Register FAQ / Rules Forum Spy Search Today's Posts Mark Forums Read
Go Back   MacRumors Forums > News and Article Discussion > MacRumors.com News Discussion

Reply
 
Thread Tools Search this Thread Display Modes
Old Mar 6, 2013, 05:07 PM   #401
repoman27
macrumors 6502
 
Join Date: May 2011
@Menneisyys2: Fantastic work. Thank you very much for taking the time to do all this and share your findings. Just awesome.
repoman27 is offline   0 Reply With Quote
Old Mar 6, 2013, 07:18 PM   #402
johnjefferson
Banned
 
Join Date: Feb 2013
Quote:
Originally Posted by Menneisyys2 View Post
OK, the first two 120 fps benchmark videos are up:

https://dl.dropbox.com/u/81986513/03...v3-airplay.mp4 - wireless AirPlay mirroring via the Apple TV3 (with the latest firmware, of course), under ideal circumstances (ATV3 hooked via Ethernet cable to the Wi-Fi access point some 2 metres from the iPhone)

https://dl.dropbox.com/u/81986513/03...ff-5-60fps.mp4 - mirroring via the new HDMI adapter

Feel free to download and play with them. (I won't upload them to YouTube as one needs to advance over them to properly assess the framerate, which isn't possible with YouTube, not even in desktop browsers without installing 3rd-party scripts.)

Both videos show the generic speed of the Springboard navigation first (scrolling between pages) and, then, a counter video, strictly in mirrored mode (played back via XBMC). I've created the latter programmatically (using QTKit on the Mac) for easy and dependable benchmarking. (The file has several versions; they're all linked from HERE.)

Both videos show both the source iPhone 5 and the target monitor. The latter is an LG model (will look up the exact signal lag of it tomorrow; I don't think it's over 15-20 ms. - after all, it's not a TV where lag isn't as significant as with computer monitors). If you pause (and, possibly, advance the video files with one frame at a time - easy to do with the QuickTime player and the right arrow key), you can easily see how much lag there's between the two videos. For example, if the iPhone's small screen shows 18 and the mirrored screen shows 9 (as is the case with the AirPlay + ATV3 video at 01:01), you will know that the difference is 9 frames. As the original video is 60 fps, you can easily compute the lag in milliseconds: 1000 / (60/9) = 150. (The one I've also mentioned in my prev. post.)

Also, you can easily see the true playback fps if you advance over the frames one by one. With AirPlay, you can easily see every second frame isn't rendered at all. An example: when I started video playback at 01:00 on the video (that is, in real time, 00:15), playback started with frame "2" on the iPhone, followed by 3, 4 etc., without a single dropped frame. The (AirPlay + ATV3-)mirrored "big" screen, however, only shows the frames with "3", 5, 7, 9, 11 etc, showing every second source frame was dropped, effectively reducing the framerate to 30 fps.

Both videos have been recorded at 120 fps but will play back at 30, which means they show everything originally happened with a four-time slowdown. (One original second lasts four in the video.)

I'll elaborate on the 60 fps direct AVCHD remuxes (meaning, generally, 28 Mpbs bitrate) and the extremely high 40 Mbps 1080p30 playback.
Cool but any idea when the lightning ton 30 pin adapter will support video out or if Apple will make an adapter to hook the new ipod touch to a car stereo for video out?
johnjefferson is offline   0 Reply With Quote
Old Mar 7, 2013, 12:03 AM   #403
Menneisyys2
macrumors 601
 
Join Date: Jun 2011
Quote:
Originally Posted by johnjefferson View Post
Cool but any idea when the lightning ton 30 pin adapter will support video out or if Apple will make an adapter to hook the new ipod touch to a car stereo for video out?
Officially, component / composite output is in no way supported, but i'll test this too. (Have both cables and the adapter.)
Menneisyys2 is offline   0 Reply With Quote
Old Mar 7, 2013, 02:05 AM   #404
Menneisyys2
macrumors 601
 
Join Date: Jun 2011
Quote:
Originally Posted by Menneisyys2 View Post
Officially, component / composite output is in no way supported, but i'll test this too. (Have both cables and the adapter.)
Checked. No video out. (Not with Cydia-based DisplayOut (tested it on the iPhone 5), either, of course.) Audio and synching works, on the other hand. The latter is painfully missing from the HDMI Lightning adapter - it's only capable of recharging but not synching.
Menneisyys2 is offline   0 Reply With Quote
Old Mar 7, 2013, 01:02 PM   #405
designaholic
macrumors regular
 
Join Date: Nov 2007
Location: Bristol, UK
Quote:
Originally Posted by jm001 View Post
Bunch o' younguns around here. My first Mac had a whopping 4MB of RAM. Thankfully I upgraded to a IIsi and it's massive 16MB of RAM which maxed out at 64MB (although RAMDoubler could theoretically make it go beyond it's max to 128MB). My B&W only came with 64MB. Wow how times have really changed.
Well, that's my first Mac I was chatting about. If we're talking about my first computer... that was a C64 (not so young)
__________________
jamiebrightmore.com
designaholic is offline   0 Reply With Quote
Old Mar 7, 2013, 01:39 PM   #406
hchung
macrumors 6502a
 
Join Date: Oct 2008
Quote:
Originally Posted by lilo777 View Post
Apple engineer that provided information to Panic stated that Lightning bandwidth limit is lower than what's required for 1080p.

On the other hand, according to Samsung specs, their MHL adapter is 1080p. So, as far as interfaces are concerned, MHL comes on top. Whether specific phone can deliver 1080p is a different matter. Is S3 can't do it, perhaps S4 will.
Not quite, the engineer stated that Lightning's bandwidth is lower than raw HDMI. Totally believable as I'd doubt Lightning would be able to do 10Gb/sec.
Neither does MHL, btw.

That doesn't mean it can't support 1080p, as 1080p doesn't suggest a datarate. Nor does it take into account that outputting a 1080p stream that has been compressed takes way less bandwidth.

