Mp4 Corruption

This forum is for video and audio help and discussion.

Postby JudgeHolden » Thu May 03, 2007 7:42 am

Ok, aerialesque's video plays perfectly in all players (to me, the perfect incode ... I don't know why people wouldn't want their encodes to be player freindly as possible). Oh, did anybody point out the fact that she forgot an extention? :P

As for yours, it works fine in VLC and mplayer. as for bframing, I have never seen a real size difference between using them in h264 and not using them (from the videos I have downloaded, I have never used bframes for h264, Dvix yes, h264 no) ... So again, I don't get why people would want to use them, when one can not use them and have a more compatible video. Anyway, so those two encodes are good ones.

I know when Rina was encoding, she was playing with every feature ... So, I do wonder if others do to .... if one dose it good, then 3 doses are better. That coupled with the fact that the codecs may not be as up to date for ppc just adds to the issue.
ImageImageImageImage
User avatar
JudgeHolden
 
Joined: 14 Mar 2005
Location: The great white north (Minneapolis)
Status: Looking at you through your window!

Postby trythil » Thu May 03, 2007 9:36 am

JudgeHolden wrote:(to me, the perfect incode ... I don't know why people wouldn't want their encodes to be player freindly as possible)


The only reason to not use encoding features is if you're aiming for an environment in which you know there is no possible way for those features to work. For example, it would be stupid to try and make a video iPod play H.264 High Profile
video.

But on the desktop, where there is a choice of video players, and some are more compliant than others, I see no reason to handicap the encode just to accommodate the least capable player.

This stance means that a lot of people, by choice or policy, will not be able to play back what I distribute, and it probably goes against common wisdom among video professionals.

It's why I'm glad I don't work in that field.

JudgeHolden wrote:as for bframing, I have never seen a real size difference between using them in h264 and not using them (from the videos I have downloaded, I have never used bframes for h264, Dvix yes, h264 no)


Whether or not B-frames make a difference is highly dependent on the input data. Long pans and motion like that tend to benefit a lot; lots of fades and flashes, not so much. Also, the B-frame difference isn't so much size as it is being able to achieve some level of quality at a smaller size.

That coupled with the fact that the codecs may not be as up to date for ppc just adds to the issue.


Well, first off, it's not a fact, it's speculation.

Second: what issue? You started out with

JudgeHolden wrote:Exactly, the mp4 the PC users here use, is not standard h264 encodes


but I've yet to see evidence for that.

If the problem is really with software efficiency, or even with features missing from a port of the decoder software, then that doesn't mean that "PC users are using non-standard h264 encodes". That would be like saying that any video that the video iPod can't play must be nonstandard: taking decoder limitations and inferring file problems in the files from those limitations.
This is a block of text that can be added to posts you make. There is a 512 character limit.
trythil
is
 
Joined: 23 Jul 2002
Location: Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch

Postby JudgeHolden » Thu May 03, 2007 10:02 am

trythil wrote:
JudgeHolden wrote:(to me, the perfect incode ... I don't know why people wouldn't want their encodes to be player freindly as possible)


But on the desktop, where there is a choice of video players, and some are more compliant than others, I see no reason to handicap the encode just to accommodate the least capable player.

This stance means that a lot of people, by choice or policy, will not be able to play back what I distribute, and it probably goes against common wisdom among video professionals.

It's why I'm glad I don't work in that field.



You see this is what it comes down to. To me a "Standard" encode will be as cross-platform and cross-player as possible. So, I'm for trying to get standards that make h264 videos on the org easier to play for the everyman (it's not like it's hard for me to try a different player if a video doesn't work in one, but I'm thinking of the other people who are downloading the videos). I know, I'm bucking the trend (Which I often seem to do :P) here and even going against my own elitest tendancies, but I would like to see this great codec really become the codec of choice. However, I don't want to leave people behind at the same time. So, what I mean by standard is that it will be a simple encode, compatible with most players (kinda like dvix/xvid has become, where it is easy to play in every player,on a computer, not just VLC). As for converting for an ipod, that will have to be done by the consumer, unless one uploads an ipod version to ... hmm that's an idea. Anyway, that's what I am getting at in the end.

