are file formats not video compression formats (CODECS). An AVI or a MOV file can contain various types of video and audio data each stored in a variety of CODEC formats. For example, you can have a MOV file with DV CODEC video or H.264. SO when converting file types, it depends on if you transcode the video data as to whether you will have a generation of loss due to recompression. Clipwrap is a utility that can "re-wrap" the data from one file format to another. It can optionally transcode the video from one CODEC to another. If your AVI file has video in a Windows only CODEC, it will have to be transcoded into one of the CODEC formats common between the Windows and Macintosh world. I'd think this is only an issue with old files or old equipment. Anymore these days there are great CODECS and software that supports them common in both worlds.

July 9th, 2014, 10:58 AM	#3
Andrew Clark Major Player Join Date: Nov 2003 Location: Bay Area, CA Posts: 477	Re: QT converting AVI to MOV @ Les - Thanks and appreciate your reply!!! What I did was, (on the MAC) opened up an AVI file (it was miniDV footage shot from either a VX1000 or XL1) in QTX and it automatically started converting the file to a MOV file. When it was finished, it played just fine ... in the QTX player. I then opened the AVI file with the VLC player. I played the the two files side by side on the same monitor and noticed that the VLC player (playing the AVI file) looked a bit more saturated than the QTX player (playing the "converted" MOV file). Don't know if it is just a player issue/setting (haven't changed any settings on either player since installation) or if it's the QTX conversion process or ??? Not a huge issue for me; more curious than anything.

July 10th, 2014, 10:07 AM	#4
Les Wilson Inner Circle Join Date: Jan 2004 Location: Boca Raton, FL Posts: 3,014	Re: QT converting AVI to MOV QTX player is doing the file format conversion only....not a transcode of the data. I believe the difference you are seeing is player dependent. Each interprets the display gamma differently. VLC will open MOV files too so open the avi and mov files side by side in VLC to compare.

July 10th, 2014, 05:48 PM	#5
Andrew Clark Major Player Join Date: Nov 2003 Location: Bay Area, CA Posts: 477	Re: QT converting AVI to MOV @ Les - Agreed that it appears to be a "player" thing. I've played both files (AVI and MOV) on both the Mac and Windows OS's and find that the footage on: - Windows Media and the VLC players look the same (colors appear more saturated compared to the QT players) - QT X and QT 7 (Windows) look the same as well (colors appear more neutral compared to Windows Media and VLC players) Neither appears bad by any means; just different. Using a film analogy ... this sort of reminds me of Provia vs. Velvia ... (both Fuji brand slide/transparency/reversal film stocks) ... where the QT players would be Provia and the WM/VLC players would be Velvia ... at least to my eyes.