Both apple's funky adapter and MHL can do 1080p.
There are caveats for both of them.

Apple can do it for precompressed media but some devices like the ipad mini in question can't compress on the fly that fast for mirroring. So 1080p60 only works for streaming unless the host device has a fast enough encoder.

Some MHL devices can do 1080p.... but the framerate is limited to 24-30 depending on the device, not the full 1080p 60fps. Given that the encoding is handled by the MHL chips, there isn't much that can be done outside replacement of device. Future MHL chips will support higher rates, but you'd need a new device and a new dongle. Something else I'm not sure of is if an older dongle with a new device would or would not be compatible at a lower datarate.

----------

Quote:
Originally Posted by Alameda View Post
You're creating a fallacy by comparing the theoretical abilities of Lightning to the actual abilities of shipping MHL-based products. You also assume that an iPhone 5 can render and compress these larger resolutions, which may not be so.

Your claim of software upgradability is also dubious, because you typically can't reprogram a hardware-based decoder to support new codecs or double the bandwidth.
The theoretical abilities arn't so theoretical when there's an anonymous engineer who so clearly states that they're working on firmware upgrades to increase quality of mirroring.

Those quality increases depend neither on a new codec, nor increasing the bandwidth, but rather tuning the encoder on the ipad side to work better for mirroring.

Tweaking the h264 knobs isn't so hard to believe when people have been doing this for their DVD/BluRay rips for ages, right?

In the case of playing back precompressed h264 streams, other people have mentioned already that the adapter decodes those at the full quality fine already.

----------

Quote:
Originally Posted by johnjefferson View Post
Cool but any idea when the lightning ton 30 pin adapter will support video out or if Apple will make an adapter to hook the new ipod touch to a car stereo for video out?
Doubt it will. Now we know that making a video encoder (harder than a decoder) would be necessary for that to happen, it's not very likely.

Last edited by hchung; Mar 7, 2013 at 01:44 PM.
hchung is offline   0 Reply With Quote
Old Mar 7, 2013, 01:41 PM   #407
Alameda
macrumors 6502
 
Join Date: Jun 2012
Quote:
Originally Posted by hchung View Post
Some MHL devices can do 1080p.... but the framerate is limited to 24-30 depending on the device, not the full 1080p 60fps.
MHL is definitely capable of 1080p60. I don't know if there are devices shipping with 1080p60 support, but it's in the standard and it runs at the same PHY rate.

When you step back from this, we're comparing these two approaches:
1) Transmit your frame buffer as baseband video
2) Compress your frame buffer, De-compress it, and transmit it as baseband video.

And you're trying to say that the second approach is better. It cannot be better. Don't be such a fanboy. We all like Apple, but it's not like they're infallible. You saw the artifacts and the reports of latency with this scheme. And you can trade artifacts for latency or latency for artifacts, but you can't have both.

But it saves them a penny or two in chip cost, because the A6 or A7 doesn't need to have a baseband video PHY.

Gotta count them beans!

Last edited by Alameda; Mar 7, 2013 at 01:50 PM.
Alameda is offline   0 Reply With Quote
Old Mar 7, 2013, 01:52 PM   #408
hchung
macrumors 6502a
 
Join Date: Oct 2008
Quote:
Originally Posted by nutjob View Post
That's about your level of understanding. There's no "transcribing" the data is delivered pixel for pixel. The Apple hack transcodes the data, reducing the quality.

----------



You don't understand even the basics here. The standard devices are just delivering the pixel data verbatim. The Apple hack is decoding compressed video data, causing artifacts and output lag. It's a horrible, horrible solution.
Not quite. Sure, in the case of MHL the source data is probably less compressed, if at all, than Apple's solution. But it's also less pixel data because they're simply not pushing as many frames.

quick google-fu for example: http://forum.xda-developers.com/show....php?t=1799157

When it comes down to it, we're looking at two different solutions for the same problem: lack of bandwidth
MHL: send only some of the data.
Apple: lossy compress all it.
hchung is offline   0 Reply With Quote
Old Mar 7, 2013, 02:03 PM   #409
hchung
macrumors 6502a
 
Join Date: Oct 2008
Quote:
Originally Posted by Alameda View Post
MHL is definitely capable of 1080p60. I don't know if there are devices shipping with 1080p60 support, but it's in the standard and it runs at the same PHY rate.

When you step back from this, we're comparing these two approaches:
1) Transmit your frame buffer as baseband video
2) Compress your frame buffer, De-compress it, and transmit it as baseband video.
Yes, there should already be an 1080p60 part in the standard. I don't know if it runs at the same PHY rate though.

Quote:
Originally Posted by Alameda View Post
And you're trying to say that the second approach is better. It cannot be better. Don't be such a fanboy. We all like Apple, but it's not like they're infallible. You saw the artifacts and the reports of latency with this scheme. And you can trade artifacts for latency or latency for artifacts, but you can't have both.

But it saves them a penny or two in chip cost, because the A6 or A7 doesn't need to have a baseband video PHY.

Gotta count them beans!
I'm not saying either's perfect. And yeah, I expect there to be artifacts from compression periodically.

Arguing about latency is meaningless as both of them discard data and add latency.

But the users of external video are typically doing three different things:
1) watching movies
2) showing what they have on screen in a game (fast video)
3) showing what they have on screen in a business app (slow video)

For #3, MHL currently gets you better frame quality.
For #1 and #2, Apple gets you a better experience and/or quality.

Last edited by hchung; Mar 7, 2013 at 03:05 PM.
hchung is offline   0 Reply With Quote
Old Mar 7, 2013, 02:38 PM   #410
Alameda
macrumors 6502
 
Join Date: Jun 2012
Quote:
Originally Posted by hchung View Post
Both of them discard data and add latency.
MHL does not "discard data," nor does it add latency. It's simply baseband (uncompressed) video transport.

