Avidemux Forum

WT,
Your encoding settings will impact quality.  You are probably not using settings that give the results you wish for.  You can experiement with higher quality settings till you get what you want.  The problem is that many setting changes are not well understood.

For example: Multi pass with variable bit rate should never be used for any streaming media copy.  Most people don't understand why that is true.  Variable bit rate introduces different number of TCP packets to each full frame sequence and when the player needs to have all packets delivered prior to playing a sequence, a variable bit rate will constantly create differently timed caching and this can cause packets to be out of order and the cache limit reached per the TCP packet settings and the player can drop a video sequence as invalid and request it again.  This causes stuttering in the video playback of streaming video over TCP.  It becomes even worse if the is a mobile packet encapsulation for users with mobile connected Internet.  So Constant Bit Rate is always preferred, even though variable does an excellent job, if media playback is direct.

Another tip is to make sure any crop or aspect ratio change results in pixels sizes for width and height that are divisible by 16 (1st preference), 8 or at least 4 as (2nd and 4rd preferences).  If you don't pick these sizes, then encoding quality will be deminished because h.264 is looking to fill in at least 8 x 8 pixel blocks.

In anycase, here are the settings I use for conversion of H.265 to H.264 with AAC audio for 1080P only.  If it is widescreen, you can get away with 2200 instead.  These settings are high to get the quality you want.  A typical Core i7 or similar without hardware encoding will take 5 hours + for a 2 hour media.  If you want the quality and go faster, you need a faster computer or hardware encoding.  Setting the encoding time down to real time or 2 hours per 2 hour media, will end up looking not so nice for h.264 1080P.  You get what you pay for.  You want faster encoding speeds, spend more on your hardware, otherwise put up with the long encoding time.  Go find something else to do, while waiting for the computer to finish encoding.

Custom Config 2400 1080P.json

Quote{
    "useAdvancedConfiguration" : true,
    "general" : {
        "params" : "CBR=2400",
        "threads" : 0,
        "preset" : "medium",
        "tuning" : "none",
        "profile" : "high",
        "fast_decode" : false,
        "zero_latency" : false,
        "fast_first_pass" : true,
        "blueray_compatibility" : false,
        "fake_interlaced" : false
    },
    "level" : -1,
    "vui" : {
        "sar_height" : 1,
        "sar_width" : 1,
        "overscan" : 0,
        "vidformat" : 5,
        "fullrange" : false,
        "colorprim" : 2,
        "transfer" : 2,
        "colmatrix" : 2,
        "chroma_loc" : 0
    },
    "MaxRefFrames" : 3,
    "MinIdr" : 25,
    "MaxIdr" : 125,
    "i_scenecut_threshold" : 40,
    "intra_refresh" : false,
    "MaxBFrame" : 3,
    "i_bframe_adaptive" : 2,
    "i_bframe_bias" : 0,
    "i_bframe_pyramid" : 2,
    "b_deblocking_filter" : true,
    "i_deblocking_filter_alphac0" : 0,
    "i_deblocking_filter_beta" : 0,
    "cabac" : true,
    "interlaced" : false,
    "constrained_intra" : false,
    "tff" : true,
    "fake_interlaced" : false,
    "analyze" : {
        "b_8x8" : true,
        "b_i4x4" : true,
        "b_i8x8" : true,
        "b_p8x8" : true,
        "b_p16x16" : false,
        "b_b16x16" : true,
        "weighted_pred" : 2,
        "weighted_bipred" : true,
        "direct_mv_pred" : 1,
        "chroma_offset" : 0,
        "me_method" : 1,
        "me_range" : 16,
        "mv_range" : -1,
        "mv_range_thread" : -1,
        "subpel_refine" : 10,
        "chroma_me" : true,
        "mixed_references" : true,
        "trellis" : 2,
        "psy_rd" : 1,
        "psy_trellis" : 0,
        "fast_pskip" : true,
        "dct_decimate" : true,
        "noise_reduction" : 0,
        "psy" : true,
        "intra_luma" : 11,
        "inter_luma" : 21
    },
    "ratecontrol" : {
        "rc_method" : 0,
        "qp_constant" : 0,
        "qp_min" : 10,
        "qp_max" : 51,
        "qp_step" : 4,
        "bitrate" : 0,
        "rate_tolerance" : 1,
        "vbv_max_bitrate" : 0,
        "vbv_buffer_size" : 0,
        "vbv_buffer_init" : 1,
        "ip_factor" : 1.4,
        "pb_factor" : 1.3,
        "aq_mode" : 2,
        "aq_strength" : 1,
        "mb_tree" : true,
        "lookahead" : 40
    }
}

