**BUG** MakeMKVs FLAC BPS tag is WRONG

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ndjamena
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Joined: Mon Jan 07, 2013 12:23 am

**BUG** MakeMKVs FLAC BPS tag is WRONG

Post by ndjamena »

It's a tenth of what it should be.

The silly thing is the duration and the stream size are correct and BPS is nothing but stream size divided by duration.

I'm not even sure why Mosu added the BPS tag in the first place, I thought the consensus was BPS was open to interpretation.

(...should BPS be derived from the duration of the file or to the active duration of the stream?)
mike admin
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Re: **BUG** MakeMKVs FLAC BPS tag is WRONG

Post by mike admin »

ndjamena wrote:It's a tenth of what it should be.
will be fixed in the next version.
ndjamena wrote:The silly thing is the duration and the stream size are correct and BPS is nothing but stream size divided by duration.
I'm not even sure why Mosu added the BPS tag in the first place, I thought the consensus was BPS was open to interpretation.
(...should BPS be derived from the duration of the file or to the active duration of the stream?)
This is actually complicated. The stream size tag specifies the size of the stream in MKV file after all compressions (header removal, zlib). The bps is calculated as original stream size divided by duration, so it may be drieved only if stream is stored without any compression. For streams with compression (like WDTV subtitles) MakeMKV also puts additional stream size flag, but that's MakeMKV extension - mkvtoolnix doesn't do it.
ndjamena
Posts: 830
Joined: Mon Jan 07, 2013 12:23 am

Re: **BUG** MakeMKVs FLAC BPS tag is WRONG

Post by ndjamena »

Yeah, I've already had stream size before compression written into the next version of MediaInfo, but Jerome has hidden it by default (apparently he didn't think it was worth displaying.)

Source ID was a bit confusing, it took me a while to figure out 0x00 was BD and 0x01 was DVD.

Are there any other rules for this new tag, or is that as far as you went? Is it for anything in particular?

So far I figure it can be use to identify the actual physical stream on the original disc that a stream was derived from (which would make more sense if MakeMKV output the PIDs and such in its actual output) and it can be used to give a GroupID to multiple streams encoded from the same source (including TrueHD and it's core).

I notice if I remux the file using MakeMKV it removes the tag, which kind of limits it's usefulness.

Jerome has used the first byte to set a field in the file data called "Original source medium" to either "Blu-ray" or "DVD" and has used the other two bytes to set a field called "ID in the original source medium" in each stream to mimic the ID as it would be presented in the output from the original source.

I tend to think the names are too long, but I've gotten used to it over the last week or so, so I'm not sure at the moment.
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