Best compression, smallest size, highest quality?

[Sullah]

What is the best possible compression attainable for a 2 hour movie?

When I say best I mean, smallest file size and highest quality. We all know it's a ratio between quality and size, does anyone know the best ratio? ...and by best I mean what has worked for you based on experimentation? Something you've been still glad to watch when it was done not a pixelfest with blurbs moving around on the screen.

The movie needs to be still watchable on a Netbook. I'm working at a vertical scan/size of 480 now. Best results I was able to obtain is 330mb. I'd like to make it to 200mb, any advice?

I'm using m4v (mp4) with H.264. Is there something better?

Thank you in advance.

[jagabo]

Every movie is different. I keep the original frame size and encode with x264 in CRF mode (constant quality) at CRF=18. That way I always get the quality I want. I don't care what the file size turn out to be. But a 720x480 24 fps movie generally turns out far more that 200 or 300 MB. More like 1 to 2 GB. But the result is nearly indistinguishable from the original DVD.

[Sullah]

Thank you jagabo, I know what you mean. I myself encode at that size when I am interested in quality and end up with files the same size as you have mentioned.

My goal here is to find the smallest possible and still watchable, I just made a file 199mb that is not bad but I'm pretty sure I could do better. 250mb may be the threshold.

As far as DVD compression I can make something nearly identical to the original at around 700mb but that is still way too big for my current purposes.

[jagabo]

There is no single answer. The smallest bearable file size will vary depending on the individual movie. Look at the videos in this post:

https://forum.videohelp.com/threads/295672-A-problem-for-video-experts?p=1811057&viewfu...=1#post1811057

Basically the same video but one required 20 times more bitrate than the other.

[Sullah]

Right, there is not one single answer and in that you are 100% correct but there are opinions.

I understand that encoding The Macy's Thanksgiving Day Parade and "My Dinner With Andre" are two very different things but there are standards, (mathematically speaking) applicable to digital video. I'm just trying to build a formula ...and yes of course, as you've aptly said, I may get 200mb on a Charlie Rose episode and 400mb on Die Hard 24 using the same exact formula but the formula would be there

What codec do you like? What container format do you use?

[edDV]

Makes a big difference watching on a Netbook vs iPhone vs large HDTV. Source type and source quality are also major variables.

The current codec of choice for high compression is h.264. A free codec x264 is used for most popular apps like Handbrake, Super, MultiAVCHD, etc.
http://www.dvd-guides.com/content/view/143/59/
https://trac.handbrake.fr/wiki/HandBrakeGuide

Various containers can be used depending on the player device requirements (e.g. mp4, mkv, m2ts).

[jagabo]

I understand that encoding The Macy's Thanksgiving Day Parade and "My Dinner With Andre" are two very different things but there are standards, (mathematically speaking) applicable to digital video. I'm just trying to build a formula ...and yes of course, as you've aptly said, I may get 200mb on a Charlie Rose episode and 400mb on Die Hard 24 using the same exact formula but the formula would be there

That's what CRF encoding is. You pick the quality you want, the encoder delivers whatever size is required for that quality. If you find that a particular movie compresses to 250 MB and looks fine to you, then figure out what CRF value that equates to. The next movie you compress with that same CRF value will have the same quality but it may be bigger or smaller depending on on how compressible the video is.

What codec do you like? What container format do you use?

I use x264 at CRF 18 (you'll be using a higher value to get files in the size range you want) and the original AC3 audio from the DVD (you'll probably want to reencode the audio to reduce its size) in an MKV container (what container you use will depend on your playback device).

[stiltman]

What I encode for my HDTV is different than that of my ipad.
For my ipad I use handbrake. I use the ipad template, with a few little modifications (CRF, deinterlace, frame rates). However the basic template is about the best you can do between quality vs file size

The template is basically x.264 at CRF 20, audio encoded as AAC
I changed mine to a CRF 22, at this the file sizes are ~300mb less than a CRF of 20.
On my ipad, I cant see the difference and the average file size is ~750mb

Would I consider a movie encoded down to say ~300mb watchable on my ipad, probable not.
Well I should say not at full screen, it may be watchable if it were in a half screen window, maybe.

