[FFmpeg-devel] doc/ffmpeg: remove reference to non-existent option

Submitted by Moritz Barsnick on July 17, 2018, 9:36 a.m.

Details

Message ID 20180717093616.3647-1-barsnick@gmx.net
State New
Headers show

Commit Message

Moritz Barsnick July 17, 2018, 9:36 a.m.
The "-deinterlace" option was removed in 481575d255195c6c2f32e04686b94de984ae78d4,
over five years ago. Refer to deinterlacing filters instead.

Signed-off-by: Moritz Barsnick <barsnick@gmx.net>
---
 doc/ffmpeg.texi | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Gyan July 17, 2018, 10:30 a.m.
The option still exists and is effective. See current line 3528 of 
fftool/ffmpeg_opt.c and the block at line 822 of fftool/ffmpeg_filter.c

On 17-07-2018 03:06 PM, Moritz Barsnick wrote:
> The "-deinterlace" option was removed in 481575d255195c6c2f32e04686b94de984ae78d4,
> over five years ago. Refer to deinterlacing filters instead.

That's a Libav no-op commit. It was merged in 
42f5fc716e932b7b015d6605f2d88fc0eea4488b.

Interestingly, the option was already deprecated at the time of merge 
but Michael then kept the option and replaced its code with yadif 
injection in 2013 in 4257b804e2354db07e66ebfd966d7d13f49c7895. However, 
he did not remove the deprecation notice.

So, if that deprecation stands, we can remove the option/doc/code 
altogether, else remove the deprecation notice.


Regards,
Gyan
Moritz Barsnick July 17, 2018, 11:22 a.m.
On Tue, Jul 17, 2018 at 16:00:33 +0530, Gyan Doshi wrote:
> 
> The option still exists and is effective. See current line 3528 of 
> fftool/ffmpeg_opt.c and the block at line 822 of fftool/ffmpeg_filter.c
> 
> On 17-07-2018 03:06 PM, Moritz Barsnick wrote:
> > The "-deinterlace" option was removed in 481575d255195c6c2f32e04686b94de984ae78d4,
> > over five years ago. Refer to deinterlacing filters instead.
> 
> That's a Libav no-op commit. It was merged in 
> 42f5fc716e932b7b015d6605f2d88fc0eea4488b.

Gee, that's no fun. I used "git -S" to search for changes, and found
this commit in git master, and it didn't look like a no-op at all. But
then, you're right, it touched avconv, and wasn't merged over to ffmpeg
probably.

> So, if that deprecation stands, we can remove the option/doc/code 
> altogether, else remove the deprecation notice.

I guess it was undeprecated by making it work properly again, which is
fair enough, as far as I'm concerned. Still, is it preferred to use a
filter? Then my doc change stands.

Whatever ;-)

Patch dropped,
Moritz
Gyan July 17, 2018, 1:07 p.m.
On 17-07-2018 04:52 PM, Moritz Barsnick wrote:

> I guess it was undeprecated by making it work properly again, which is
> fair enough, as far as I'm concerned. Still, is it preferred to use a
> filter?

Yes, the CLI option is global, so applies to all video streams. Most 
invocations I've seen of it are it set as an input option. Since those 
uses generally involve a single input and the filter passes through 
progressive content, no harm no foul. But it reinforces a wrong 
impression. Best to have it removed.

Gyan

Patch hide | download patch | download mbox

diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
index 3717f22d42..071ed7b1bc 100644
--- a/doc/ffmpeg.texi
+++ b/doc/ffmpeg.texi
@@ -835,8 +835,8 @@  factor if negative.
 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
 Use this option if your input file is interlaced and you want
 to keep the interlaced format for minimum losses.
-The alternative is to deinterlace the input stream with
-@option{-deinterlace}, but deinterlacing introduces losses.
+The alternative is to deinterlace the input stream by use of a filter
+such as @code{yadif} or @code{bwdif}, but deinterlacing introduces losses.
 @item -psnr
 Calculate PSNR of compressed frames.
 @item -vstats