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

[Li, Zhong]

> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces at ffmpeg.org] On Behalf
> Of Linjie Fu
> Sent: Friday, July 12, 2019 9:19 PM
> To: ffmpeg-devel at ffmpeg.org
> Cc: Fu, Linjie <linjie.fu at intel.com>
> Subject: [FFmpeg-devel] [PATCH] fftools/ffmpeg_filter: use -reinit_filter to
> disable/enable auto scale
> 
> 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;
>      }
> -
>      if (!ifilter->ist->reinit_filters && fg->graph)
>          need_reinit = 0;
> 
> diff --git a/fftools/ffmpeg.h b/fftools/ffmpeg.h index
> 7b6f802082..0c289b439f 100644
> --- a/fftools/ffmpeg.h
> +++ b/fftools/ffmpeg.h
> @@ -285,6 +285,7 @@ typedef struct FilterGraph {
> 
>      AVFilterGraph *graph;
>      int reconfiguration;
> +    int auto_scale;
> 
>      InputFilter   **inputs;
>      int          nb_inputs;
> diff --git a/fftools/ffmpeg_filter.c b/fftools/ffmpeg_filter.c index
> 72838de1e2..856ba48de7 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->auto_scale) {
>          char args[255];
>          AVFilterContext *filter;
>          AVDictionaryEntry *e = NULL;
> --
> 2.17.1

Is there any big difference with https://patchwork.ffmpeg.org/patch/8173/, especially for the purpose of disabling scaling for HWACCEL?