Ivan Myles
Forum Replies Created
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Firstly, yes, MainConcept is the default H.264 encoder in the last few Adobe releases.
Secondly, regarding GPU acceleration, one needs to distinguish between rendering and compression. As of October/December 2013 AME supports GPU acceleration with CUDA and Open CL for a limited set of rendering tasks initiated within the encoder. Please refer to this Adobe Help page for more details.
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Yes, that is one option. I believe that codec has a luma shift that makes the encoded file darker. Export a short clip, import to FCP, and compare to the timeline.
The DPX codec is another potential option if available. Check with your client to be sure.
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Maximum H.264 resolution is 4096×2304. Try encoding your videos at allowable dimensions such as 4096×231 and 2731×2304 to see if that is the root cause.
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The short answer is no, I don’t have a concise reference to recommend.
The general topic consists of three main components: rendering in the NLE, compression with an encoder and codec, and resource constraint analysis of the computer hardware.
NLE Rendering: There are some good discussions at adobe.com and related blogs, but they tend to focus on individual effects. I found a great article on the overall rendering pipeline and how bit depth and color space affect results, but it won’t necessarily help you with hardware constraint analysis.
Compression: These discussions tend to be codec-centric. There are numerous books available. Ben Waggoner is a noted author in the field.
Hardware: I am familiar with the PC side, but there are certainly resources available for Apple systems. The general approach is to monitor your computer in real time using system software to identify hardware bottlenecks. Most of the business occurs in the CPU; the other components (memory, storage, GPU, I/O) only become an issue when a problem exists, such as insufficient memory, slow response (especially spindle hard disks and older I/O like USB2), full disk, etc.
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There are many potential causes, but it sounds like the TV or possibly the video player or playback device.
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Sorry, I made a mistake in the previous post. Been a while since I used MPEG2. I will edit the post shortly.
M = Number of B frames between I/P frames. For IBBP, M=3 produces a P or I-frame every third frame. The minimum is M=1, which corresponds to zero B-frames.
N = Number of frames between I frames. N=4 produces IBBPIBBPIBBP… Setting N=15 produces IBBPBBPBBPBBPBP as a group of pictures. Your spec doesn’t state GOP length. Admittedly, 4 is pretty short, and a number about half the frame rate is more common. Setting N=15 instead of a multiple of 4 (such as N=16) just changes the last frames in the group from BBP (16) to BP (15).
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Refer to “Video Export Settings”
https://help.adobe.com/en_US/mediaencoder/cs/using/adobemediaencoder_cs5_help.pdf
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MPEG2 codec with GOP settings:
M frames: 3
N frames: 4 for IBBPIBBPIBBP…
Closed GOP every: 4 (or possibly a multiple of 4)The other settings are marked accordingly.
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While the article states that Premiere Pro is 8- or 10-bpc studio swing, I don’t think that’s an accurate statement. It is my understanding that the application can render and encode in either RGB or Y’CbCr (YUV) at up to 32-bpc depending on the source footage, depth settings, effects applied, and codec.
In addition, you might choose to apply effects that change the color and/or luminance distributions. Referencing the scopes will help you stay within acceptable guidelines.
In the current HDTV era broadcasters might accept MPEG-2, H.264, ProRes, DNxHD, or other formats. It is important to understand and conform with each broadcaster’s specific delivery requirements. It might not be appropriate to apply the Levels effect, but you should not assume the source footage is broadcast-ready. Work from the broadcasters’ delivery specs and manage your color and luminance levels accordingly.
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No, you don’t need to transcode the source material to edit in Premiere Pro.
The Levels settings should work as outlined, but might not be appropriate depending on the footage. Use the YC Scope and RGB Parade to check the luminance and color distributions; adjust as necessary to keep luminance within requirements. There is a green vertical line on the right side of the YC Scope that shows the full range on each frame.
Also use the Vectorscope to check saturation levels; Use secondary color correction in the 3-Way Color Corrector effect to mask and adjust oversaturated areas.
If you are editing in 8-bpc color, the Broadcast Color filter could be applied in addition to or instead of the other effects.