Frequently Asked Questions
For your convenience, a list of frequently asked questions is provided below. Please be sure to review this list, as it is very possible that your question has already been answered here. If the solution you seek is not here, please feel free to contact us.
- Q01: What is MP4?
- Q02: What is AVI?
- Q03: After I convert video files to AVI files, some of them files can’t be played or I can only get the audio playback, why?
- Q04: I have finished the conversion to the iPod/iPhone/Apple TV; what do I need to do so that I can transfer the output files into my iPod?
- Q05: The size of the output video is too large, why and how can I get it smaller?
- Q06: I’d like to adjust the order of the videos that I want to convert. How should I do?
- Q07: How long will it take to convert a video to audio file?
- Q08: How can I know what codec an AVI file is using?
- Q09: Is there some limitation to the format of the input?
- Q10: I am not satisfied with the output file? How can I make it better?
A: MP4, standing for MPEG-4 Part 14, is a multimedia container format standard specified as a part of MPEG-4. It is most commonly used to store digital audio and digital video streams, especially those defined by MPEG, but can also be used to store other data such as subtitles and still images. Almost any kind of data can be embedded in MPEG-4 Part 14 files through private streams. The registered codecs for MPEG-4 Part 12-based files are published on the website of MP4 Registration authority (mp4ra.org), but most of them are not widely supported by MP4 players.
A: AVI, Audio Video Interleave, is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows technology. AVI files can contain both audio and video data in a file container that allows synchronous audio-with-video playback. AVI files support multiple streaming audio and video and use the file format extensions developed by the Matrox OpenDML group in February 1996.
Q03: After I convert video files to AVI files, some of them files can’t be played or I can only get the audio playback, why?
A: There are many reasons can cause this error. The most common reason is that the proper codec can’t be detected. Maybe the following information can give you some help in downloading and installing AVI video codec.
Intel Indeo Video Codec and I263 Video Codec, download from (http://support.intel.com/support/createshare/camerapack/CODINSTL.HTM)
Microsoft MPEG-4 Video Codec (Version 1, 2, 3), these codecs are included in the Windows Media Tool, download it from (http://www.microsoft.com/windows/windowsmedia/)
DivX Codec, download it from (http://www.divx.com/divx/)
Aware Inc.’s Motion Wavelets Video Codec, download it from (http://www.aware.com/telechoice/products/compression/motionwavelets.htm)
Q04: I have finished the conversion to the iPod/iPhone/Apple TV; what do I need to do so that I can transfer the output files into my iPod?
A: Do you have iTunes installed? It is a must. Please download it from (www.apple.com). The transferring job must be done by this tool.
Q05: The size of the output video is too large, why and how can I get it smaller?
A: The size of the output video is decided by the quality of it. If you want to get it smaller, please decrease the quality by selecting a preset with lower parameters such as Video Bitrate, Audio Bitrate, Sample Rate, etc. And of course, the shorter the time duration, the smaller the file size is.
Q06: I’d like to adjust the order of the videos that I want to convert. How should I do?
A: After loading videos, please highlight the video you want to move and click “Move Up” or “Move Down” to move it to the ideal position. You can also directly drag it to the place you want.
Q07: How long will it take to convert a video to audio file?
A: It is hard to answer it generally. The time depends on many elements such as the speed of the CPU, duration of the input video, quality of the output video and so on. The converter shows an estimated “Time Remaining” when the conversion is processed.
Q08: How can I know what codec an AVI file is using?
A: At first, right-click on the AVI file in Windows Explorer, and then click Properties item in the popup menu. At last, please select the Summary tab in the popup dialog, and you can get all information you need.
Q09: Is there some limitation to the format of the input?
A: Free MP4 to AVI Converter allows you to convert video files in nearly all popular video formats like AVI, MPEG, H.264, SWF, MOV, WMV, etc. for playback on popular devices like iPod, iPad, iPhone, PSP and so on.
Q10: I am not satisfied with the output file? How can I make it better?
A: The output file quality depends largely on the source file. You may choose a higher bit rate or modify settings like contrast, dimensions, length, and audio volume, etc, if the output one is not as good as the original one.