MHL is 1080p60 capable.

I cannot find any link where Apple states that their Lightning to HDMI adapter supports 1080p60. Can you?
Alameda is offline   0 Reply With Quote
Old Mar 7, 2013, 03:05 PM   #411
hchung
macrumors 6502a
 
Join Date: Oct 2008
Quote:
Originally Posted by Alameda View Post
MHL does not "discard data," nor does it add latency. It's simply baseband (uncompressed) video transport.

MHL is 1080p60 capable.
If you take multiple data streams and pack them into one serial stream, you'll add latency. Latency is a fact. If you want to tell me it's less latency than Apple's solution, sure, I'll concede that.

I should have been more clear as well. The solution currently requires that the original data (what would have gone to the device's onboard display) be trimmed down by discarding data, before feeding through the MHL encoder, and will result in the end user seeing less data than they originally had.

MHL is 1080p60 capable if you have a device/dongle pair that supports it. I know of none. Let me know if you have a shipping product capable of checking out. Otherwise telling us this is no different then if somebody were to claim an iPhone 5 could output 1080p60 over DisplayPort. It's all theoretical unless somebody has an example.

Quote:
Originally Posted by Alameda View Post
I cannot find any link where Apple states that their Lightning to HDMI adapter supports 1080p60. Can you?
I can't either because I haven't bothered to look. Menneisyys2 above already said he got 1080p60 from an iPhone 5, and his testing methodology sounds pretty credible. So it's not even really up for debate anymore. Another person on panic.com's article mentioned that precompressed video gets full quality as well, because it's passed off to the dongle to decode instead of decoded on the phone/tablet.
hchung is offline   0 Reply With Quote
Old Mar 7, 2013, 04:03 PM   #412
Menneisyys2
macrumors 601
 
Join Date: Jun 2011
Quote:
Originally Posted by hchung View Post
Not quite, the engineer stated that Lightning's bandwidth is lower than raw HDMI. Totally believable as I'd doubt Lightning would be able to do 10Gb/sec.
RAW 1080p30 (or even 1080p60 - after all, the "old" VGA / HDMI adapters both drive external monitors at 1080p60 during both video playback and mirroring) wouldn't require 10 Gbps.

----------

Quote:
Originally Posted by Alameda View Post
MHL does not "discard data," nor does it add latency. It's simply baseband (uncompressed) video transport.

MHL is 1080p60 capable.

I cannot find any link where Apple states that their Lightning to HDMI adapter supports 1080p60. Can you?
It can in (of course) both iOS-native video playback (native decoding in the dongle itself) and even mirroring. See my 120 fps test videos.

BTW, today, I've run several tests with 60 fps 28 Mbps 1080p videos: the ones at (I've selected these as they have a LOT of movement / panning / water surface / sand / detail, all meaning large decoding load):

http://movies.dpreview.com.s3.amazon...00/trolley.MTS
http://s3.amazonaws.com/movies.dprev...diagonal01.MTS
http://s3.amazonaws.com/movies.dprev...57/beach02.MTS
http://movies.dpreview.com.s3.amazon...7/seaplane.MTS

after quickly remuxing (NOT reencoding!!) them into M4V files by iVI, which offers excellent MTS -> M4V (mov / mp4) remuxing capabilities. (Too bad, otherwise, for other kinds of remuxing / reencoding, it's not a very good app.)

On the Lightning HDMI adapter, I haven't encountered any glitches / stutters playing them back. Interestingly, my ATV3 played these back very well too. On the latter (ATV3), I've only seen some stuttering - in about every third playback - in the http://s3.amazonaws.com/movies.dprev...diagonal01.MTS video. Neither did I encounter stutters (after adding an AAC audio track so that I can remux it into an ATV3-streamable, iOS-native M4V file) with the 40 Mbps 1080p24 "Birds" video at http://www.auby.no/files/video_tests...mbps_birds.mkv

Will go on benchmarking and testing with even higher bitrates - for example, 1080p60 at 40 Mbps. (Albeit that's pretty unrealistic as, for example, most 1080p60 cameras record at 28 Mbps and only very few of them can go further with even higher bitrates.)

So far, I kinda like the adapter. Definitely MUCH better than wireless AirPlay. Just not really suited for action gaming or anything where lag is not wanted.

Last edited by Menneisyys2; Mar 7, 2013 at 04:14 PM.
Menneisyys2 is offline   1 Reply With Quote
Old Mar 7, 2013, 04:11 PM   #413
Alameda
macrumors 6502
 
Join Date: Jun 2012
Quote:
Originally Posted by Menneisyys2 View Post

It can in (of course) both iOS-native video playback (native decoding in the dongle itself) and even mirroring. See my 120 fps test videos.

BTW, today, I've run several tests with 60 fps 28 Mbps 1080p videos: the ones at (I've selected these as they have a LOT of movement / panning / water / sand / detail):

http://movies.dpreview.com.s3.amazon...00/trolley.MTS
http://s3.amazonaws.com/movies.dprev...diagonal01.MTS
http://s3.amazonaws.com/movies.dprev...57/beach02.MTS
http://movies.dpreview.com.s3.amazon...7/seaplane.MTS
This is some great stuff. Now, if they're passing the video without transcoding it, does that mean they have no on-screen display, or do you think they perform OSD within the dongle?
Alameda is offline   0 Reply With Quote
Old Mar 7, 2013, 04:13 PM   #414
hchung
macrumors 6502a
 
Join Date: Oct 2008
Quote:
Originally Posted by Menneisyys2 View Post
RAW 1080p30 (or even 1080p60 - after all, the "old" VGA / HDMI adapters both drive external monitors at 1080p60 during video playback) wouldn't require 10 Gbps.[COLOR="#808080"]
Sorry, mind went for the spec rate as opposed to the necessary rate when I was thinking raw HDMI. You're right:
1920*1080*60*24 = 2985984000 = Tad under 3Gbps

As for VGA->HDMI though, that's a bit different because it's an analog stream converted to a digital stream. I recall there being sync issues with VGA at higher resolutions a decade ago, and some necessary workarounds for shaky pictures. Not sure how accurate the end signal is compared to an all-digital pipeline.

