[FFmpeg-devel,v2,2/2] doc/ffmpeg.texi: update docs for autoscale/autorotate

Submitted by Linjie Fu on July 16, 2019, 11:20 a.m.

Details

Message ID 20190716112028.22745-1-linjie.fu@intel.com
State New
Headers show

Commit Message

Linjie Fu July 16, 2019, 11:20 a.m.
Add docs for autoscale.

Update information for autorotate according to ffplay.

Signed-off-by: Linjie Fu <linjie.fu@intel.com>
---
 doc/ffmpeg.texi | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

Comments

U. Artie Eoff July 17, 2019, 1:47 p.m.
> -----Original Message-----

> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces@ffmpeg.org] On Behalf Of Linjie Fu

> Sent: Tuesday, July 16, 2019 4:20 AM

> To: ffmpeg-devel@ffmpeg.org

> Cc: Fu, Linjie <linjie.fu@intel.com>

> Subject: [FFmpeg-devel] [PATCH, v2 2/2] doc/ffmpeg.texi: update docs for autoscale/autorotate

> 

> Add docs for autoscale.

> 

> Update information for autorotate according to ffplay.

> 

> Signed-off-by: Linjie Fu <linjie.fu@intel.com>

> ---

>  doc/ffmpeg.texi | 14 ++++++++++----

>  1 file changed, 10 insertions(+), 4 deletions(-)

> 

> diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi

> index cd35eb49c8..b91da2b2b4 100644

> --- a/doc/ffmpeg.texi

> +++ b/doc/ffmpeg.texi

> @@ -734,10 +734,6 @@ ffmpeg -dump_attachment:t "" -i INPUT

>  Technical note -- attachments are implemented as codec extradata, so this

>  option can actually be used to extract extradata from any stream, not just

>  attachments.

> -

> -@item -noautorotate

> -Disable automatically rotating video based on file metadata.

> -

>  @end table

> 

>  @section Video Options

> @@ -819,6 +815,16 @@ Create the filtergraph specified by @var{filtergraph} and use it to

>  filter the stream.

> 

>  This is an alias for @code{-filter:v}, see the @ref{filter_option,,-filter option}.

> +

> +@item -autorotate

> +Automatically rotate the video according to file metadata. Enabled by

> +default, use @option{-noautorotate} to disable it.

> +

> +@item -autoscale

> +Automatically scale the video according to the resolution of first frame.

> +Enabled by default, use @option{-noautoscale} to disable it. Each frame of

> +the output raw video can be in different resolutions and is in need to be

> +handled next.


This last sentence has strange grammar.  Here's my shot at it:

"When autoscale is disabled, all output frames might not be in the
same resolution and may require some additional explicit processing
according to your final rendering/output destination."

>  @end table

> 

>  @section Advanced Video options

> --

> 2.17.1

> 

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> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
Nicolas George July 17, 2019, 7:07 p.m.
Linjie Fu (12019-07-16):
> Add docs for autoscale.
> 
> Update information for autorotate according to ffplay.
> 
> Signed-off-by: Linjie Fu <linjie.fu@intel.com>
> ---
>  doc/ffmpeg.texi | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
> index cd35eb49c8..b91da2b2b4 100644
> --- a/doc/ffmpeg.texi
> +++ b/doc/ffmpeg.texi
> @@ -734,10 +734,6 @@ ffmpeg -dump_attachment:t "" -i INPUT
>  Technical note -- attachments are implemented as codec extradata, so this
>  option can actually be used to extract extradata from any stream, not just
>  attachments.
> -
> -@item -noautorotate
> -Disable automatically rotating video based on file metadata.
> -
>  @end table
>  
>  @section Video Options
> @@ -819,6 +815,16 @@ Create the filtergraph specified by @var{filtergraph} and use it to
>  filter the stream.
>  
>  This is an alias for @code{-filter:v}, see the @ref{filter_option,,-filter option}.
> +
> +@item -autorotate
> +Automatically rotate the video according to file metadata. Enabled by
> +default, use @option{-noautorotate} to disable it.
> +

> +@item -autoscale
> +Automatically scale the video according to the resolution of first frame.
> +Enabled by default, use @option{-noautoscale} to disable it. Each frame of
> +the output raw video can be in different resolutions and is in need to be
> +handled next.

