MP4 or AVCHD

Tim Knapp · July 21st, 2015, 04:46 PM

Oh, and here is a real "kick in the pants" ... or at least a monkey in the wrench:

I recently bought a 70D which is great for video, and actually looks better than my XA25's video overall (mostly because it is a bigger sensor, better lenses, improved shallow DOF, etc.), but as far as the codec, it is:

MP4/AVC, High@L4.1, and NO CABAC. And again, it looks at least as good, and often better. So codec isn't everything I suppose.

Seth Bloombaum · July 21st, 2015, 10:42 PM

One thing not mentioned in this thread: It's very worthwhile testing the variations your camera provides in your usual NLE.

For example, IIRC the Canon XA20's version of MP4 requires timeline rendering in Premiere/Mac, while the AVCHD doesn't. Shoot AVCHD on this cam/NLE for better workflow. LPCM was mentioned above - this uncompressed audio is a good thing to have in many NLEs, and is better sound too.

Of course if I had a camera doing 1080p60 like Mark R. above, I'd probably use that quite a bit, even if it did require a little more work.

Tim K., no, codec isn't everything. CABAC is just another compression algorithm, packing more data into a smaller space. If you have more space, you can get the same quality at lesser compression/greater bitrate. The info you provided is virtually identical across that MP4/AVCHD implementation, but the biggest determining factor for quality will be bitrate.

h.264 levels are a little misleading. A "level" specifies the maximum samples, resolution, framerate, etc. That one version is MP4/4.1 and the other AVCHD/4.2 doesn't say that the specific 4.2 hardware codec in use actually *does* include any higher spec video than the 4.1 video. The real story for a camcorder's video codec is resolution, framerate, bitrate, and compression quality.

One of the best ways to try and break a codec is to point your cam at water that is being rippled by the wind. It can really stress the codec, as every pixel is changing on every frame. This should quickly reveal any macroblocking problems, where individual pixels get ganged up into groups of pixels, 8x8, 16x16, sometimes bigger, when the codec can't keep up.

Jody Arnott · July 24th, 2015, 05:47 AM

The video quality isn't the only consideration. For example, I import AVCHD footage from my C100 into Avid Media Composer using the AMA function (which is importing the files directly without transcoding). It works well, without much lag when working with the footage.

However when importing MP4 files with AMA, it is almost impossible to work with the footage because it takes a good 4-5 seconds whenever I need to scrub through the timeline to a different position. Transcoding the MP4 files to Avid's native DNxHD codec solves the problem - but it takes a VERY long time to transcode (almost 1:1), even with a very powerful computer.

So knowing what file types your NLE works best with is also worth considering.

Seth Bloombaum · July 26th, 2015, 05:55 PM

Quote:

Originally Posted by Seth Bloombaum

One thing not mentioned in this thread: It's very worthwhile testing the variations your camera provides in your usual NLE...

Quote:

Originally Posted by Jody Arnott

The video quality isn't the only consideration. For example...

...when importing MP4 files with AMA, it is almost impossible to work with the footage because it takes a good 4-5 seconds whenever I need to scrub through the timeline to a different position. Transcoding the MP4 files to Avid's native DNxHD codec solves the problem - but it takes a VERY long time to transcode (almost 1:1), even with a very powerful computer.

So knowing what file types your NLE works best with is also worth considering.

Um, right ;-)

Two examples from Jody's and my experience; sometimes finding a good workflow for your particular camera and NLE will make the decision for you!

As Jody points out, transcoding is always an option. This is worth considering if you find that the most time-efficient workflow for your systems sometimes doesn't provide the quality you want, EG,
Greenscreen compositing,
Heavy color correction or grading.
High-motion video, sometimes including movement from handheld work, as well as moving subjects.

Mostly, if you can get away without transcoding one of your camera's codecs, that's the one you want... until you run into a problem.

July 21st, 2015, 04:46 PM	#16
Tim Knapp New Boot Join Date: Aug 2013 Location: Baltimore, MD Posts: 22	Re: MP4 or AVCHD Oh, and here is a real "kick in the pants" ... or at least a monkey in the wrench: I recently bought a 70D which is great for video, and actually looks better than my XA25's video overall (mostly because it is a bigger sensor, better lenses, improved shallow DOF, etc.), but as far as the codec, it is: MP4/AVC, High@L4.1, and NO CABAC. And again, it looks at least as good, and often better. So codec isn't everything I suppose.

July 21st, 2015, 10:42 PM	#17
Seth Bloombaum Inner Circle Join Date: Sep 2003 Location: Portland, Oregon Posts: 3,420	Re: MP4 or AVCHD One thing not mentioned in this thread: It's very worthwhile testing the variations your camera provides in your usual NLE. For example, IIRC the Canon XA20's version of MP4 requires timeline rendering in Premiere/Mac, while the AVCHD doesn't. Shoot AVCHD on this cam/NLE for better workflow. LPCM was mentioned above - this uncompressed audio is a good thing to have in many NLEs, and is better sound too. Of course if I had a camera doing 1080p60 like Mark R. above, I'd probably use that quite a bit, even if it did require a little more work. Tim K., no, codec isn't everything. CABAC is just another compression algorithm, packing more data into a smaller space. If you have more space, you can get the same quality at lesser compression/greater bitrate. The info you provided is virtually identical across that MP4/AVCHD implementation, but the biggest determining factor for quality will be bitrate. h.264 levels are a little misleading. A "level" specifies the maximum samples, resolution, framerate, etc. That one version is MP4/4.1 and the other AVCHD/4.2 doesn't say that the specific 4.2 hardware codec in use actually does include any higher spec video than the 4.1 video. The real story for a camcorder's video codec is resolution, framerate, bitrate, and compression quality. One of the best ways to try and break a codec is to point your cam at water that is being rippled by the wind. It can really stress the codec, as every pixel is changing on every frame. This should quickly reveal any macroblocking problems, where individual pixels get ganged up into groups of pixels, 8x8, 16x16, sometimes bigger, when the codec can't keep up. __________________ 30 years of pro media production. Vegas user since 1.0. Webcaster since 1997. Freelancer since 2000. College instructor since 2001.

July 24th, 2015, 05:47 AM	#18
Jody Arnott Major Player Join Date: Mar 2012 Location: Hamilton, New Zealand Posts: 747	Re: MP4 or AVCHD The video quality isn't the only consideration. For example, I import AVCHD footage from my C100 into Avid Media Composer using the AMA function (which is importing the files directly without transcoding). It works well, without much lag when working with the footage. However when importing MP4 files with AMA, it is almost impossible to work with the footage because it takes a good 4-5 seconds whenever I need to scrub through the timeline to a different position. Transcoding the MP4 files to Avid's native DNxHD codec solves the problem - but it takes a VERY long time to transcode (almost 1:1), even with a very powerful computer. So knowing what file types your NLE works best with is also worth considering.