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Started by wojtek.mm, January 08, 2021, 08:27:58 PM

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wojtek.mm

When my weather recording starts, I click A at the beginning and B at the end, but after saving the recording, there is an advertisement for half a second, but I want it to be so when the weather starts, so that there is no advertisement for half a second. What can be done in what settings?

eumagga0x2a

#1
The navigation slider seeks to keyframes (direct access frames, from where a decoder can start decoding the video) only, like the up / down arrow keys and the thumb slider do. Only keyframes are suitable as starting point for saving in copy mode.

If you need to start saving at a different type of frame (P- or B-frame), you need to choose a video encoder (e.g. "Mpeg4 AVC (x264)") instead of "Copy" and re-encode the video. If the source video is interlaced, you absolutely must either insert a deinterlacer (a video filter like Yadif) or enable interlacing in the configuration of the encoder. I would prefer the former.

If you re-encode, please make sure post-processing in Avidemux Preferences --> "Display" is disabled.

Use left / right keys to navigate to the previous / next frame.

wojtek.mm

I opened avidemux and uploaded the weather recording, I click A at the beginning and B at the end, I cut but after saving the video there is an ad for half a second, but I want it to be like that when the weather starts, so that there is no ad for half a second because I did A the beginning of the weather and the end of the weather B but after recording the weather video the advertisement is 0.5 sec and the weather is just starting and I want to get the ad 0.5 seconds when the weather starts. Please write in the order where should I set? I will know how and where to enter the avidemux settings. Because e.g. Time 00: 00: 00: 890 and I move backward 1 click and 00: 00: 00: 850 etc. for 40 seconds :(. I want 00: 00: 00: 15 and move backward 00: 00: 00: 14 , 00: 00: 00: 13 and so on for 1 sec.;)

eumagga0x2a

First of all, navigating frame-by-frame backward is always very slow because the decoder has to go to the last keyframe before the current position and decode from that point forward until the desired frame pops out. Maximum of 16 decoded frames can be kept in a cache, but once you have navigated 15 more frames backward, the procedure (the decoder goes back to keyframe and decodes forward) has to be repeated.

It is always better to navigate to a keyframe shortly before the desired position and navigate frame-by-frame forward.

Alongside frame-by-frame and keyframe-based navigation, you can seek 1, 2 or 4 seconds forward or backward by using keyboard shortcuts Shift + right / left, Ctrl + right / left and Ctrl + Shift + right / left. Also direct seek to a given time (Ctrl + T) is available.

dosdan

Quote from: eumagga0x2a on January 08, 2021, 09:12:46 PMIf you re-encode, please make sure post-processing in Avidemux Preferences --> "Display" is disabled.

What is the reason for disabling any PP if you re-encode?

Dan.

eumagga0x2a

@wojtek.mm:

Quote from: wojtek.mm on January 08, 2021, 09:52:28 PMI click A at the beginning and B at the end, I cut but after saving the video there is an ad for half a second, but I want it to be like that when the weather starts, so that there is no ad for half a second because I did A the beginning of the weather and the end of the weather B but after recording the weather video the advertisement is 0.5 sec and the weather is just starting and I want to get the ad 0.5 seconds when the weather starts.

I struggle to parse this. Could you please write in your native language (presumably in Polish)? I'll have to reply in English, however.

I assume that you want to save video exactly from the frame where the weather forecast or report starts, but there is no keyframe at the right spot, so when saving in copy mode, Avidemux has to seek back to the last keyframe which happens to be half a second earlier, during an advert.

You need to change the video codec from the default "Copy" (no re-encoding at all, the video stream is copied mostly unchanged) to an encoder for the codec you need.

I cannot tell you what codec you need with the intormation you have provided. H.264 is simply the most popular one, with x264 being probably the most popular and also the best encoder for H.264. There are more encoders for different codecs (HEVC, VP9, Mpeg4 ASP, Mpeg2 etc) in the dropdown menu.

Once you have chosen the video codec, you can set the A marker to any type of frame and Avidemux won't need to seek back to a keyframe.

This should solve your problem.

@dosdan:

Mostly unwanted quality loss / ruins deinterlacing if the source is interlaced / degraded performance when active; no-op with hardware decoders with only little clues for the user.

wojtek.mm

I threw avidemux recordings I cut the recordings A the beginning and B at the end and A at the beginning there are firecrackers the beginning of the recording but after saving the recording I turned on the recording and in the first second you will see firecrackers and it should be like after opening the recording what I cut out on the beginning are firecrackers should be. What to do?


1 picture should be the beginning of the firecracker and 2 pictures before 1 second is after saving the avidemux video



eumagga0x2a

Please write in Polish, I fail to understand your English (as you seem to fail to understand what I write you).

You use Avidemux in copy mode ("Wyjście wideo: Copy"). In copy mode Avidemux can cut only at keyframes ("Typ klatki: I-FRM" for progressive or "Typ klatki: I-TFF" for interlaced video with the top field coming first). To cut at other frame types like at B-frames as shown on your first screenshot, you need to re-encode.

"Typ klatki: B-TFF" means the video is interlaced. You should insert a deinterlacing filter when you re-encode.

wojtek.mm

Zrobiłem i nie wiem jak zrobić dla mnie chyba za trudne. Ale bardzo prosiłbym nagraj zrzut ekranu lub wstaw na YouTube i zrób to i wyślij tu albo linka, obejrzę to jak to się robi i będę wiedział jak :)

eumagga0x2a

Thank you, now I can at least understand. I'm very sorry, but no, there won't be any screenshots or video tutorials from me. Just explanations as text :)