Here's a patch that fixes decoding of Indeo 4 B-frames.
Now the main problem is Indeo 4 B-frames reconstruction. For that I
need to modify IVI context to store the second pair of vectors (that
is not hard at all) and make it perform the averaging motion
compensation for B-blocks (that one seems to require some more
hacking).
From 22b32375f8680540a73607269602f584e81182d1 Mon Sep 17 00:00:00 2001
From: Dirk Ausserhaus <[email protected]>
Date: Sun, 8 Jun 2014 13:44:17 +0200
Subject: [PATCH] indeo4: parse B-frame motion vectors correctly
---
libavcodec/indeo4.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)
diff --git a/libavcodec/indeo4.c b/libavcodec/indeo4.c
index 3e97221..0c93706 100644
--- a/libavcodec/indeo4.c
+++ b/libavcodec/indeo4.c
@@ -535,8 +535,25 @@ static int decode_mb_info(IVI45DecContext *ctx, IVIBandDesc *band,
mv_delta = get_vlc2(&ctx->gb, ctx->mb_vlc.tab->table,
IVI_VLC_BITS, 1);
mv_x += IVI_TOSIGNED(mv_delta);
- mb->mv_x = mv_x;
- mb->mv_y = mv_y;
+ if (mb->type != 2) {
+ mb->mv_x = mv_x;
+ mb->mv_y = mv_y;
+ } else {
+ mb->mv_x = -mv_x;
+ mb->mv_y = -mv_y;
+ }
+ if (mb->type == 3) {
+ mv_delta = get_vlc2(&ctx->gb,
+ ctx->mb_vlc.tab->table,
+ IVI_VLC_BITS, 1);
+ mv_y += IVI_TOSIGNED(mv_delta);
+ mv_delta = get_vlc2(&ctx->gb,
+ ctx->mb_vlc.tab->table,
+ IVI_VLC_BITS, 1);
+ mv_x += IVI_TOSIGNED(mv_delta);
+ //mb->mv_x[1] = -mv_x;
+ //mb->mv_y[1] = -mv_y;
+ }
}
}
}
--
1.7.9.5
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