As for not updating the mplayer codec of ppc, it looks like the last update on their site was 2004 ... I could be wrong.

Anyway, I will continue to move back and forth in players. I just wanted to voice a different view on the subject of AMVs encoded in h264 on this site. :wink: [/i]
ImageImageImageImage
User avatar
JudgeHolden
 
Joined: 14 Mar 2005
Location: The great white north (Minneapolis)
Status: Looking at you through your window!

Postby Zero1 » Thu May 03, 2007 2:11 pm

JudgeHolden wrote:It all depends on the video. One might sutter in VLC and then play great in mplayer or may not play at all in one and play in the other

As you may appreciate, H.264 requires more processing power than MPEG-4 ASP (eg XviD/DivX). In addition to this, that complexity can vary a lot between two videos. For example XviD uses 2 reference frames (which is an option you do not see or can change); in x264 you can set it to 0, or way up to 16. There's even options such as how the bitstream is coded, you can use CAVLC which is more efficient than Huffman (Huffman is the algorithm used in Zip files), but doesn't require huge amounts of processing power, and then you have CABAC which gets awesome savings but eats CPU time. Even the bitrate has effect since the higher the bitrate, the more stuff there is to decode with CABAC.

JudgeHolden wrote:Like some people trying to do to much and not really undersatnding what they are doing. Confused Anyway, if you are on a PC, you would never see these issues.

I appreciate you may not be familliar with opensource, or the community or people who write these programs, but they are all very well capable of what they are doing, and unlike MKV where there may be an amount of guessing at how things are handled, stuff like H.264 and MP4 is fully documented by MPEG, and these developers have a copy of those documents (it's simply in .pdf format), so it's not as though they are reverse engineering. Trust me on this one, but please show some more respect for the people who are doing this for free. Without them you wouldn't have VLC, FFDShow, XviD, x264, MP4box, MKVMerge, Virtualdub, AVISynth, DGIndex, or even the org itself. If you doubt the ability of the developers, pengvado the developer of x264 now works at Nero (the CD/DVD writing software people) after seeing x264; and MP4Box has seems to have some kind of ties with ENST, which I think is some French telecom company (but since I don't know French, I can't look into it).

JudgeHolden wrote:Oh, and mplayer seems to be the more relaible player for mp4s on a Macs, so it could also be a problem with VLC.

I had a sneaking suspicion this would end up being CPU related, but this seems to be a coincidence. mplayer usually has lower CPU requirements than VLC, so that may be why VLC stutters and mplayer doesnt. That isn't inconsistant implementation, that's your CPU being too slow to run the file in VLC. Given a fast enough CPU, I would lay money that VLC would run fine too; after all MP4 has been around since 2000, and has had major usage in the last 2 or 3 years. Do you think the developers would still not have got it right by now despite having the documents?

trythil wrote:such as the ffmpeg decoder (used in mplayer and VLC)

That's the other thing; both players use the same decoder, so the fact that it plays in one and not the other seems fishy.

JudgeHolden wrote:Now, why the difference? It can't be processing power, cuz then the first two wouldn't work in any player.

As I said, processing requirement can vary a lot between files of even the same framerate and resolution, not to mention that even players that use the same decoders have different CPU and memory requirements.

JudgeHolden wrote:Now h264 became big on this site AFTER the new intel processors, so maybe there is a glitch between intel macs and G5/4 macs?

lol what? H.264 became big here in particular because I was continually pimping it in the AMV channel, wrote a guide and would help people if they wanted it (although I do not want to come across as big headed, but I have tried pretty damn hard to put the wheels in motion). They saw how awesome the codec was, and it spread via word of mouth. In addition to that, I was also doing my damndest to promote it to some fansub groups, and there is a hugeass thread on Animesuki where I discuss it extensively, so hopefully people can gain something from that. Not to mention it's being used in iPod, PSP, HD-DVD, Bluray and some hardware players (like KiSS 1600); it's generally the buzzword now.

Also not everyone who is encoding and playing back H.264 is doing so on a Mac, so the fact that Mac now has Intel CPUs has little to no bearing.

