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Topic: Mp4 bit rate extraction from its metadata (Read 5387 times) previous topic - next topic

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Mp4 bit rate extraction from its metadata
Hi All,


i am trying to extract the bitrate of a mp4 file problematically but could not. can some one please let me know how we can find the bit rate of the mp4 file.
I tried searching on google but could not find much.

I have few queries :

1. Is bitrate stored in the file in some atom.
2. If not do we have any standard formula to calculate the bitrate.

Any help would be highly appreciated.

Thanks in Advance.

  • greynol
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  • Global Moderator
Mp4 bit rate extraction from its metadata
Reply #1
Why was this dumped in the General Audio Forum when we have one dedicated for aac?

Did you read the rules that were presented to you when you registered?
  • Last Edit: 19 April, 2013, 10:17:21 AM by greynol
13 February 2016: The world was blessed with the passing of a truly vile and wretched person.

Your eyes cannot hear.

  • db1989
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Mp4 bit rate extraction from its metadata
Reply #2
By “mp4”, should we assume that you specifically mean AAC? MP4 is only a container, which can encapsulate MP4, MP3, or other formats. Whichever format you are referring to, is it CBR or VBR? If it’s CBR, you might find the bitrate already supplied in a field such as avgBitrate (from a quick search on Google). If such a field is not available and/or if the stream is VBR, chances are you will have to perform the calculation yourself from the duration of the stream and size of the file (corrected for metadata and other forms of padding if you want to be really accurate). In any case, I suspect the information is already available, but perhaps other users can repost it here.

Edit: My first question was related to what greynol has said, but I decided to wait for confirmation before pointing that out. If you are talking about AAC, this should go in the subforum so-named. In any case, the format in question is the kind of basic element that you need to specify when asking questions; people can only guess otherwise, which is not very productive for anyone involved.
  • Last Edit: 19 April, 2013, 10:17:33 AM by db1989

Mp4 bit rate extraction from its metadata
Reply #3
Will move this to ACC.

Thanks, n Yes its ACC.

  • greynol
  • [*][*][*][*][*]
  • Global Moderator
Mp4 bit rate extraction from its metadata
Reply #4
You cannot move it, that work has to be done by a member of the staff.

Why was this double-posted to the A/V sub-forum?

Please don't now triple-post.
13 February 2016: The world was blessed with the passing of a truly vile and wretched person.

Your eyes cannot hear.