ffmpeg | branch: release/3.4 | Michael Niedermayer <mich...@niedermayer.cc> | Sun Aug 5 16:13:24 2018 +0200| [848726afc642fbe8aea7773594506bfb495bd8ab] | committer: Michael Niedermayer
avcodec/gdv: Replace divisions by shifts in rescale() Divisions tend to be slower than shifts unless the compiler optimizes them out. And some of these are in inner loops. Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> (cherry picked from commit b90d8cc7466386a166dd72107457498aa5a7c43d) Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=848726afc642fbe8aea7773594506bfb495bd8ab --- libavcodec/gdv.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/libavcodec/gdv.c b/libavcodec/gdv.c index dc91869edf..d4d24931c9 100644 --- a/libavcodec/gdv.c +++ b/libavcodec/gdv.c @@ -85,14 +85,14 @@ static void rescale(GDVContext *gdv, uint8_t *dst, int w, int h, int scale_v, in int y = h - j - 1; for (i = 0; i < w; i++) { int x = w - i - 1; - dst[PREAMBLE_SIZE + x + y * w] = dst[PREAMBLE_SIZE + x/2 + (y/2) * (w/2)]; + dst[PREAMBLE_SIZE + x + y * w] = dst[PREAMBLE_SIZE + (x>>1) + (y>>1) * (w>>1)]; } } } else if (gdv->scale_h) { for (j = 0; j < h; j++) { int y = h - j - 1; for (x = 0; x < w; x++) { - dst[PREAMBLE_SIZE + x + y * w] = dst[PREAMBLE_SIZE + x + (y/2) * w]; + dst[PREAMBLE_SIZE + x + y * w] = dst[PREAMBLE_SIZE + x + (y>>1) * w]; } } } else if (gdv->scale_v) { @@ -100,26 +100,26 @@ static void rescale(GDVContext *gdv, uint8_t *dst, int w, int h, int scale_v, in int y = h - j - 1; for (i = 0; i < w; i++) { int x = w - i - 1; - dst[PREAMBLE_SIZE + x + y * w] = dst[PREAMBLE_SIZE + x/2 + y * (w/2)]; + dst[PREAMBLE_SIZE + x + y * w] = dst[PREAMBLE_SIZE + (x>>1) + y * (w>>1)]; } } } if (scale_h && scale_v) { - for (y = 0; y < h/2; y++) { - for (x = 0; x < w/2; x++) { - dst[PREAMBLE_SIZE + x + y * (w/2)] = dst[PREAMBLE_SIZE + x*2 + y*2 * w]; + for (y = 0; y < (h>>1); y++) { + for (x = 0; x < (w>>1); x++) { + dst[PREAMBLE_SIZE + x + y * (w>>1)] = dst[PREAMBLE_SIZE + x*2 + y*2 * w]; } } } else if (scale_h) { - for (y = 0; y < h/2; y++) { + for (y = 0; y < (h>>1); y++) { for (x = 0; x < w; x++) { dst[PREAMBLE_SIZE + x + y * w] = dst[PREAMBLE_SIZE + x + y*2 * w]; } } } else if (scale_v) { for (y = 0; y < h; y++) { - for (x = 0; x < w/2; x++) { + for (x = 0; x < (w>>1); x++) { dst[PREAMBLE_SIZE + x + y * w] = dst[PREAMBLE_SIZE + x*2 + y * w]; } } _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog
