[FFmpeg-trac] #8329(ffmpeg:new): Rotation metadata not overridden when the input video has rotation metadata set to 180

[FFmpeg]

#8329: Rotation metadata not overridden when the input video has rotation metadata
set to 180
-----------------------------------+----------------------------------
             Reporter:  hungryTux  |                    Owner:
                 Type:  defect     |                   Status:  new
             Priority:  important  |                Component:  ffmpeg
              Version:  4.2        |               Resolution:
             Keywords:             |               Blocked By:
             Blocking:             |  Reproduced by developer:  0
Analyzed by developer:  0          |
-----------------------------------+----------------------------------
Changes (by d3im):

 * priority:  normal => important
 * version:  unspecified => 4.2


Comment:

 The problem code is here: (in ffmpeg.c)
 It only solves rotation when autorotate is set (its easy - autorotate
 rotates to correct rotation and sets rotate metadata to 0 deg.).
 {{{
 /*
          * Add global input side data. For now this is naive, and copies
 it
          * from the input stream's global side data. All side data should
          * really be funneled over AVFrame and libavfilter, then added
 back to
          * packet side data, and then potentially using the first packet
 for
          * global side data.
          */
         if (ist) {
             int i;
             for (i = 0; i < ist->st->nb_side_data; i++) {
                 AVPacketSideData *sd = &ist->st->side_data[i];
                 uint8_t *dst = av_stream_new_side_data(ost->st, sd->type,
 sd->size);
                 if (!dst)
                     return AVERROR(ENOMEM);
                 memcpy(dst, sd->data, sd->size);

                 if (ist->autorotate && sd->type ==
 AV_PKT_DATA_DISPLAYMATRIX)
                     av_display_rotation_set((uint32_t *)dst, 0);
             }
         }
 }}}
 This helps a little:
 Set rotation to 0 autorotate and manual also.
 {{{
         if (ist) {
             int i;
             for (i = 0; i < ist->st->nb_side_data; i++) {
                 AVPacketSideData *sd = &ist->st->side_data[i];
                 uint8_t *dst = av_stream_new_side_data(ost->st, sd->type,
 sd->size);
                 if (!dst)
                     return AVERROR(ENOMEM);

                 if (sd->type == AV_PKT_DATA_DISPLAYMATRIX) {
                         av_display_rotation_set((uint32_t *)dst, 0);
                 } else {
                         memcpy(dst, sd->data, sd->size);
                 }
             }
         }
 }}}
 Anyway the original code should be corrected not to copy all side data.
 This is just a quick fix not for all situations.

--
Ticket URL: <https://trac.ffmpeg.org/ticket/8329#comment:6>
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