Avidemux Forum

Participate => User interface and Usability => Topic started by: sark on January 19, 2023, 10:47:42 AM

Title: Playback issues.
Post by: sark on January 19, 2023, 10:47:42 AM
Hi all.

I've recently moved from 2.7.8 to the latest 2.8.2. Why, when I click on a control button does my (Win 7) cursor convert to the circular timer icon? It didn't do this in the earlier version.

If you make a cut with A and B markers that are not on keyframes, preview of the cut video will stall for a second or so on the cut point/s. How long varies for different cut points. If markers were on keyframes the cut points do not stall. It doesn't occur with exported output, but it's still annoying. Is this just a limitation of my system?

Finally, most annoying of all. Why, after a filter is applied, does play return to the first frame at the end of the clip?

Sark
Title: Re: Playback issues.
Post by: szlldm on January 19, 2023, 08:27:31 PM
Quote from: sark on January 19, 2023, 10:47:42 AMcursor convert to the circular timer icon
it's a feature, not a bug. it indicates that it is working to accomplish a task (like go to the next frame, etc.)
previously there was no indication, if it is done with the move, or still decoding in the background

Quote from: sark on January 19, 2023, 10:47:42 AMHow long varies for different cut points. If markers were on keyframes the cut points do not stall.
if the cut point is not on a keyframe, then avidemux has to decode many frames in the background, until the desired frame pops out the decoder. this takes time (especially on slower machines); btw. this is also a case where the timer icon cursor could be useful imho.
Title: Re: Playback issues.
Post by: eumagga0x2a on January 19, 2023, 09:42:13 PM
Quote from: sark on January 19, 2023, 10:47:42 AMFinally, most annoying of all. Why, after a filter is applied, does play return to the first frame at the end of the clip?

Because we cannot be sure to be able to seek when the output is passed through a filter chain. Some filters operate strictly in "one picture in, one picture out" mode, other filters need to consume some pictures before being able to output something, again some filters modify timing and some allow no unambiguous assignment from output picture to the input like the "stillimage" filter. The only safe way to handle this: rewind to the location where we started.

Title: Re: Playback issues.
Post by: sark on January 21, 2023, 11:44:25 AM
Quote from: szlldm on January 19, 2023, 08:27:31 PMit's a feature, not a bug. it indicates that it is working to accomplish a task (like go to the next frame, etc.)
previously there was no indication, if it is done with the move, or still decoding in the background

Hmm! Not convinced it is necessary but, I can live with it.

Quote from: szlldm on January 19, 2023, 08:27:31 PMif the cut point is not on a keyframe, then avidemux has to decode many frames in the background, until the desired frame pops out the decoder. this takes time (especially on slower machines); btw. this is also a case where the timer icon cursor could be useful imho.

As I expected. Shame it cannot save the rebuilt information so that when playing a second time it replays smoothly.

Quote from: eumagga0x2a on January 19, 2023, 09:42:13 PMBecause we cannot be sure to be able to seek when the output is passed through a filter chain. Some filters operate strictly in "one picture in, one picture out" mode, other filters need to consume some pictures before being able to output something, again some filters modify timing and some allow no unambiguous assignment from output picture to the input like the "stillimage" filter. The only safe way to handle this: rewind to the location where we started.

OK, but why can the filters own dialogue preview stop on the last frame?

Sark
Title: Re: Playback issues.
Post by: eumagga0x2a on January 21, 2023, 02:19:22 PM
In filter configuration preview dialog, we preserve the filter chain and simply pause outputting pictures.

In the main window, we tear down the filter chain (because else such stuff like saving video won't work) when playback is stopped. When the chain is recreated on resuming playback, there is no way to seek reliably to the state (position and the result of filtering) where we were before.
Title: Re: Playback issues.
Post by: sark on January 22, 2023, 10:25:32 AM
Understood.

Thanks

Sark