By the way, awesome work with the testing. It's always appreciated to see somebody with the resources step up and provide concrete data.
hchung is offline   0 Reply With Quote
Old Mar 7, 2013, 04:38 PM   #415
Menneisyys2
macrumors 601
 
Join Date: Jun 2011
Quote:
Originally Posted by hchung View Post
As for VGA->HDMI though, that's a bit different because it's an analog stream converted to a digital stream. I recall there being sync issues with VGA at higher resolutions a decade ago, and some necessary workarounds for shaky pictures. Not sure how accurate the end signal is compared to an all-digital pipeline.
I have both the "old" VGA and HDMI adapters. They deliver indistinguishable image (both at 1080p60) on the same LG monitor having a HDMI, VGA and DVI inputs. I've spotted no differences in their effective resolution, for example. The only real difference between them is the audio passthru with the HDMI adapter and the 720p vs. XGA maximal resolution on all A4-based iDevices. (Not an issue with A5+-based iDevices any more.)

----------

Quote:
Originally Posted by Alameda View Post
This is some great stuff. Now, if they're passing the video without transcoding it, does that mean they have no on-screen display, or do you think they perform OSD within the dongle?
As with older models (with all kinds of A/V cables: from composite to HDMI / VGA), there's no local on-screen playback while playing back iDevice-native files over the HDMI connector, not using any software (=no-GPU) decoding (in third-party apps).

BTW, during my tests, the adapter did warm up a bit (unlike, of course, the "passive" old HDMI / VGA adapters). I'll run some very long (several hours of both mirroring and iOS-native video decoding without pauses) tests to see whether this can be an issue.

BTW2, to find out whether there's ANY kind of local decoding on the iDevice, I'll run some CPU tests with "top" - or, if it doesn't show any meaningful result, with my usual long-time battery drain tests (an example of tests like this: http://forums.macrumors.com/showthread.php?t=1547504 )

Last edited by Menneisyys2; Mar 7, 2013 at 04:44 PM.
Menneisyys2 is offline   0 Reply With Quote
Old Mar 7, 2013, 04:54 PM   #416
hchung
macrumors 6502a
 
Join Date: Oct 2008
Quote:
Originally Posted by Menneisyys2 View Post
I have both the "old" VGA and HDMI adapters. They deliver indistinguishable image (both at 1080p60) on the same LG monitor having a HDMI, VGA and DVI inputs. I've spotted no differences in their effective resolution, for example. The only real difference between them is the audio passthru with the HDMI adapter and the 720p vs. XGA maximal resolution on all A4-based iDevices. (Not an issue with A5+-based iDevices any more.)
Ack, I misread. I thought you meant a generic VGA->HDMI converter, as opposed to the apple dongles, when we were talking about bandwidth.
hchung is offline   0 Reply With Quote
Old Mar 7, 2013, 06:12 PM   #417
iSunrise
macrumors regular
 
Join Date: May 2012
@Menneisyys2:
Thanks again for your time doing this very comprehensive testing. Not only did you provide some truly priceless bits of info of the actual adapter and the lightning capabilities, I´ve also learned a lot about the different media players for iOS and e.x. OS X tools for tagging MP4 files by reading your articles. The funny thing about this is that I currently don´t even own any OS X device, yet (just my iPad 3) but I plan to buy the next iteration of the Macbook Pro Retina with an integrated Haswell CPU/GPU, so I can fully enjoy my iPad more and maybe use it as a base for e.x. AirVideo, for which I currently have to use my PC (which is a bit annoying, because I have to turn on my PC just for transcoding stuff). The realtime transcoding for incompatible/not hw-accelerated files is just too important for me to lose it. It also has awesome quality on my iPad, I wouldn´t trade that for anything.

Since you seem to know a lot about the actual hardware itself, do you happen to have an iPad 3 and an iPad 4, too? Do you know if the hardware decoding capabilities of the iPad 4 have changed compared to the iPad 3? I´ve not found a comparison about that anywhere on the net. The most demanding file I had on my iPad 3 was a blu-ray compatible (Level 4.1) 720p60fps video with a rather high bitrate that isn´t smooth at all (it constantly skips several frames and the native Apple player becomes very unstable, I´ve not tested with iOS 6/6.1 though, that was still on 5.1.1). Apart from that, my iPad 3 has worked with everything else I´ve thrown at it. Do you happen to know if the iPad 4 has improved on that? Thanks a lot!

OT: What media player do you recommend for OS X? VLC?

Last edited by iSunrise; Mar 7, 2013 at 06:32 PM.
iSunrise is offline   0 Reply With Quote
Old Mar 8, 2013, 01:12 AM   #418
Menneisyys2
macrumors 601
 
Join Date: Jun 2011
Quote:
Originally Posted by hchung View Post
Ack, I misread. I thought you meant a generic VGA->HDMI converter, as opposed to the apple dongles, when we were talking about bandwidth.
Yup, active converters do introduce at least some resolution hit. For example, the one at http://dx.com/p/hdmi-to-vga-video-converter-71816 (I have that) reduces 1080p to about 900p-950p effectively. (But definitely not to "604 x 480@60Hz / 800 x 600", as is listed on the page of the device. Dunno why they added that entry in the list - when I purchased mine a year ago, it wasn't there. Is it a new, dumbed-down, severely cripped revision of the old, much superior adapter? Dunno.) Otherwise, it's perfectly usable.

