[FFmpeg-devel] [PATCH] fftools/ffmpeg_filter: use -reinit_filter to disable/enable auto scale

[Fu, Linjie]

> -----Original Message-----
> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces at ffmpeg.org] On Behalf
> Of mypopy at gmail.com
> Sent: Friday, July 12, 2019 13:28
> To: FFmpeg development discussions and patches <ffmpeg-
> devel at ffmpeg.org>
> Cc: Fu, Linjie <linjie.fu at intel.com>
> Subject: Re: [FFmpeg-devel] [PATCH] fftools/ffmpeg_filter: use -reinit_filter
> to disable/enable auto scale
> 
> On Fri, Jul 12, 2019 at 1:19 PM Linjie Fu <linjie.fu at intel.com> wrote:
> >
> > Currently, ffmpeg inserts scale filter in the filter graph to force
> > the whole decoded stream to scale into the same size with the first
> > frame. It's not quite make sense in resolution changing cases if user
> > wants the rawvideo without any scale.
> >
> > Option -reinit_filter 0 could be used to realize similar function, but
> > it fails when ifilter has hw_frame_ctx.
> >
> > Add auto_scale flag set by -reinit_filter to indicate whether auto
> > inserting the scale filter in the filter graph.
> >
> > Signed-off-by: Linjie Fu <linjie.fu at intel.com>
> > ---
> > Request for comments.
> > As we have discussed in the rawdump filter patch, here is a simpler
> > solution based on -reinit_filter, and reuse this option.(maybe it's not
> > easy to be accepted to add a separate option)
> >
> >  fftools/ffmpeg.c        | 2 +-
> >  fftools/ffmpeg.h        | 1 +
> >  fftools/ffmpeg_filter.c | 2 +-
> >  3 files changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
> > index 01f04103cf..5305b87bd4 100644
> > --- a/fftools/ffmpeg.c
> > +++ b/fftools/ffmpeg.c
> > @@ -2133,6 +2133,7 @@ static int ifilter_send_frame(InputFilter *ifilter,
> AVFrame *frame)
> >
> >      /* determine if the parameters for this input changed */
> >      need_reinit = ifilter->format != frame->format;
> > +    fg->auto_scale = ifilter->ist->reinit_filters;
> >
> >      switch (ifilter->ist->st->codecpar->codec_type) {
> >      case AVMEDIA_TYPE_AUDIO:
> > @@ -2145,7 +2146,6 @@ static int ifilter_send_frame(InputFilter *ifilter,
> AVFrame *frame)
> >                         ifilter->height != frame->height;
> >          break;
> >      }
> > -
> Unrelated change

Yep, this should be recalled. 

> >
> Add an option to disable/enable "auto insert" is Ok for me, but I
> think if you reuse the -reinit_filter option, you need to update doc
> part at the same time.

I prefer to add a separate option, too.
Depending on the comments, I'll either update doc for reinit_filter, or add
a new option and related doc.

Thanks.