Since this is completely hackish in lavfi, I think it needs to warn the
user much more strongly to expect problems.

>  @end table
>  
>  @section Advanced Video options

Regards,
Linjie Fu July 18, 2019, 8:57 a.m.
> -----Original Message-----

> From: Eoff, Ullysses A

> Sent: Wednesday, July 17, 2019 21:48

> To: FFmpeg development discussions and patches <ffmpeg-

> devel@ffmpeg.org>

> Cc: Fu, Linjie <linjie.fu@intel.com>

> Subject: RE: [FFmpeg-devel] [PATCH, v2 2/2] doc/ffmpeg.texi: update docs

> for autoscale/autorotate

> 

> > -----Original Message-----

> > From: ffmpeg-devel [mailto:ffmpeg-devel-bounces@ffmpeg.org] On

> Behalf Of Linjie Fu

> > Sent: Tuesday, July 16, 2019 4:20 AM

> > To: ffmpeg-devel@ffmpeg.org

> > Cc: Fu, Linjie <linjie.fu@intel.com>

> > Subject: [FFmpeg-devel] [PATCH, v2 2/2] doc/ffmpeg.texi: update docs for

> autoscale/autorotate

> >

> > Add docs for autoscale.

> >

> > Update information for autorotate according to ffplay.

> >

> > Signed-off-by: Linjie Fu <linjie.fu@intel.com>

> > ---

> >  doc/ffmpeg.texi | 14 ++++++++++----

> >  1 file changed, 10 insertions(+), 4 deletions(-)

> >

> > diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi

> > index cd35eb49c8..b91da2b2b4 100644

> > --- a/doc/ffmpeg.texi

> > +++ b/doc/ffmpeg.texi

> > @@ -734,10 +734,6 @@ ffmpeg -dump_attachment:t "" -i INPUT

> >  Technical note -- attachments are implemented as codec extradata, so this

> >  option can actually be used to extract extradata from any stream, not just

> >  attachments.

> > -

> > -@item -noautorotate

> > -Disable automatically rotating video based on file metadata.

> > -

> >  @end table

> >

> >  @section Video Options

> > @@ -819,6 +815,16 @@ Create the filtergraph specified by

> @var{filtergraph} and use it to

> >  filter the stream.

> >

> >  This is an alias for @code{-filter:v}, see the @ref{filter_option,,-filter

> option}.

> > +

> > +@item -autorotate

> > +Automatically rotate the video according to file metadata. Enabled by

> > +default, use @option{-noautorotate} to disable it.

> > +

> > +@item -autoscale

> > +Automatically scale the video according to the resolution of first frame.

> > +Enabled by default, use @option{-noautoscale} to disable it. Each frame

> of

> > +the output raw video can be in different resolutions and is in need to be

> > +handled next.

> 

> This last sentence has strange grammar.  Here's my shot at it:

> 

> "When autoscale is disabled, all output frames might not be in the

> same resolution and may require some additional explicit processing

> according to your final rendering/output destination."

> 


This sounds much better, thanks a lot.
Will update.