----------

Quote:
Originally Posted by iSunrise View Post
@Menneisyys2:
The realtime transcoding for incompatible/not hw-accelerated files is just too important for me to lose it.
BTW, what about

1, remuxing those files? It can be done automaticall with batc h operation-enabled, top remuxers like Subler and MP4Tools. (These are the two remuxers I recommend the most. While iVI, iFlicks, MKV2M4V etc. too have batch modes, they're either considerably slower or have severe restrictions.)

2, if you have an SMB-enabled NAS source, using It's Playing or jailbreaking and using XBMC? (These two players are able to play back non-iOS-native (e.g., MKV) content over SMB hardware accelerated, unlike other players.)


Quote:
Originally Posted by iSunrise View Post
Do you know if the hardware decoding capabilities of the iPad 4 have changed compared to the iPad 3? I´ve not found a comparison about that anywhere on the net. The most demanding file I had on my iPad 3 was a blu-ray compatible (Level 4.1) 720p60fps video with a rather high bitrate that isn´t smooth at all (it constantly skips several frames and the native Apple player becomes very unstable, I´ve not tested with iOS 6/6.1 though, that was still on 5.1.1). Apart from that, my iPad 3 has worked with everything else I´ve thrown at it. Do you happen to know if the iPad 4 has improved on that? Thanks a lot!
Strange - in all my past 1080p60 (but not high-bitrate 720p60 - this problem may be specific to 720p60 only?) tests, the iPad 3 (and all other A5(X)-based iDevices) worked wonderfully. Haven't ever encountered hiccups, unlike on the somewhat lower-efficiency ATV3. Now that I create some really high-bitrate 1080p60 videos to find out how the Lightning HDMI adapter compares to the single-core ATV3, I'll also re-run those tests on my iPad 3 and compare it to my iPad 4 too.


Quote:
Originally Posted by iSunrise View Post
OT: What media player do you recommend for OS X? VLC?
Yup, generally, I use VLC. It works wonderfully on my late 2009 17" MBP. It's only high-bitrate 1080p60 files that it can't properly (w/o stuttering) play back - on a 2.8 GHz C2D. On a significantly newer (=faster) platform, it should even be able to decode 4K videos, I think.
Menneisyys2 is offline   0 Reply With Quote
Old Mar 8, 2013, 01:58 AM   #419
hchung
macrumors 6502a
 
Join Date: Oct 2008
Quote:
Originally Posted by Menneisyys2 View Post
Yup, active converters do introduce at least some resolution hit. For example, the one at http://dx.com/p/hdmi-to-vga-video-converter-71816 (I have that) reduces 1080p to about 900p-950p effectively. (But definitely not to "604 x 480@60Hz / 800 x 600", as is listed on the page of the device. Dunno why they added that entry in the list - when I purchased mine a year ago, it wasn't there. Is it a new, dumbed-down, severely cripped revision of the old, much superior adapter? Dunno.) Otherwise, it's perfectly usable.
My guess from ordering from dealextreme in the past is that the item switched vendors. It's probable that a different vendor is building the board now, and then reused the same shells from the past product, but has a worse design. It's also quite possible that the spec sheet given to dx is wrong too, but they just entered it in.

They had some SD card bridges which were labeled as supporting SDHC. But had problems using SDHC cards because the controllers in the picture, when you look at the datasheets, were too old to actually support SDHC. So that was a matter of incorrect spec sheets.

I haven't purchased active converters in a long time, the last one I got was a gefen VGA->DVI converter. Maxes out at about 1600x1024 with a little bit of noise, but still cost over $200. Somewhere I also had a VGA->Composite video converter. Ancient little bugger, but it worked.
hchung is offline   0 Reply With Quote
Old Mar 8, 2013, 06:00 AM   #420
iSunrise
macrumors regular
 
Join Date: May 2012
Quote:
Originally Posted by Menneisyys2 View Post
BTW, what about

1, remuxing those files? It can be done automaticall with batc h operation-enabled, top remuxers like Subler and MP4Tools. (These are the two remuxers I recommend the most. While iVI, iFlicks, MKV2M4V etc. too have batch modes, they're either considerably slower or have severe restrictions.)

2, if you have an SMB-enabled NAS source, using It's Playing or jailbreaking and using XBMC? (These two players are able to play back non-iOS-native (e.g., MKV) content over SMB hardware accelerated, unlike other players.)
I want to avoid remuxing if possible, because it would take a lot of time. I have a lot of different container formats and codecs (some very old stuff I recorded with my SVHS). But it certainly is an option to think about, especially if it´s possible to play MKV after jailbreaking with XBMC, but I haven´t played with that yet. Still a bit unsure if I want to jailbreak my iPad 3, because it does everything I want it to right now.

Quote:
Originally Posted by Menneisyys2 View Post
Strange - in all my past 1080p60 (but not high-bitrate 720p60 - this problem may be specific to 720p60 only?) tests, the iPad 3 (and all other A5(X)-based iDevices) worked wonderfully. Haven't ever encountered hiccups, unlike on the somewhat lower-efficiency ATV3. Now that I create some really high-bitrate 1080p60 videos to find out how the Lightning HDMI adapter compares to the single-core ATV3, I'll also re-run those tests on my iPad 3 and compare it to my iPad 4 too.
I´m going to prepare a sample of that with MakeMKV if you want to so you can double-check. It was a MakeMKV remux that I remuxed again with XMedia Recode to MP4 so I have hw-accelerated playback in the native Apple player. If you have no problems with 1080p60 though, it´s either related to the very high bitrate of the 720p60 file or maybe because XMedia Recode did something to the MP4 structure that my iPad 3 didn´t like.

