[mythtv] Bugfix: ATSC shouldn't = 25 fps
Brian Foddy
bfoddy at visi.com
Mon Jun 6 16:58:46 UTC 2005
On Mon, 6 Jun 2005, Keith Irwin wrote:
>
> Presently, if someone has a mix of ATSC and NTSC cards installed, in the
> if/else statement which begins on line 69 in libs/libmythtv/recorderbase.cpp,
> there is no ATSC case, so it falls through to the PAL case. Clearly this has
> not been updated since whenever ATSC was added as an option on the TV Format
> drop-down in setup/backendsettings.cpp.
>
> As a result, if you tell it that your TV Format is ATSC, you get 25 fps for
> any analog capture cards which you have attached. This would only be
> desirable, if a user had both ATSC and PAL or SECAM capture cards, which
> seems highly unlikely. Because an ATSC capture card does not do frame-rate
> adjustments since the frame rate is determined by the incoming MPEG stream,
> these settings do not affect ATSC capture. But if a user had a mix of ATSC
> and NTSC cards (as I do), this results in the NTSC cards capturing at 25 fps.
> The obvious work-around is to switch to NTSC as your listed TV Format, but
> there are several HOWTO's (including the one from the EFF) which specifically
> tell people using ATSC cards to switch it to ATSC, so really we should fix it
> so that 29.97fps is the default when ATSC is selected, especially for people
> who might use the NTSC mode on their HD2/3000 sometimes.
>
> As such, I have included a .diff below which is a bug fix for this issue. It
> adds one more case to the first if clause to add ATSC in addition to NTSC and
> NTSC-J. It also adds comments to that section both about the change and what
> the code is doing in general. Hopefully they aren't too verbose for the
> liking of the code maintainer, but I wanted to make sure that all the bases
> were covered since the issue may need to be revisited at some point in the
> future if someone makes a card which can capture HD via component inputs or
> some other similar method where MPEG-2 streams are not automatically
> produced.
>
> Thanks,
> Keith Irwin
>
Keith,
Is this what causes my ATSC recordings to show 1:06 for a 1 hour show;
and also mess up the fast forward so the first jump will actually go
backwards? If so, this will be great.
Brian
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