[FFmpeg-devel] [PATCH 38/42] fftools/ffmpeg: add support for multiview video

[Anton Khirnov]

Quoting James Almer (2024-08-30 02:40:49)
> On 8/29/2024 8:26 PM, Michael Niedermayer wrote:
> > On Tue, Aug 27, 2024 at 05:05:18PM +0200, Anton Khirnov wrote:
> >> This extends the syntax for specifying input streams in -map and complex
> >> filtergraph labels, to allow selecting a view by view ID, index, or
> >> position. The corresponding decoder is then set up to decode the
> >> appropriate view and send frames for that view to the correct
> >> filtergraph input(s).
> >> ---
> >>   doc/ffmpeg.texi           |  30 +++-
> >>   fftools/cmdutils.c        |   2 +-
> >>   fftools/cmdutils.h        |   2 +
> >>   fftools/ffmpeg.h          |  45 ++++-
> >>   fftools/ffmpeg_dec.c      | 355 +++++++++++++++++++++++++++++++++++++-
> >>   fftools/ffmpeg_demux.c    |  24 ++-
> >>   fftools/ffmpeg_filter.c   |  71 +++++---
> >>   fftools/ffmpeg_mux_init.c |  29 +++-
> >>   fftools/ffmpeg_opt.c      |  70 +++++++-
> >>   9 files changed, 575 insertions(+), 53 deletions(-)
> > 
> > breaks build on mingw64
> > 
> > src/fftools/ffmpeg_dec.c: In function ‘packet_decode’:
> > src/fftools/ffmpeg_dec.c:811:19: error: implicit declaration of function ‘ffs’ [-Werror=implicit-function-declaration]
> >    811 |             pos = ffs(outputs_mask) - 1;
> >        |                   ^~~
> > cc1: some warnings being treated as errors
> > make: *** [src/ffbuild/common.mak:81: fftools/ffmpeg_dec.o] Error 1
> > make: *** Waiting for unfinished jobs....
> > 
> > thx
> 
> Would ff_clz(outputs_mask) work here?

In principle yes, but it's private and I'd rather not include a private
header in ffmpeg CLI.

We could either make it public, or I could add a ffs() implementation
for Windows to compat/. Anyone has a preference?

-- 
Anton Khirnov