There is no reason to use a temporary buffer as destination
for the new macroblock before copying it into its proper place.
(History: 3994623df2efd2749631c3492184dd8d4ffa9d1b changed
the precursor of ff_mpv_reconstruct_mb() to always decode
to the first row of macroblocks for B pictures when
a draw_horiz_band callback is set (they are exported to the caller
via said callback and each row overwrites the previously decoded
row; this was probably intended as a cache-optimization).
Later b68ab2609c67d07b6f12ed65125d76bf9a054479 changed this
to the current form in which a scratchpad buffer is used when
decoding B-pictures without draw_horiz_band callback, followed
by copying the block from the scratchpad buffer to the actual
destination. I do not know what the aim of this was. When thinking
of it as a cache optimization, it makes sense to not use it
when the aforementioned draw_horiz_band optimization is in effect,
because then the destination row can be presumed to be hot
already. But then it makes no sense to restrict this optimization
to B-frames.)
Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@outlook.com>
---
libavcodec/mpegpicture.h | 1 -
libavcodec/mpv_reconstruct_mb_template.c | 23 ++---------------------
2 files changed, 2 insertions(+), 22 deletions(-)
diff --git a/libavcodec/mpegpicture.h b/libavcodec/mpegpicture.h
index 86504fe8ca..d3f39bbae6 100644
--- a/libavcodec/mpegpicture.h
+++ b/libavcodec/mpegpicture.h
@@ -35,7 +35,6 @@ typedef struct ScratchpadContext {
uint8_t *obmc_scratchpad;
union {
uint8_t *scratchpad_buf; ///< the other *_scratchpad point into this
buffer
- uint8_t *b_scratchpad; ///< scratchpad used for writing into write
only buffers
uint8_t *rd_scratchpad; ///< scratchpad for rate distortion mb
decision
};
int linesize; ///< linesize that the buffers in this
context have been allocated for
diff --git a/libavcodec/mpv_reconstruct_mb_template.c
b/libavcodec/mpv_reconstruct_mb_template.c
index 6ad353ddfd..e39b3d0e73 100644
--- a/libavcodec/mpv_reconstruct_mb_template.c
+++ b/libavcodec/mpv_reconstruct_mb_template.c
@@ -80,11 +80,10 @@ void mpv_reconstruct_mb_internal(MpegEncContext *s, int16_t
block[12][64],
s->avctx->mb_decision != FF_MB_DECISION_RD)) // FIXME precalc
#endif /* IS_ENCODER */
{
- uint8_t *dest_y, *dest_cb, *dest_cr;
+ uint8_t *dest_y = s->dest[0], *dest_cb = s->dest[1], *dest_cr =
s->dest[2];
int dct_linesize, dct_offset;
const int linesize = s->cur_pic.linesize[0]; //not s->linesize as
this would be wrong for field pics
const int uvlinesize = s->cur_pic.linesize[1];
- const int readable = IS_ENCODER || lowres_flag || s->pict_type !=
AV_PICTURE_TYPE_B;
const int block_size = lowres_flag ? 8 >> s->avctx->lowres : 8;
/* avoid copy if macroblock skipped in last frame too */
@@ -106,16 +105,6 @@ void mpv_reconstruct_mb_internal(MpegEncContext *s,
int16_t block[12][64],
dct_linesize = linesize << s->interlaced_dct;
dct_offset = s->interlaced_dct ? linesize : linesize * block_size;
- if (readable) {
- dest_y = s->dest[0];
- dest_cb = s->dest[1];
- dest_cr = s->dest[2];
- } else {
- dest_y = s->sc.b_scratchpad;
- dest_cb = s->sc.b_scratchpad + 16 * linesize;
- dest_cr = s->sc.b_scratchpad + 32 * linesize;
- }
-
if (!s->mb_intra) {
/* motion handling */
/* decoding or more than one mb_type (MC was already done
otherwise) */
@@ -169,7 +158,7 @@ void mpv_reconstruct_mb_internal(MpegEncContext *s, int16_t
block[12][64],
if( (s->avctx->skip_idct >= AVDISCARD_NONREF && s->pict_type
== AV_PICTURE_TYPE_B)
||(s->avctx->skip_idct >= AVDISCARD_NONKEY && s->pict_type
!= AV_PICTURE_TYPE_I)
|| s->avctx->skip_idct >= AVDISCARD_ALL)
- goto skip_idct;
+ return;
}
/* add dct residue */
@@ -288,14 +277,6 @@ void mpv_reconstruct_mb_internal(MpegEncContext *s,
int16_t block[12][64],
}
} //gray
}
- }
-skip_idct:
- if (!readable) {
- s->hdsp.put_pixels_tab[0][0](s->dest[0], dest_y, linesize, 16);
- if (!CONFIG_GRAY || !(s->avctx->flags & AV_CODEC_FLAG_GRAY)) {
- s->hdsp.put_pixels_tab[s->chroma_x_shift][0](s->dest[1],
dest_cb, uvlinesize, 16 >> s->chroma_y_shift);
- s->hdsp.put_pixels_tab[s->chroma_x_shift][0](s->dest[2],
dest_cr, uvlinesize, 16 >> s->chroma_y_shift);
- }
#endif /* !IS_ENCODER */
}
}
--
2.40.1
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