MP4 to AVI conversion results in a ghost-effect video .. !

[ahmadka]

Hi guys ... Well I have some old university lectures which I'd like to convert from MP4 to AVI, as in MP4 form they take a lot of space ..

I'm using this software called Pazera free MP4 to AVI Converter ... The tool itself seems to be working fine .. The only problem I'm getting is this effect which causes stuff from previous frames to remain in the visual area, till a keyframe comes along and clears all old data ..

Here's a picture of this effect:
http://img853.imageshack.us/img853/9853/convertedavisnapshot002.jpg

Here is the snapshot from two frames later:
http://img155.imageshack.us/img155/9853/convertedavisnapshot002.jpg

This is an upload (around 200 MB) which has an original 5 minute record and its converted form .. The effect can be seen in this ..Its very simple and straight forward to download from here:

http://ifile.it/yxakob4

For conversion I'm using the FFmpeg MPEG4 codec .. Unfortunately the tool doesn't have the option to open the codec dialog box to fully tweak its settings .. I can only see the bitrate and frame rate from the main window .. However, this is the commandline the program used to do the encode:

-y -i <input_file> -vcodec mpeg4 -b 1500k -acodec libmp3lame -ar 44100 -ac 1 -s 848x480 <output_file>

... so maybe I can change parameters manually myself from the commandline ..

So any clues on how I can get rid of this 'ghost-like' effect .. ?

I tried many different freeware/shareware/trailware tools for the conversion .. This one seems to provide the best result .. others gave my problems such as a/v sync issues, incorrect resolutions, etc .., as well as the issue discussed here ..

[Ghitulescu]

Could you please define AVI (what is an AVI for you)?

[ahmadka]

As in an AVI format with MPEG4/DivX/Xvid encoding, as this is the most backward compatible codec I think ..

[yetanotherid]

The program doesn't appear to be reading the original file correctly and it's encoding the decoding errors.
Try a different one. Format Factory and AnyVideoConverter are both "one-click" type conversion programs which should convert it fine. You'll find them with Google and both will convert to an XviD/AVI.
If you want more control maybe try something like MeGUI or HDConvertToX.

I just ran a quick conversion on your MP4 using AutoGK and it converted to AVI fine. AutoGK doesn't encode MP4s though, (you need to do it via an AVISyth script wrapped into an AVI and convert the audio separately) but I just ran it to see if I could convert the video okay, which it did.
Keep in mind if you want compatibility with standard AVI-DVD players you'll need to reduce the resolution to a maximum width of 720 pixels. In the case of the video you uploaded, 704x400 would be the best choice.

[yetanotherid]

Could you please define AVI (what is an AVI for you)?

Does that make it easier to download the converted sample and have a look? ;)

[SeeMoreDigital]

Does that make it easier to download the converted sample and have a look? ;)I disagree...

Ghitulescu question is attempting to establish ahmadka's knowledge of "formats" and "containers".

And please stop picking fights with Ghitulescu!

[yetanotherid]

I disagree...

Ghitulescu question is attempting to establish ahmadka's knowledge of "formats" and "containers".

And please stop picking fights with Ghitulescu!

I disagree.....
The OP explained what he was doing and even posted code which shows exactly what an AVI means to him.
While Ghitulescu was posting for the sake of posting as he often does, I was actually trying to answer the question being asked.

And please stop picking fights with me.

[AnonCrow]

Well I have some old university lectures which I'd like to convert from MP4 to AVI, as in MP4 form they take a lot of space ..
If you'd like to keep it as simple as possible (and considering the type of content it is) you could save plenty of space without transcoding by just dropping some frames: decimate the framerate by 2 or 3 , dropping the framerate from the original ~23.838 to ~11.9 or 7.9, respectively.



I'm using this software called Pazera free MP4 to AVI Converter
...
For conversion I'm using the FFmpeg MPEG4 codec ..

Assuming the software also uses FFmpeg for decoding the input file, what version/build of FFmpeg did the software come with ?

Again considering the type of source , and assuming that like in the sample, you can't really make out most of the text on the whiteboards anyway:
drop framerate, reduce resolution, possibly apply some filters to the audio to try to make it sound a bit better (especially if someone wants to watch a lecture at 1.5x-2.5x speed).

Consider just using plain VLC to convert the entire thing if you don't want to test another half a dozen different transcoding apps.

Hint: the video in original mp4 is already in MPEG4 format (SP@5)

[Ghitulescu]

Does that make it easier to download the converted sample and have a look? ;)

There's no conversion to AVI, because AVI is a container not a codec/format. And by conversion the OP wanted a method to make the files smaller, read compression.

That's another thing you've learned today.

[yetanotherid]

There's no conversion to AVI, because AVI is a container not a codec/format. And by conversion the OP wanted a method to make the files smaller, read compression.

Aside from stating the obvious, what's your point?
He said he's using the using the FFmpeg MPEG4 encoder, specified the birtrate and stated he's using the AVI container, so what else is there to know? What else is an AVI likely to be if you want to compress the video to make it smaller, and which other encoder would you use depending on what an AVI "means" to someone? What further suggestions could you make without actually looking at the original video? Is any of it even relevant to the OPs questions as to why his encodes weren't coming out right?
I also suggested he reduce the resolution to make the files compatible with standalone players which will also make them smaller. Thinking about it, he's probably using a higher bitrate than necessary, given the video is fairly static.

That's another thing you've learned today.

Grow up.

[SeeMoreDigital]

Just pack it in... both of you!

[yetanotherid]

Bite me.

[manono]

Thread closed.