C100: Canon c100 markll : Mp4 or AVCHD

L

Langenmedia

New member
Can anyone advice of using which codec: mp4 or AVCHD. I own a C100 Markll. The manual says MP4 is for more web related shooting but
it stands well in FCPX for editing. MP4 has a higher bitrate (35) but more audio compressing. I want to shoot in 1920 X 1080 50P. Any tips??.
 
I find no discernible difference between the two wrappers when it comes to IQ. Yes AVCHD has the Dolby LPCM audio, but the AAC inside the MP4 has made some pretty significant advances (it used to be pretty poor).

Also, just because one wrapper has a higher bit rate does not always mean it will be higher quality than a lower bit rate in another wrapper. It could just mean the higher bit rate wrapper is simply less efficient.

With all that being said, I much prefer the file structure of MP4, so I shoot in that almost exclusively.
 
The higher bitrate is only for the 60p frame rate. I don't notice any quality difference at all. In Premiere, the audio is instantly converted to floating 32 bit for editing, so I don't think the difference in audio will have any effect. I would just focus on which is the easier workflow in Final Cut, as it seems more picky than Premiere Pro.

In Premiere, I can drag either type right off the card and on to the timeline instantly (apart from the audio conforming thing).

I find the frame rates much easier to deal with using MP4 in Premiere. On the Mark I, the 60i and 30p both appear as 29.976, and you have to interpret the footage differently to get the 30p to play properly. Now that the Mark II has actual 60p, this is less of a problem. But at least I know 30p will show up as actual progressive 30p in the MP4 wrapper.
 
I did a little testing yesterday in the studio, shooting a contrasty scene with lots of sharp diagonals, highlights, shadows, and a bright red fire extinguisher thrown in for good measure. The methodology was shooting Wide DR, exact same settings across both shots, MP4 at 24 Mbps 25P and AVCHD at 24 Mbps LCPM 25P.

I found the IQ of each pretty close in terms of resolution, edge fidelity, etc. Where I did see a big difference was in the shadows, where AVCHD was significantly cleaner and exhibited far less artifacting than MP4, particularly in the blue and red channels. It was visually quite noticeable when viewing the clip at 100%. MP4 displayed the shadows as large, blotchy artifacts, the sort we've come to know (though not love) in our H264 compressions. AVCHD on the other hand seemed to comb the shadows with a much finer dithering filter (I'm not a compressionist, so forgive my terminology). The result was it held the fine details much better than MP4.

Bit of a pity really - much like others here I was looking forward to the simplicity of the MP4 file structure.
 
pmcdonald said:
I did a little testing yesterday in the studio, shooting a contrasty scene with lots of sharp diagonals, highlights, shadows, and a bright red fire extinguisher thrown in for good measure. The methodology was shooting Wide DR, exact same settings across both shots, MP4 at 24 Mbps 25P and AVCHD at 24 Mbps LCPM 25P.

I found the IQ of each pretty close in terms of resolution, edge fidelity, etc. Where I did see a big difference was in the shadows, where AVCHD was significantly cleaner and exhibited far less artifacting than MP4, particularly in the blue and red channels. It was visually quite noticeable when viewing the clip at 100%. MP4 displayed the shadows as large, blotchy artifacts, the sort we've come to know (though not love) in our H264 compressions. AVCHD on the other hand seemed to comb the shadows with a much finer dithering filter (I'm not a compressionist, so forgive my terminology). The result was it held the fine details much better than MP4.

Bit of a pity really - much like others here I was looking forward to the simplicity of the MP4 file structure.
Click to expand...

I'd be interested in seeing some screen grabs from your camera test.
 
Same settings (25P, 1/50, ISO850 from memory, locked WB), slight bump in this case so a slight difference in framing, blue channel with a uniform level filter applied to both, image blown up to 200%. You may need to view them at full size to get the effect.

