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I'm comparing duplicate media files using MediaInfo, so that I can keep the one with the best quality and delete the other one. However, I'm confused by some of the information.

One Duplicate enter image description here Another Duplicate enter image description here

Of course Overall bit rate mode: Variable means that the bit rate varies throughout the file or playback.

But what does Overall bit rate mean? Is this the average?

If so, how can the Maximum Overall bit rate be lower than the average?

This issue is prevalent for many of my duplicate files and I'd really love to free up some storage space. Any help would be greatly appreciated.

oldboy
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2 Answers2

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But what does Overall bit rate mean? Is this the average?

Average bit rare of the whole file (all streams + container overhead)

If so, how can the Maximum Overall bit rate be lower than the average?

The maximum is a container metadata so ever the calculation of overall bit rate is wrong or the metadata is wrong.

so that I can keep the one with the best quality [...] I'd really love to free up some storage space.

Looks like you consider that keeping the file with highest bit rate is a good method for selecting by quality, this assumption is wrong. And for freeing space, it is best to choose the best quality/bitrate rather then highest quality at any bitrate (and no, this is not easy to do it automaticaly as the quality also depends on the source)

Jérôme Martinez
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  • I'm not sure what you mean by 'container metadatam so ever the calculation of overall bit rate is wrong or the metadata is wrong'?? notably, i'm not looking to save space, i'm looking to free up space by deleting duplicates. bit rate is just one of a few other factors like frame rate that i also use to select the best quality. – oldboy Feb 18 '19 at 09:34
  • im not sure which bit rate is the correct to use? overall or what about nominal bit rate which is sometimes listed under the video section? what does nominal bit rate refer to? – oldboy Feb 18 '19 at 09:35
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    @user2230470 See also: https://superuser.com/questions/338725/compare-two-video-files-to-find-out-which-has-best-quality — you cannot just compare based on bitrate/framerate alone, even with the same content. – slhck Feb 18 '19 at 16:42
  • "nominal bit rate" is a bit rate indicated in metadata (in your case video bitstream metadata) – Jérôme Martinez Feb 18 '19 at 16:45
  • @slhck more often than not the duplicate videos im comparing are identical in all other regards, except these particular bit rate values. thanks for the link to your other comment nonetheless. lots of valuable info – oldboy Feb 18 '19 at 21:29
  • @JérômeMartinez so which one is more accurate/reliable: Overall bit rate or Nominal bit rate? im still confused by your description of the maximum overall bit rate? – oldboy Feb 18 '19 at 21:38
  • There is no "more accurate/reliable", information comes from different sources, and you are in charge to decide which one you prefer. On my side I would prioritize (Overall) bit rate as I trust more the estimation than stored metadata. – Jérôme Martinez Feb 20 '19 at 08:49
  • "Overall bit rate or Nominal bit rate?" you talk on one side about bit rate of the whole file, on another side about bit rate of the video part. It is difficult to answer a question when lot of things are mixed up in the question. There are 2 parts in the report because it is 2 different things. – Jérôme Martinez Feb 20 '19 at 08:51
  • FFmpeg does not even write Maximum Overall bit rate for m2ts. If you have some nice HEVC sample TsMuxer writes Maximum Overall bit rate wrong. – Валерий Заподовников May 27 '23 at 15:11
  • @JérômeMartinez Was just a bug in TsMuxer, see my answer. – Валерий Заподовников Jun 04 '23 at 00:13
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If so, how can the Maximum Overall bit rate be lower than the average?

That was a bug in tsMuxer. Also as I understand that value is not real, as M2TS is Blu-ray specification, but SIT's peak_rate is not part of it, you just write maximum value allowed. It is not calculated, it is just a default https://github.com/justdan96/tsMuxer/commit/206fffcd4ce9dfa080d47ee6005e3620089f6b43

TsMuxer author comments

Валерий Заподовников
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