[FFmpeg-cvslog] avcodec/mpeg4videodec: Remove unnecessary ff_xvid_idct_init()

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Mon May 19 17:18:38 2025 +0200| [eb5d900f87faeaca5a79b96a2faee0153ad8c7b1] | committer: Andreas Rheinhardt

avcodec/mpeg4videodec: Remove unnecessary ff_xvid_idct_init()

It is unnecessary: If the dst context is not already initialized,
then it will be initialized by memcpy(dst, src, sizeof(*dst),
which already initializes the IDCT to the desired one, potentially
followed by ff_mpv_common_init(), which does not touch the IDCT.

(This call has been added in f89d76c10355242c39b08f253c1d1524f45ef778;
the aforementioned copying took place back then, too, but
ff_mpv_common_init() reinitialized the IDCT to a non-xvid one,
therefore the initialization here has been added to fix
multithreaded decoding.)

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=eb5d900f87faeaca5a79b96a2faee0153ad8c7b1
---

 libavcodec/mpeg4videodec.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c
index 82b552356a..c4eed9136a 100644
--- a/libavcodec/mpeg4videodec.c
+++ b/libavcodec/mpeg4videodec.c
@@ -48,7 +48,6 @@
 #include "profiles.h"
 #include "qpeldsp.h"
 #include "threadprogress.h"
-#include "xvididct.h"
 #include "unary.h"
 
 #if 0 //3IV1 is quite rare and it slows things down a tiny bit
@@ -3880,9 +3879,6 @@ static int mpeg4_update_thread_context(AVCodecContext *dst,
     memcpy(s->sprite_shift, s1->sprite_shift, sizeof(s1->sprite_shift));
     memcpy(s->sprite_traj,  s1->sprite_traj,  sizeof(s1->sprite_traj));
 
-    if (!init && s1->xvid_build >= 0)
-        ff_xvid_idct_init(&s->m.idsp, dst);
-
     return av_buffer_replace(&s->bitstream_buffer, s1->bitstream_buffer);
 }