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Comparing H.265 (HEVC) and H265 video file size

janstechtalk.blogspot.com

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Re: Comparing H.265 (HEVC) and H265 video file size

#111

Post by dylan604 »

bawolff wrote: post #100
dylan604 wrote: post #90

Earlier quoted context omitted.

that's not how Zip works though Edit: You can disagree, but video files do not compress with zip. Feel free to do the experiments on your own time. Zip looks for combinations of letters/sequences. That's not how a video file structured. To make video smaller, smart people created a dedicated type of compressors.

Which part is not how zip works? > That's not how a video file structured You're under the impression that uncompresed raw video does not contain repeated bit patterns??? How do you think it is structured?

please, show me an example with downloadable samples to recreate the experiment where zipping a video file decreases the file size.

Re: Comparing H.265 (HEVC) and H265 video file size

#112

Post by bawolff »

dylan604 wrote: post #111
bawolff wrote: post #100

Earlier quoted context omitted.

Which part is not how zip works? > That's not how a video file structured You're under the impression that uncompresed raw video does not contain repeated bit patterns??? How do you think it is structured?

please, show me an example with downloadable samples to recreate the experiment where zipping a video file decreases the file size.

Using https://archive.org/download/ElephantsDream/ed_hd.mp4

Convert to uncompressed YUV420P:

  $ ffmpeg -i ed_hd.mp4 elephant_dream_uncompressed.yuv
Compress with zip with default compression (I also tried -9 but it didn't make much difference):

  $ zip compressed_elephants_dream.zip elephant_dream_uncompressed.yuv
     adding: elephant_dream_uncompressed.yuv (deflated 64%)

  $ ls -la elephant_dream_uncompressed.yuv compressed_elephants_dream.zip 
  -rw-r--r-- 1 bawolff bawolff 1961679613 Mar 25 08:54 compressed_elephants_dream.zip
  -rw-r--r-- 1 bawolff bawolff 5422809600 Mar 25 08:46 elephant_dream_uncompressed.yuv
1-1961679613/5422809600 = .63826

-----

So, 63.8% compression ratio. This is terrible compared to any lossy video codec obviously, but its hardly nothing.

i would expect even better ratio if the source contained mostly solid colours like a screencast

Re: Comparing H.265 (HEVC) and H265 video file size

#113

Post by jolmg »

fuzxi wrote: post #89
fireattack wrote: post #85

Content aside, the title alone makes no sense.

Seems like a typo. It should be, "Comparing H.265 (HEVC) and H26*4* video file size".

There's a missing dot, too. "H.264" not "H264".

With the current title, I thought maybe there were 2 formats that differed in name only by a dot, and that this post was about clearing up that confusion between the nearly identical names.

Re: Comparing H.265 (HEVC) and H265 video file size

#114

Post by Dylan16807 »

chii wrote: post #107
Dylan16807 wrote: post #102

Earlier quoted context omitted.

We have to make two distinctions here. The first distinction is between streaming from the start of a file, without needing any storage space, versus streaming from a random point in the middle of the file. With a zip you can do the former, but you cannot do the latter. The second distinction is between streaming the zip itself, versus streaming from the zip without needing any storage space. If you stream the zip it…

Let's imagine the scenario : you have a video file on a http server, and you want to serve the video to the end user. The end user can buffer the entire video, but that takes too long. So ideally, the player can download the video partially, and start watching while buffering the remaining. (assume the video is in a format that's streamable). So is it possible to zip the video on the server, and rewrite the http serv…

Okay, so I have a couple answers to that.

If the user is viewing the video from the start, then there's no problem. There are multiple ways to make this work.

If the user wants to jump into the middle of the video, it won't work.

That's the short answer.

The long answer goes into more detail on how to make it work:

It would be possible to have the http server unzip a megabyte at a time and send it to the client, but you said you want to send the zip to the user so we'll cross out this possibility.

That leaves two ways of doing things.

