[FFmpeg-devel] [PATCH] fftools/ffmpeg_filter: add -autoscale to disable/enable the default scale
Fu, Linjie
linjie.fu at intel.com
Mon Feb 10 11:32:35 EET 2020
> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of
> Mark Thompson
> Sent: Saturday, February 1, 2020 22:18
> To: ffmpeg-devel at ffmpeg.org
> Subject: Re: [FFmpeg-devel] [PATCH] fftools/ffmpeg_filter: add -autoscale
> to disable/enable the default scale
>
> On 15/01/2020 07:05, Linjie Fu wrote:
> > Currently, ffmpeg inserts scale filter by default 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.
> >
> > Using autoscale/noautoscale to indicate whether auto inserting the scale
> > filter in the filter graph:
> > -noautoscale or -autoscale 0:
> > disable the default auto scale filter inserting.
> >
> > Update docs.
> >
> > Signed-off-by: U. Artie Eoff <ullysses.a.eoff at intel.com>
> > Signed-off-by: Linjie Fu <linjie.fu at intel.com>
> > ---
> > doc/ffmpeg.texi | 16 ++++++++++++----
> > fftools/ffmpeg.c | 1 +
> > fftools/ffmpeg.h | 4 ++++
> > fftools/ffmpeg_filter.c | 2 +-
> > fftools/ffmpeg_opt.c | 8 ++++++++
> > 5 files changed, 26 insertions(+), 5 deletions(-)
> >
> > diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
> > index dd461c0..716dd2c 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.
> > -
> > - at item -noautorotate
> > -Disable automatically rotating video based on file metadata.
> > -
> > @end table
> >
> > @section Video Options
> > @@ -819,6 +815,18 @@ 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}.
> > +
> > + at item -autorotate
> > +Automatically rotate the video according to file metadata. Enabled by
> > +default, use @option{-noautorotate} to disable it.
> > +
> > + at item -autoscale
> > +Automatically scale the video according to the resolution of first frame.
> > +Enabled by default, use @option{-noautoscale} to disable it. When
> autoscale is
> > +disabled, all output frames of filter graph might not be in the same
> resolution
> > +and may be inadequate for some encoder/muxer. Therefore, it is not
> recommended
> > +to disable it unless you really know what you are doing.
> > +Disable autoscale at your own risk.
> > @end table
> >
> > @section Advanced Video options
> > diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
> > index 6bcd7b9..864c1fb 100644
> > --- a/fftools/ffmpeg.c
> > +++ b/fftools/ffmpeg.c
> > @@ -2125,6 +2125,7 @@ static int ifilter_send_frame(InputFilter *ifilter,
> AVFrame *frame)
> >
> > /* determine if the parameters for this input changed */
> > need_reinit = ifilter->format != frame->format;
> > + fg->autoscale = ifilter->ist->autoscale;
> >
> > switch (ifilter->ist->st->codecpar->codec_type) {
> > case AVMEDIA_TYPE_AUDIO:
> > diff --git a/fftools/ffmpeg.h b/fftools/ffmpeg.h
> > index 7b6f802..1602406 100644
> > --- a/fftools/ffmpeg.h
> > +++ b/fftools/ffmpeg.h
> > @@ -133,6 +133,8 @@ typedef struct OptionsContext {
> > int nb_hwaccel_output_formats;
> > SpecifierOpt *autorotate;
> > int nb_autorotate;
> > + SpecifierOpt *autoscale;
> > + int nb_autoscale;
> >
> > /* output options */
> > StreamMap *stream_maps;
> > @@ -285,6 +287,7 @@ typedef struct FilterGraph {
> >
> > AVFilterGraph *graph;
> > int reconfiguration;
> > + int autoscale;
> >
> > InputFilter **inputs;
> > int nb_inputs;
> > @@ -335,6 +338,7 @@ typedef struct InputStream {
> > int guess_layout_max;
> >
> > int autorotate;
> > + int autoscale;
> >
> > int fix_sub_duration;
> > struct { /* previous decoded subtitle and related variables */
> > diff --git a/fftools/ffmpeg_filter.c b/fftools/ffmpeg_filter.c
> > index 40cc4c1..dafcab7 100644
> > --- a/fftools/ffmpeg_filter.c