Last edited by iSunrise; Mar 8, 2013 at 06:06 AM.
iSunrise is offline   0 Reply With Quote
Old Mar 8, 2013, 01:39 PM   #421
Menneisyys2
macrumors 601
 
Join Date: Jun 2011
Quote:
Originally Posted by iSunrise View Post
@Menneisyys2:
Since you seem to know a lot about the actual hardware itself, do you happen to have an iPad 3 and an iPad 4, too? Do you know if the hardware decoding capabilities of the iPad 4 have changed compared to the iPad 3?
Tested with my new, custom-reencoded, high-bitrate (100 and 50 Mbps versions of http://s3.amazonaws.com/movies.dprev...diagonal01.MTS with the "Normal" preset of Handbrake and, apart from setting the target bitrate, nothing else) 1080p60 videos. The two iPads have exactly the same performance (along with the iPhone 5) decoding those videos.

Will also test high-bitrate 720p60 performance this evening but I'm pretty sure they'll be the same too.
Menneisyys2 is offline   0 Reply With Quote
Old Mar 8, 2013, 05:01 PM   #422
Menneisyys2
macrumors 601
 
Join Date: Jun 2011
Guys, during testing, I needed to be able to transfer my high-bitrate / framerate videos to the stock Videos app so that I can drive the HDMI adapter at 1080p. During this, I've made some discoveries. As this might prove useful for all of you (for generic high-bitrate / framerate video importing to iDevices - but can be used for plain video transfer too), I'm posting my tutorial directly here.


Tutorial: This is How You Can Put Videos on Your iDevice Without iTunes

SUMMARY: In the article below, I explain how one can transfer videos to the stock Videos application on any iDevice with a brand new version of the excellent, free, all-in-one iDevice transfer tool “iFunBox”. Uploading videos to the Videos app, so far, has only been possible via the “Movies” tab in iTunes. iTunes, however, had several restrictions and, in many cases, makes it entirely impossible to transfer several kinds of videos to the iDevice.

THE MAIN ARTICLE:
iTunes, Apple's only desktop tool to transfer videos / movies to the stock “Videos” app delivered on all iDevices by default, has several restrictions and problems:
  • transferring any(!) videos from more than one desktop computer is problematic if not downright impossible. You can't just give your iDevice to your friend to quickly copy a video / movie to it so that you can watch it in the Videos app: he most likely won't have an iTunes synchronized with your iDevice. Sure, he can copy from non-synchronized iTunes too to third-party video player applications via iTunes File Sharing (which doesn't require any kind of synchronization partnership) or via the (at least an order of magnitude slower) built-in Web / FTP server of those third-party apps (if supported - recommended players like AVPlayer(HD) or GoodPlayer almost all have such servers). However, this can only be done with third-party apps and not the stock Videos app: to the latter, it's simply not possible to copy anything with Apple's own tools. All he can do is creating a new synchronization partnership to your device, which, on the other hand, would most likely wipe out all the existing videos you may already have synchronized to your iDevice.
  • iTunes doesn't let for synchronizing high-framerate videos to the device - and there are plenty of them, particularly now with consumer cameras recording into 50p / 60p formats getting very common. (And several Blu-ray / DVD discs you can purchase in stores / off the Web also have 60p content; for example, volume 3 of the MindCandy demo series (Vol1 and 2 are 29.97fps)). iDevices could play them back just fine – even 50 Mbps(!) 1080p60 videos can be played back on anything A5(X) or A6(X)-based without stuttering. (50 Mbps is almost the double of the bitrate (28 Mbps) consumer cameras use for 1080p60 recording.) Nevertheless, Apple doesn't offer any way of synchronizing these videos to your iDevice. Sure, you can use a third-party player (preferably with hardware decoding support) and transfer the files viathe standard iTunes File Sharing. However, for example HDMI / VGA out may be restricted in these cases to a somewhat less-than-ideal (900p) resolution.
  • iTunes doesn't let for synchronizing anything with more than 4.1 of the so-called “H.264 level”. While it's pretty much understandable they've chosen 4.1 as the upper, hard-coded limit not to have to allow users synchronize anything on iDevices that could stutter during playback, this restriction also made it impossible to synchronize perfectly playable videos. Or, for that matter, ones that have too high a H.264 level by mistake – for example, the vast majority of the 1080p-capable Canon cameras belong to this category. (They, absolutely unnecessarily, use H.264 level 5.0 even for 1080p24 footage, which is certainly an overkill – even 4.1 would be an overkill. This means those videos just can't be directly synchronized to the stock Videos app via iTunes without manually editing / changing the H.264 level first. If it works at all – Canon 1080p24 videos are well-known for very problematic H.264 level editing compliance.)


Unfortunately, for some videos, none of the above-listed methods work. For example, regarding high-framerate videos, my open-source Camera Roll importer utility (link) can only import 720p60 videos up to around 15-20 Mbps; for videos with 30 (or more) Mbps, it won't work. Neither will it work for any 1080p60 video. In addition, FreeSync (and other utilities) have never worked under iOS 5 or 6 and the, latest version (currently, 3.2.1.3 for OS X) of the otherwise, excellent iExplorer can't do desktop-to-device transfers either, only in the opposite direction.

iFunBox for the rescue! The recently-released, new preview of the Windows version of this free(!) app does what we need: to import any(!) kind of videos – even ones with extremely high (for example, 100 Mbps) video bitrates.

Using iFunBox for video import

(Note that this tutorial only explains video transferring to the iDevice. iFunBox has a lot of other functionalities as well.)

Get the (currently) 2.5 preview (direct EXE installer link; linked from THIS Version History page) from the homepage of iFunBox. Don't bother with the Mac version: as of now (version 1.1), it doesn't support video importing at all. Don't even try.

Install it (will work just fine in the 64-bit version of Windows 8 too). If you haven't installed iTunes on the given desktop (including virtual machines on, say, a Mac running Parallels), also install iTunes. It doesn't need to be in any kind of a synchronization relationship with the iDevice you want to access from iFunBox. For example, I use OS X 10.8 (Mountain Lion) on my 17” MBP most of the time. However, to run Windows apps (not compatible with the “lightweight” CrossOver), I'm using Parallels 8. As I sync my iDevices from under OS X, I couldn't synchronize them from under Windows – the operating system I need to run iFunBox on. Nevertheless, this isn't a problem as, as has already been explained, all you need to do to let iFunBox access the iDevice is install iTunes on the same desktop and nothing else.

