[FFmpeg-devel] [PATCH][RFC] avcodec/dpxenc: add option to force color transfer characteristics

[Hendrik Leppkes]

On Wed, Apr 11, 2018 at 10:42 AM, Tobias Rapp <t.rapp at noa-archive.com> wrote:
> On 11.04.2018 10:23, Kieran O Leary wrote:
>>
>> Hi Carl,
>>
>> On Sat, Dec 16, 2017 at 2:31 PM, Carl Eugen Hoyos <ceffmpeg at gmail.com>
>> wrote:
>>>
>>> 2017-12-15 22:22 GMT+01:00 Tobias Rapp <t.rapp at noa-archive.com>:
>>>
>>>> +    { "dpx_color_trc",  "Transfer Characteristics", OFFSET(color_trc),
>>>> AV_OPT_TYPE_INT, { .i64 = DPX_TRC_UNDEFINED }, DPX_TRC_UNDEFINED,
>>>> DPX_TRC_NB-1, VE, "trc" },
>>>
>>>
>>> This seems wrong to me, we have colour characteristics in general code.
>>>
>>
>> There is a method in this patch that takes values from -color_trc, is
>> that not sufficient?
>>
>> [...]
>
>
> If I understand it correctly Carl wants to have the DPX_TRC_* enum values
> merged into AVCOL_TRC_*. My feeling is that I currently don't have enough
> knowledge about all those TRC specifications to properly sort them into the
> list, and did not find time to dig into the topic. Also I doubt the general
> usefulness of DPX_TRC_USER_DEFINED or DPX_TRC_UNSPECIFIED_VIDEO outside of
> DPX encoding.

All the AVColor* enums track the values from ISO/IEC 23001-8, which is
also the same numeric values most major codecs follow, any values not
defined in that standard should not get into those enums at this
point.

Somwhat related to that, the two 601 values probably have mappings in AVCOL_TRC.

- Hendrik