[MPlayer-dev-eng] [PATCH v3] loosen requirements on error resilence flags

[Reimar Döffinger]

On Fri, Feb 10, 2012 at 09:23:44PM +0100, Reinhard Tartler wrote:
> On Fri, Feb 10, 2012 at 7:41 PM, Reimar Döffinger
> <Reimar.Doeffinger at gmx.de> wrote:
> >
> >
> > On 10 Feb 2012, at 19:19, Reinhard Tartler <siretart at gmail.com> wrote:
> >
> >> On Mon, Feb 6, 2012 at 7:32 AM, Reinhard Tartler <siretart at gmail.com> wrote:
> >>> $subj
> >>
> >> Variant two.
> >>
> >> This patch effectively restores the behavior prior to svn r34634 if
> >> those offending macros are not defined.
> >> By this, compilation with older releases of FFmpeg become easier.
> >
> > That makes no sense, you did not restore the old behaviour. The MPlayer option takes values from 0 to 4 or so, err_recognition takes flags.
> > If you want to restore the old behaviour you have to assign error_recognition, but if you do that by checking for the flags you'll break compilation with current Libav.
> 
> I see. Right, I clearly misunderstood the point of the FF_API_ER deprecation.
> 
> Variant 3 attached.
> 
> -- 
> regards,
>     Reinhard

> Index: libmpcodecs/vd_ffmpeg.c
> ===================================================================
> --- libmpcodecs/vd_ffmpeg.c	(Revision 34684)
> +++ libmpcodecs/vd_ffmpeg.c	(Arbeitskopie)
> @@ -266,6 +266,7 @@
>      avctx->coded_width = sh->disp_w;
>      avctx->coded_height= sh->disp_h;
>      avctx->workaround_bugs= lavc_param_workaround_bugs;
> +#if defined AV_EF_COMPLIANT && defined AV_EF_CAREFUL && defined AV_EF_AGGRESSIVE
>      switch (lavc_param_error_resilience) {
>      case 5:
>          avctx->err_recognition |= AV_EF_EXPLODE | AV_EF_COMPLIANT | AV_EF_CAREFUL;
> @@ -280,6 +281,11 @@
>      case 1:
>          avctx->err_recognition |= AV_EF_CAREFUL;
>      }
> +#else
> +    /* FF_ER_CAREFUL   (==1) implies AV_EF_CRCCHECK (== 1<<1 - 1),
> +       FF_ER_COMPLIANT (==2) implies AV_EF_{CRCCHECK,BITSTREAM} (== 1<<2 - 1), et cetera} */
> +    avctx->err_recognition |= (1<<(lavc_param_error_resilience)) - 1;

This is rather obfuscated and depends on internals like the exact values
of AV_EF.
The bigger problem however is that these flags only go by _type_ of
error, however the point of lavc_param_error_resilience is to allow
selecting them by _severity_.
E.g. AV_EF_BUFFER treats both the MP3 decoder running out of bits
and bits being left over as an error, but running out of bits is
clearly a far severe problem, the other is most likely just a sloppy
encoder.
I don't see the point of mapping that option if it can't be
mapped to anything compatible with the old meaning.
The err_recognition setting is still available via the generic
o=... settings that allow setting any option through FFmpeg's
option system.