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

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

#61
Wat. This is totally offtopic, but in the linked screenshot, https://1.bp.blogspot.com/-4qInHSs_urA/YFvYMbVGmgI/AAAAAAAA4..., the border between the titlebar and the window content on the left Show Info window is, um, so misaligned it's eating into the text.

199x called, it wants its human interface guidelines back

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

#62
post #60

Earlier quoted context omitted.

> No, DivX refers to MPEG-4 Part 2 which is a completely different codec. Poster is referring to the DivX Plus HD codec [1]. [1] https://en.m.wikipedia.org/wiki/DivX_Plus_HD

Show me any popular torrent using the word "DIVX" to refer to that.

show me any popular torrent using the word DIVX that isn't actually using Xvid

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

#63
post #27
post #25

Earlier quoted context omitted.

zipping the raw avi would probably get most of the way to 95%

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%

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

#64
post #40

The comparison of H.264 and H.265 in this article doesn't make any sense. Lossy codecs can make files almost arbitrarily small at the expanse of quality. You should look at both quality and size; size alone doesn't mean anything. Also H.264 and H.265 are just formats; there are many encoders of varying quality which can generate such files and each encoder has tons of settings. I don't know which encoder macOS uses b…

>there are many encoders of varying quality which can generate such files and each encoder has tons of settings. I don't know which encoder macOS uses but ffmpeg includes state-of-the-art H.264 encoder (x264). Simply reencoding video from H.264 to H.264 using ffmpeg can give you better quality/size ratio than the original file.

It's actually even more complicated than that. Each encoder has multiple settings on how much CPU to spend on the compression. Live screen recording (which this was) usually has the setting set to spend little CPU and get little compression. So like you said you don't need to change which format you use to get better compression, but you also often don't even need to change what encoder you use, you can just change the compression setting to use extra CPU (which might not be possible on a live recording).

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

#66
post #60

Earlier quoted context omitted.

Show me any popular torrent using the word "DIVX" to refer to that.

show me any popular torrent using the word DIVX that isn't actually using Xvid

Well at least DivX and Xvid use the same video format: MPEG-4 Part 2.

MPEG-4 Part 10/H.264/AVC is a different format.

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

#67
post #64
post #40

The comparison of H.264 and H.265 in this article doesn't make any sense. Lossy codecs can make files almost arbitrarily small at the expanse of quality. You should look at both quality and size; size alone doesn't mean anything. Also H.264 and H.265 are just formats; there are many encoders of varying quality which can generate such files and each encoder has tons of settings. I don't know which encoder macOS uses b…

>there are many encoders of varying quality which can generate such files and each encoder has tons of settings. I don't know which encoder macOS uses but ffmpeg includes state-of-the-art H.264 encoder (x264). Simply reencoding video from H.264 to H.264 using ffmpeg can give you better quality/size ratio than the original file. It's actually even more complicated than that. Each encoder has multiple settings on how m…

Another factor is keyframe rate, which makes the bitrate requirement much higher at the same quality but is needed to let people join the stream more than every 30 seconds.

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

#68
post #40

The comparison of H.264 and H.265 in this article doesn't make any sense. Lossy codecs can make files almost arbitrarily small at the expanse of quality. You should look at both quality and size; size alone doesn't mean anything. Also H.264 and H.265 are just formats; there are many encoders of varying quality which can generate such files and each encoder has tons of settings. I don't know which encoder macOS uses b…

ffmpeg only uses x264 if you tell it too. if you don't set -c:v libx264 when creating a .mp4 output, i'm pretty sure it uses the libav h264 encoder. if you use a binary of ffmpeg without --non-free/--non-gpl (forget which) enabled, do you even get x264?

It doesn't have a builtin h264 encoder unless I'm very out of date (looks like I'm not). It has support for some hardware encoders, which can be good enough for livestreaming.

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

#69

Earlier quoted context omitted.

Can you clarify this please? Does h.265 have some better deduplication compression or does reencoding apply something that the original recording could not, meaning h.264 would have the same benefit.

h.265 makes files smaller than h.264 for a given bit rate. So an h.265 I-frame will be smaller than an h.264 I-frame. If it's a mostly static computer screen, then you can get even better encoding effeciency by using a longer GOP structure so the I-frames are spread out even futher. Of course, the trade of is seeking gets worse, but works out great for push play and watch type of deliverables. h.264 can do this as we…

> h.265 makes files smaller than h.264 for a given bit rate.

You mean for a given CRF ("crf" isn't an official term, it's what x264/x265 call their fixed quality mode). "Bitrate" is literally how big the file is.

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

#70
post #36
post #24

Earlier quoted context omitted.

Most Turing and above Nvidia cards have support for hardware accelerated decode of h.265 [0]. Modern Intel chips also support hardware accelerated decode (support started with Skylake [1]). Not sure about AMD. [0] https://developer.nvidia.com/video-encode-and-decode-gpu-sup... [1] https://en.wikipedia.org/wiki/Intel_Quick_Sync_Video#Hardwar...

Right, so that's 2 of the top 10 and 4 of the top 20 gpus per the steam hardware survey, representing 10% of steam users: https://store.steampowered.com/hwsurvey But I don't think desktops are the problem anyway as opposed to laptops/tablets. Desktop cpus are perfectly capable of decoding h265 in real time without acceleration

Looks like most of the cards in the top 20 support H.265 4:2:0 (NVidia 10XX and up), just not 4:4:4 (NVidia 16XX and up).

I don't think the steam hardware survey is a good sample of the wider computer market though - the majority of people using youtube/netflix/etc on x86 devices are probably using Intel laptop chips with integrated graphics, not $500+ dedicated GPUs.

(Although presumably this is probably becoming less true over time, those low end users are moving more and more to mobile devices and smart TVs/chromecast/console, leaving workstation/gaming systems to be a larger percentage of the market)

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