[Ivan Myles]

I should have noted in my previous comment that the 422 and DC precision options are only available with MPEG-2. The potential quality advantages of MPEG-2 won’t necessarily be realized when comparing MPEG2 Blu-ray to H.264 Blu-ray. Again, it is worth rendering test files.

[Ivan Myles]

At low bitrates H.264 is typically better when using a good encoder. (Older versions of Premiere/AME were lacking.)

At higher bit rates you could go either way. MPEG-2 offers a 422 profile and DC Precision up to 11-bits (10-bits with 422, IIRC). Both parameters improve image quality, especially with respect to macro-blocking. That said, H.264 from CS6 produces good results.

The choice ultimately depends on several factors: the encoder, encoder settings, the nature of the footage, and delivery requirements. When quality is the primary concern, it is best to render test clips and/or consider other encoders and codecs. If the alternatives are limited to H.264 or MPEG-2 from a recent release of Premiere/AME, I tend to use H.264 because the codec is ubiquitous.

[Ivan Myles]

Thanks for the comment. Most of the problem clips are from two mpeg files. However, not all clips from the those files have issues. In some cases there are copies of the same clip edited to different in/out points; some copies work, and others do not.

I also created uncompressed 4:4:4 intermediate files from the mpeg source files. Again, some work, others don’t.

Disabling effects applied to a clip allows all scopes to work properly. I moved the problem clips to another timeline, removed all effects, and then applied effects to the nested sequence. No issues so far.

[Ivan Myles]

Try: Edit > Preferences > Audio Hardware and check the Default Device.

The computer’s sound application will show which output is receiving the audio signal, also.

[Ivan Myles]

To help narrow down the list of potential root causes, I suggest creating two test projects (one for each source file). Try exporting a short clip from each using the desired export settings.

[Ivan Myles]

The end results appear to be the same whether using After Effects or Premiere Pro. However, Premiere requires the sequence and clip settings to match (resolution, pixel ratio, frame rate), but AE is more flexible. An oversized composition shows how the image floats outside the screen; this makes it easier to add animation keyframes if you want to reduce border size and/or scaling. The grid overlay in AE is helpful, too. Both of these features can be emulated in Premiere, though.

[Ivan Myles]

One more consideration is licensing. In general, H.264 movies under 12 minutes do not require distribution fees, while MPEG-2 requires fees.* Here is some general information from the MPEG LA web site:

SUMMARY OF AVC/H.264 LICENSE TERMS (PDF)
AVC/H.264 FAQ (web page)

MPEG-2 License Terms: Summary (PDF)
MPEG-2 License Agreement (web page)

* Provided for informational purposes only. I am not a lawyer and cannot provide legal advice. Please seek legal consultation.

[Ivan Myles]

The main advantage of H.264 is high compression and better relative quality at low bit rates. As data rates drop from Blu-ray to DVD to web, H.264 maintains better quality compared to other codecs. This is why it is popular format for internet and mobile distribution.

At high bit rates quality is relatively comparable for H.262, H.264, and VC-1, too. Other factors become more important than the choice of codec.

The biggest issue with MPEG2 at this point is that it has not received any further development for the past several years, so it does not incorporate advances in compression technology. But on a 30″ screen or smaller those DVDs still hold up well.

Issues with H.264 include color and luma shifts, and susceptibility to compression artifacts such as banding and macro-blocking. In truth, other 4:2:0 codecs experience similar problems, but the issues are more prevalent at low data rates (where H.264 is more likely to be used).

[Ivan Myles]

Turns out re-creating the problem clips only worked until effects were added, then the scopes froze up again. Nested sequences seem to be OK, but the approach is cumbersome.

[Ivan Myles]

Does the 1.5GB include preview files?