Video editing software

I'm a beginner to all this.

I have some video files that have either no sound or no picture.

I discovered that the files with no sound are missing an AAC audio codec. I'm not sure which video codec is missing at this time.

Is there video editing software I can use that will allow me to import the file (mp4), add an AAC codec and export to a file that will then have audio? Similar question for video.

This is for home/personal use. I'm willing to purchase and use a Mac.
Thank you,
Paul

I have several questions that might get us going on the right track. I'm sure that others will also chime in with their thoughts as well.

1. Are we sure that the files involved ever had an audio track at all? The problem you are describing could be due to a missing codec but could also be due to there being no audio in the file to start. It's possible the audio was not saved properly.
2. What hardware and software are you currently using to try and play these files?
3. Do you know what was used to create these files?

Thanks so much for the help!

Background: I play a game called Go and take lessons from a strong European player. The lessons are in the form of videos which he posts on Vimeo. Over the past few years I have downloaded the videos so I could watch them off-line. In the past couple of weeks there has been no sound to the videos I download. I can watch them on Vimeo and everything is fine. I've written his tech guy but received no reply.

I do not know how the videos were created.

I assume there was at one time both audio source and an audio codec since I could stream from Vimeo.

I download the files using Firefox, Video DownloadHelper. They are all in mp4 format.
I am running on a MacBook Pro. To view the files I use VLC and Movist. I have the latest versions of everything.

I used VLC to list the codecs in the videos. When I look at videos that play sound VLC shows me that they contain an AAC codec.
I am not sure if the .mp4 file is missing the audio in addition to the codec and I'm not sure how I would determine that (but would be glad to investigate if you would tell me how).

Paul

I just found an app called Media-Info. When I inspect a good mp4 file it shows two 'streams'. One for video and one for audio. When I look at the files with no sound it shows only the video stream. So, the input stream is missing, not just the codec. Thanks so much for your help, I think I now need to contact Vimeo.
Paul

Good detective work on your part pohmart. That suggests to me that something went wrong during the download/save. Since the
audio portion of the file is missing I'd suspect that the Firefox Video DownloadHelper is at least partly to blame. Here's something I might try next if I were you:

1. go to one of the files that you might want to download and let the file play for a few seconds to make sure there is sound present.
2. Instead of using your regular download program try tight-clicking the file that you just played. If there is an option that says something like "download linked file" in the menu choose that.
3. This should put the file in whatever folder your browser uses to store downloads. Now try the file and see if it plays.

If you can provide a link to the site perhaps I can test and see if I get similar results.

BTW VLC is a good choice since it plays almost anything but if those files are mp4 video with .aac audio they usually play in QuickTime Player as well.

I just thought os something that might be confusing so I will add it as a separate post. When you download one of these video files and load it into VLC are you trying to convert the file to something else and then play it? I have had a problem lately with some conversions in VLC where the files don't seem to save properly. I haven't spent much time sorting this out so it may be just a quirk in my system.

A really good app to edit videos is VideoPlus