The MP4 file format and the .mp4 filename extension refer to the MPEG-4 part 14 digital multimedia format developed by the Moving Picture Experts Group. It is used as a multimedia container to wrap encoded digital video and audio streams, including subtitles and still images if required. In recent decades, the format has been popularized as one of the main standards for streaming media over the internet and other computer networks and for the digital distribution of large multimedia files. MP4 supports a large number of compression audio codecs allowing files in this format to maintain a relatively small size without discounting playback quality.
Files with the .ac3 filename extension refer to the proprietary audio file format Dolby digital AC-3, developed by Dolby Laboratories. The AC-3 format is from the lossy family of audio compression formats. It supports a variety of audio channel configurations and was the first of its kind to support the full surround sound experience. Because of this, the format has been commonly used in the development of motion picture features designed for theaters and in consumer homes through DVDs and surround sound home theater systems. The AC-3 format is one of the supported audio codecs of the ATSC standard ' a set of standards developed for digital television transmission in several affiliated countries.
FreeFileConvert uses tuned encoding for MP4 to AC3 conversions, preserving clarity while trimming file size. Finished audio streams instantly across phones, tablets, desktops, and modern browsers without extra tweaks.
Upload MP4 files from desktop, tablet, or cloud storage, queue multiple jobs, and let the converter finish autonomously. Return whenever convenient to download synchronized AC3 results on any device you rely on.
Process up to 5 files sized 1000 MB per batch without splitting queues manually. Mixed-format uploads convert together, producing consistent AC3 audio with dependable progress tracking.
The MPEG-4 Part 14 is standardized as part of the MPEG-4 format in ISO/IEC 14496-14:2003. It is recognized as a container format for audio and video streams and references several filename extensions of which .mp4 is one. The MPEG-4 Part 14 is in many ways identical to Apple's QuickTime format which formed the basis of MPEG-4. However, there are slight differences in compatibility with other previously standardized MPEG features and the added support for IOD or initial object descriptors which describe elementary data streams and set profile information of the resources needed for content playback.
The AC-3 audio encoding format supports between one and six channels with frequency ranges from 20 hertz to 20 kilohertz. The format contains frame headers which detail information about the rate of sampling, encoded channels, bit-rate among other details. It also consists of six audio blocks.
Upload your video file in the MP4 format from your device, Dropbox, or Google Drive.
Select AC3 as the output format and click Convert. Adjust optional settings if needed.
Download the converted audio file. Each file stays available for up to 5 downloads.