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

[Linjie Fu]

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