Author Topic: How to Convert video.mp4 to video.avi with Avidemux?  (Read 243 times)

ettore88

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How to Convert video.mp4 to video.avi with Avidemux?
« on: January 01, 2019, 11:57:38 PM »
Hi guys.I'd like to ask the procedure to convert an MP4 video to AVI format with Avidemux.I want to put the video on a usb drive.(max 4GB FAT 32)

I have tried several times but unfortunately the video is too big(6.22GB)!

These are the settings that I use:(Am I wrong?)

http://i63.tinypic.com/1joi9i.jpg

These are the mp4 video data:


Format : MPEG-4
Format profile : Base Media
Codec ID : isom (isom/iso2/avc1/mp41)
File size : 2.86 GiB
Duration : 3 h 30 min
Overall bit rate : 1 948 kb/s
Writing application : Lavf57.72.101

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Main@L3
Format settings : CABAC / 1 Ref Frames
Format settings, CABAC : Yes
Format settings, RefFrames : 1 frame
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 3 h 30 min
Bit rate : 1 804 kb/s
Width : 720 pixels
Height : 576 pixels
Display aspect ratio : 16:9
Original display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 25.000 FPS
Standard : PAL
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.174
Stream size : 2.65 GiB (93%)
Codec configuration box : avcC

Audio
ID : 2
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 3 h 30 min
Bit rate mode : Constant
Bit rate : 140 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 210 MiB (7%)
Language : Italian
Default : Yes
Alternate group : 1

I use the last vs of Avidemux 2.7


What would be the step by step procedure to be used to get an AVI format?

How do I change the bitrate to decrease the size of the video?THX in advance
« Last Edit: January 02, 2019, 12:00:23 AM by ettore88 »

dosdan

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Re: How to Convert video.mp4 to video.avi with Avidemux?
« Reply #1 on: January 02, 2019, 03:39:32 AM »
What video compression are you wanting to use for the video stream in the AVI?  AVC is HQ/high compression codec. So using anything else will increase the video stream size.  I presume you want to use an AVI container because you have some old playback device that doesn't support the MP4 container.

Do you understand the difference between the stream compression format and container format?  The container does not compress either the video or audio streams. It packages them together and syncs their playback. It may also contain some extra streams, like subtitles.

A bitrate calculator indicates, that with an 128kbps  audio stream, (use MP3 steam format if it's an old playback device), and 720x576 @25fps progressive video, to squeeze the whole 3hr30min AVI into "4GB" ie. about 3.72 GiB (as shown by Windows 10. GB = 10^9 bytes; GiB is 2^32 bytes), you'll require a video-steam bitrate of 2,400kps:

https://www.dr-lex.be/info-stuff/videocalc.html



You need to get 2,400kps with accuracy, so you'll need two-pass encoding.  You could try:

Video: MPEG2 (ff) which means it is using the MPEG-2 encoder from FFMPEG.
Configure | Basic Settings | Encoding mide: 2 Pass -  Video Size.  Target Video Size = 2400KB. OK

Audio: MP3 (lame)  i.e. uses the LAME codec.
Configure | check that bitrate is 128kbps. OK

Output Format:  AVI muxer.

File | Save: give it a name and destination to suit.

First off: try a 1 minute portion test encode and view it. 

Make sure that the AR (aspect ratio) is OK.
That you can accept the quality of MPEG-2 at 2400kbps. (MP2 is less efficient than AVC.) If unhappy, try MPEG 4 ASP (ff).
Check with Mediainfo that that the video stream bitrate is very close to the bitrate you requested.
Check that your playback device can play this AVI.
Check that the audio is in sync with the video. If not, you may need to apply a time "Shift" offset in ADM. Start with about +/-200ms.

Then encode the full thing. Hopefully it will just fit. 
If the playback device can not handle a 3.72GiB AVI, split it at the half-way point into two 1.66GiB AVIs.

Dan.
« Last Edit: January 02, 2019, 04:00:15 AM by dosdan »

ettore88

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Re: How to Convert video.mp4 to video.avi with Avidemux?
« Reply #2 on: January 02, 2019, 08:50:25 AM »
Many thx m8.What would be the procedure for testing the test encoding on Avidemux 2.7? ;)

"try a 1 minute portion test encode and view it. "

dosdan

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Re: How to Convert video.mp4 to video.avi with Avidemux?
« Reply #3 on: January 02, 2019, 08:45:25 PM »
What would be the procedure for testing the test encoding on Avidemux 2.7? ;)

Encode a shot segment of a clip, say 1 minute, in ADM. Then play it back in the device that accepts an AVI, but will not accept the original MP4.  (Reverting from AVI to MP4 is a retrograde step, so I presume the reason you are doing this because of a limitation of a particular playback device.)

Don't use ADM to test the playback as it will playback both AVIs and MP4s.

By the way, what is this problematic playback device?


Dan.
« Last Edit: January 02, 2019, 08:51:24 PM by dosdan »