[FFmpeg-devel] [PATCH] Add detail to the documentation for ffmpeg -map.

Stefano Sabatini stefano.sabatini-lala
Mon Mar 7 11:36:15 CET 2011


On date Wednesday 2011-03-02 16:15:21 +0100, Stefano Sabatini encoded:
> On date Wednesday 2011-03-02 14:53:35 +0100, Diego Biurrun encoded:
> > On Mon, Feb 28, 2011 at 03:35:40PM +0100, Stefano Sabatini wrote:
> [...]
> > > +Specify an input stream to be a source for the output file. An input
> > > +stream is identified by two numbers: an input file index, specified by
> > > + at var{input_file_id}, and an input stream index within that file,
> > > +specified by @var{input_stream_id}. Both start counting from 0.  If
> > > +used, @var{sync_file_id}. at var{sync_stream_id} specifies which input
> > > +stream is used as a presentation sync reference.
> > 
> > Designate an input stream as a source for the output file. Each input
> > stream is identified by the input file index @var{input_file_id} and the
> > input stream index @var{input_stream_id} within the input file. Both
> > indexes start at 0.
> 
> Changed.
> 
> > > +For example, if you have two streams in the first input file, these
> > > +streams are identified by "0.0" and "0.1". You can use @code{-map} to
> > > +select which one to map to the single stream of an output file.
> > 
> > Let's not overuse the verb map too much here: 
> > 
> >   You can use @code{-map} to select which stream to place in an output file.
> 
> Changed.
> 
> > > For example:
> > > + at example
> > > +ffmpeg -i INPUT OUTPUT -map 0.1
> > > + at end example
> > > +will map the input stream identified by "0.1" to the (single) output
> > > +stream.
> > 
> > will mark the input stream identified by "0.1" as (single) output stream.
> 
> I'm not happy about this, as "marking" is not denoting precisely the
> operation done, because it doesn't imply the mapping operation, so I
> kept "map".
> 
> > > +For example, to select stream 2 from input file @file{A.mov}
> > > +(specified by the identifier "0.2"), and stream 6 from input
> > > + at file{B.mov} (specified by the identifier "1.6"), and copy them to
> > > +output file @file{out.mov}:
> > 
> > Didn't you say above that counting starts at 0?
> 
> I admit this is a bit confusing, "stream 2" in this case means "stream
> with index 2" rather than "the second stream". Replaced with "to select
> stream with index 2 from ...".

Ping.
-- 
FFmpeg = Furious & Free Mortal Purposeless Energized Gadget



More information about the ffmpeg-devel mailing list