- linjie
Linjie Fu July 18, 2019, 8:59 a.m.
> -----Original Message-----
> From: Nicolas George [mailto:george@nsup.org]
> Sent: Thursday, July 18, 2019 03:07
> To: FFmpeg development discussions and patches <ffmpeg-
> devel@ffmpeg.org>
> Cc: Fu, Linjie <linjie.fu@intel.com>
> Subject: Re: [FFmpeg-devel] [PATCH, v2 2/2] doc/ffmpeg.texi: update docs
> for autoscale/autorotate
> 
> Linjie Fu (12019-07-16):
> > Add docs for autoscale.
> >
> > Update information for autorotate according to ffplay.
> >
> > Signed-off-by: Linjie Fu <linjie.fu@intel.com>
> > ---
> >  doc/ffmpeg.texi | 14 ++++++++++----
> >  1 file changed, 10 insertions(+), 4 deletions(-)
> >
> > diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
> > index cd35eb49c8..b91da2b2b4 100644
> > --- a/doc/ffmpeg.texi
> > +++ b/doc/ffmpeg.texi
> > @@ -734,10 +734,6 @@ ffmpeg -dump_attachment:t "" -i INPUT
> >  Technical note -- attachments are implemented as codec extradata, so this
> >  option can actually be used to extract extradata from any stream, not just
> >  attachments.
> > -
> > -@item -noautorotate
> > -Disable automatically rotating video based on file metadata.
> > -
> >  @end table
> >
> >  @section Video Options
> > @@ -819,6 +815,16 @@ Create the filtergraph specified by
> @var{filtergraph} and use it to
> >  filter the stream.
> >
> >  This is an alias for @code{-filter:v}, see the @ref{filter_option,,-filter
> option}.
> > +
> > +@item -autorotate
> > +Automatically rotate the video according to file metadata. Enabled by
> > +default, use @option{-noautorotate} to disable it.
> > +
> 
> > +@item -autoscale
> > +Automatically scale the video according to the resolution of first frame.
> > +Enabled by default, use @option{-noautoscale} to disable it. Each frame
> of
> > +the output raw video can be in different resolutions and is in need to be
> > +handled next.
> 
> Since this is completely hackish in lavfi, I think it needs to warn the
> user much more strongly to expect problems.

Yes, will update as Artie had suggested if no more comments:

When autoscale is disabled, all output frames might not be in the
same resolution and may require some additional explicit processing
according to your final rendering/output destination.
Nicolas George July 18, 2019, 9:01 a.m.
Fu, Linjie (12019-07-18):
> Yes, will update as Artie had suggested if no more comments:
> 
> When autoscale is disabled, all output frames might not be in the
> same resolution and may require some additional explicit processing
> according to your final rendering/output destination.

That is not enough. You have to tell the user that this option will most
likely not work at all, and why.

Regards,
U. Artie Eoff July 18, 2019, 2:31 p.m.
> -----Original Message-----
> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces@ffmpeg.org] On Behalf Of Nicolas George
> Sent: Thursday, July 18, 2019 2:01 AM
> To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org>
> Subject: Re: [FFmpeg-devel] [PATCH, v2 2/2] doc/ffmpeg.texi: update docs for autoscale/autorotate
> 
> Fu, Linjie (12019-07-18):
> > Yes, will update as Artie had suggested if no more comments:
> >
> > When autoscale is disabled, all output frames might not be in the
> > same resolution and may require some additional explicit processing
> > according to your final rendering/output destination.
> 
> That is not enough. You have to tell the user that this option will most
> likely not work at all, and why.
> 

@Nicolas, do you have any "examples" of what you might add to this?

Maybe something additional like this is enough:

Disabling autoscale may not work in all situations.  Therefore, it is not
recommended to disable it unless you really know what you are doing.
Disable autoscale at your own risk.

> Regards,
> 
> --
>   Nicolas George

Patch hide | download patch | download mbox

diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
index cd35eb49c8..b91da2b2b4 100644
--- a/doc/ffmpeg.texi
+++ b/doc/ffmpeg.texi
@@ -734,10 +734,6 @@  ffmpeg -dump_attachment:t "" -i INPUT
 Technical note -- attachments are implemented as codec extradata, so this
 option can actually be used to extract extradata from any stream, not just
 attachments.
-
-@item -noautorotate
-Disable automatically rotating video based on file metadata.
-
 @end table
 
 @section Video Options
@@ -819,6 +815,16 @@  Create the filtergraph specified by @var{filtergraph} and use it to
 filter the stream.
 
 This is an alias for @code{-filter:v}, see the @ref{filter_option,,-filter option}.
+
+@item -autorotate
+Automatically rotate the video according to file metadata. Enabled by
+default, use @option{-noautorotate} to disable it.
+
+@item -autoscale
+Automatically scale the video according to the resolution of first frame.
+Enabled by default, use @option{-noautoscale} to disable it. Each frame of
+the output raw video can be in different resolutions and is in need to be
+handled next.
 @end table
 
 @section Advanced Video options