trouble with audio after appending a .jpg turned .mp4 to another .mp4

[canadianjameson]

Hi,

I've been trying to add a static intro screen to several speeches that were recorded at a conferences (we want to put them up on the website).

I managed to turn the .jpg into a 5 second .mp4, and I matched it's resolution to that of the movie that I want to append to it. The problem arises in avidemux 2.5 when I append them, the audio (which was fine before) gets funky. On one video (after the 5 secs elapsed and the actual movie began) the audio was SUPER staticky. I tried the same process with another video and the audio slowed down tremendously (deep slow voices).

What am I doing wrong?

Thanks,



Jay

[poisondeathray]

did the 5 second jpg video have similar audio characteristics as the other section ?

[canadianjameson]

I'm guessing not because i didn't know i had to set any (although I should have known).

What do i need to match up, and how do I do that?

Thanks,


Jay

[poisondeathray]

to provide more info on the audio, use mediainfo (view=>text)

you need audio (even if it's blank audio) with the same characteristics, sample rate, average bitrate, etc... in order to append

same with the video - it has to have the same codec, encoding settings, etc....

just "mp4" isn't enough

[canadianjameson]

Hey,

Okay, I've attached 2 files: movie.jpg is the properties of the actual movie, and 'static movie.jpg'

How do I get the channels on the static movie to 6 channels? right now it's set to 'stereo', which seems to be the only difference between the two.

Thanks,


Jay

[poisondeathray]

You would have to upmix stereo to 6 channel . You can do this in any audio program (e.g. audacity)

In avidemux you can use audio ,filters, mixer and select 5.1

Is this 1.5 AR content ? or do you have letterboxing ? 720x480 1:1 will probably look distorted on a webpage . 720x480 is usually 4:3 or 16:9

[canadianjameson]

Hey,

sorry for the delay - I was fiddling about but i got it working.

Is it normal that after appending them I have to resave them with the mp4-avc, AAC, and MP4 settings (and reprocess the whole job?). When I didn't do that and just left the settings as 'copy' the output wouldn't play in my player - is that expected? I guess what I'm asking is if I have to spend the time to re-encode them all (probably 50+ movies) or did I do something wrong?

regarding the aspect ratio: I didn't play with that - should I have? is 4:3 a better ratio? (sorry, I'm new to this)

Thanks,



Jay

[poisondeathray]

There can be many reasons for it not appending properly. Usually mismatched encoding settings or parameters. Sometimes it just doesn't work and you have to re-encode the whole thing. Sometimes another program may work better. Something like an intro should have been done the 1st time during the encoding, instead of appending after encoding

Aspect ratio should be the same as your original footage. Do circles look like ovals? Do people have egg shaped heads ? Provide more info on the original source footage and the camera used. Use mediainfo if you don't know

Embedded videos on webpages almost always use "square pixels" . But if you used a DV cam for example, it will have either a 16:9 or 4:3 aspect ratio. You would probably deinterlace, then resize to a square pixel format