H264 movs

Hi,

I have just used the Catalyst file processor to convert various movs and mps, which mostly seem to use H264 and are in various sizes from 1920 x 1080 downwards. I chose AIC same as source. (The files came from vimeo mostly).

Some of the newly outputted files won't play in Catalyst or quicktime, displaying either a whitescreen, or a whitescreen with flickers of colour. I can't see any noticeable difference between what's worked and what's failed (using Quicktime movie Inspector), and the original files play in Quicktime. I've tried converting the same files again and it seems to be a problem with the specific files.

Is there anything that I should look at/for? I will try re-encoding prior to loading into Catalyst for conversion.

Thanks in advance for your time!

Thanks in advance

H.264 will play in Catalyst although AIC is the preferred. My first thought is that there are other issues beyond catalyst with you media. Have you tried converting a test group with something like Mpeg Stream Clip, Compressor, After Effects, or Adobe Media Encoder? Try a test batch and see if you still have the same problem. There may be other aspects within the H.264 you don't know about.

Hi,

thanks for the reply. I re-encoded (AIC) all the problem files prior to loading into Catalyst and they worked. I never did spot why some worked, and some didn't...

H264 as is uses interframe compression which is completely unsuitable for use in Catalyst. Interframe compression uses interframe prediction to make use of redundancy between neighbouring frames, and thus achieve higher compression ratios. Interframe compression codecs use a series of frames which are interdependent on each other called a group of pictures (GOP) structure. This comprises of Intra (I) frames, Bidirectional (B) frames, and Predictive (P) frames in a particular sequence. This is why it is tricky to playback MPEG-2 backwards or do Inframe/ Outframe stuff with it.

H264 is also rather processor intensive to decode.

Catalyst likes codecs that use intraframe compression where the frames use spatial compression only, such as DV, Photo-Jpeg, AIC, ProRes etc.

AIC is a bit old school. You are much better off with ProRes Lt or Proxy. They are 10 bit, 4:2:2 and look much nicer than AIC, which is 8 bit, 4:2:0. Also ProRes supports hyper-threading. Macs love ProRes of any flavour, but ProRes Proxy gives blistering performance on Catalyst.

Hugh