AMV Encoders - A/V Sync Test

[Mister Hatt]

Sure is EVERYONE MISSING THE POINT IN HOW HARDWARE RESTRICTIONS ARE AFFECTED BY VIDEO DECODING. Seriously, it's ALL about algorithm complexity and vbv and nothing to do with resolution/framerate. Also it seems there is still a strong misconception here that sharpness makes things harder to decode. You'll find that one way to throw it right out is to preserve heavy dither; that will put the vbv requirements way up and thus stress your hardware more.

[Quu]

Mister Hatt, can you help me by providing a sample file that I can use in my testing? It does not have to be an uncompressed file itself, the AVS script like the one that mirkosp provided would work. So would a purely synthetic video (I have one that is alternating tones and colours) in AVS.

also... I am planning on using these x264 command lines

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x264 --profile high  --level 4.2 --preset veryslow --crf 18 -o %outputfile% %inputAVS%
x264 --profile high10 --level 4.2 --preset veryslow --crf 18 -o %outputfile% %inputAVS%

(not sure if I should add a tune?)

[mirkosp]

Quu, I think a very good stress test for playback would be a clip exclusively made of noise of all colors all over the place. Perhaps something like:

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blankclip(width=1920,height=1080,fps=60000,fps_denominator=1001,length=1200,pixel_type="YV12")
addgrain(var=10000,uvar=10000)

Assuming a 20 secs clip is fine for your test.
Although I'm not sure how you could test the sync/drop rate. Perhaps put a song in the background and add the waveform with audiograph too?

[Zarxrax]

also... I am planning on using these x264 command lines

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x264 --profile high  --level 4.2 --preset veryslow --crf 18 -o %outputfile% %inputAVS%
x264 --profile high10 --level 4.2 --preset veryslow --crf 18 -o %outputfile% %inputAVS%

(not sure if I should add a tune?)

It's useless to test 10bit encoding. Completely useless.
Also, unless x264 has changed this behavior recently, specifying a level does NOT ensure that your video will meet the requirements of that level, it merely sets a flag which says the video is at that level. To meet specific bitrate requirements, you must use vbv.
http://mewiki.project357.com/wiki/X264_ ... V_Encoding

[Quu]

I like that example... I think i am going to merge it into one of my existing synthetic tests... so I will have the following

1) blank clip, with noise added, then audiodub with song from free music archive. finally audiograph of said song overlaid and time code added.

2) two blank clips, 5 seconds long each... each merged with different generated tone, then appended togethor and looped 30 times for a 5 minute video

to test for sync on the first one, I check frame 4000, for the second I check frame 7079 and 7080. I can make my test samples any resolution and frame rate I want then.

I am not familiar with the addgrain plugin... will be fun to play with (I am free tonight, so I can get on it)

is there a standard AVS->AVI or AVS->WAV command line tool? I have been thinking of using vdub (the command line interface for virtualdub)

Zaxrax, thanks... I did not know that, I will remove High10... I can't check that link at work, but will check it at home. (if it is useless, who would use it?)

[mirkosp]

I am not familiar with the addgrain plugin... will be fun to play with (I am free tonight, so I can get on it)

Be sure to get v1.5.1: http://forum.doom9.org/showthread.php?p ... ost1403052 ─ explanation of the settings here: http://forum.doom9.org/showthread.php?t=111849
The ones I set there will give you a very fast noise both for luma and chroma, so it should be fine. hcorr and vcorr will specify the dimension of the single grain, so you could toy with them depending on how big (or small) you want the noise to be.

[Zarxrax]

is there a standard AVS->AVI or AVS->WAV command line tool?

avs2avi

[Quu]

is there a standard AVS->AVI or AVS->WAV command line tool?

avs2avi

and i bet there is an avs2wav also

-_-;;;

sometimes i feel like such the old man

[Qyot27]

is there a standard AVS->AVI or AVS->WAV command line tool? I have been thinking of using vdub (the command line interface for virtualdub)

Video only:
avs2avi

Audio only:
wavi (http://sourceforge.net/projects/wavi-avi2wav/)

Video and audio:
ffmpeg, mencoder

Zaxrax, thanks... I did not know that, I will remove High10... I can't check that link at work, but will check it at home. (if it is useless, who would use it?)

The uselessness of it is more about the fact that you need an entirely separate build of x264 to do 10-bit encoding, and that the corresponding optimizations haven't taken 10-bit into account. There's also not really any readily-available 10-bit source footage outside of test sequences and professional mastering copies, meaning that for AMVs one would have to take existing 8-bit material and use that instead.

In time, those things will change (well, at least the case of the 10-bit stuff being optimized), but at the current moment it's not really something that should be counted on. 10-bit H.264 also has fewer supported decoders - the only widely-available one I thought was verified to work was DivX 7, but that might have changed in the couple of months or so since 10-bit was committed.

[Qyot27]

There's also not really any readily-available 10-bit source footage outside of test sequences and professional mastering copies, meaning that for AMVs one would have to take existing 8-bit material and use that instead.

On top of the fact that x264 currently only supports 8-bit input at the moment anyway; much of any true benefit will come when it can use 10-bit material from start to finish, along with having the assembly code needed to speed it up, and more decoders to be able to properly handle it. Where it is now is just a beginning point needed to hopefully jump-start all of that process.