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

[Marvin Scholz]

On 5 Jun 2020, at 16:50, Rémi Denis-Courmont wrote:

> Le perjantaina 5. kesäkuuta 2020, 1.13.10 EEST Marvin Scholz a écrit 
> :
>> 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
>
> have*. Could use shorter sentences.
>
> Code LGTM.
>

Thanks. Maybe I messed up but only the part before the --- is the
actual commit message I have locally.

I always get confused where to add the annotations that are for the
mail only…

>> 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"
>> );
>
>
> -- 
> レミ・デニ-クールモン
> http://www.remlab.net/
>
>
>
> _______________________________________________
> vlc-devel mailing list
> To unsubscribe or modify your subscription options:
> https://mailman.videolan.org/listinfo/vlc-devel