H264 and mkvtoolnix for Youtube woes

[mindwalker]

Hi all,

I've been trying to upload a video on to youtube using the H264 video format but so far I've been having a lot of issues!

The video will be 1280x720, 25 fps progressive.

My video is edited in Sony Vegas Movie Studio. Using it's direct Youtube upload feature yelds a video that youtube will never finish processing (I mean.. really never... not even after 7 days).
Rendering the video as Sony AVC mp4 with AAC sound and manually uploading the video to youtube, yelds the same result i.e. a video that will never process.

So then I installed Debugmode's frameserver, and render to a frameserve file from Vegas. Using the x264 executable with an avisynth script (to convert the colorspace to YU12 or something) it will the encode nicely to mkv or mp4, but without sound. If I upload this output of x264.exe in either container (mkv or mp4) to youtube, it works properly.
To mux the sound (mp3), I use mkvmerge, latest version, disabling compression on both tracks (as the new version of mkvmerge compresses track headers and screws up a lot of players). If I upload the resulting MKV file to youtube, it will be processed and will play with sound and in time, but the screen will be mostly all grey with lots of decoding artifacts and it just looks terrible.

So then I think mkvmerge screwed something up.. so I demux the video stream and the sound stream with mkvextract thinking that mkvmerge screwed up the MKV container produced by x264. So now I have the raw .h264 file and the mp3 sound.
At this point, if I use ffplay on the h264 file it doesn't work properly and I get some strange artifacts. Nevertheless, I install mp4box and I mux the h264 file to the mp3 file, and upload the result to youtube. This time an mp4 file. Youtube processes the file but the result is again the gray screen with bad artifacts.

Somehow I think mkvmerge changed the raw h264 stream itself and now it's hopeless ?

I will try at some point to use x264 to encode a raw h264 stream, and the use mp4box to mux that with the mp3 file without having mkvtoolnix's tools touch the h264. If that works, the I can only assume that there's something seriously wrong with mkvtoolnix and youtube..

I'm sorry for the long post.. I hope the amount of information will help someone find some smelly issue in my method

Just for the record, mkvtoolnix produced MKV files that can be played with no problems on my DIVX player (from DIVX).. as long as I disabled comrpession on the MKV tracks (otherwise I get a black screen).

[aedipuss]

there is nothing wrong with the sony avc encoder. use one of the presets and don't mess with it. about the only thing in the options to change is the bitrate if you want an hd link on youtube, make it 6-8 mbps.

i've got lots of vids on youtube that were made with it.

[mike20021969]

about the only thing in the options to change is the bitrate if you want an hd link on youtube, make it 6-8 mbps.

For YouTube to give the HD viewing option, the video resolution needs to be 1280x720.

Upload a 16:9 video at its original aspect ratio (1280x720 recommended)

[mindwalker]

maybe my Sony Vegas is faulty but, nevertheless, after a bit of trial and error I found the combination of factors that leads to catastrophe:

- On Sony Vegas I insert before my video a simple text that will then fade into the real video. If I render the 5 secs that takes morphing from Vegas's effects into my video, and then try to use x264.exe with the following

x264.exe --bitrate 4000 --deblock -1:-1 --b-adapt 2 --ref 5 --me umh --direct auto --subme 6 --partitions all --trellis 2 --output "output" "input"

It will create a video that youtube will then compress resulting into a gray screen with lots of artifacts but still it's possible to see that it's my video behind all that mess. However, if I use --b-adapt 1 on the x264.exe command line, everything suddenly works like a charm.

And even more strange is the fact that if I use the original command line but only compress part of the video where there is no vegas text fading anywhere, then it also works...

I suppose this might be the wrong forum for this so I might try posting it on Doom9 or x264 support itself...

[poisondeathray]

But eitherway it works fine locally right? on a media player on your pc before uploading ?

If so, you should post on youtube forum, it would be more relevant because it's a youtube issue. If so, this observation would also suggest vegas is not the issue either

This sounds more like a weightp issue for the fades (youtube's decoder might not like weightp, so use --weightp 0). --b-adapt 1 might have worked in this scenario, because frametype decision for the fade was different (might have been a p frame instead of a b-frame)

[mindwalker]

Yep, only affects youtube, it works fine on my computer.
And you're quite right.. the first half a second of the text on black background is fine, seems like as soon as the fade starts it gets messy and never really catches up. I'll try your weight-p hint and also post the issue on youtube itself.

Thanks a lot for the help

[poisondeathray]

Adobe flash in general supports weightp on pc platform, but weightp causes glitches like you describe on linux & mac versions of flash. (this is on not re-encoded versions, so hosting the original file). If you played that file locally through flash and html on a PC I suspect it would work too. It really sounds like a youtube decoding issue

I doubt your earlier tests with playing rawavc prove anything. Most software cannot decode rawavc properly. If you used mkvextract, then re-wrapped it with mp4box, I suspect the file would play normally (i.e. I doubt mkvextract did anything to damage the file)

[mindwalker]

It is indeed a weight P issue. If I keep -b-adapt 2 and use --weightp 0 then it works

And you're right about mkvmerge being fine.. it was! If I would encode in MP4 with mp4box it would still generate a file that youtube would go bananas with. The problem is that I would never think the problem would only occur if I would include the initial fade in the equation because I was taking 5 second samples throughout the movie before (out of the fading region) and then it would work with the mp4 but not with the mkv which was based on the beginning.

I don't know much about H264 but I understand it's probably not a good thing to have --weightp 0. I will post this on youtube anyway, maybe they will do something about it.. even if it seems a tad difficult to recreate the problem without my exact same inputs..

[poisondeathray]

I don't know much about H264 but I understand it's probably not a good thing to have --weightp 0

weightp is fully part of mpeg-4 avc spec. It's just that some decoders do not fully support it. Even most hardware decoding chips (most blu-ray decoders, media players etc...) support it. It's a good thing in terms of quality and encoding efficiency. It significantly improves fades (hence your observations with the fades, where weightp was "activated" on the 1st encode). If you have to use youtube, then just disable it for now (until they fix it)

Again, it works fine with Adobe flash. I have flash videos with weightp that work fine (not re-encoded by youtube, hosted on different site). It's youtube's decoder that is the issue, which passes the errors onto the encode