List of some well-known formats which YouTube supports:
WebM files (Vp8 video codec and Vorbis Audio codec)
.MPEG4, 3GPP and MOV files - (typically supporting h264 and mpeg4 video codecs and AAC audio codec)
.AVI (Many cameras output this format - typically the video codec is MJPEG and audio is PCM)
.MPEGPS (Typically supporting MPEG2 video codec and MP2 audio)
.FLV (Adobe - FLV1 video codec, MP3 audio)
YouTube accepts all of the above video formats uploaded from users. To most users, we find that the below video settings have the best visual effect:
Video format: H.264, MPEG-2 or MPEG-4 recommended
Aspect ratio: Original screen aspect ration without top or bottom black border, for example, 4:3, 16:9
Resolution: 640x360 (16:9) or 480x360 (4:3) Recommended
Audio format: MP3 or AAC Recommended
FPS (Frame per second): 30
Video length limit: 15 minutes (2 to 3 minutes recommended)
Video size limit: 1 GB
a. If you think your video won't be accepted by YouTube, you can convert it to video format MPEG4 with audio format MP3 to get the best visual effect.
b. To convert any video format to the 'YouTube supported video formats', you can use some free or paid video converter. Good Freeware for this purpose are FormatFactory or FFMPEG. The former is graphic user interface, while the latter is command line user interface.
c. By default, Windows Movie Maker will save your video item as . MSWMM file. MSWMM is project file, which is not accepted by YouTube on uploading. To upload your Windows Movie Maker video to YouTube, please choose 'save it to my computer' option to save your video project as an accepted video format, and then you can upload the saved video to YouTube.