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H.264 vs MPEG4?


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I'm confused.

 

Not with life in general but with the options in VP to generate in either H.264 or MPEG4.

 

Now I fully understand that H.264 is now enshrined in the MP4 standards etc but here's the thing: yesterday I generated a video in both H.264 (quality factor 15, whatever that means) and also in MPEG4 (8192 Mbits which is recommended by YouTube, apparently).

 

When generating the H.264 I could wash the dishes, walk the dog, take out the trash... in short it took forever, as it always does. So a 20 minute video takes about twice that time on a quad-core I5 with 12Gb memory. The CPU runs at 100% for the entire render period. Poor thing.

 

When generating the MPEG4 it romped through it in about 10 minutes - in fact it was so quick I initially thought it had failed.

 

The H.264 size was about 2.5Gb and the MPEG4 about 750Mb. Wow! Quite a difference.

 

In a like-for-like comparison, full-screen, on a 24" monitor I could not tell the difference.

 

So what's up with these two formats? I thought H.264 was supposed to be ultra-compressed and the new boy-on-the-block, but frankly, I'm now thinking about generating all my videos in MPEG4 8192 Mbits as it's quicker, smaller and looks just like the H.264 equivalent.

 

So I remain confused and would welcome Real World enlightenment on these formats. Anyone?

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Interesting. I have only tried using H264 but now it looks like it's worth trying out MPEG4. Though I think the reason for the drop in size in MPEG4 is because you may have specified a way smaller average and maximum bitrate. This number was much bigger when you used the H264 codec.

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...and maximum bitrate. This number was much bigger when you used the H264 codec.

How can I tell what the bitrate is for H.264-generated mp4s? All I get is that 'quality' slider in VP (set to the default of 15). Is the bitrate embedded in the file details?

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Right click the H264 file, and in the menu that shows up, select Properties. Go to the Details tag, and you should find the bitrate there.

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I would think H264 is at higher quality than MPEG4 when the file size is the same.

 

We didn't expose all settings for H264 though.

 

It would be interesting to see what happen if you get the exported file size similar to MPEG4 by changing the quality factor.

 

BTW: I think YouTube is recommending H264 instead of MPEG4? Link: https://support.google.com/youtube/answer/1722171?hl=en

 

Best Regards,

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I would think H264 is at higher quality than MPEG4 when the file size is the same.

Quite possibly, although my understanding was that H.264 was also supposed to be smaller than legacy MPEG4 files due to the better compression? Yes, YouTube suggests H.264 but I bet they would prefer MPEG4 if the size difference was of the order that I show above! Something weird is going on here, I'm sure.

 

However, as my empirical test indicates above, the MPEG file I generated is significantly smaller than the H.264 file - with comparable quality. So as you suggest, I'll adjust the slider to see if I can get the H.264 file size down to around the MPEG4 file size with the quality remaining consistent. And I'll check out the bitrate of my previously generated H.264 files (at quality factor 15) as suggested above too.

 

I'll may generate my next video using MPEG4 and upload it to YouTube - I bet no-one notices a drop in quality! And I get my life back instead of waiting for videos to render!

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So here are the inconclusive results of the United Kingdom jury.

 

For a 3-minute video. 25 frames/sec. 1920 x 1080p.

 

[Attempt at pasting in a Word table here was thwarted when pressing SAVE]

 

Video Resultant File

Encoding Bit Rate Size

H264 Q15 20,020 2.08Gb

H264 Q21 9,487 203Mb

H264 Q25 5,848 125Mb

MPEG4 8192 6,791 145Mb

 

Even with the lowest H264 Q25 it took significantly longer than real-time to encode (about 1.5 - 2.0 times).

 

The MPEG4 was quicker than real-time (about 2 mins to encode a 3-min video) which really adds up for a 20-min video.

 

Given that the last two in the table are not miles apart in their final renderings, the fact that the H264 took significantly longer might indicate that the super compression algorithm is working overtime trying to cram stuff in (and failing) but taking an age to do it.

 

Quality was perfectly acceptable from all rendered .mp4 movies at full screen on a 24" monitor.

 

Anybody have any comments (especially the VP developers).

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Thanks for the testing, the numbers look reasonable.

 

One of the reason that MPEG4 faster than H264 might because MPEG4 codec is built in VP while H264 is an external (downloadable) component. There are overheads while using H264 codec. Another reason is that H264 provides more precision so the implementation could be less efficient.

 

If you happy with the quality, then yes, MPEG4 is a better choice.

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If you happy with the quality, then yes, MPEG4 is a better choice.

Well, I'd be fine with MPEG4 if only to get my life back inasmuch that the video is rendered much more quickly.

 

However, I don't want to be left in the unfortunate position of YouTube suddenly demanding all videos are encoded using H.264 and all others will be removed (in, say, 5 years' time). However unlikely it seems I just want to protect my YouTube investment - but would happily use MPEG4 as the quality is fine when encoded at a 8192 bitrate (although the final bit rate seems to be less - see my results above!?!) and, as said before, it renders in about 2 x realtime.

 

Anyone else have any ideas on MPEG4 as a long-term encoding options (instead of MPEG4-part 10 aka H.264)?

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  • 5 months later...

I'm still using MPEG4 and the quality is fine and so is the file size. I use Custom Bitrate of 8192 and Audio bitrate of 128kbits. Thus, the Custom Quality is greyed out and not relevant.

 

My YouTube videos look as they are supposed to (full HD) and I have now reclaimed about a month of my life in not having to wait for my video to be rendered using H.264 (since I started this thread). So all's well in VP-land.

 

That damn "Generating Preview" message is still hounding me, however, but that's a different story (and thread)!

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