Aspect ratio error, uploading Huffyuv AVI to YouTube?
 

When I upload a captured file to YouTube as losseless AVI HuffYUV, YouTube uploads the file fine with little degradation but the problem is it cannot detect the aspect ratio, How do I insert the aspect ratio flag in the file without converting it? Also is it possible to tell VertDub to flag the file as 4/3 during capture ?

Lossless unencoded AVI has no aspect ratio flag. The aspect ratio is the same as the native aspect ratio of the frame. If your losslesss AVI has a frame size of 720x480, its native aspect ratio is 1.5:1. IF the frame size is 720x576 PAL, its native aspect ratio is 5:4. YouTube techs are not going to attempt to "guess" what the DAR should be. For computer display use the video is encoded as square pixel at the video's native aspect ratio.

You can't.

No. Not with VirtualDub or anything else.

Resize your huffyuv to square pixel at the proper aspect ratio. If it's interlaced or telecined, you should make it progressive yourself before resizing, or YouTube will screw it up for you and make it progressive on their own. Your video will not be displayed or mounted using huffyuv or any other lossless codec. It will be encoded to h264/mp4 or a similar lossy, low-bitrate, encoded format. To expect "no quality loss" from YouTube processing is fantasy. If you think so, download youir video off YouTube and play it full screen to see for yourself.

No I never said I want youtube to upload it to be streamed as lossless for others, see my post again, My only concern is the DAR.
If using QTMG to convert to MP4 is there a setting for DAR, if so what is the script?

What is QTMG ?

Deinterlace and resize to a 4:3 frame (640x480 will do). Any h.264 encoder can encode to square-pixel, which in this case would be a pixel aspect ratio of 1:1, which would also be the DAR. Spline36Resize is probably better than or as good as the resizer YouTube would use.

Youtube is stupid. It has almost no video intelligence. You have to hold its hand.

Huffyuv cannot have aspect ratio flags. That's an intermediary format, and Youtube does not expect it. For one thing, it's far too large to try and upload more than a brief minute-long clip.

You need to pre-encode the video. Sometimes Youtube will just accept your encode. But I often prefer to give it a large bitrate, and then let Youtube transcode it more compressed if it wishes. I've grown tired of trying to figure out what specs Youtube is currently abiding by.

If the video was super-important, I wouldn't use Youtube anyway. It's just a low-quality compressed version to show others.

If using Avisynth to convert to MP4 can I set the aspect ratio flag without changing the resolution, In other words youtube should see the file as 720x480 4/3 ? Just like DVD players or media players see it.

No.

Deinterlace your original. You cannot post interlaced video on YouTube.
You cannot post anamorphic video on YouTube.
Resize to square pixel 640x480.
Encode to h264/mp4.
Send it to YouTube.

YouTube has online help and tutotials. Haven't you looked at YouTube's online requirements and specs? https://support.google.com/youtube/answer/1722171?hl=en