After installing iFunBox, start it and let it recognize your iDevice: the area annotated with a red rectangle below should show your iDevice's name:


(as always, click for the original-sized, high-quality screenshot)

Now, click the Quick Toolbox icon at the top (annotated by a green rectangle above) and, then, select “iPod video” (annotated with blue above) in the “Import files and data” group.

Then, just drag-and-drop the videos you'll want to transfer onto the new dialog that is displayed (annotated with a purple rectangle). After starting the import process, when the progress bar reaches 100%, you can safely close it with the “X” icon in the upper left, annotated with a red rectangle below:



Quick tips

Video files transferred this way won't be manually deletable from, say, the iTunes instance you use for (officially) synchronizing video files to the stock Videos app on the iDevice. (A side note: you don't need to have any kind of video synchronization relationship for iFunBox's video transfer to work.) Left-swipes etc. won't work either in the Videos filelist. The easiest way of (mass-)getting rid of your transferred files is just disabling synching in iTunes (removing the checkmark from the “Synch Movies” checkbox), it'll delete the otherwise non-deletable ones.

The Videos app won't generate thumbnails for the list view. An example screenshot (also showing my high-framerate and, for the most part, high-bitrate test suite I use for benchmarking the new HDMI adapter):




Warning

1, During the testing (the current, 2.5 version of) iFunBox, I've found it stable. However, with an incompatible video on a non-jailbroken iPad 1 running on iOS 5.1.1, the Videos app stopped working: all it presented was a black screen. Not even restarting the entire device helped this. I needed to clean up the entire Videos library by forcing a Videos library wipeout with reassigning the library synchronized into another, previously non-synchronized iTunes. After the iTunes-initiated Videos library wipeout, Videos started working again.

The same file didn't do anything bad (except for not showing any picture, as opposed to the played-back audio) to my 6.1.2 devices (tested on an iPad 3 and an iPhone 5). The file was a direct Subler remux (with AC3 → AAC audio conversion) of the MKV file discussed and linked to from HERE. Note that, unless you transfer plain incompatible videos to your iDevice, this is very unlikely to happen - iFunBox, in its present state, worked without such problems with playable videos.

If you encounter the same (black screen problems), do the same – that is, uncheck the “Sync Movies” checkbox in the Movies tab in iTunes you have synched the device to. (Or check it in if you haven't ever synched videos to your iDevice. It'll also wipe out all the existing videos.)

2, iFunBox doesn't transfer any kind of metadata in the files (if they exist), including (possible) chapter info and, as has already been mentioned, the main video thumbnail to be presented in the file list.

Other discussion


I've created the high-bitrate, high-framerate, high-resolution videos for benchmarking Apple's latest Lightning-HDMI adapter, which received a lot of misinformation (see THIS article for more info). I'm discussing the adapter in the above-linked thread. Probably my most important posts in the thread on the results of my already-done tests of the HDMI adapter, as of Friday evening (will post a lot more on the weekend!), are THIS, THIS, THIS and THIS. As you can see, apart from the somewhat bigger lag of the adapter, making it pretty much unsuitable for action gaming, I like the adapter pretty much. (Some of the answers I've received are HERE, HERE, HERE and HERE.)

EDIT (Sunday): THIS post also shows how important it is to be able to transfer videos to iDevices not officially supported by the iTunes synchronization.



----------

Other stuff: I've very thoroughly checked the mirroring quality of standard text. I could in no way spot excessive compression artefacts - or, for that matter, any kind of static JPEG compression artefacts around letters. I don't know where the following shot (from the original Panic article) is from, but the situation is definitely MUCH better:

http://www.panic.com/blog/wp-content...ompression.jpg

The reason for this may be that I may have an adapter with a newer, better firmware, or, the Panic folks just messed up something? Dunno.

EDIT: 1, What is more, iFunBox's video import works on all iOS versions (I've specifically tested 6.1.2 and 5.1.1), iDevice models (I've tested both iPhones (including the iPhone 5) and iPads (incl. the iPad 1) and without jailbreaking.

2, changed the embedded Panic image to a link.

Last edited by Menneisyys2; Mar 10, 2013 at 09:36 AM.
Menneisyys2 is offline   0 Reply With Quote
Old Mar 8, 2013, 05:21 PM   #423
Menneisyys2
macrumors 601
 
Join Date: Jun 2011
Quote:
Originally Posted by iSunrise View Post
The most demanding file I had on my iPad 3 was a blu-ray compatible (Level 4.1) 720p60fps video with a rather high bitrate that isn´t smooth at all (it constantly skips several frames and the native Apple player becomes very unstable, I´ve not tested with iOS 6/6.1 though, that was still on 5.1.1).
I'm absolutely sure your files are somewhat messed up. I've just finished testing video playback at 720p60 with 60 Mbps video streams (made from http://s3.amazonaws.com/movies.dprev...diagonal01.MTS ) on the 6.1.2 iPad 3. Not a single stutter. (60 Mbps is even more than the maximal allowed Blu-ray bitrate, that is, 40 Mbps.) BTW, regarding the A5 vs. A6 question, the iPad 4 / iPphone 5 played back my 720p60 videos in exactly the same way as the A5-based iPad 3: no stutters at 60 Mbps but plenty of them at 100 Mbps.

BTW, the case was the same back in early September, when the then-current 5.1.1 played 20-30 Mbps 1080p60 just fine. (Using HW acceleration, of course.)

Feel free to upload heavily stuttering videos (or just some 30-40-second-long parts of them) to, say, Dropbox so that I can check why they stutter.

