[FFmpeg-devel] [PATCH 1/2] lavf: allow setting AVStream.discard as an AVOption

[Anton Khirnov]

Quoting James Almer (2023-12-19 13:09:05)
> On 12/19/2023 7:41 AM, Anton Khirnov wrote:
> > Quoting James Almer (2023-12-18 20:30:47)
> >> On 12/18/2023 4:19 PM, Anton Khirnov wrote:
> >>> ---
> >>>    libavformat/options.c | 10 ++++++++++
> >>>    1 file changed, 10 insertions(+)
> >>>
> >>> diff --git a/libavformat/options.c b/libavformat/options.c
> >>> index bf6113ca95..cc89dd6c72 100644
> >>> --- a/libavformat/options.c
> >>> +++ b/libavformat/options.c
> >>> @@ -229,6 +229,16 @@ static const AVOption stream_options[] = {
> >>>            { "metadata",           .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_METADATA          },    .unit = "disposition" },
> >>>            { "dependent",          .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_DEPENDENT         },    .unit = "disposition" },
> >>>            { "still_image",        .type = AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_STILL_IMAGE       },    .unit = "disposition" },
> >>> +
> >>> +    { "discard", NULL, offsetof(AVStream, discard), AV_OPT_TYPE_INT, { .i64 = AVDISCARD_DEFAULT }, INT_MIN, INT_MAX,
> >>> +        .flags = AV_OPT_FLAG_DECODING_PARAM, .unit = "avdiscard" },
> >>> +        { "none",               .type = AV_OPT_TYPE_CONST, {.i64 = AVDISCARD_NONE     }, .unit = "avdiscard" },
> >>> +        { "default",            .type = AV_OPT_TYPE_CONST, {.i64 = AVDISCARD_DEFAULT  }, .unit = "avdiscard" },
> >>> +        { "noref",              .type = AV_OPT_TYPE_CONST, {.i64 = AVDISCARD_NONREF   }, .unit = "avdiscard" },
> >>> +        { "bidir",              .type = AV_OPT_TYPE_CONST, {.i64 = AVDISCARD_BIDIR    }, .unit = "avdiscard" },
> >>> +        { "nointra",            .type = AV_OPT_TYPE_CONST, {.i64 = AVDISCARD_NONINTRA }, .unit = "avdiscard" },
> >>> +        { "nokey",              .type = AV_OPT_TYPE_CONST, {.i64 = AVDISCARD_NONKEY   }, .unit = "avdiscard" },
> >>> +        { "all",                .type = AV_OPT_TYPE_CONST, {.i64 = AVDISCARD_ALL      }, .unit = "avdiscard" },
> >>>        { NULL }
> >>>    };
> >>
> >> Should be ok.
> >>
> >> Maybe also add "id" like i did for AVStreamGroup while at it.
> > 
> > The problem with id is how to flag it - it's read-only for demuxing and
> > user-settable for muxing.
> 
> Wouldn't the AV_OPT_FLAG_ENCODING_PARAM flag be enough for the CLI to 
> reject it for demuxing cases?

Those flags should be set for all callers, not just the CLI. And for
demuxing the proper flag is AV_OPT_FLAG_EXPORT

-- 
Anton Khirnov