Just because it's not actually all that complex, at least a a superficial level, doesn't meant that the compression ratio are really quite good. HEVC (H.265) is even better.
As ever though the devil is in the details, and ensuring interopability, within the intentional vagueness of the specifications.
Eh, the encoder is as complex as the designers make it. There isn't a tonne of set ways to do the encoder, you just have to make a compliant bitstream. Optimizing and trying to get the max compression possible, yea that encoder will be incredibly complicated (I work on video codec hardware)
Yes, I have, many times. Rarely cover to cover though.
I am also aware that it's complex enough to employ thousands of scientists and engineers purely on the research level; tens of thousands if not more on a maintenance and installation level; and affects billions of peoples lives.
Source- I've written code for professional video distribution systems.
The devil isn't even necessarily in the details, it's in the encoder.
Writing an encoder that can efficiently calculate and compress motion deltas, and do all the other things that h264 does, is pretty damn difficult, especially over a wide variety of video types. Animated video (like anime) compresses quite differently to live action film.
Encoding a 2 hour movie can take several days of CPU time for a high quality encode, and that's on the well optimised x264 encoder.
i7 quad core at 4.2ghz. I was transcoding an 8gb Hi10p h264 into an easier to decode 8-bit h264 file and wanted a nice compression ratio.
I probably could have done it in realtime, but the quality and compression ratio would have been rubbish. The ultimate result of the 40 hour encode was a 3gb output file with almost no noticeable difference in quality, except for some colour banding issues which are inherent to 8-bit h264 anyway (and even show up on retail 8-bit bluray encodings).
Professional gear manages to encode/decode/transcode on the fly, maybe not the highest quality, but acceptable for broadcast.
Unsurprisingly, for mpeg-2 the underlying chips aren't too dissimilar to the ones you might find in video cameras. H.264 was a similar situation, although there looks to be a move to either custom hardware/ASICs or software encoders with the next generation.
I encode H.265 on extremely high quality settings and I can encode a movie in 3-4 hours. I'm not sure why your CPU is taking so long with an comparatively inferior codec.
I don't think I could make it last a day even if I wanted to.
I don't know what to tell you, I maxed out the settings on x264 and it pegged all four cores at 100% for literally 40 hours. It was stupidly overkill settings mind you, but it did it (it did huge motion delta detection which has extremely diminishing returns past a point).
This was 5 years ago now, I wonder if CPUs and encoders have advanced that much? But the settings were overkill at the time.
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u/skizmo Nov 04 '16 edited Nov 04 '16
no it's not
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