US Original is sped up for UK playback:
US made films to playback on DVD for PAL UK market.  24 fps are simply changed often to 25fps and the audio is sped up.  The tuning tone of A above middle C at 440 Hz will be turned in 458 Hz which is about 70% of the way to A#.  All music will be wrong and too sharp.

In order to fix this issue, the whole media needs to slow down to 24/25 fraction of the speed.  People's voices, sound effects and music keys will return to normal as well as the tempo of any scene.  I personally immediately notice this sped up content in the voices and in any music from my Sound engineering days.

The process of trying to change the video and not change the audio from US original of 24 fps to 25 fps to play on British TV's was just not practical to do any other way.

I believe this issue has changed with the advent of HD playback which supports 24 fps and other rates in the UK.

As early as 2016 or so, i already did a .vbs script, using 7zip 15.05, that had worked for NSIS based ADM install exes at that time (afair), eg. for avidemux_2.6.13_r160911_win64.exe, but i never really pursued it, as the zip based delivery was fully appropriate for me.
Obviously it's much different today, so i searched for installer extract around NSIS and QT install framework and saw:   https://nsis.sourceforge.io/Can_I_decompile_an_existing_installer%3F

QuoteSince version 4.42 [May 2006] 7-zip supports decompressing NSIS installers.
Since version 9.34 [Jun 2014] 7-zip was also able to extract the compiled scriptcode, but this functionality was removed in 15.06.

So 15.05 had been the last 7zip version which supported decompressing NSIS installers. But even 7zip 15.05 failed with status 2 on the recent .exe.

But: there's a 7z-build-nsis modification:   https://github.com/myfreeer/7z-build-nsis
Tried that too -> similar error (file "" cannot be opened as archive").

But, with both versions (the regular one as well as the "7z-bukld-nsis") i can see the internal structure of the install binary now:
via context menu, "Open inside #"  -> result list showing the files (1 exe, some text files i guess being json, some 7z's).
And, here one might select all or some 7z's and do "extract" for to store them in a folder.
And then extract all resulting 7z's one after another, move the result folders to their final position and see how far this goes.
Don't know what might be the command line equivalent for this approach.

But actually it appears to me that would be like reinventing the wheel ....

Ich hatte mal ein ähnliches Problem, als ich zwei Videos aus unterschiedlichen Quellen zusammenschneiden wollte. Die Auflösung und Framerate waren komplett verschieden, und bei mir wurde es richtig nervig mit verschiedenen Audio-Einstellungen. Ich musste beide Videos erst mit passender Größe und Bildrate neu exportieren, bevor sie zusammengepasst haben. Tools wie Avidemux sind praktisch, aber ich habe da oft auch viele Arbeitsschritte gebraucht, bis das Ergebnis gestimmt hat.

Thousand thanks eumagga0x2a for your detailed response! .... And, btw, i wish you merry Christmas!

About the scope of the Audio preferences: thank you, now one can be sure that it really doesn't affect the output.

About the MP4v2 muxer: ok, maybe i'll try to get some additional info in the net about the outside fate (and reasons why) of the abandoned underlying libmp4v2 library later.
(I already just saw "Yet the project has been abandoned since 2015 with the last official release dating back even further to 2012." in mp4v2.org)
I'd interprete for now that basically MP4 at least fully valid replaced it today. If i assume wrong, please correct me ...

Configurable options for indexing: this would be a very good thing indeed.

