Questions about decoding and rendering speeds

[CasualObserver]

I have a video that I intend to compress to a given size at a low-medium bitrate. I would like to be able to watch this video on a somewhat older computer. Previous experience with this computer (using VLC) is that it cannot display h265 videos properly (even at low bitrates), can sometimes display h264 videos properly, and can almost always display xvid videos properly. I will not be streaming or uploading the video. It is only for my personal viewing on this older computer.

Q1: I have read some sources that state that the Matroska container is rendered faster than the MP4 container. Is this true? If it is true, is the speed difference significant?

Q2: I'm not exactly clear on what is meant by "rendering" as opposed to "decoding or decompressing". Can someone explain the difference (if one exists)?

Q3: I'm trying to narrow down what video codec to use. Clearly, h265 is out of the question and I assume this is true for VP9 as well. My priorities are fixed size and quality of viewing. The amount of time to compress is not a factor. I know that the decoding speed of h264 is considered "slow"... what codecs are known to have faster decoding speeds than h264 yet still have better quality than xvid? For example, am I likely to be better off using VP8? Or maybe Theora?

Thanks in advance for your answers.

[sneaker]

Q1: there is practically no difference between mp4 and mkv containers in regards to CPU time.
Q2: "decoding or decompressing": take compressed e.g. H.264 video data and convert it to raw, uncompressed video data. "rendering": take said raw, uncompressed video data, scale it to the viewing resolution and colorspace and send it to the OS/graphic drivers for display.
Those terms are sometimes used loosely and may overlap.
Q3: try x264 with --tune fastdecode. limit bitrate spikes using --vbv-maxrate/--vbv-bufsize

What hardware (CPU/GPU) and OS are you using exactly?

[El Heggunte]

Besides telling us the OS and the CPU+GPU you'll be using, please also give us more details about the videos you're trying to watch.

"H264" and "Xvid" are not enough information. Resolution (width X height) and playback rate (frames per second) are important as well.

If you have a 32-bit Windows, the Strongene Lentoid Decoder is the fastest option for H265 videos —
however it cannot do miracles, if your computer is excessively-outdated

Besides: assuming you're not afraid of the command-line interface, I recommend you replace VLC with MPlayer, because "nice GUIs" are resource hogs.

For example, am I likely to be better off using VP8? Or maybe Theora?

VP8 is more "CPU-hungry" than Xvid/DivX. Theora is not very-efficient, regarding filesize.

[redwudz]

Even a 'very slow' PC can encode a video to H.264 format. But it may take quite a while. H.265 even longer.
Divx/Xvid shorter, but larger files.

I always call 'rendering' encoding.

Playback is a bit harder. I would also suggest MPC-HC as a program with fairly low CPU usage.
VLC is usually higher CPU usage.

A good video card is vital for playback with a slow CPU.

If you don't mind larger files, then Xvid/Divx may be your best choice.

If your computer details are up to date, you do have a slow PC.

[KarMa]

A good video card is vital for playback with a slow CPU.

With MPC-HC using LAV Filters, I can get my 2010 Netbook to play x264/CABAC 720p videos smoothly. Utilizing the weak mobo GPU, so it does not take much of GPU to enhance playback decoding. VLC is out of the question on my netbook.

[CasualObserver]

Thank you all for your answers.

* Like KarMa, I am using an older Netbook (Dual Core Atom w/ Windows 7), so I may investigate LAV Filters.

* I also appreciate sneaker's suggestion of using "--tune fastdecode" and limiting bitrate spikes when encoding.

* El Heggunte's mention of the Strongene decoder is very interesting, but TBH, I don't have an inkling as to how one incorporates it into one's player of choice.

* Both KarMa and redwudz mentioned MPC-HC. I was already familiar with the old MPC which seemed to handle higher bitrate videos only slightly better than VLC. It was my understanding that MPC-HC fixed some bugs over MPC, but was not more efficient. Perhaps I'm mistaken or perhaps the LAV Filters makes the difference.

* The comment that most caught my attention was El Heggunte's

assuming you're not afraid of the command-line interface, I recommend you replace VLC with MPlayer, because "nice GUIs" are resource hogs.

Well, I've already downloaded and used MPlayer (not via CLI, though I doubt that's relevant. I know DOS, but haven't the patience for it anymore) and wow, were you right about VLC being a "resource hog". MPlayer plays cleanly some videos that VLC had issues with. In addition, I had some higher bitrate videos that VLC couldn't handle at all ... MPlayer can play those videos (the audio/video is out of sync, but at least the video does get rendered). One minor note: I've noticed that with several videos, MPlayer is a bit out of sync for the first 10 seconds or so, but plays the rest of video perfectly... a trifling irritation compared to the issues I had with VLC.

Thanks again to all.

[anana]

Do you know mpv? It's more powerful & easier to use than mplayer for me

Download here
https://mpv.srsfckn.biz/

latest compiled version by me 10-may-2016 (only for win vista, 7, 8, 8.1, 10)
https://openload.co/f/frt4XCe0wgw/mpv_%2810-may-2016%29.7z