From 7f9926a45eeab7e25b9e381fc35b1342fde826cb Mon Sep 17 00:00:00 2001 From: Mike Melanson Date: Sat, 21 May 2005 01:12:41 +0000 Subject: [PATCH] another bitstream extraction to optimize: fixed-length motion vectors Originally committed as revision 4286 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/vp3.c | 11 +++++++++++ libavcodec/vp3data.h | 11 +++++++++++ 2 files changed, 22 insertions(+) diff --git a/libavcodec/vp3.c b/libavcodec/vp3.c index 1f0718e3d7..160dcfb5a8 100644 --- a/libavcodec/vp3.c +++ b/libavcodec/vp3.c @@ -1540,9 +1540,15 @@ static int unpack_vectors(Vp3DecodeContext *s, GetBitContext *gb) motion_y[0] = get_motion_vector_vlc(gb); #endif } else { +#if 1 + motion_x[0] = fixed_motion_vector_table[get_bits(gb, 6)]; + motion_y[0] = fixed_motion_vector_table[get_bits(gb, 6)]; +#else motion_x[0] = get_motion_vector_fixed(gb); motion_y[0] = get_motion_vector_fixed(gb); +#endif } + for (k = 1; k < 6; k++) { motion_x[k] = motion_x[0]; motion_y[k] = motion_y[0]; @@ -1572,8 +1578,13 @@ static int unpack_vectors(Vp3DecodeContext *s, GetBitContext *gb) motion_y[k] = get_motion_vector_vlc(gb); #endif } else { +#if 1 + motion_x[k] = fixed_motion_vector_table[get_bits(gb, 6)]; + motion_y[k] = fixed_motion_vector_table[get_bits(gb, 6)]; +#else motion_x[k] = get_motion_vector_fixed(gb); motion_y[k] = get_motion_vector_fixed(gb); +#endif } motion_x[4] += motion_x[k]; motion_y[4] += motion_y[k]; diff --git a/libavcodec/vp3data.h b/libavcodec/vp3data.h index 9fa1ffa62b..8bead2fc15 100644 --- a/libavcodec/vp3data.h +++ b/libavcodec/vp3data.h @@ -163,6 +163,17 @@ static const int motion_vector_table[63] = { 24, -24, 25, -25, 26, -26, 27, -27, 28, -28, 29, -29, 30, -30, 31, -31 }; +static const int8_t fixed_motion_vector_table[64] = { + 0, 0, 1, -1, 2, -2, 3, -3, + 4, -4, 5, -5, 6, -6, 7, -7, + 8, -8, 9, -9, 10, -10, 11, -11, + 12, -12, 13, -13, 14, -14, 15, -15, + 16, -16, 17, -17, 18, -18, 19, -19, + 20, -20, 21, -21, 22, -22, 23, -23, + 24, -24, 25, -25, 26, -26, 27, -27, + 28, -28, 29, -29, 30, -30, 31, -31 +}; + /* only tokens 0..6 indicate eob runs */ static const int eob_run_base[7] = { 1, 2, 3, 4, 8, 16, 0