Last edited by Menneisyys2; Mar 8, 2013 at 05:26 PM.
Menneisyys2 is offline   0 Reply With Quote
Old Mar 9, 2013, 04:12 PM   #424
iSunrise
macrumors regular
 
Join Date: May 2012
Quote:
Originally Posted by Menneisyys2 View Post
I'm absolutely sure your files are somewhat messed up. I've just finished testing video playback at 720p60 with 60 Mbps video streams (made from http://s3.amazonaws.com/movies.dprev...diagonal01.MTS ) on the 6.1.2 iPad 3. Not a single stutter. (60 Mbps is even more than the maximal allowed Blu-ray bitrate, that is, 40 Mbps.) BTW, regarding the A5 vs. A6 question, the iPad 4 / iPphone 5 played back my 720p60 videos in exactly the same way as the A5-based iPad 3: no stutters at 60 Mbps but plenty of them at 100 Mbps.

BTW, the case was the same back in early September, when the then-current 5.1.1 played 20-30 Mbps 1080p60 just fine. (Using HW acceleration, of course.)

Feel free to upload heavily stuttering videos (or just some 30-40-second-long parts of them) to, say, Dropbox so that I can check why they stutter.
First of all, thanks a lot for mentioning iFunBox. The ability to transfer high-bitrate video or files that iTunes just won´t accept is amazing. It´s also extremely fast in transfering the files to the iPad 3. The GUI looks extremely messy though, wish it would look a bit more professional. Also, it seems to mess up the metadata of the files (or at least changes some of them) which is a bit annoying. But it works perfectly for video files I´ve tested it with that I couldn´t get on the iPad before so that´s a definite plus.

I´ve uploaded you the blu-ray sample here (about 500MB):
http://www.mediafire.com/download.php?xofbiuvvml94fio
Note: This is directly taken off of the blu-ray with MakeMKV and split with MKVToolNix.

What I did so I can play the file with the iPad 3s native hw-decoder:

I´ve extracted (demuxed) the H.264 video track and AC3 audio track from MKV and repackaged (muxed) to M4V and added a second AAC audio track as the primary track (so the native Apple player can hw-decode it). The result is even worse than I remembered it. With iOS 6.1 currently on my iPad 3, I cannot make this file to play, with 5.1.1 I could at least make it play, even though it stuttered a lot. I even tested the MKV as well as the repackaged M4V in AirVideo with the video pass-through option and with the live transcoding option. The result is always the same, the file itself starts to play and the timecode advances, but I only get a black screen with audio. Can you please double-check and try to repackage the MKV with tools from OS X and see if you can make that file play without re-encoding the h.264 video?

Now, since the repackaged file could not be played back on my iPad 3 I´ve done a re-encode with Handbrake and the MKV as source:

I used the "regular High Profile" profile, changed the average bitrate to 15mbps (I wanted the file size to be about the same to the original), changed to a constant framerate of 59.94fps, (which is the native framerate of the original file, according to mediainfo) and added a 2nd AAC track as the primary along with the original AC3 audio. This re-encode works perfectly fine, when I transfer it with iFunBox to my iPad, it´s perfectly smooth.

I´ve also uploaded that here if you´re interested:
http://www.mediafire.com/download.php?w803c0vhu7qcn48

I think I know why the original file cannot be played with my iPad 3. It seems that (only an assumption) the PowerVR VXD decoder does have a problem with some advanced settings that were used during encoding of the video track. It´s still a bit strange though, since the original video track is taken directly off of a regular sold blu-ray and plays back perfectly fine on my PC or a blu-ray player.

Unfortunately I have not found any detailed documents, forum posts or useful details about the exact decoding limits of the hardware-decoder of the iPad 3 on the internet. It seems capable of very high bitrates (according to PowerVR docs I´ve found, about 50mbps peak at 1080p60), but according to my blu-ray sample it isn´t capable of decoding every advanced setting that was used during encoding. You can take a look at the encode settings with MediaInfo.

I would be very interested to know the limits (what exact advanced setting does it have a problem with?) of the hw-videodecoder.

Last edited by iSunrise; Mar 9, 2013 at 04:43 PM.
iSunrise is offline   0 Reply With Quote
Old Mar 9, 2013, 06:00 PM   #425
Menneisyys2
macrumors 601
 
Join Date: Jun 2011
Quote:
Originally Posted by iSunrise View Post
I´ve extracted (demuxed) the H.264 video track and AC3 audio track from MKV and repackaged (muxed) to M4V and added a second AAC audio track as the primary track (so the native Apple player can hw-decode it). The result is even worse than I remembered it. With iOS 6.1 currently on my iPad 3, I cannot make this file to play, with 5.1.1 I could at least make it play, even though it stuttered a lot. I even tested the MKV as well as the repackaged M4V in AirVideo with the video pass-through option and with the live transcoding option. The result is always the same, the file itself starts to play and the timecode advances, but I only get a black screen with audio. Can you please double-check and try to repackage the MKV with tools from OS X and see if you can make that file play without re-encoding the h.264 video?
I've remuxed it with Subler (prolly the best OS X remuxer) into both an AAC-only and an AAC + AC3 video with default save params (m4v + no-64-bit video). On my 6.1.2 iPad 3, 4 and iPhone 5, apps directly using the HW decoder (including the stock Video apps itself, using iFunBox to directly transfer the video to it) show a black screen. "It's Playing" displays right at the beginning it's unable to play back the video using HW decoder and needs to fall back to SW decoding. That is, a no-go here either.

The problem MAY be something like malformed H.264 (e.g., the video doesn't start with a keyframe), which may cause problems like messed-up playback in the first 1-2 seconds (see THIS for an explanation). I'll run some further tests and report back.
Menneisyys2 is offline   0 Reply With Quote

Reply
MacRumors Forums > News and Article Discussion > MacRumors.com News Discussion

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 03:10 PM.

Mac Rumors | Mac | iPhone | iPhone Game Reviews | iPhone Apps

Mobile Version | Fixed | Fluid | Fluid HD
Copyright 2002-2013, MacRumors.com, LLC