[FFmpeg-devel] [PATCH 1/2] Support HDR dynamic metdata (HDR10+) in HEVC decoder.

[James Almer]

On 1/4/2019 3:53 PM, Rostislav Pehlivanov wrote:
> On Fri, 4 Jan 2019 at 18:12, Mohammad Izadi <moh.izadi at gmail.com> wrote:
> 
>> You mean a pointer in HEVCSEIDynamicHDRPlus, not in HEVCSEIContentLight?
>> --
>> Best,
>> Mohammad
>>
>>
>> On Thu, Jan 3, 2019 at 5:08 PM Rostislav Pehlivanov <atomnuker at gmail.com>
>> wrote:
>>
>>> On Thu, 3 Jan 2019 at 20:13, Mohammad Izadi <moh.izadi at gmail.com> wrote:
>>>
>>>>
>>>>  /**
>>>> @@ -94,6 +95,50 @@ typedef struct HEVCSEIMasteringDisplay {
>>>>      uint32_t min_luminance;
>>>>  } HEVCSEIMasteringDisplay;
>>>>
>>>> +typedef struct HEVCSEIDynamicHDRPlus{
>>>> +    int present;
>>>> +    uint8_t itu_t_t35_country_code;
>>>> +    uint8_t application_version;
>>>> +    uint8_t num_windows;
>>>> +    struct {
>>>> +        AVRational window_upper_left_corner_x;
>>>> +        AVRational window_upper_left_corner_y;
>>>> +        AVRational window_lower_right_corner_x;
>>>> +        AVRational window_lower_right_corner_y;
>>>> +        uint16_t center_of_ellipse_x;
>>>> +        uint16_t center_of_ellipse_y;
>>>> +        uint8_t rotation_angle;
>>>> +        uint16_t semimajor_axis_internal_ellipse;
>>>> +        uint16_t semimajor_axis_external_ellipse;
>>>> +        uint16_t semiminor_axis_external_ellipse;
>>>> +        uint8_t overlap_process_option;
>>>> +        AVRational maxscl[3];
>>>> +        AVRational average_maxrgb;
>>>> +        uint8_t num_distribution_maxrgb_percentiles;
>>>> +        struct {
>>>> +            uint8_t percentage;
>>>> +            AVRational percentile;
>>>> +        } distribution_maxrgb[15];
>>>> +        AVRational fraction_bright_pixels;
>>>> +        uint8_t tone_mapping_flag;
>>>> +        AVRational knee_point_x;
>>>> +        AVRational knee_point_y;
>>>> +        uint8_t num_bezier_curve_anchors;
>>>> +        AVRational bezier_curve_anchors[15];
>>>> +        uint8_t color_saturation_mapping_flag;
>>>> +        AVRational color_saturation_weight;
>>>> +    } params[3];
>>>> +    AVRational targeted_system_display_maximum_luminance;
>>>> +    uint8_t targeted_system_display_actual_peak_luminance_flag;
>>>> +    uint8_t num_rows_targeted_system_display_actual_peak_luminance;
>>>> +    uint8_t num_cols_targeted_system_display_actual_peak_luminance;
>>>> +    AVRational targeted_system_display_actual_peak_luminance[25][25];
>>>> +    uint8_t mastering_display_actual_peak_luminance_flag;
>>>> +    uint8_t num_rows_mastering_display_actual_peak_luminance;
>>>> +    uint8_t num_cols_mastering_display_actual_peak_luminance;
>>>> +    AVRational mastering_display_actual_peak_luminance[25][25];
>>>> +} HEVCSEIDynamicHDRPlus;
>>>> +
>>>>
>>>
>>> There's no reason to create a new struct for this if all you're going to
>> do
>>> is to copy it over and over to new frames.
>>> What you can do is this: on every SEI containing this thing just
>> allocate a
>>> AVDynamicHDRPlus struct via av_dynamic_hdr_plus_alloc, wrap it as an
>>> AVBufferRef via av_buffer_create, populate it, put it as a pointer in
>>> HEVCSEIContentLight and then on every frame just add it to the frame via
>>> av_frame_new_side_data_from_buf. If a new SEI is received unref your
>>> pointer in HEVCSEIDynamicHDRPlus and repeat by allocating a new struct,
>>> wrapping it as a buffer, populating it, etc.
>>> I figure the only reason this wasn't done with other metadata was because
>>> they were much smaller and because av_frame_new_side_data_from_buf didn't
>>> exist until recently.
>>>
>>>
>>> +            av_log(s->avctx, AV_LOG_DEBUG, ")");
>>>> +            if (metadata->params[w].color_saturation_mapping_flag) {
>>>> +                av_log(s->avctx, AV_LOG_DEBUG,
>>>> +                       " color_saturation_weight=%5.4f",
>>>> +
>>>>  av_q2d(metadata->params[w].color_saturation_weight));
>>>> +            }
>>>> +            av_log(s->avctx, AV_LOG_DEBUG, "}\n");
>>>> +        }
>>>> +        av_log(s->avctx, AV_LOG_DEBUG,
>>>> +               "} End of HDR10+ (SMPTE 2094-40)\n");
>>>> +    }
>>>>
>>>
>>> Don't spam stuff like than in the debug log, especially not on every
>> single
>>> frame. Tools exist to print side data so just don't.
>>> _______________________________________________
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>>> ffmpeg-devel at ffmpeg.org
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>>>
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> 
> 
> No, I mean in HEVCSEIContentLight. Like I said, HEVCSEIDynamicHDRPlus
> shouldn't exist.

By "HEVCSEIDynamicHDRPlus shouldn't exist" you mean it shouldn't contain
a copy of every bitstream field in the SEI?

Content Light and Dynamic HDR10+ are two different SEI types. There's no
reason to merge them into a single struct within the HEVC decoder.