[FFmpeg-devel] [PATCH] CrystalHD: Improve detection of field pair -> two fields content.
philipl at overt.org
Sat May 5 18:58:39 CEST 2012
Istvan Sebok provided a sample where field pair -> two fields content
was being misdetected by the existing logic. I added an additional
test to check the input picture type as identified by our h.264
Signed-off-by: Philip Langdale <philipl at overt.org>
libavcodec/crystalhd.c | 15 ++++++++++++---
1 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/libavcodec/crystalhd.c b/libavcodec/crystalhd.c
index 9acb512..62e713e 100644
@@ -713,11 +713,20 @@ static inline CopyRet copy_frame(AVCodecContext *avctx,
- * Testing has shown that in all cases where we don't want to return the
- * full frame immediately, VDEC_FLAG_UNKNOWN_SRC is set.
+ * The logic here is purely based on empirical testing with samples.
+ * If we need a second field, it could come from a second input packet,
+ * or it could come from the same field-pair input packet at the current
+ * field. In the first case, we should return and wait for the next time
+ * round to get the second field, while in the second case, we should
+ * ask the decoder for it immediately.
+ * Testing has shown that we are dealing with the fieldpair -> two fields
+ * case if the VDEC_FLAG_UNKNOWN_SRC is not set or if the input picture
+ * type was PICT_FRAME (in this second case, the flag might still be set)
return priv->need_second_field &&
- !(output->PicInfo.flags & VDEC_FLAG_UNKNOWN_SRC) ?
+ (!(output->PicInfo.flags & VDEC_FLAG_UNKNOWN_SRC) ||
+ pic_type == PICT_FRAME) ?
RET_COPY_NEXT_FIELD : RET_OK;
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