The file formats accepted by Wikimedia Commons are listed in this page
Can't I upload mp3, mpeg, avi?
No. These are not opensource formats. Commons accepts only opensource formats. But these can be converted to open source formats easily.
Audio Files - .ogg (Ogg vorbis) and .midi are required. For creating them directly many free softwares are available in the internet. To convert file formats like .mp3 to .ogg, use the free software Audacity. For more help on Audio files click here.
Video Files - .ogv (Ogg theora) is required. For converting .avi, mpeg files to .ogv format many free softwares are available in the internet. For more help click here.
"Own work" is something that is completely created by a person - a image taken by him, an audio/video recorded by him or an animation created by him. Scans of already existing printed material, copyrighted images manipulated using image editing software like Photoshop are not considered "own work".
When a media file is one’s "Own work", but has been published somewhere else before, can the file be uploaded in the contest?
1) If the owner has retained the copyright while publishing it elsewhere, the file can be uploaded in the contest.
2) If the owner has sold or transferred rights to the publishing entity, the file cannot be uploaded in the contest
Can copyright expired old images be uploaded for the contest?
No. This contest is exclusively for own original work.
Can an entry already uploaded to Wikimedia Commons be entered in the contest?
No. Only files uploaded after November 15 can be entered in the contest.
A contestant can win only one of the general category (First-Second-Third-Consolation) prizes. A winner among these four can also win in the continuous contribution and special prize categories. But a single entry can win only one prize. A prize winning entry in the general categories will not be considered for prizes in the continuous contribution and special prize categories.
How many files can a contestant upload? How will they be judged?
A contestant can upload any number of files. There is no upper limit. But similar files from the same contestant (e.g. If a contestant uploads 100 pronunciation files or many images of the same place, they will treated as a single entry and judged accordingly) will be rated together. All other files will be rated individually by each of the five judges.