yetanotherid
11th March 2009, 17:41
I'm mostly an AutoGK user but recently I tried StaxRip to convert a HD mpeg file because AutoGK was producing an AVI where the audio was going out of sync. If anyone who hasn't seen it but may have any ideas as to why, this is the thread:
Audio sync issue - PCM (AC3) audio in mpeg (http://forum.doom9.org/showthread.php?t=145547)
As a result of trying StaxRip (I'm using it to convert to XviD/AVI at the moment) I have some questions.
The first is the simplest to ask and relates to de-interlacing. The original mpeg I used StaxRip to convert was 1920x1080 interlaced video... sigh. I resized it to a width of 720 in the process and it produced a perfectly in-sync AVI whereas AutoGK could not, but the image was terrible in terms of motion blur. I'm sure it's the result of the de-interlacing but don't know how to fix it. Watching the original mpeg using Media Player Classic and de-interlacing it with ffdshow produces far less motion blur, and even the video AutoGK produced was far better in that respect.
My second question relates to converting a couple of DVDs and resizing issues. I'll use the last one I converted (Terminator 2) as an example. I don't want this to become a debate on resizing methods as such, but I'll start by saying that I've tried converting using AutoGK with it's ITU image option enabled and disabled, and each time I've done so and compared the two different AVIs with the original DVD, as displayed by Media Player Classic, the image using the ITU method always looks distorted in some way, while the default resizing method is virtually identical to the original. But that only partly relates to converting using StaxRip, which has ITU resizing enabled by default. So here's the differences as far as the way StaxRip works that I don't quite understand....
When I converted T2 using AutoGK and told it to give me a width of 704, it gave me a height of 304. The resulting video was of course smaller than the original, but showed no distortion of the image.
When I first tried StaxRip I left ITU resizing enabled, loaded the original vobs and enabled the resize filter, and StaxRip chose 704x384. I opened the crop filter and used autocrop but StaxRip's chosen size didn't change. It seems to me it'd be nice if it did without you having to move the resize slider back and forth to make it do so. After moving the slider I had 704x288. I opened crop again and selected smart crop, which removed an extra 4 pixels from the top and bottom. While suspecting AutoGK's 704x304 to be a better choice, moving the resize slider only showed 288 as an option using a width of 704, so I converted the DVD and confirmed the height Staxrip seemed to think was the correct one (288) was less than it should have been (the video looked squashed).
I tried the same process again with ITU resizing disabled. This time smart crop subtracted a few pixels from each side as AutoGK would, 704x304 was the size available using it's resize fader, and the resulting AVI looked just like the original and exactly like AutoGK's AVI.
Lastly I went back to using the ITU resizing method, and typed in a 704x304 resolution rather than use the slider, and when I used smart crop it sliced an extra 12 pixels from each side. Even had that process produced a perfect looking video, the ITU resizing method seems to require the user to second guess the ideal height in relation to the chosen width, whereas the non ITU resizing method seems to get it right, but even when typing in what I thought was the correct height manually, and even after so much more was cropped from the sides, the resulting video looked distorted in the same way it looked when using that resize method with AutoGK. The best analogy I can think of is to imagine pinching the image with a thumb and finger around the centre and squashing it in a bit, which would in turn stretch it a bit at the sides.
Sorry about the mega post but I figured it's best to explain things in detail for clarity. The relative merits of the two resizing methods aside, my main question is why does StaxRip seem to get the height wrong when using the ITU method, or is there something I've missed that'd stop me worrying about having to second guess what it's doing? Admittedly after those tests I'd disable the ITU resizing method myself anyway, but given that StaxRip recommends not to disable it, why does it effect the chosen height so badly?
Thanks.
Audio sync issue - PCM (AC3) audio in mpeg (http://forum.doom9.org/showthread.php?t=145547)
As a result of trying StaxRip (I'm using it to convert to XviD/AVI at the moment) I have some questions.
The first is the simplest to ask and relates to de-interlacing. The original mpeg I used StaxRip to convert was 1920x1080 interlaced video... sigh. I resized it to a width of 720 in the process and it produced a perfectly in-sync AVI whereas AutoGK could not, but the image was terrible in terms of motion blur. I'm sure it's the result of the de-interlacing but don't know how to fix it. Watching the original mpeg using Media Player Classic and de-interlacing it with ffdshow produces far less motion blur, and even the video AutoGK produced was far better in that respect.
My second question relates to converting a couple of DVDs and resizing issues. I'll use the last one I converted (Terminator 2) as an example. I don't want this to become a debate on resizing methods as such, but I'll start by saying that I've tried converting using AutoGK with it's ITU image option enabled and disabled, and each time I've done so and compared the two different AVIs with the original DVD, as displayed by Media Player Classic, the image using the ITU method always looks distorted in some way, while the default resizing method is virtually identical to the original. But that only partly relates to converting using StaxRip, which has ITU resizing enabled by default. So here's the differences as far as the way StaxRip works that I don't quite understand....
When I converted T2 using AutoGK and told it to give me a width of 704, it gave me a height of 304. The resulting video was of course smaller than the original, but showed no distortion of the image.
When I first tried StaxRip I left ITU resizing enabled, loaded the original vobs and enabled the resize filter, and StaxRip chose 704x384. I opened the crop filter and used autocrop but StaxRip's chosen size didn't change. It seems to me it'd be nice if it did without you having to move the resize slider back and forth to make it do so. After moving the slider I had 704x288. I opened crop again and selected smart crop, which removed an extra 4 pixels from the top and bottom. While suspecting AutoGK's 704x304 to be a better choice, moving the resize slider only showed 288 as an option using a width of 704, so I converted the DVD and confirmed the height Staxrip seemed to think was the correct one (288) was less than it should have been (the video looked squashed).
I tried the same process again with ITU resizing disabled. This time smart crop subtracted a few pixels from each side as AutoGK would, 704x304 was the size available using it's resize fader, and the resulting AVI looked just like the original and exactly like AutoGK's AVI.
Lastly I went back to using the ITU resizing method, and typed in a 704x304 resolution rather than use the slider, and when I used smart crop it sliced an extra 12 pixels from each side. Even had that process produced a perfect looking video, the ITU resizing method seems to require the user to second guess the ideal height in relation to the chosen width, whereas the non ITU resizing method seems to get it right, but even when typing in what I thought was the correct height manually, and even after so much more was cropped from the sides, the resulting video looked distorted in the same way it looked when using that resize method with AutoGK. The best analogy I can think of is to imagine pinching the image with a thumb and finger around the centre and squashing it in a bit, which would in turn stretch it a bit at the sides.
Sorry about the mega post but I figured it's best to explain things in detail for clarity. The relative merits of the two resizing methods aside, my main question is why does StaxRip seem to get the height wrong when using the ITU method, or is there something I've missed that'd stop me worrying about having to second guess what it's doing? Admittedly after those tests I'd disable the ITU resizing method myself anyway, but given that StaxRip recommends not to disable it, why does it effect the chosen height so badly?
Thanks.