[FFmpeg-devel] [PATCH v2 4/4] fftools/cmdutils: pass sws_flags to scale filter in simple filter graph

[Linjie Fu]

From: Linjie Fu <linjie.justin.fu at gmail.com>

Pass sws_flags to scale filter through scale_sws_opts and correct the
dumped flags information.

CMD:
$ffmpeg -v verbose -i input.mp4 -sws_flags lanczos+bitexact+accurate_rnd \
        -vf format=yuv420p,scale=800x600 -an -vframes 10 -f md5 -

Before:
[auto_scaler_0 @ 0x7f899a418780] w:iw h:ih flags:'bilinear' interl:0
[auto_scaler_0 @ 0x7f899a418780] w:1920 h:1080 fmt:yuvj420p sar:0/1 -> w:1920 h:1080 fmt:yuv420p sar:0/1 flags:0x2
[Parsed_scale_1 @ 0x7f899a417100] w:1920 h:1080 fmt:yuv420p sar:0/1 -> w:800 h:600 fmt:yuv420p sar:0/1 flags:0x2
MD5=ff1d6091690c6fcd36d458d2a9f648ce

After:
[auto_scaler_0 @ 0x7fc7a3a06080] w:iw h:ih flags:'lanczos+bitexact+accurate_rnd' interl:0
[auto_scaler_0 @ 0x7fc7a3a06080] w:1920 h:1080 fmt:yuvj420p sar:0/1 -> w:1920 h:1080 fmt:yuv420p sar:0/1 flags:0xc0200
[Parsed_scale_1 @ 0x7fc7a3a04780] w:1920 h:1080 fmt:yuv420p sar:0/1 -> w:800 h:600 fmt:yuv420p sar:0/1 flags:0xc0200
MD5=ff1d6091690c6fcd36d458d2a9f648ce

Signed-off-by: Linjie Fu <linjie.justin.fu at gmail.com>
---
 fftools/ffmpeg_filter.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fftools/ffmpeg_filter.c b/fftools/ffmpeg_filter.c
index 958d74f008..94838adc56 100644
--- a/fftools/ffmpeg_filter.c
+++ b/fftools/ffmpeg_filter.c
@@ -977,7 +977,11 @@ int configure_filtergraph(FilterGraph *fg)
         }
         if (strlen(args))
             args[strlen(args)-1] = 0;
-        fg->graph->scale_sws_opts = av_strdup(args);
+
+        if (!strncmp(args, "sws_flags=", 10)) {
+            // keep the 'flags=' part
+            fg->graph->scale_sws_opts = av_strdup(args+4);
+        }
 
         args[0] = 0;
         while ((e = av_dict_get(ost->swr_opts, "", e,
-- 
2.31.1