[FFmpeg-cvslog] libavcodec/zmbvenc: motion estimation improvements/bug fixes:
Matthew Fearnley
git at videolan.org
Tue Feb 19 22:25:42 EET 2019
ffmpeg | branch: master | Matthew Fearnley <matthew.w.fearnley at gmail.com> | Thu Feb 7 12:54:59 2019 +0000| [f2e89fe4d34a7f53711ccea952331d2c77f04f19] | committer: Tomas Härdin
libavcodec/zmbvenc: motion estimation improvements/bug fixes:
- Clamp ME range to -64..63 (prevents corruption when me_range is too high)
- Allow MV's up to *and including* the positive range limit
- Allow out-of-edge ME by padding the prev buffer with a border of 0's
- Try previous MV before checking the rest (improves speed in some cases)
- More robust logic in code - ensure *mx,*my,*xored are updated together
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=f2e89fe4d34a7f53711ccea952331d2c77f04f19
---
libavcodec/zmbvenc.c | 71 +++++++++++++++++++++++++++++++++++++++-------------
1 file changed, 53 insertions(+), 18 deletions(-)
diff --git a/libavcodec/zmbvenc.c b/libavcodec/zmbvenc.c
index 3df6e724c8..c9d50b6adf 100644
--- a/libavcodec/zmbvenc.c
+++ b/libavcodec/zmbvenc.c
@@ -45,11 +45,11 @@
typedef struct ZmbvEncContext {
AVCodecContext *avctx;
- int range;
+ int lrange, urange;
uint8_t *comp_buf, *work_buf;
uint8_t pal[768];
uint32_t pal2[256]; //for quick comparisons
- uint8_t *prev;
+ uint8_t *prev, *prev_buf;
int pstride;
int comp_size;
int keyint, curfrm;
@@ -61,7 +61,6 @@ typedef struct ZmbvEncContext {
/** Block comparing function
* XXX should be optimized and moved to DSPContext
- * TODO handle out of edge ME
*/
static inline int block_cmp(ZmbvEncContext *c, uint8_t *src, int stride,
uint8_t *src2, int stride2, int bw, int bh,
@@ -100,23 +99,42 @@ static inline int block_cmp(ZmbvEncContext *c, uint8_t *src, int stride,
static int zmbv_me(ZmbvEncContext *c, uint8_t *src, int sstride, uint8_t *prev,
int pstride, int x, int y, int *mx, int *my, int *xored)
{
- int dx, dy, tx, ty, tv, bv, bw, bh;
+ int dx, dy, txored, tv, bv, bw, bh;
+ int mx0, my0;
- *mx = *my = 0;
+ mx0 = *mx;
+ my0 = *my;
bw = FFMIN(ZMBV_BLOCK, c->avctx->width - x);
bh = FFMIN(ZMBV_BLOCK, c->avctx->height - y);
+
+ /* Try (0,0) */
bv = block_cmp(c, src, sstride, prev, pstride, bw, bh, xored);
+ *mx = *my = 0;
if(!bv) return 0;
- for(ty = FFMAX(y - c->range, 0); ty < FFMIN(y + c->range, c->avctx->height - bh); ty++){
- for(tx = FFMAX(x - c->range, 0); tx < FFMIN(x + c->range, c->avctx->width - bw); tx++){
- if(tx == x && ty == y) continue; // we already tested this block
- dx = tx - x;
- dy = ty - y;
- tv = block_cmp(c, src, sstride, prev + dx + dy * pstride, pstride, bw, bh, xored);
+
+ /* Try previous block's MV (if not 0,0) */
+ if (mx0 || my0){
+ tv = block_cmp(c, src, sstride, prev + mx0 + my0 * pstride, pstride, bw, bh, &txored);
+ if(tv < bv){
+ bv = tv;
+ *mx = mx0;
+ *my = my0;
+ *xored = txored;
+ if(!bv) return 0;
+ }
+ }
+
+ /* Try other MVs from top-to-bottom, left-to-right */
+ for(dy = -c->lrange; dy <= c->urange; dy++){
+ for(dx = -c->lrange; dx <= c->urange; dx++){
+ if(!dx && !dy) continue; // we already tested this block
+ if(dx == mx0 && dy == my0) continue; // this one too
+ tv = block_cmp(c, src, sstride, prev + dx + dy * pstride, pstride, bw, bh, &txored);
if(tv < bv){
bv = tv;
*mx = dx;
*my = dy;
+ *xored = txored;
if(!bv) return 0;
}
}
@@ -181,7 +199,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
int x, y, bh2, bw2, xored;
uint8_t *tsrc, *tprev;
uint8_t *mv;
- int mx, my;
+ int mx = 0, my = 0;
bw = (avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
bh = (avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
@@ -269,7 +287,7 @@ static av_cold int encode_end(AVCodecContext *avctx)
av_freep(&c->work_buf);
deflateEnd(&c->zstream);
- av_freep(&c->prev);
+ av_freep(&c->prev_buf);
return 0;
}
@@ -283,6 +301,7 @@ static av_cold int encode_init(AVCodecContext *avctx)
int zret; // Zlib return code
int i;
int lvl = 9;
+ int prev_size, prev_offset;
/* Entropy-based score tables for comparing blocks.
* Suitable for blocks up to (ZMBV_BLOCK * ZMBV_BLOCK) bytes.
@@ -295,9 +314,13 @@ static av_cold int encode_init(AVCodecContext *avctx)
c->curfrm = 0;
c->keyint = avctx->keyint_min;
- c->range = 8;
- if(avctx->me_range > 0)
- c->range = FFMIN(avctx->me_range, 127);
+
+ /* Motion estimation range: maximum distance is -64..63 */
+ c->lrange = c->urange = 8;
+ if(avctx->me_range > 0){
+ c->lrange = FFMIN(avctx->me_range, 64);
+ c->urange = FFMIN(avctx->me_range, 63);
+ }
if(avctx->compression_level >= 0)
lvl = avctx->compression_level;
@@ -323,11 +346,23 @@ static av_cold int encode_init(AVCodecContext *avctx)
av_log(avctx, AV_LOG_ERROR, "Can't allocate compression buffer.\n");
return AVERROR(ENOMEM);
}
- c->pstride = FFALIGN(avctx->width, 16);
- if (!(c->prev = av_malloc(c->pstride * avctx->height))) {
+
+ /* Allocate prev buffer - pad around the image to allow out-of-edge ME:
+ * - The image should be padded with `lrange` rows before and `urange` rows
+ * after.
+ * - The stride should be padded with `lrange` pixels, then rounded up to a
+ * multiple of 16 bytes.
+ * - The first row should also be padded with `lrange` pixels before, then
+ * aligned up to a multiple of 16 bytes.
+ */
+ c->pstride = FFALIGN(avctx->width + c->lrange, 16);
+ prev_size = FFALIGN(c->lrange, 16) + c->pstride * (c->lrange + avctx->height + c->urange);
+ prev_offset = FFALIGN(c->lrange, 16) + c->pstride * c->lrange;
+ if (!(c->prev_buf = av_mallocz(prev_size))) {
av_log(avctx, AV_LOG_ERROR, "Can't allocate picture.\n");
return AVERROR(ENOMEM);
}
+ c->prev = c->prev_buf + prev_offset;
c->zstream.zalloc = Z_NULL;
c->zstream.zfree = Z_NULL;
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