[FFmpeg-devel] [PATCH v6 1/2] ffmpeg: Add display_{rotation, hflip, vflip} options

[Thilo Borgmann]

Am 04.10.22 um 10:44 schrieb Anton Khirnov:
> Quoting Thilo Borgmann (2022-09-26 07:57:52)
>> From: Jan Ekström <jeebjp at gmail.com>
>>
>> This enables overriding the rotation as well as horizontal/vertical
>> flip state of a specific video stream on the input side.
>>
>> Additionally, switch the singular test that was utilizing the rotation
>> metadata to instead override the input display rotation, thus leading
>> to the same result.
>> ---
>>   doc/ffmpeg.texi             | 29 +++++++++++++++++++++
>>   fftools/ffmpeg.h            |  6 +++++
>>   fftools/ffmpeg_opt.c        | 50 +++++++++++++++++++++++++++++++++++++
>>   tests/fate/filter-video.mak |  2 +-
>>   4 files changed, 86 insertions(+), 1 deletion(-)
>>
>> diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
>> index 42440d93b4..6016b43892 100644
>> --- a/doc/ffmpeg.texi
>> +++ b/doc/ffmpeg.texi
>> @@ -912,6 +912,35 @@ If used together with @option{-vcodec copy}, it will affect the aspect ratio
>>   stored at container level, but not the aspect ratio stored in encoded
>>   frames, if it exists.
>>   
>> + at item -display_rotation[:@var{stream_specifier}] @var{rotation} (@emph{input,per-stream})
>> +Set the video display rotation in degrees specified by @var{rotation}.
>> +
>> + at var{rotation} is a floating point number that describes a pure
>> +counter-clockwise rotation in degrees.
>> +When setting this, @code{-autorotate} logic will be affected.
>> +For additional parameters affecting display matrix side data into which this
>> +information is saved, see @code{-display_hflip}, @code{-display_vflip}.
>> +
>> +These options work as a unit, so if only one of them is set, then the display
>> +matrix will be overridden to that specific value with the rest being set to
>> +default values.
>> +
>> +If unset, the default value if a display matrix is being defined is a rotation
>> +of zero degrees.
>> +
>> + at item -display_hflip[:@var{stream_specifier}] (@emph{input,per-stream})
>> +Set whether on display the image should be horizontally flipped.
>> +
>> +If unset, the default value if a display matrix is being defined is that there
>> +is no additional horizontal flip. See @code{-display_rotation}.
>> +
>> + at item -display_vflip[:@var{stream_specifier}] (@emph{input,per-stream})
>> +Set whether on display the image should be vertically flipped.
>> +
>> +If unset, the default value if a display matrix is being defined is that there
>> +is no additional vertical flip. See @code{-display_rotation}.
> 
> @item -display_rotation[:@var{stream_specifier}] @var{rotation} (@emph{input,per-stream})
> Set video rotation metadata.
> 
> @var{rotation} is a decimal number specifying the amount in degree by
> which the video should be rotated counter-clockwise before being
> displayed.
> 
> This option overrides the rotation/display transform metadata stored in
> the file, if any. When the video is being transcoded (rather than
> copied) and @code{-autorotate} is enabled, the video will be rotated at
> the filtering stage. Otherwise, the metadata will be written into the
> output file if the muxer supports it.
> 
> If the @code{-display_hflip} and/or @code{-display_vflip} options are
> given, they are applied after the rotation specified by this option.
> 
> @item -display_hflip[:@var{stream_specifier}] (@emph{input,per-stream})
> Set whether on display the image should be horizontally flipped.
> 
> See the @code{-display_rotation} option for more details.
> 
> @item -display_vflip[:@var{stream_specifier}] (@emph{input,per-stream})
> Set whether on display the image should be vertically flipped.
> 
> See the @code{-display_rotation} option for more details.
> 
>> +static void add_display_matrix_to_stream(OptionsContext *o,
>> +                                         AVFormatContext *ctx, AVStream *st)
>> +{
>> +    double rotation = DBL_MAX;
>> +    int hflip = -1, vflip = -1;
>> +    int hflip_set = 0, vflip_set = 0, rotation_set = 0;
>> +    uint8_t *buf = NULL;
> 
> should be int32_t*

av_stream_new_side_data() returns uint8_t*.

So it is either add a cast to if(...) or two casts to av_display_...().

All else in v7.

Thanks,
Thilo