H.264 playback and Quicktime - a bug?

[Andrew Reid]

Now ProRes 444 will always have the edge on 8bit H.264 but something is not right with Quicktime.

At the point of transcoding the Blackmagic Cinema Camera raw (Cinema DNG) in AE CS5.5 to H.264 and importing that file to Premiere CS5.5, H.264 looks superb.

Grab that same file and play it in VLC - looks as good.

Play it in Quicktime and it turns a pale yellow, and the reds de-saturate. Also notice her sparkly green/blue eyes in the ProRes version - but really washed out on the QT H.264 screen grab. Again, VLC Player doesn't have same issue with H.264 nor does Premiere.

Now Mountain Lion can finally play AVCHD I also notice this with my GH2 H.264 based AVCHD as well. Quicktime lifts the blacks and washes out the colour.

So Apple... Questions to answer I think.

This is major problem because H.264 is the most common codec in the world for us filmmakers to deliver material to the viewer.

Click to enlarge -

[img]http://www.eoshd.com/uploads/prores-h264-red.jpg[/img]

[Axel]

Interesting, thank you. Looks like a bug.

Generally it's wise not to be the first to upgrade to a new OSX. I had this two times already: With Jaguar and with Snow Leopard, both unvoluntarily, because they came with a new Mac. It's a VERY BIG pain in the ass to have to downgrade to an earlier version - and a RETAIL one in these instances, because installation DVDs don't work on other Macs. With brand new Snoleo, the Cinema Desktop Preview in FCP was torn (something between rolling shutter and interlace flickering), completely unacceptable. It took Apple a few weeks to fix that, but I was so shocked, that I waited a few weeks more, until everyone gave his go-ahead.

I still have Lion, and I'm glad. Unfortunately, I didn't find your description via Google. So this is a rare complaint, and only thousands of outcries make Big Apple move. Mountain Lion users, join in!

[see ya]

I've just ran Shot 1 through AE CS6 on Windows and viewed the output in VLC, QT Player 7.2.2 and in a color managed player I trust. :-) All three are identical. AE is the odd one out.

AE is the culprit as far as I can see, preview I'd say is right, ie: the redder dress, but probably screwed up color management with icc profiles and confusion over sRGB iec61966 and rec709 gamma curve encoding to h264. The h264 out of AE is flagged rec709 prims, transfer & matrix and luma levels are limited range, all correct.

Assume AE is not transferring the color matrix to the h264. Or stuffed up linear raw to gamma rec709. Not sure what ACR bakes into the files as way of colorspace etc or leaves that to the color management in AE, who knows.

AE window looks same red in dress as your ProRes 444 but more orange in the h264. Typical of using wrong color matrix BT601 vs BT709.

[Andrew Reid]

I'll see if I can fix it in AE.

But odd that GH2 H.264 straight off the card looks different in Quicktime compared to Premiere & VLC Player. What is going on there?

Seems like more of a OSX issue than AE to me. Windows box may not have same issue as I am seeing.

[see ya]

I don't know mac at all but I believe OSX has a go at color managing QT player using whatever display profile is configured.

VLC I don't think is color managed at all.

But certainly AE on Windows doesn't encode what is previewed so far.

Can you post your Prores 444 and h264 from AE on mac for comparison.

I'm not surprised AE is suspect, its not even possible to put a Canon MOV into a linear light 32bit project and do the right degamma and regamma for encoding because of sRGB vs rec709 curves differing. But that's a seperate problem. :-)

[Andrew Reid]

Seems the problem swapped to VLC and QT was fine, this after using my laptop display and then reconnecting the monitor.

Seems like a colour management / display profile bug in OSX?

