AVCHD vs MP4

[Tech9]

Hello, I am new here but look forward to spending much more time on this forum. I have a question maybe someone well versed in codecs can answer. Recently I upgraded my older Canon Vixia HF G10 to an HF G40. I do a lot of editing with FCPX and AVCHD has always been an issue unless I converted it. I saw that the G40 can use the MP4 codec at 1920x1080 60P at 35Mbs! The AVCHD maxed out at I think 28Mps which I believe is the limit for this codec. Considering that AVCHD and MP4 are very similar to each other would it not be beneficial for both quality and compatibility to use the MP4 at 35Mps?

Eric

[Case]

There may be devices that can show AVCHD as-is, that will not treat your MP4 at 35 Mbps in the same way. In such a case, your compatibility would decrease. If that is no issue, then the higher bitrate option would allow for increased quality, and be a good choice.

[ChapmanDolly]

As a G40 user I can confirm that the MP4 option at the highest bit and frame rate is the way to go. Also, if uploading to YouTube, keep the bit and frame rates the same. It pays off quality wise.

[LMotlow]

AVCHD has certain format requirements. https://www.videohelp.com/hd#tech. Scroll down the page for AVCHD specs.

[smrpix]

AVCHD has certain structural advantages, particularly in spanning long duration clips to make them more playable in NLEs.

If your problem is sloggy editing, consider a proxy workflow. Link to your files directly, convert to a low resolution i-frame only format (in FCPX you have options for low bitrate Pro-Res for example) and then link back to your sources for output.

[ChapmanDolly]

NLEs can have problems with any flavour of h264, though I have had no problems with MP4 1080 50p 35Mbps in Davinci Resolve 14. One advantage that the Canon G40 has is it uses the same CABAC encoding algorithm for both AVCHD and MP4, something a lot of camcorders do not do. It is this that gives MP4 an advantage at 35Mbps. Canon also state that this gives a higher quality picture on this camcorder, and models above.