[FFmpeg-devel] [PATCH] ffmpeg: fix order between field order autodetection and override

Jan Ekström jeebjp at gmail.com
Wed Jul 21 20:29:16 EEST 2021


Somehow I missed this in fbb44bc51a647862eb05ae3f9d7d49a0be9bed57 ,
even though the lines were within the context. Probably the code
originally being after the this logic had something to do with it,
but previously it only touched the avformat context's codecpar,
which did not affect the encoder codec context whatsoever.

Fixes #9320
Fixes #9339
---
 fftools/ffmpeg.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
index 40e8010096..b0ce7c7c32 100644
--- a/fftools/ffmpeg.c
+++ b/fftools/ffmpeg.c
@@ -3483,12 +3483,7 @@ static int init_output_stream_encode(OutputStream *ost, AVFrame *frame)
             enc_ctx->bits_per_raw_sample = frame_bits_per_raw_sample;
         }
 
-        if (ost->top_field_first == 0) {
-            enc_ctx->field_order = AV_FIELD_BB;
-        } else if (ost->top_field_first == 1) {
-            enc_ctx->field_order = AV_FIELD_TT;
-        }
-
+        // Field order: autodetection
         if (frame) {
             if (enc_ctx->flags & (AV_CODEC_FLAG_INTERLACED_DCT | AV_CODEC_FLAG_INTERLACED_ME) &&
                 ost->top_field_first >= 0)
@@ -3503,6 +3498,13 @@ static int init_output_stream_encode(OutputStream *ost, AVFrame *frame)
                 enc_ctx->field_order = AV_FIELD_PROGRESSIVE;
         }
 
+        // Field order: override
+        if (ost->top_field_first == 0) {
+            enc_ctx->field_order = AV_FIELD_BB;
+        } else if (ost->top_field_first == 1) {
+            enc_ctx->field_order = AV_FIELD_TT;
+        }
+
         if (ost->forced_keyframes) {
             if (!strncmp(ost->forced_keyframes, "expr:", 5)) {
                 ret = av_expr_parse(&ost->forced_keyframes_pexpr, ost->forced_keyframes+5,
-- 
2.31.1



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