From: emcodem <emco...@ffastrans.com>
AviSynth works on frame-based video by default, which can
be either progressive or interlaced. Some filters can break
frames into half-height fields, at which point it considers
the clip to be field-based (avs_is_field_based can be used
to check for this situation).
To properly detect the field order of a typical video clip,
the frame needs to have been weaved back together already,
so avs_is_field_based should actually report 'false' when
checked.
Signed-off-by: Stephen Hutchinson <qyo...@gmail.com>
---
libavformat/avisynth.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/libavformat/avisynth.c b/libavformat/avisynth.c
index 350ac6d11d..1e862a6a85 100644
--- a/libavformat/avisynth.c
+++ b/libavformat/avisynth.c
@@ -250,15 +250,12 @@ static int avisynth_create_stream_video(AVFormatContext
*s, AVStream *st)
st->nb_frames = avs->vi->num_frames;
avpriv_set_pts_info(st, 32, avs->vi->fps_denominator,
avs->vi->fps_numerator);
- av_log(s, AV_LOG_TRACE, "avs_is_field_based: %d\n",
avs_is_field_based(avs->vi));
- av_log(s, AV_LOG_TRACE, "avs_is_parity_known: %d\n",
avs_is_parity_known(avs->vi));
- /* The following typically only works when assumetff (-bff) and
- * assumefieldbased is used in-script. Additional
- * logic using GetParity() could deliver more accurate results
- * but also decodes a frame which we want to avoid. */
st->codecpar->field_order = AV_FIELD_UNKNOWN;
- if (avs_is_field_based(avs->vi)) {
+ /* AviSynth works with frame-based video, detecting field order can
+ * only work when avs_is_field_based returns 'false'. */
+ av_log(s, AV_LOG_TRACE, "avs_is_field_based: %d\n",
avs_is_field_based(avs->vi));
+ if (avs_is_field_based(avs->vi) == 0) {
if (avs_is_tff(avs->vi)) {
st->codecpar->field_order = AV_FIELD_TT;
}
--
2.32.0
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
To unsubscribe, visit link above, or email
ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
