Reasonable bitrate for x264 DVD rip?

[Octo-puss]

Or more like resulting size of the file. What would you say? For movies that are about 1.5 hours, I just set the output to ~1400MB - that's roughly 2000kbit. Question is, is there any noticeable difference between 2k and say 1500? Or so? I guess you get the general idea :)

[dat720]

That question can be answered by ripping the same movie at both bitrate's then comparing the results...... if you have a resonable computer it should take no more than 2 hours per movie!

Higher bitrate generally equals higher quality!

There are 3 things that will effect quality of a rip, Resolution, Motion Speed (ie Action Movies) and Aspect Ratio....

A 720x576 Action Movie with a 4:3 aspect will require higher bitrate's to keep good quality, on the other hand a Slow scene movie like a drama at 16:9 or 2.35:1 ratio will require much lower bitrate to acheive good results, it all comes down to the content you are ripping.

[Octo-puss]

How comes the AR plays so important role?

As for the rest, well, I encode all my movies into 720x576 and 16:9.
I remember the old movies we downloaded were all 1CD in size and usually even resized a little, and the results were just horrible when played in fullscreen. Now that people moved onto 1400ish MB size, it's pretty decent. But the ultimate question is whether 500 or so extra would "change the world"...

[smok3]

full SD res with mpeg2 at 2Mbits just won't look good imho (start with 2x that).

[CWR03]

How comes the AR plays so important role?
Just as a larger photo requires more drive space than a smaller one, so does a higher resolution video. If you increase the resolution and keep the bitrate the same, it must reduce detail to do it.

[Octo-puss]

full SD res with mpeg2 at 2Mbits just won't look good imho (start with 2x that).

Well, what do you suggest then? Four gigabytes per movie? Looking at 99% of torrents floating around, the usual size is roughly 2xCD, so I assume it's sufficient. What I wanted to know is whether increasing the bitrate by making the output file bigger by ~1CD would bring any noticeable difference.



What's "full SD res" anyway?

[Dark Shikari]

Well, what do you suggest then? Four gigabytes per movie? Looking at 99% of torrents floating around, the usual size is roughly 2xCDThose torrents aren't MPEG-2, they're MPEG-4 ASP or AVC.

[dat720]

What's "full SD res" anyway?

He was refering to a Standard Definition DVD which would have a resolution of 720x576 if it were a PAL DVD.

Now go and encode the same movie at 2 different bitrate's and compare them!!!

[dat720]

The reason Aspect ratio effect's file size so much is because a 2.35 pal movie will have a vertical resolution of around 300 pixels, the other 270 odd pixels are just black, so thats a total of around 223,000 pixels in a 2.35 movie, a 16/9 movie will have around 400 vertical pixels, which is roughly 290,000 pixels, where as a 4/3 movie will have 414,000 pixels, see where i am going with this? 4/3 movies have more pixels with information, rather than just black, hence they require more bits to encode!

[Octo-puss]

Those torrents aren't MPEG-2, they're MPEG-4 ASP or AVC.

Well, of course. I am talking about the encoded stuff all the time, not the source... Or am I missing anything? :)

[FlimsyFeet]

I think you're missing a good thread title. The title is "Reasonable bitrate for encoded DVD". Video encoded for DVD is MPEG-2. But you're talking about DVD rips encoded in MPEG-4, which is why you have confused everyone.

[dat720]

Well, of course. I am talking about the encoded stuff all the time, not the source... Or am I missing anything? :)

Yes you are missing something, the source is mpeg2, the encode is mpeg4, it looks like smok3 was refering to converting a xvid to dvd.

[Octo-puss]

I think you're missing a good thread title. The title is "Reasonable bitrate for encoded DVD". Video encoded for DVD is MPEG-2. But you're talking about DVD rips encoded in MPEG-4, which is why you have confused everyone.

lol ok, I get your point :D
Thought it's obvious :)

[smok3]

ok, sorry for confusion, i was pretty sure this is about valid videoDVD :)

[Octo-puss]

No, no, I really meant normal encodes/rips/whatever you call it.
Shall we start again? :D
Reasonable bitrate for x264 DVD rip :D

[CWR03]

"Reasonable bitrate" is a subjective figure. Many things dictate what is "reasonable," including your own perception of quality. Movie length, amount of motion, film grain, the number of colors in the source, the selected resolution, the type of audio used, all these affect bitrate in relation to the final file size. It's all up to you to do a few test encodes and determine what suits your needs. There's no "magic number" to select.

[Octo-puss]

Ok I hoped for some rough estimates applicable to most movies... Thanks for answers anyway.
And thanks for edit of the title :)

[dat720]

As CWR03 said there is no magic number, as he put very well there are a huge number of factors which determine the bitrate of the final product, as a guide i generally don't go below 1500kbps and i never resize below original resolution, i simply crop the borders off, there are 3 42" plasma's and a 60" rear pro in my house! quality is of the highest concern.

[Octo-puss]

i generally don't go below 1500kbps
See? That is EXACTLY that kind of example I wanted :) Not definite numbers, but just what people use to give me an idea where to start.
I just tried one older movie - ~1600 and ~2600kbit - and while there were VERY small differences in the screenshots I made (in bmp of course), I assumed it was not worth extra 700ish MB. So something between 1500 and 2000 seems generally ok. I gotta try with some action-like movie with sharp and detailed source though.

[dat720]

Remember i did say Generally, some movies you can get away with 1000 and still have great quality, some need upto 2000 to keep good quality, Die Hard 2 is a great example, it has many explosions, fast paced action and scene's with falling snow! it requires high bitrate's to even look resonable.

