[FFmpeg-devel] [PATCH] lavc: clarify color_range semantics

[Gyan Doshi]

On 2023-01-15 11:11 pm, Stefano Sabatini wrote:
> Mark this option as encode-only and extend description.

There are scripts which set this (and other color props) on the input, 
and then those streams can be sent to multiple filters with the props 
set, instead of having to use setparams in each chain.

Regards,
Gyan

>
> Address issue: http://trac.ffmpeg.org/ticket/443
> ---
>   libavcodec/avcodec.h       |  6 +++++-
>   libavcodec/options_table.h | 14 +++++++-------
>   2 files changed, 12 insertions(+), 8 deletions(-)
>
> diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
> index 0ac581d660..53ae40255f 100644
> --- a/libavcodec/avcodec.h
> +++ b/libavcodec/avcodec.h
> @@ -976,7 +976,11 @@ typedef struct AVCodecContext {
>   
>       /**
>        * MPEG vs JPEG YUV range.
> -     * - encoding: Set by user
> +     *
> +     * - encoding: Set by user to override the default output color range value,
> +     *   it might cause a failure in case the specified value is not legal. If
> +     *   not specified, libavcodec sets the color range depending on the output
> +     *   format.
>        * - decoding: Set by libavcodec
>        */
>       enum AVColorRange color_range;
> diff --git a/libavcodec/options_table.h b/libavcodec/options_table.h
> index 7924ca6144..a668d39d79 100644
> --- a/libavcodec/options_table.h
> +++ b/libavcodec/options_table.h
> @@ -338,13 +338,13 @@ static const AVOption avcodec_options[] = {
>   {"ycocg",             "YCGCO",              0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_SPC_YCGCO },              INT_MIN, INT_MAX, V|E|D, "colorspace_type"},
>   {"bt2020_ncl",        "BT.2020 NCL",        0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_SPC_BT2020_NCL },         INT_MIN, INT_MAX, V|E|D, "colorspace_type"},
>   {"bt2020_cl",         "BT.2020 CL",         0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_SPC_BT2020_CL },          INT_MIN, INT_MAX, V|E|D, "colorspace_type"},
> -{"color_range", "color range", OFFSET(color_range), AV_OPT_TYPE_INT, {.i64 = AVCOL_RANGE_UNSPECIFIED }, 0, INT_MAX, V|E|D, "color_range_type"},
> -{"unknown", "Unspecified",     0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_UNSPECIFIED }, INT_MIN, INT_MAX, V|E|D, "color_range_type"},
> -{"tv", "MPEG (219*2^(n-8))",   0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_MPEG },        INT_MIN, INT_MAX, V|E|D, "color_range_type"},
> -{"pc", "JPEG (2^n-1)",         0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_JPEG },        INT_MIN, INT_MAX, V|E|D, "color_range_type"},
> -{"unspecified", "Unspecified", 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_UNSPECIFIED }, INT_MIN, INT_MAX, V|E|D, "color_range_type"},
> -{"mpeg", "MPEG (219*2^(n-8))", 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_MPEG },        INT_MIN, INT_MAX, V|E|D, "color_range_type"},
> -{"jpeg", "JPEG (2^n-1)",       0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_JPEG },        INT_MIN, INT_MAX, V|E|D, "color_range_type"},
> +{"color_range", "color range", OFFSET(color_range), AV_OPT_TYPE_INT, {.i64 = AVCOL_RANGE_UNSPECIFIED }, 0, INT_MAX, V|E, "color_range_type"},
> +{"unknown", "Unspecified",     0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_UNSPECIFIED }, INT_MIN, INT_MAX, V|E, "color_range_type"},
> +{"tv", "MPEG (219*2^(n-8))",   0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_MPEG },        INT_MIN, INT_MAX, V|E, "color_range_type"},
> +{"pc", "JPEG (2^n-1)",         0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_JPEG },        INT_MIN, INT_MAX, V|E, "color_range_type"},
> +{"unspecified", "Unspecified", 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_UNSPECIFIED }, INT_MIN, INT_MAX, V|E, "color_range_type"},
> +{"mpeg", "MPEG (219*2^(n-8))", 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_MPEG },        INT_MIN, INT_MAX, V|E, "color_range_type"},
> +{"jpeg", "JPEG (2^n-1)",       0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_JPEG },        INT_MIN, INT_MAX, V|E, "color_range_type"},
>   {"chroma_sample_location", "chroma sample location", OFFSET(chroma_sample_location), AV_OPT_TYPE_INT, {.i64 = AVCHROMA_LOC_UNSPECIFIED }, 0, INT_MAX, V|E|D, "chroma_sample_location_type"},
>   {"unknown",     "Unspecified", 0, AV_OPT_TYPE_CONST, {.i64 = AVCHROMA_LOC_UNSPECIFIED }, INT_MIN, INT_MAX, V|E|D, "chroma_sample_location_type"},
>   {"left",        "Left",        0, AV_OPT_TYPE_CONST, {.i64 = AVCHROMA_LOC_LEFT },        INT_MIN, INT_MAX, V|E|D, "chroma_sample_location_type"},