> > +++ b/fftools/ffmpeg_filter.c
> > @@ -469,7 +469,7 @@ static int configure_output_video_filter(FilterGraph
> *fg, OutputFilter *ofilter,
> > if (ret < 0)
> > return ret;
> >
> > - if (ofilter->width || ofilter->height) {
> > + if ((ofilter->width || ofilter->height) && fg->autoscale) {
> > char args[255];
> > AVFilterContext *filter;
> > AVDictionaryEntry *e = NULL;
> > diff --git a/fftools/ffmpeg_opt.c b/fftools/ffmpeg_opt.c
> > index 1510e02..37083f2 100644
> > --- a/fftools/ffmpeg_opt.c
> > +++ b/fftools/ffmpeg_opt.c
> > @@ -743,7 +743,9 @@ static void add_input_streams(OptionsContext *o,
> AVFormatContext *ic)
> > MATCH_PER_STREAM_OPT(ts_scale, dbl, ist->ts_scale, ic, st);
> >
> > ist->autorotate = 1;
> > + ist->autoscale = 1;
> > MATCH_PER_STREAM_OPT(autorotate, i, ist->autorotate, ic, st);
> > + MATCH_PER_STREAM_OPT(autoscale, i, ist->autoscale, ic, st);
> >
> > MATCH_PER_STREAM_OPT(codec_tags, str, codec_tag, ic, st);
> > if (codec_tag) {
> > @@ -3650,6 +3652,12 @@ const OptionDef options[] = {
> > { "autorotate", HAS_ARG | OPT_BOOL | OPT_SPEC |
> > OPT_EXPERT | OPT_INPUT, { .off =
> OFFSET(autorotate) },
> > "automatically insert correct rotate filters" },
> > + { "autoscale", HAS_ARG | OPT_BOOL | OPT_SPEC |
> > + OPT_EXPERT | OPT_INPUT, { .off =
> OFFSET(autoscale) },
> > + "automatically insert a scale filter at the end of the filter graph if a
> resolution"
> > + "change is detected. This ensures all frames are the same resolution
> as the first frame"
> > + "when they leave the filter chain (this option is enabled by default)."
> > + "If disabled, some encoders/muxers may not support this mode."},
>
> This isn't right as an input option. Consider
>
> diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
> index 638abda330..25a09c4fec 100644
> --- a/fftools/ffmpeg.c
> +++ b/fftools/ffmpeg.c
> @@ -2125,6 +2125,8 @@ static int ifilter_send_frame(InputFilter *ifilter,
> AVFrame *frame)
>
> /* determine if the parameters for this input changed */
> need_reinit = ifilter->format != frame->format;
> + av_log(NULL, AV_LOG_ERROR, "Overwriting autoscale for FG %p
> with %d.\n",
> + fg, ifilter->ist->autoscale);
> fg->autoscale = ifilter->ist->autoscale;
>
> switch (ifilter->ist->st->codecpar->codec_type) {
>
> on top of your patch.
>
> $ ./ffmpeg_g -y -autoscale 0 -i in1.mp4 -autoscale 1 -i in2.mp4 -an -
> filter_complex '[0:v][1:v]overlay[out]' -map '[out]' out.mp4
> ...
> Overwriting autoscale for FG 0x563ee2a7d000 with 1.
> Overwriting autoscale for FG 0x563ee2a7d000 with 0.
> Overwriting autoscale for FG 0x563ee2a7d000 with 1.
> Overwriting autoscale for FG 0x563ee2a7d000 with 0.
> Last message repeated 1 times
> Overwriting autoscale for FG 0x563ee2a7d000 with 1.
> Overwriting autoscale for FG 0x563ee2a7d000 with 0.
> Last message repeated 1 times
> Overwriting autoscale for FG 0x563ee2a7d000 with 1.
> Overwriting autoscale for FG 0x563ee2a7d000 with 0.
> Last message repeated 1 times
> Overwriting autoscale for FG 0x563ee2a7d000 with 1.
> Overwriting autoscale for FG 0x563ee2a7d000 with 0.
> Last message repeated 1 times
> Overwriting autoscale for FG 0x563ee2a7d000 with 1.
> ...
>
> and then you have weird nondeterminism depending on which input stream
> has been read most recently.
>
> That is, it should be attached to the output rather than the input.
>
> The rest of this, including the need for the option, makes sense to me.
>
Refined and resend the patch, please help to comment.
(Also noted that autorotate seems to have similar issue, and should also be attached
to output IMHO)
Thx.
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