[FFmpeg-devel] [PATCH] Allow DTS audio copy to TS streams

goodthanks tamlyn at internode.on.net
Sun Apr 27 06:23:25 CEST 2014

Timothy Gu <timothygu99 <at> gmail.com> writes:

> On Apr 26, 2014 11:01 AM, "Tamlyn Ellis" <tamlyn <at> internode.on.net> wrote:
> > Also I was supposed to put "fixes ticket 1398" on the description but
> > I'm a bit of a noob at this stuff. More details here
> > http://trac.ffmpeg.org/ticket/1398
> I added a comment on Git usage on the ticket. You might want to check it
> out. Also, please don't top post here:
> https://en.wikipedia.org/wiki/Posting_style#Top-posting
> [...]
> Timothy

Sorry I just replied on my email client and it has caused a top post here. I
just found this site on google.
Not overly impressed about my full name and email address placed on a public
site that doesn't require a login to see. Guess that is my own fault for not
understanding the process...

Too late to do anything about it now I suppose?

So do I need to run the patch again with the changes you suggested or just
leave it now?

Probably a couple of things that should be noted.
This doesn't allow encoding of DTS or TrueHD. It just sets the correct
stream ID in the TS output file when a DTS or TrueHD audio stream is copied.

Also there are actually 3 different DTS types that matroska gives the
codec_ID of A_DTS to
DTS 0x82
DTS-HR (High Resolution)0x85
DTS-MA (Master Audio)0x86

Because matroska lists all of these as A_DTS this patch will mean ffmpeg
sets 0x82 as the stream ID for all 3 DTS types above in TS output files.

Personally it works for me as my hardware plays the DTS-HR stream correctly
with either the correct stream ID of 0x85 or the technically incorrect 0x82.
I have not been able to confirm the DTS-MA stream yet. I cant find a sample
that will actually display on my DLNA client.

I would think it will cause issues on hardware/software with stricter
compliance to the stream ID's.

The only way to get it completely accurate for matroska input files would be
check the stream for number of channels, bitrate and sampling frequency.

I have no idea how to code that....

All that being said, currently DTS is not copied correctly at all, so at the
least it is an improvement for people using sony hardware.

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