[FFmpeg-devel] [PATCH] libavfilter/vf_pad: Try round up w/h for odd resolution to avoid failure

[Linjie Fu]

Try round_up output w/h for the clips with odd resolution to avoid failure if no
padding is required(e.g. iw/ih+0+0).

$ffmpeg -i input.mp4 -vf "scale=1241x1234,pad=iw+0+0:ih+3+3:0:3" -f null -

Before:
Round down to 1240x1234 and failed since s->w < inlink->w (e.g. 1240 < 1241)
[Parsed_pad_1 @ 0x7f849090f840] Padded dimensions cannot be smaller than input dimensions.
[Parsed_pad_1 @ 0x7f849090f840] Failed to configure input pad on Parsed_pad_1
Error reinitializing filters!
Failed to inject frame into filter network: Invalid argument
Error while processing the decoded data for stream #0:0
Conversion failed!

After:
Try to Round up for odd resolution (1241x1234 -> 1242x1240)
Stream #0:0(und): Video: wrapped_avframe, yuv420p(tv, progressive), 1242x1240

Signed-off-by: Linjie Fu <linjie.justin.fu at gmail.com>
---
 libavfilter/vf_pad.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/libavfilter/vf_pad.c b/libavfilter/vf_pad.c
index e52f7284d4..c9a0a75630 100644
--- a/libavfilter/vf_pad.c
+++ b/libavfilter/vf_pad.c
@@ -107,6 +107,7 @@ static int config_input(AVFilterLink *inlink)
     AVFilterContext *ctx = inlink->dst;
     PadContext *s = ctx->priv;
     AVRational adjusted_aspect = s->aspect;
+    int round_w, round_h;
     int ret;
     double var_values[VARS_NB], res;
     char *expr;
@@ -178,9 +179,13 @@ static int config_input(AVFilterLink *inlink)
     if (s->y < 0 || s->y + inlink->h > s->h)
         s->y = var_values[VAR_Y] = (s->h - inlink->h) / 2;
 
-    s->w    = ff_draw_round_to_sub(&s->draw, 0, -1, s->w);
-    s->h    = ff_draw_round_to_sub(&s->draw, 1, -1, s->h);
-    /* sanity check params */
+    round_w = ff_draw_round_to_sub(&s->draw, 0, -1, s->w);
+    round_h = ff_draw_round_to_sub(&s->draw, 1, -1, s->h);
+
+    s->w = round_w < inlink->w ? ff_draw_round_to_sub(&s->draw, 0, 1, s->w) : round_w;
+    s->h = round_h < inlink->h ? ff_draw_round_to_sub(&s->draw, 0, 1, s->h) : round_h;
+
+   /* sanity check params */
     if (s->w < inlink->w || s->h < inlink->h) {
         av_log(ctx, AV_LOG_ERROR, "Padded dimensions cannot be smaller than input dimensions.\n");
         return AVERROR(EINVAL);
-- 
2.31.1