The easy way is to have the client make an HTTP Range request to get the last 100KB of the zip file, then make a second request to start at the beginning of the zip file. This will let the client act like a completely normal unzipper, and it can start playing immediately.

The hard way is to go into more detail about how a zip file is structured. We don't actually need the directory to start decompressing. A zip file is structured as [file header][file data][file header][file data][file header][file data][directory]. You can just start decompressing the first file in the zip and feeding it into your media decoder. It'll work.

For watching videos from the start, zipping is only be a problem if you put multiple videos into a single zip and use a web server that doesn't support Range requests.

Re: Comparing H.265 (HEVC) and H265 video file size

#116

Post by janandonly »

miles wrote: post #2

> Some more Ducking made me aware that using '-tag:v hvc1' in FFmpeg creates files that QuickTime can eat. Can you please share the full ffmpeg syntax used for converting the H.264 files to H.265?

The author here. :-)

Sorry for my lame English. I really should not write blogs after midnight... Anyways, a lot of you are asking for what command-line options I used for FFMPEG.

So here it is:

ffmpeg -i input1.mov -c:v libx265 -tag:v hvc1 output1.mp4

Re: Comparing H.265 (HEVC) and H265 video file size

#118

Post by boomboomsubban »

fireattack wrote: post #101
dylan604 wrote: post #99

Earlier quoted context omitted.

Sure. Don't believe some random dude from the internet. But if you're not going to go through the hassle of running the tests on your own, your "meaningless" claims are meaningless. Have you spent time in your career as a compressionist? Have you encoded hundred of hours in various codecs looking at the best tweaks to get the highest visual quality for the smallest file sizes? The test files that I produced resulted…

Yes, I have spent hundreds of hours in comparing video encoder results, but that's beside the point. One don't need to have done that to be able to tell your experiment is flawed. All you have is literally one datapoint, 970kbps h264 has "no visible difference" compared with 800kbps h265, and I believe that . But maybe 800kbps h264 also doesn't have visible difference from it. Maybe there is just not much difference…

>Again, my point is your experiment has too few samples (literally 1 pair).

This experiment was to show that the gains the original post made wasn't solely due to the video being an unchanging desktop. There were enough samples done to show that claim seems to be false, though more data could change that.

Basically, you're misunderstanding the theory tested, and while your complaints would make sense testing a different theory, they don't discount the experimental evidence for the tested theory.

Re: Comparing H.265 (HEVC) and H265 video file size

#119

Post by kiririn »

dylan604 wrote: post #63
chii wrote: post #27

Earlier quoted context omitted.

but can you stream a zip file compressed this way to play the video on a streaming protocol?

i seriously don't see zipping a RAW video file achieving any compression gains let alone 95%

It does for extreme static videos. E.g. test patterns for monitor/TV calibration are commonly distributed inside zip files with substantial compression ratios, even though they are already in compressed (h264/h265) video formats

Re: Comparing H.265 (HEVC) and H265 video file size

#120

Post by dylan604 »

bawolff wrote: post #112
dylan604 wrote: post #111

Earlier quoted context omitted.

please, show me an example with downloadable samples to recreate the experiment where zipping a video file decreases the file size.

Using https://archive.org/download/ElephantsDream/ed_hd.mp4 Convert to uncompressed YUV420P: $ ffmpeg -i ed_hd.mp4 elephant_dream_uncompressed.yuv Compress with zip with default compression (I also tried -9 but it didn't make much difference): $ zip compressed_elephants_dream.zip elephant_dream_uncompressed.yuv adding: elephant_dream_uncompressed.yuv (deflated 64%) $ ls -la elephant_dream_uncompressed.yuv compressed_…

sorry, i forgot about this thread, and absolutely did not think you'd respond. kudos.

yay, you proved a RAW video can be zipped. you're right, i'm wrong. i have to ask though, why? what in the world is this trying to achieve? this has to be one of the worst ideas for making video smaller and useable.

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