[vlc-devel] [RFC] [PATCH] avcodec: remove avcodec-fast support

[Marvin Scholz]

The avcodec-fast option, if enabled, sets the AV_CODEC_FLAG2_FAST
option. Using AV_CODEC_FLAG2_FAST can cause use of unsafe code in
avcodec which could lead to crashes.
---

It seems a bad idea to haven an option that can enable unsafe code
especially with such a option name and description as it does not
sound at all like it would enable possibly unsafe behavior that can
lead to crashes.

Alternatively if we really want to keep it, we probably should
adjus the name of the option and description to make it clear
what other effects it has, other than improving speed.

 modules/codec/avcodec/avcodec.c | 2 +-
 modules/codec/avcodec/avcodec.h | 4 ----
 modules/codec/avcodec/video.c   | 3 ---
 3 files changed, 1 insertion(+), 8 deletions(-)

diff --git a/modules/codec/avcodec/avcodec.c b/modules/codec/avcodec/avcodec.c
index ad2201cb1f..dc2d3d3550 100644
--- a/modules/codec/avcodec/avcodec.c
+++ b/modules/codec/avcodec/avcodec.c
@@ -118,7 +118,7 @@ vlc_module_begin ()
     add_obsolete_integer( "avcodec-vismv" ) /* removed since 3.0.0 */
     add_obsolete_integer ( "ffmpeg-lowres" ) /* removed since 2.1.0 */
     add_obsolete_bool( "ffmpeg-fast" ) /* removed since 2.1.0 */
-    add_bool( "avcodec-fast", false, FAST_TEXT, FAST_LONGTEXT, false )
+    add_obsolete_bool( "avcodec-fast" ) /* removed since 4.0.0 */
     add_obsolete_integer ( "ffmpeg-skiploopfilter" ) /* removed since 2.1.0 */
     add_integer ( "avcodec-skiploopfilter", 0, SKIPLOOPF_TEXT,
                   SKIPLOOPF_LONGTEXT, false)
diff --git a/modules/codec/avcodec/avcodec.h b/modules/codec/avcodec/avcodec.h
index 1df39c613a..184ceb11d7 100644
--- a/modules/codec/avcodec/avcodec.h
+++ b/modules/codec/avcodec/avcodec.h
@@ -84,10 +84,6 @@ int ffmpeg_OpenCodec( decoder_t *p_dec, AVCodecContext *, const AVCodec * );
     "when there is not enough time. It's useful with low CPU power " \
     "but it can produce distorted pictures.")
 
-#define FAST_TEXT N_("Allow speed tricks")
-#define FAST_LONGTEXT N_( \
-    "Allow non specification compliant speedup tricks. Faster but error-prone.")
-
 #define SKIP_FRAME_TEXT N_("Skip frame (default=0)")
 #define SKIP_FRAME_LONGTEXT N_( \
     "Force skipping of frames to speed up decoding " \
diff --git a/modules/codec/avcodec/video.c b/modules/codec/avcodec/video.c
index c359dffe57..b74d77e0f5 100644
--- a/modules/codec/avcodec/video.c
+++ b/modules/codec/avcodec/video.c
@@ -573,9 +573,6 @@ int InitVideoDec( vlc_object_t *obj )
     else if( i_val == 1 ) p_context->skip_loop_filter = AVDISCARD_NONREF;
     else p_context->skip_loop_filter = AVDISCARD_DEFAULT;
 
-    if( var_CreateGetBool( p_dec, "avcodec-fast" ) )
-        p_context->flags2 |= AV_CODEC_FLAG2_FAST;
-
     /* ***** libavcodec frame skipping ***** */
     p_sys->b_hurry_up = var_CreateGetBool( p_dec, "avcodec-hurry-up" );
     p_sys->b_show_corrupted = var_CreateGetBool( p_dec, "avcodec-corrupted" );
-- 
2.24.1 (Apple Git-126)