3 ms·

I thought I'll learn something special about H.264, but all information here is high level and generic. For example if you replace H.264 with a much older tech

by szemet 10y ago

I thought I'll learn something special about H.264, but all information here is high level and generic. For example if you replace H.264 with a much older technology like mpeg-1 (from 1993) every sentence stays correct, except this: "It is the result of 30+ years of work" :)

phire 10y ago
Also the fleeting mention of b-frames, which mpeg-1 doesn't have. And I believe mpeg-1 doesn't use 16×16 macroblocks. Still, it's a good overview of generic video compression.
- szemet 10y ago
  https://en.wikipedia.org/wiki/MPEG-1#B-frames https://en.wikipedia.org/wiki/MPEG-1#B-frames https://en.wikipedia.org/wiki/MPEG-1#Macroblocks https://en.wikipedia.org/wiki/MPEG-1#Macroblocks
striking 10y ago
Sure, but also keep in mind that the technology hasn't changed much over time. Even HEVC, which causes extreme gains in compression on high-res video with minimal loss in quality, is still mostly the same algorithm as H.264 but with larger blocks, slightly more flexible coding units rather than frame-wide interpolation changes, and 35 rather than 9 directions recognized for predictions.
BEEdwards 10y ago
"This post will give insight into some of the details at a high level - I hope to not bore you too much with the intricacies." Did you miss the third paragraph? As someone who knew nothing about it before, I found it lived up to it's goal.
- iainmerrick 10y ago
  I think they just mean it shouldn't be "H.264 is magic", it should just be "video compression is magic" or some such. That irked me a little bit too.
warpzero 10y ago
I was a bit disappointed in this article for the same reason: this is a great primer for people new to MPEG video compression, but it doesn't have anything to do with H.264. I was hoping the author would write about H.264 specifically, for instance, how it was basically the "dumping ground" of all the little tweaks and improvements that were pulled out of MPEG-4 for one reason or another (usually because they were too computationally expensive), and why, as a result, it has thousands of different combinations of features that are extremely complicated to support, which is why it had to be grouped into "profiles" (e.g., Baseline, Main, High): http://blog.mediacoderhq.com/h264-profiles-and-levels/ http://blog.mediacoderhq.com/h264-profiles-and-levels/ I was also hoping that he would at least touch on the features that make H.264 unique from previous MPEG standards, like in-loop deblocking, CABAC Entropy Coding, etc.. Again, it's fine as an introduction to video encoding, but there's nothing in here specific to H.264.

by szemet 10y ago

phire 10y ago

Also the fleeting mention of b-frames, which mpeg-1 doesn't have. And I believe mpeg-1 doesn't use 16×16 macroblocks. Still, it's a good overview of generic video compression.

szemet 10y ago
https://en.wikipedia.org/wiki/MPEG-1#B-frames https://en.wikipedia.org/wiki/MPEG-1#B-frames https://en.wikipedia.org/wiki/MPEG-1#Macroblocks https://en.wikipedia.org/wiki/MPEG-1#Macroblocks

striking 10y ago

Sure, but also keep in mind that the technology hasn't changed much over time. Even HEVC, which causes extreme gains in compression on high-res video with minimal loss in quality, is still mostly the same algorithm as H.264 but with larger blocks, slightly more flexible coding units rather than frame-wide interpolation changes, and 35 rather than 9 directions recognized for predictions.

BEEdwards 10y ago

"This post will give insight into some of the details at a high level - I hope to not bore you too much with the intricacies." Did you miss the third paragraph? As someone who knew nothing about it before, I found it lived up to it's goal.

iainmerrick 10y ago
I think they just mean it shouldn't be "H.264 is magic", it should just be "video compression is magic" or some such. That irked me a little bit too.

warpzero 10y ago

I was a bit disappointed in this article for the same reason: this is a great primer for people new to MPEG video compression, but it doesn't have anything to do with H.264. I was hoping the author would write about H.264 specifically, for instance, how it was basically the "dumping ground" of all the little tweaks and improvements that were pulled out of MPEG-4 for one reason or another (usually because they were too computationally expensive), and why, as a result, it has thousands of different combinations of features that are extremely complicated to support, which is why it had to be grouped into "profiles" (e.g., Baseline, Main, High): http://blog.mediacoderhq.com/h264-profiles-and-levels/ http://blog.mediacoderhq.com/h264-profiles-and-levels/ I was also hoping that he would at least touch on the features that make H.264 unique from previous MPEG standards, like in-loop deblocking, CABAC Entropy Coding, etc.. Again, it's fine as an introduction to video encoding, but there's nothing in here specific to H.264.