What is likely the issue (and trythil may well confirm or deny my theory) is the architecture difference between the G4/G5 and Intel Macs. Programs like VLC, mplayer, or rather the decoder, are written for x86 instruction sets, and generally not optimised for Mac because it's a relative minority. If the Intel Macs are similar or the same CPUs as Windows PCs, then performance shouldn't be an issue because it's a similar architecture. Having said that, I'm not that keyed up on CPU architecture so it would be great to get another opinion.

I hate to come across abruptly, but you are blaming things without fully understanting what or why it's happening.

JudgeHolden wrote:You see this is what it comes down to. To me a "Standard" encode will be as cross-platform and cross-player as possible.

To me a "Standard" encode is anything I produce that complies with what MPEG specify. That is pretty much any encode I've produced using x264; and I could probably verify that if I had a compile of the H.264 reference software (where if it decodes with that, it's standard as far as MPEG are concerned).

I'm doing my part right; I'm complying with MPEG's specification (which is available to any company that wants to implement H.264 and/or MP4) as best I can, even using the recommended audio and container, if Apple only has a partial implementation of a decoder that's a shame for Mac users, but it's not my problem, they need to bitch at Apple to give them a full decoder.

There has to be a cutoff point somewhere. I mean do you expect me to release stuff in 320x240 DivX 3.11 just because there is a minority still with 500Mhz CPUs? If you don't take H.264 for everything it's worth, you may as well stick with XviD and just have larger filesizes.

Also Alternate Dimensions plays flawlessly with CoreAVC, FFDShow and VLC, having said that it's 29.97 fps and is high motion with a high bitrate, so it's likely your CPU is lagging.

Hate the player, not the game :)
User avatar
Zero1
 
Joined: 02 Jan 2004
Location: Sheffield, United Kingdom

Postby Kevmaster » Thu May 03, 2007 2:13 pm

I use Total Video Convertor to convert the H264's to the right format for my Ipod..but somehow..it doesnt seem to work on some videos, but it works for other videos...
Kevmaster
Eisenbahnmörser
 
Joined: 28 May 2006

Postby Willen » Fri May 04, 2007 6:48 am

What it boils down to is that MPEG-4 is such a flexible set of standards that while videos that are encoded with MPEG-4 SP/ASP codecs like XviD and DivX may play fine on nearly all hardware configurations out there, videos encoded with MPEG-4 AVC aka. H.264 may or may not depending on the complexity of the video, its resolution, certain encoding features, how powerful the hardware is, and what software is used to playback (decoder and player).

As mentioned before, H.264 can be used for low resolution, fairly low processing power player videos (iPod, etc.), and all the way to high definition/resolution, high processing demand videos (Blu-ray, HD-DVD, etc.) and beyond. This is a reason why virtually all portable players restrict video resolutions, bitrates, and encoding options to certain parameters and the MPEG-4 standards specify a set of Profiles and Levels. Of course, this means that a player capable of handling videos encoded for the Baseline profile and the lower set of Levels will probably not be capable of playing Extended, Main or higher Profile, higher Level videos.

Most computers have the capability of playing H.264 videos, but as you've experienced, depending on the encoding settings and/or material involved, you'll either have a smooth playing, choppy playing, or an essentially unplayable video. As the videos are encoded with lower and lower profiles and levels, the videos will be more compatible due to lower hardware playback requirements. But at a certain point, I feel that you'll be better off encoding with MPEG-4 SP/ASP (XviD) instead. Obviously, a more efficient decoder like CoreAVC will help playback performance on older hardware computers, but that option isn't available (yet) on the Mac (and may never be for older G4/G5 computers).

All that being said, IF there were certain 'standard' settings defined for x264 encoding of AMVs (resolutions, max. bitrates, B-frame usage, CABAC, etc.) a la iPod and PSP videos, it may solve playback issues for certain people. The problem is that this may essentially create a 'lowest common denominator' issue, and in the long term this won't help the community move toward H.264 (and MP4) adoption -- we'd be better off sticking with XviD and/or MPEG-1. :P
Having trouble playing back videos? I recommend: Image
User avatar
Willen
Now in Hi-Def!
 
Joined: 10 Jul 2005
Location: SOS-Dan HQ
Status: Melancholy

Previous

Return to Video & Audio Help

Who is online

Users browsing this forum: No registered users and 2 guests