[Octo-puss]

Remember i did say Generally, some movies you can get away with 1000 and still have great quality, some need upto 2000 to keep good quality, Die Hard 2 is a great example, it has many explosions, fast paced action and scene's with falling snow! it requires high bitrate's to even look resonable.
Yup I thought about something like Die Hard or Aliens to test the upper limit.

[Octo-puss]

Oh one last thing. Not totally the same topic but similar.
On one movie I wanted to test some other bitrate AND some filters. Naturally, I only want to see a few seconds of encoded material to judge whether to go for it or not. How do I encode only a part of a movie? Do I need some video editing software to cut it out? Or is it doable within MeGUI?

[dat720]

I use mencoder for virtually all my encoding work, it is a full command line utility but it allows me to use options like -ss 30:00 which starts encoding 30 mins into the clip and -endpos 01:30 which stops encoding after 1 minute and 30 secs

[stax76]

Most reasonable bitrate is IMHO not using any bitrate modes but crf mode, a reasonable one fits all CRF value is 22. Since sources vary greatly in complexity using 2pass it's reasonable to perform a compressibility check in order to get a raw idea.

[Octo-puss]

Most reasonable bitrate is IMHO not using any bitrate modes but crf mode, a reasonable one fits all CRF value is 22. Since sources vary greatly in complexity using 2pass it's reasonable to perform a compressibility check in order to get a raw idea.

Allright, I give up. Got no idea what are you talking about :)
I got my answers anyway.

[smok3]

he meant that if you don't have to fill some fixed media size, then it is better to use quality based encoding.

[Octo-puss]

Then you obviously cannot use MeGUI as I didn't see any such profile/option there.

[smok3]

obviously i have no idea (but i'am pretty sure megui can handle that).

[Octo-puss]

I am blind. Found it. There is even such predefined profile... Only it is not too clearly named :)
So, the CRF mode, how exactly it works? It is encoding very quickly... I usually just use HQ-slowest mode with specified bitrate I get from calculator and it takes about five hours per movie.

[smok3]

try http://trac.videolan.org/x264/browser/trunk/doc/ratecontrol.txt?format=txt

[LoRd_MuldeR]

try http://trac.videolan.org/x264/browser/trunk/doc/ratecontrol.txt?format=txt

At least some of that info appears outdated:
"H.264 allows each macroblock to have a different QP. x264 does not do so. Ratecontrol returns one QP which is used for the whole frame."

I think since VAQ was committed this is no longer true...

[Octo-puss]

That link doesn't explain anything, at least not to me.

Most reasonable bitrate is IMHO not using any bitrate modes but crf mode, a reasonable one fits all CRF value is 22. Since sources vary greatly in complexity using 2pass it's reasonable to perform a compressibility check in order to get a raw idea.
he meant that if you don't have to fill some fixed media size, then it is better to use quality based encoding.
I just feel like an idiot because I just do not understand jack sh** of this, given the circumstances (if CRF is the way to go /if it is "quality based encoding"/ when you don't care for size of the output, how can it encode a movie twice faster?)

[dat720]

I'm not a huge fan of Constant Quality encodes, i still prefer to use a fixed bitrate albeit highbitrate as it jsut seems to produce better results for me!

[stax76]

That link doesn't explain anything, at least not to me.

Here (http://www.avidemux.org/admWiki/index.php?title=H264)is another explanation.

[dat720]

Quick question, i see crf 22 mentioned is the 22 the quantizer without a decimal point? ie 22 = 2.2? im used to mencoder which uses decimal values.

[jethro]

(if CRF is the way to go /if it is "quality based encoding"/ when you don't care for size of the output, how can it encode a movie twice faster?)

faster because CRF encodes 1-pass, not twice.
CRF with same quantizer, e.g. CRF 20 encodes each movie with roughly similar quality.The resulting CRF bitrate tells how compressible the movie was for x264.

[foxyshadis]

I am blind. Found it. There is even such predefined profile... Only it is not too clearly named :)
So, the CRF mode, how exactly it works? It is encoding very quickly... I usually just use HQ-slowest mode with specified bitrate I get from calculator and it takes about five hours per movie.

Use HQ slowest and modify the rate control to "Constant Quality" and your desired quality (start with 16-18 or so, since you like nice high bitrates). This is in the same dropdown as "2 pass auto" normally shows up. Xvid CQ2 equivalent CRF is a fast, mid-quality profile, not really comparable to HQ-Slowest. It should be the same speed as the second pass in a 2-pass encode.

[Octo-puss]

I get it now. Thanks.

[smok3]

At least some of that info appears outdated:
"H.264 allows each macroblock to have a different QP. x264 does not do so. Ratecontrol returns one QP which is used for the whole frame."

I think since VAQ was committed this is no longer true...

any suggestions on the most up to date x264 docs/usage? is there a wiki?

[LoRd_MuldeR]

any suggestions on the most up to date x264 docs/usage? is there a wiki?

Well, that is from the Avidemux wiki, most parts written/updated by me:
http://avidemux.org/admWiki/index.php?title=X264

Corrections always welcome :)

[smok3]

yes i saw that, however it is not clear what are real x264 values/commands and what is patched/modified to work with avidemux.

[LoRd_MuldeR]

yes i saw that, however it is not clear what are real x264 values/commands and what is patched/modified to work with avidemux.

You are right, the equivalent CLI parameters are not named there. However it shouldn't be too hard to find out (e.g. using --help).
Also x264 was not patched/modified to work with Avidemux. Only an alignment fix is currently needed to use x264 as a library. That is a simple "one line" patch.
Furthermore the are "experimental" builds that come with the "Psy RDO" patch, but that is not an Avidemux-specific modification....

[Unhandled]

Another page that may help: http://mewiki.project357.com/wiki/X264_Settings

Has details on x264 options.