A lot of folks have asked me this and hence the following explanation by Adobe’s Mike Kanfer should help debunk this conundrum.
“Yes, H.264 is definitely not considered a finishing codec, but to be clear, Premiere Pro does not use it in that way. The H.264 is read natively by Premiere and once it is decoded into the app. it “resides” internally in a 32 bit float extended color space that is unmatched for color fidelity and dynamic range. Your tests at Laser Pacific have proven that. There is no need to transcode to Pro Res, although if one prefers to work with that type of intermediate, the Adobe workflow can handle it just fine…ProRes is a great intermediate codec, but depending on the original content, some information might be lost compared to how Premiere Pro decodes the same file. For a full explanation, please refer the poster to my longer explanation below:
Adobe CS5 reads the H.264 files natively into Premiere Pro and After Effects at the highest possible quality. Our color gamut and dynamic range for tonal detail from shadow to highlight is unsurpassed. There is even support for over-brights beyond 100% in After Effects. i.e. in plain English, we squeeze more out of these files than anything else out there! Shane Hurlbut’s filmout tests at Laser Pacific have verified that our interpretation of the H.264 is the smoothest and most filmic representation available. The magic comes from the use of proprietary interpretation algorithms and I might also mention that we bypass QuickTime for this process, which avoids the whole gamma conundrum. Once the file is living inside our apps on the timeline or project, we deal with the image information at the 32 bit float level. Now that is not saying we can make an 8 bit H.264 DSLR video capture look like perfectly shot IMAX footage scanned at 16 bits, but what we do offer up is the ability to edit, apply effects and color corrections within our apps. at an unprecedented level of quality. So edit, do your VFX and color correction in Premiere Pro and After Effects with confidence that you are getting the best results. Now for the next step…we have all the typical options for exporting these files, so if they have to be passed on to another vendor for DI or another system, use the best option that suits you. For Shane’s bootcamp, we exported edited Premiere Pro projects to industry standard uncompressed 10 bit DPX files, which were then color corrected by a Quantel Pablo and projected on a huge screen. They looked absolutely amazing. Cineform is also an amazingly good compressed or uncompressed intermediate codec that rivals Pro Res and DNX and works great with CS5 on both Mac and PC. If you have Final Cut Pro on your MAC, you can choose to export all the various flavors of Pro Res through our Media Encoder, if that works better for you. Then, and only then in the process would you want to choose it as an output option. Converting your files to Pro Res beforehand for use in Adobe CS5 works great, but will not take full advantage of all the image processing that we offer by working natively in H.264. What you NEVER want to do though is to output H.264 as an intermediate. As the blogger mentions, yes…it would be like re-compressing an already compressed format…like saving a JPEG as a JPEG again. One caveat here is for the PC folks…Adobe can’t directly output Pro Res through the Media Encoder on Windows for obvious reasons (Final Cut is only for MAC), and that is where the Pro Res codec is supplied. So if you are on a PC, I recommend that you use uncompressed 10 bit DPX output as an intermediate (now available in Premiere Pro’s 5.0.2 free update which includes timecode support), a Cineform workflow, or use AJA’s KiPRO in conjunction with Adobe CS5 to layoff your finished timeline to Pro Res through this amazing and affordable device.”