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| author | Mike Melanson <mike@multimedia.cx> | 2009-12-19 07:33:10 +0000 |
|---|---|---|
| committer | Mike Melanson <mike@multimedia.cx> | 2009-12-19 07:33:10 +0000 |
| commit | e6e32bdc5f3c4b221d330cc9c58cb7ca3d1fd396 (patch) | |
| tree | 7ac351cbfd3f8ef56847e2468f160b9497be6055 /libavcodec/vp3.c | |
| parent | b2cc8111d65c3377ed9f2e1216023c91f7ca45a9 (diff) | |
| download | ffmpeg-e6e32bdc5f3c4b221d330cc9c58cb7ca3d1fd396.tar.gz | |
Optimize unpack_vectors() by not shuffling around redundant vectors.
Inspired by guidance from Dark Shikari. On a Core 2 Duo 2.0 GHz, this
change decodes the 10-minute Big Buck Bunny 1080p short about 2 seconds
faster.
Originally committed as revision 20895 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/vp3.c')
| -rw-r--r-- | libavcodec/vp3.c | 22 |
1 files changed, 7 insertions, 15 deletions
diff --git a/libavcodec/vp3.c b/libavcodec/vp3.c index 0593d4ec24..d67f91ec2d 100644 --- a/libavcodec/vp3.c +++ b/libavcodec/vp3.c @@ -891,11 +891,6 @@ static int unpack_vectors(Vp3DecodeContext *s, GetBitContext *gb) motion_y[0] = fixed_motion_vector_table[get_bits(gb, 6)]; } - for (k = 1; k < 6; k++) { - motion_x[k] = motion_x[0]; - motion_y[k] = motion_y[0]; - } - /* vector maintenance, only on MODE_INTER_PLUS_MV */ if (s->macroblock_coding[current_macroblock] == MODE_INTER_PLUS_MV) { @@ -946,10 +941,6 @@ static int unpack_vectors(Vp3DecodeContext *s, GetBitContext *gb) /* all 6 fragments use the last motion vector */ motion_x[0] = last_motion_x; motion_y[0] = last_motion_y; - for (k = 1; k < 6; k++) { - motion_x[k] = motion_x[0]; - motion_y[k] = motion_y[0]; - } /* no vector maintenance (last vector remains the * last vector) */ @@ -960,10 +951,6 @@ static int unpack_vectors(Vp3DecodeContext *s, GetBitContext *gb) * last motion vector */ motion_x[0] = prior_last_motion_x; motion_y[0] = prior_last_motion_y; - for (k = 1; k < 6; k++) { - motion_x[k] = motion_x[0]; - motion_y[k] = motion_y[0]; - } /* vector maintenance */ prior_last_motion_x = last_motion_x; @@ -974,8 +961,8 @@ static int unpack_vectors(Vp3DecodeContext *s, GetBitContext *gb) default: /* covers intra, inter without MV, golden without MV */ - memset(motion_x, 0, 6 * sizeof(int)); - memset(motion_y, 0, 6 * sizeof(int)); + motion_x[0] = 0; + motion_y[0] = 0; /* no vector maintenance */ break; @@ -992,8 +979,13 @@ static int unpack_vectors(Vp3DecodeContext *s, GetBitContext *gb) current_fragment, s->fragment_count); return 1; } + if (s->macroblock_coding[current_macroblock] == MODE_INTER_FOURMV) { s->all_fragments[current_fragment].motion_x = motion_x[k]; s->all_fragments[current_fragment].motion_y = motion_y[k]; + } else { + s->all_fragments[current_fragment].motion_x = motion_x[0]; + s->all_fragments[current_fragment].motion_y = motion_y[0]; + } } } } |