About the extraction of the installer executable, sounds that would, additionally on top, imply a nested loop along embedded 7z archives inside, anchored at certain offsets, oh.
For the script you mentioned: if you occasionally should remember the location of the script some day, there is at least one interested party here ... ;-)
Some specific meaningful keywords that might point and limit a net research to find it could be helpful too though ...

But, i'd like to mention: don't know how the setup exe actually is made (earlier it had been via NSIS afaik), and in how far it is actually influenced by own scripts controlling the flow. Obviousluy it already allows command line parameters, eg. -silent.
Why no allowing something like "-silent -expandonly" skipping all ops not dealing with the content expansion?
Would make the life easier for portable fans.
I'd give to consider.

Thanks for the info.
A quick Google confirms Wayland is only an experimental option in Linux Mint (Cinnamon), not a default or requirement. X11 is the default, so should not be an issue.

Quote from: me444 on December 23, 2025, 09:25:59 PMis there really no chance to extract the installation executable from the VC distrib via any tool??

In principle, this is absolutely possible as the installer (which includes a full, statically linked Qt, making it huge) is just a set of concatenated 7z archives (open the installer in a hex editor and search for bytes "0x37 0x7A 0xBC 0xAF" marking the start of each archive). Someone from a Russian computer forum posted a (PowerShell?) script to automate extraction, can't find it ATM.

Quote from: me444 on December 23, 2025, 09:25:59 PMI don't really needed the internal player for working when doing cuts (stepping forwards or backwards when location the cut markers is sufficient), and once i'd set Audio: "Local playback downmixing" to "Stereo headphones" and "Andio device" to "Dummy".

Well, having a picture for a specific time offset is the whole purpose of using the graphical Avidemux app instead of the CLI one (or ffmpeg). Audio settings regarding playback affect only playback of the source video in Avidemux app(s) using the given Avidemux profile where this setting is stored. They bear no relation to output.

Quote from: me444 on December 23, 2025, 09:25:59 PMI'd read now in some threads here that "MP4v2" is old and obsolete and shouldn't be used any longer.
Q: is the anywhere some more information known that explains a bit more why MP4v2 is obsolete, and in how far it might have drawbacks to use?

For a prolonged period of time, the underlying libmp4v2 library was abandoned, i.e. no development whatever, not even security fixes. Recently, development has been resumed. However, the libmp4v2 version bundled with Avidemux is ancient even in comparison with libmp4v2 when it was abandoned. The muxer plugin in Avidemux has received no improvements, especially regarding more suitable time bases (MP4v2 uses just 1/90000 hardcoded) or codec support.

Configurable options for indexing will be added, sorry for dropping the ball for so long.

Quote from: sark on December 24, 2025, 04:45:15 PMI did try updating via the Linux route, mainly due to the frustration of Windows 10, but I would lose some important (to me) apps. However, I did like Mint enough to decide to install it on an older small form PC I have. I'll see how Avidemux performs on this setup.

Please be aware that Avidemux for Linux is unusable with Wayland. If you cannot use an X11 session, please make sure you set environment variable QT_QPA_PLATFORM for Avidemux to "xcb", e.g. call it like

QT_QPA_PLATFORM=xcb /full/path/to/avidemux3_qt6
to force XWayland. On PCs with NVIDIA graphics using recent NVIDIA drivers, even hardware acceleration (VDPAU, NVDEC and NVENC as well as OpenGL) works just fine with XWayland in a Wayland session. The experience with non-NVIDIA or older hw or oder drivers may be much worse.

I understand.

I did try updating via the Linux route, mainly due to the frustration of Windows 10, but I would lose some important (to me) apps. However, I did like Mint enough to decide to install it on an older small form PC I have. I'll see how Avidemux performs on this setup.

Thanks for clarifying.

It is somewhat complicated. There is no supply of official cross-compiled nightly builds, but whoever bothers to build it from source following the how-to, will find such builds as fully supported as Avidemux builds can be. On the other hand, while native, VC++-compiled official builds may be provided in the future, they are definitely worse supported as I cannot produce such builds myself.