Avidemux Forum

Participate => Documentation & Tips => Topic started by: EFuggerth on April 10, 2018, 06:06:48 PM

Title: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: EFuggerth on April 10, 2018, 06:06:48 PM
I have used and enjoyed AVIDEMUX as a tool to archive films taken from TV-broadcast.
Until now.
Now problems start even at loading… most of the stepping-functions fail… but the worst is that the resulting video is rather a set of flashing pictures than a smooth film when replaying.
Due to a change is service: the broadcast-rate has increased drastically. Now it is at ~15,000 kb/s (previously ~4000 kb/s), at 720*576 resol. and 25 frame/s.
My system is Win7 64bit, and Avidemux_2.7.0r180405_win64.exe is (freshly) installed. Video/Audio output are both in “Copy” mode, Output-format is set as “Mpeg TS Muxer”, other options left as installed.
I guess (and hope) that setting properly some of the “million switches” your software offers will eliminate my problems.
Since I am a complete stranger in the video-terms applied, I would need a set of instructions to follow.
Could you help me, please?
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: eumagga0x2a on April 10, 2018, 06:20:43 PM
Please provide a sample video (e.g. using WeTransfer) in which Avidemux fails to seek. Does an older Avidemux version work for you for this particular sample?

By the way, completely wrong part of the forum.
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: EFuggerth on April 10, 2018, 06:52:32 PM
Thanks for your care.
I will be preparing a short sample (both source and Avidemux-manipulated) as soon as I learn the way of sending/attaching them in a message to you.
Previously I loaded +worked with versions 2.6.14 (32 bit) and 2.6.21 (64 bit), and encountered no such problems with source-videos of ~4000kb/s rate, while none of them works with these new ~15000kb/s rate videos.
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: EFuggerth on April 11, 2018, 10:28:24 AM
Since size of files are somewhat a limiting factor in sending samples over, the videos behind the links (offered by “WeTransfer”, as you suggested) are excerpts of about 30 sec (~30Mb).
Two sets are being sent for your perusal. Under each link there is a source-sample (in 3 parts, as is generated by the devices at recording) and 2 “manipulated” results: one with 2.6.21 version and another with 2.7._the_latest. [Manipulation here was practically limited to loading & saving – with testing the stepping-keys, too.]
1.)   from News M1-hu media: https://we.tl/Cne2XFzKzq
2.)   from a film: https://we.tl/16PnRTLrPG
The “Av 2-6_manip” files clearly show the flashing-effect.
While as to the Avidemux 2.7. I have to correct my previous statement. All that was said stood for an earlier 2.7. version. [Which, however, has been overwritten on refreshing it with the latest (e.g.: 2.7.0r180405_win64.exe).] That is, this latest 2.7. version gives free-of-flashing results.
HOWEVER:
•   On loading the source-video you can discern that while the “1 minute” and “the smallest” steps (back&forth) are functioning proper, neither the “medium-stepping” nor dragging-on-timeline works as they should: the screen is gray-blank – just as it is right after loading.
•   Another big difference exists in loading: This latest version do not offer concatenation of sequential files while all previous versions did. [And since recording TV-broadcasts (at least in my arrangement) is done by breaking the film’s content into 1GB portions (separated by those 64kb service-files), such an option back would be a welcome.]
These side-effects together make fine-manipulations quite tedious, especially when problem appears at saving (marked as “Video is too short/incomplete”) due to unhappy gaps under recording, and the erroneous part to be dropped is to be searched for by fine-tuning.
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: eumagga0x2a on April 11, 2018, 11:27:55 AM
Thanks for the samples, I'll look at them as soon as possible. I need only source videos and precise editing steps, no output videos. Test with legacy versions matter only if the latest nightly fails at something which works in 2.7.0 release or in 2.6.x and other unsupported EOL versions.

While as to the Avidemux 2.7. I have to correct my previous statement. All that was said stood for an earlier 2.7. version. [Which, however, has been overwritten on refreshing it with the latest (e.g.: 2.7.0r180405_win64.exe).] That is, this latest 2.7. version gives free-of-flashing results.

Fine.

Quote

On loading the source-video you can discern that while the “1 minute” and “the smallest” steps (back&forth) are functioning proper, neither the “medium-stepping” nor dragging-on-timeline works as they should: the screen is gray-blank – just as it is right after loading.

Maybe wrong frames are marked as IDR (as keyframes). I'll check this.

Quote
Another big difference exists in loading: This latest version do not offer concatenation of sequential files while all previous versions did. [And since recording TV-broadcasts (at least in my arrangement) is done by breaking the film’s content into 1GB portions (separated by those 64kb service-files), such an option back would be a welcome.]

It has been disabled because it was both severely broken as well as unnecessary for MpegTS. It is mandatory only for DVD structures.
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: EFuggerth on April 11, 2018, 12:03:02 PM
I understand disabling concatenation of sequential files, and there exists a route to overcome this point by using your built-in “appending” option in the “File” menu, indeed.
The visibility and tracking ALL frames are however of paramount import to clear all possible blemishes. [Is there anything necessary detail I have missed to describe?]
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: eumagga0x2a on April 11, 2018, 05:03:13 PM
While very similar from the user's perspective, appending videos at the application level and concatenation at the demuxer level are fundamentally different. The former operates with technically independent videos (i.e. each video can be loaded separately, with timestamps starting from zero), the latter assumes that the files are just portions of a single big file split in binary way. If this assumption does not match the reality, things go very wrong. With all this in mind, in order to implement a more fine-grained approach, it would be required to find out what your recording device is actually doing.