[FilmMan]

Quicktime issues.
[url="https://discussions.apple.com/thread/4002810?start=0&tstart=0"]https://discussions.apple.com/thread/4002810?start=0&tstart=0[/url]
[url="http://ahrengot.com/tutorials/fixing-quicktime-h264-gamma-bug/"]http://ahrengot.com/tutorials/fixing-quicktime-h264-gamma-bug/[/url]
[url="http://www.videocopilot.net/blog/2008/06/fix-quicktime-gamma-shift/"]http://www.videocopilot.net/blog/2008/06/fix-quicktime-gamma-shift/[/url]

Also be careful using AE for final delivery unless lossless. Better approaches.

[Axel]

@FilmMan:
Your second link is the solution. Long time ago, a [url="http://www.streaminglearningcenter.com/articles/h264-encoding-tools-five-popular-encoders-compared.html"]test[/url] was conducted to find out the best results in encoding H.264 as a distribution format. The QT encoder turned out to be inferior. My solution - also before I knew of this test - was always to use x264 (as plugin in QT), and export .mp4 from QT-pro or MpegStreamclip. You get the same quality (visually, that is, but that's all that counts for me) at half the file size, the encoding speed is much faster, and there is no color or gamma shift compared to the master. It looks the same in all players.

You needn't despair of all the complicated settings, leave them at default, just (for quality) change these two values:
[img]https://dl.dropbox.com/u/57198583/X264.jpg[/img]

Edit: Be careful to use x264 as final output format only. Even at full quality ('100 %') the video is not a lossless copy of the original. Don't re-import these clips into your NLE. Holds for H.264 movs as well. This warning may look obvious to all FCP users, it's not so clear for many Premiere fans. Their great results exporting with Mainconcept and the whole native workflow philosophy seems to suggest that recompressing can be excusable. Work exclusively with the original from beginning to end, first export a lossless master. [i]Or [/i]enhance the reliability of your preview by baking in the unevoidable rounding errors with a high quality intermediate/master codec.

Weird though, that Andrew reports the AVCHD in Mountain Lions QT player to look washed out too. Because afaik the player then doesn't apply any QT routines anymore. Estimate native clips with VLC, transcode them to ProRes, encode x264.

[see ya]

Does AE even use QT for encoding looks like its MainConcept in Adobes Mediacore to me certainly on Windows it is and I have QT installed.

I've had another go at it via AE and I really don't know where such a saturated result as the Prores has come from unless graded that way.

AE settings are 32bit linear project, sRGB work space on this occasion although as thesr are raw and assume no colorspace baked in could use wider than that in theory, comp 24p 1080 and output simulation as rec709.

Encoding out to h264 using AEs own, x264 is possible with Premiere I think, shows same preview in all players, that is the more orange dress not saturated red.

Don't even see saturated red in any other raw developing tool I've tried.

Interesting article here:

[url="http://www.guillermoluijk.com/tutorial/dcraw/index_en.htm"]http://www.guillermo...aw/index_en.htm[/url]

With reference to the multitude of assumptions a raw converter will do many out of reach of user.

Really, think the problem here is comparing against the Prores and how that wad derived, not QT playback of h264 dragging up three year old 'bugs' and work arounds. Although I don't use mac so defer to those with more experience of the OS.

Yes this could be different handling vs Windows, I also see same results using Linux and Linux based raw tools. fwiw.

**EDIT**

Playing around with some of the wider gamut choices via dcraw for raw developing to 16bit Linear Tiffs, outputting to the ProPhoto colorspace rather than sRGB I get the Prores saturated look and deep red to the dress, all with the other developing choices the same as sRGB such as default dcraw RGB channel multipliers and automatic white balance assumptions and then output simulation to sRGB.

Still this may have nothing to do with it, but...

btw regarding h264, there are many profiles available, it's not all 4:2:0 c--p vs Prores, h264 specifiction including x264 implementation offeres 4:4:4 also 8 and 10bit lossless. There's also support in h264 for xvYCC a wider gamut than rec709 / sRGB. Its quite easy to have 300mbps lossless h264. :-) Not that its to suggest bitrate determines quality.