[Sullah]

@edDV thank you, that is the codec I am using for this so I am glad it is giving good results to others. I'll keep experimenting.

@jagabo, thank you for the info. I've been playing between 21 and 31 @CFR with varying results. Glad to hear you also use h.264/x264. I think I have made the right choice on the codec as far as ability to compress. I'm glad you've mentioned the audio, I've brought the sample rate from 128 to 96 and the khz to 44. I'm not really sure how much space I am saving by doing this. I wonder if I could move into the 60s and see what I get. Thanks again for the info.

[Sullah]

@stiltman thank you, 750mb is way too big for my purposes but I know exactly what you mean, I've used handbrake templates and they do have good results.

Of course I have to compromise the quality but I've watched some movies encoded for psp (file size 360mb) that looked amazing, they were compressed using h.264 at 480 as opposed to the 720 horizontal lines of dvd. I tested them on a Netbook and it was pretty surprising.

As I keep experimenting if I get to something real good I'll post the results here. Meanwhile any further input is always appreciated.

[poisondeathray]

Mild prefilter treatment like denoising + more efficient encoding settings can probably help you reduce bitrate requirements even more. It's rare that you get a completely noiseless DVD source.

However, netbook might have problems playing back with more compressed settings (e.g. higher # reference frames, strings of b-frames, b-pyramid, longer GOP sizes)

[mike20021969]

I'd like to make it to 200mb, any advice?

In addition to what's already been said regarding Constant Quality (btw, I use CQ for my encodes ), if using HandBrake why not enter 200MB for the "Target Size" and check 2-Pass Encoding and see what result you get.
Watchable maybe, but the quality could be rather poor (depending on the film content).

[Sullah]

Thank you Mike, I did try the Target Size option with mixed results as you said it is related to the type of movie converted.

So far my best result size/quality was obtained as follows: mp4, width 480, bitrate (kbps) 400, video codec: x264, audio codec: AAC. File size 334mb for 1:33mins.

I hope this can help someone if they are looking to compress down their movie to a size proper for Netbook, PSP or mobile phones. As previously mentioned this may be a little too small for ipad and certainly unacceptable for any type of HD display.

I'll continue experimenting.

[Soltaris]

poisondeathray brought up a great point. With these small file sizes, using denoisers properly can greatly improve compressibility and allow you to increase the bitrate considerably for a better overall result.

One denoiser I found works especially well is MSmooth.
http://www.aquilinestudios.org/avsfilters/spatial.html#msmooth

Although it's mostly for anime, I found you can also use it with films. For films, I'd recommend lowering the strength setting and then following up with a second denoiser designed mainly toward films. It's amazing how much crisper the end result looks compared to just using a single denoiser that blankets the entire frame.

[ConverterCrazy]

poisondeathray brought up a great point. With these small file sizes, using denoisers properly can greatly improve compressibility and allow you to increase the bitrate considerably for a better overall result.

One denoiser I found works especially well is MSmooth.
http://www.aquilinestudios.org/avsfilters/spatial.html#msmooth

Although it's mostly for anime, I found you can also use it with films. For films, I'd recommend lowering the strength setting and then following up with a second denoiser designed mainly toward films. It's amazing how much crisper the end result looks compared to just using a single denoiser that blankets the entire frame.

If you are still around, please share the entire process that you used.

Thanks.

[VoodooFX]

If you are still around, please share the entire process that you used.

He's not around anymore.
Avisynth example if you want to do a micro encode:

LWLibAvVideoSource("D:\Video_1920x1080.mkv")
Spline16Resize(1024,576)
MCDegrainSharp(csharp=0.0)

Use x265 to encode this with CRF 24.

Sample from this post compressed from 165MB to 10MB.

[ConverterCrazy]

If you are still around, please share the entire process that you used.

He's not around anymore.
Avisynth example if you want to do a micro encode:

LWLibAvVideoSource("D:\Video_1920x1080.mkv")
Spline16Resize(1024,576)
MCDegrainSharp(csharp=0.0)

Use x265 to encode this with CRF 24.

Sample from this post compressed from 165MB to 10MB.

What a pleasant surprise! Was not expecting a reply.

Thanks.



Will check and get back asap.

[RogerTango]

AVIDEMUX with HEVC/H265