I'll try to check why decoding of some frames fails. Didn't have a chance to look at the samples yet.
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: eumagga0x2a on April 11, 2018, 09:12:26 PM
At the first glance, the problem of not decodable keyframes is related to this video being interlaced with the bottom field shown first.
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: EFuggerth on April 11, 2018, 10:01:46 PM
“To find out what the recording device is actually doing” – especially in the binary kingdom – is certainly beyond me. It was to serve the trial of whatever depth that I sent over the short source-videos as they were: that is, in 3 parts [“000”(64kb)+”000”(2.2MB)+”info3”(32kb) – for the “News M1-hu].
Anyway, bigger source-files are built up as:
“000”(64kb)+”000”(1GB)+”001”(64kb)+”001”(1GB)+”002”(64kb)+”002”(1GB)+…+”00n”(64kb)+”00n”(residue)+”info3”(32kb)
Meanwhile, tentatively I tried appending sequential parts of the same source with success – except that manipulations were done mostly “in the dark”, due to described failures in visibility while stepping.
So, the core to cure is visibility all-round. For which I am patiently waiting.
…and waiting “for the 2nd glance”…
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: EFuggerth on April 17, 2018, 08:07:07 PM
Newbie to Hero Member:
Something’s up? (Dee-day’s looming…)
Over.
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: eumagga0x2a on April 17, 2018, 08:21:41 PM
No, not yet. I don't have time and peace of mind for any non-trivial Avidemux-related work ATM.
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: EFuggerth on April 17, 2018, 08:58:27 PM
So I wait, with full of hope. (As submissive Nubians in the line should.)
[Yet, conundrum of non-triviality: Stepping by 1 frame or by 1 minute works fine (back&forth), while the stepping maneuver in between them fails (i.e. gives blank instead of the actual picture). It seems a central blemish, isn’t it?]
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: eumagga0x2a on May 11, 2018, 09:44:45 AM
How was this channel broadcast? Over a satellite? Which one? Terrestrial? DVB-T? We would like to be able to capture the channel ourselves, if possible.
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: EFuggerth on May 12, 2018, 10:01:57 AM
The signal arrives to my abode through a cable, however the service-provider offers satellite-signal also for “un-cabled” territories. The contact page/address is https://www.tarr.hu/ , with seemingly no clue for global attainability neither to the signal nor for any details in English.
Their email address is info@tarr.hu . Good luck for the try.
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: EFuggerth on May 22, 2018, 06:13:45 PM
On contacting the service-provider, they assured me of their readiness to provide Avidemux’s programmers information regarding “technical parameters”, as soon as you write them (Orbán Roland TARR Kft., info@tarr.hu, my letter’s ID is 2170976).
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: eumagga0x2a on May 22, 2018, 07:02:14 PM
Thanks, we are on it at the moment, don't think that we need new samples. Currently, the problem looks like a ffmpeg bug, there is a workaround as the last resort.

The stream is field-encoded, which is very uncommon nowadays. When the keyframe (the first field) is fed to lavcodec after decoder flush, it immediately pops out a bogus gray image instead of waiting for the second field.
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: EFuggerth on May 22, 2018, 07:28:01 PM
While embracing the good news, I beg of Lord this bug not to escalate into buggery.
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: eumagga0x2a on May 24, 2018, 07:17:59 PM
Mean has independently found the solution and then identified the upstream fix for FFmpeg (https://trac.ffmpeg.org/ticket/6677) which solves this issue and pushed the changes (https://github.com/mean00/avidemux2/commit/48e3b37c2a141f98b5f3f364998c7c06501ce7c1) necessary to integrate this patch into Avidemux. You might want to try the latest nightly (http://avidemux.org/nightly/win64/) (r180524 at the moment). Please be aware that you won't be able to save a similar field-encoded mpeg2 video in copy mode yet.
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: EFuggerth on May 31, 2018, 04:35:17 PM
This Mean-news is happy-news, rather.
(Sorry for my being late with checking your newest “nightly”.)
Full visibility on tracking the frames is restored, indeed. (So, manipulations can now be followed again.)
HOWEVER: The complete (cut) film [if it comes from appending and saving the Avidemux-manipulated segments of the fixed broadcast] (on the usual “VLC” replay) exhibits a marked, extremely disturbing asynchrony between pictures and voices. [N.B.: the saving-process of the appended parts onto a single-part film is unusually slow.] On the contrary: No such asynchrony emerges if the resulting film is made by appending the original segments first and then Avidemux-manipulating the whole [and saving it (in an output format “Mpeg2 TS muxer (ff)”)]. (Wherefore, incorporating a direction running this way into your next nightly could be useful.)
This I experienced after several trials.
How further then?
Your last sentence in the latest message warns as “Please be aware that you won't be able to save a similar field-encoded mpeg2 video in copy mode yet.” Does it mean I should be expecting some further refining?
Title: Re: "Flashing sequence of pictures" instead of smooth video resulted...
Post by: eumagga0x2a on May 31, 2018, 10:56:36 PM
As stated above, the copy mode for field-encoded video is broken. Fix upcoming.

Re-encoding (adding a good deinterlacer is highly recommended) should work.