They're obviously both noisy as hell and not the sort of thing you'd ever try and achieve this side of art school, but to my eyes the AVCHD exhibits a finer compression block profile with some interesting dithering happening between the blocks that preserves detail better and overall appears less noisy. This is particularly evident when looking at moving footage.

There's not a huge amount of difference between the two, but until I do some more testing across a range of shots I'll be leaning towards AVCHD (sigh). I want to stress that this is the result of one test I ran in a reasonably controlled but far from scientific setting. I encourage everyone interested in this question to do their own testing before coming to any conclusions. Personally I'd sleep easy at night with either format. Obviously if this level of pixel peeping is important to you, you'd probably be using an external recorder.

AVCHD:
AVCHD.jpg
Full link: http://s10.postimg.org/4nck2jm8p/AVCHD.jpg

MP4:
MP4.jpg
Full link: http://s29.postimg.org/icaanw5wn/MP4.jpg
 
AVCHD vs MP4....Anyone else care to weigh in on this, for those of us who shoot onto SD cards?

The manual says MP4 is for more web related shooting
Click to expand...

The actual quote from the manual: "MP4 format is more suitable for uploading to the Web and for file transfer."

I'd like to keep things simple and shoot MP4 since that is where you can exercise slow motion. AND the content I shoot and edit is for web delivery. (web series, short videos, etc) If the file structure is easier, any strong reason I should shy away from MP4? Thanks in advance, this forum has been helpful for a new C100 shooter here.
 
Unless there's a dramatic image quality difference, I'd just stick to MP4. It's easier all around.

I don't really see much a difference in the two images pmcdonald posted above.

Isn't it the same codec and bitrate? Just in a different container?
 
drummondb said:
Isn't it the same codec and bitrate? Just in a different container?
Click to expand...

Pretty sure that's the case... I think they're both H.264, it's just the wrapper and audio specs that change between them.

Lets be clear on terminology here though because I think there's some confusion above...

CODEC: Is how the video (and audio for that matter) is encoded. It has a bitrate and affects the image quality.
WRAPPER (or container): Is the file format that "wraps" the video and audio files. It has no real impact on video quality EXCEPT that certain containers can only hold certain codecs.

AVCHD and MP4 are wrappers. In the C100 Mark II, they both contain the AVC/H.264 encoded video and differently-encoded audio. All of the bitrates are the same except the MP4 container can hold a higher (35Mbps) bitrate for use on 1080p60 video to get equivalent quality to 1080p30 at 28Mbps.
 
High everyone. We just received delivery of a C100 MrkII and i"ve had the same question. Weighing different things I've read and a few brief tests we've decided on AVCHD 24mbps LPCM. Sigh, I was hoping to get away from the crazy AVCHD file structure, but we will continue to use clipwrap as it doe's not re-encode. Just wraps things nicely in one package. A pain to have to do this, but it works. We've been using it for a while with another AVCHD camera.

Here's why we choose AVCHD. Everything I've read about the Mpeg4 spec is in reference to delivery not acquisition. We wanted the higher bitrate that mpeg4 offers, but the audio is extremely low. The AAC audio on the Mpeg4 is only 256 kbps, AVCHD is 1,536 kbps. At least for us we are sticking with AVCHD for now.

Oh, someone may have mentioned this, and it took me a while to find it out, both are using the H.264 codec AVC (Part 10).
 
littlefish said:
....Here's why we choose AVCHD. Everything I've read about the Mpeg4 spec is in reference to delivery not acquisition. We wanted the higher bitrate that mpeg4 offers, but the audio is extremely low. The AAC audio on the Mpeg4 is only 256 kbps, AVCHD is 1,536 kbps. At least for us we are sticking with AVCHD for now....
Click to expand...

To each their own. I'm going with MP4. Premiere Pro converts the audio to floating 32 bit for editing, and I don't hear any difference once the files are on the timeline. The other benefits that MP4 offer outweigh, in my mind, the higher bitrate audio that I don't notice. A lot of the time the audio from the C100 is a scratch track anyway.
 
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