/*
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include "libavutil/avstring.h"

 #include "libavutil/display.h"

 #include "libavutil/common.h"
 #include "libavutil/opt.h"
 
 #include "bsf.h"
 #include "cbs.h"
 #include "cbs_h264.h"
 #include "h264.h"
 #include "h264_sei.h"
 
 enum {
     PASS,
     INSERT,
     REMOVE,

     EXTRACT,
 };
 
 enum {
     FLIP_HORIZONTAL = 1,
     FLIP_VERTICAL   = 2,

 };
 
 typedef struct H264MetadataContext {
     const AVClass *class;
 
     CodedBitstreamContext *cbc;
     CodedBitstreamFragment access_unit;
 

     int done_first_au;
 

     int aud;
 
     AVRational sample_aspect_ratio;
 
     int video_format;
     int video_full_range_flag;
     int colour_primaries;
     int transfer_characteristics;
     int matrix_coefficients;
 
     int chroma_sample_loc_type;
 
     AVRational tick_rate;
     int fixed_frame_rate_flag;
 
     int crop_left;
     int crop_right;
     int crop_top;
     int crop_bottom;
 
     const char *sei_user_data;

 
     int delete_filler;

 
     int display_orientation;
     double rotate;
     int flip;

 } H264MetadataContext;
 
 
 static int h264_metadata_update_sps(AVBSFContext *bsf,
                                     H264RawSPS *sps)
 {
     H264MetadataContext *ctx = bsf->priv_data;
     int need_vui = 0;
     int crop_unit_x, crop_unit_y;
 
     if (ctx->sample_aspect_ratio.num && ctx->sample_aspect_ratio.den) {
         // Table E-1.
         static const AVRational sar_idc[] = {
             {   0,  0 }, // Unspecified (never written here).
             {   1,  1 }, {  12, 11 }, {  10, 11 }, {  16, 11 },
             {  40, 33 }, {  24, 11 }, {  20, 11 }, {  32, 11 },
             {  80, 33 }, {  18, 11 }, {  15, 11 }, {  64, 33 },
             { 160, 99 }, {   4,  3 }, {   3,  2 }, {   2,  1 },
         };
         int num, den, i;
 
         av_reduce(&num, &den, ctx->sample_aspect_ratio.num,
                   ctx->sample_aspect_ratio.den, 65535);
 
         for (i = 1; i < FF_ARRAY_ELEMS(sar_idc); i++) {
             if (num == sar_idc[i].num &&
                 den == sar_idc[i].den)
                 break;
         }
         if (i == FF_ARRAY_ELEMS(sar_idc)) {
             sps->vui.aspect_ratio_idc = 255;
             sps->vui.sar_width  = num;
             sps->vui.sar_height = den;
         } else {
             sps->vui.aspect_ratio_idc = i;
         }
         sps->vui.aspect_ratio_info_present_flag = 1;
         need_vui = 1;
     }
 
 #define SET_OR_INFER(field, value, present_flag, infer) do { \
         if (value >= 0) { \
             field = value; \
             need_vui = 1; \
         } else if (!present_flag) \
             field = infer; \
     } while (0)
 
     if (ctx->video_format             >= 0 ||
         ctx->video_full_range_flag    >= 0 ||
         ctx->colour_primaries         >= 0 ||
         ctx->transfer_characteristics >= 0 ||
         ctx->matrix_coefficients      >= 0) {
 
         SET_OR_INFER(sps->vui.video_format, ctx->video_format,
                      sps->vui.video_signal_type_present_flag, 5);
 
         SET_OR_INFER(sps->vui.video_full_range_flag,
                      ctx->video_full_range_flag,
                      sps->vui.video_signal_type_present_flag, 0);
 
         if (ctx->colour_primaries         >= 0 ||
             ctx->transfer_characteristics >= 0 ||
             ctx->matrix_coefficients      >= 0) {
 
             SET_OR_INFER(sps->vui.colour_primaries,
                          ctx->colour_primaries,
                          sps->vui.colour_description_present_flag, 2);
 
             SET_OR_INFER(sps->vui.transfer_characteristics,
                          ctx->transfer_characteristics,
                          sps->vui.colour_description_present_flag, 2);
 
             SET_OR_INFER(sps->vui.matrix_coefficients,
                          ctx->matrix_coefficients,
                          sps->vui.colour_description_present_flag, 2);
 
             sps->vui.colour_description_present_flag = 1;
         }
         sps->vui.video_signal_type_present_flag = 1;
         need_vui = 1;
     }
 
     if (ctx->chroma_sample_loc_type >= 0) {
         sps->vui.chroma_sample_loc_type_top_field =
             ctx->chroma_sample_loc_type;
         sps->vui.chroma_sample_loc_type_bottom_field =
             ctx->chroma_sample_loc_type;
         sps->vui.chroma_loc_info_present_flag = 1;
         need_vui = 1;
     }
 
     if (ctx->tick_rate.num && ctx->tick_rate.den) {
         int num, den;
 
         av_reduce(&num, &den, ctx->tick_rate.num, ctx->tick_rate.den,
                   UINT32_MAX > INT_MAX ? UINT32_MAX : INT_MAX);
 
         sps->vui.time_scale        = num;
         sps->vui.num_units_in_tick = den;
 
         sps->vui.timing_info_present_flag = 1;
         need_vui = 1;
     }
     SET_OR_INFER(sps->vui.fixed_frame_rate_flag,
                  ctx->fixed_frame_rate_flag,
                  sps->vui.timing_info_present_flag, 0);
 
     if (sps->separate_colour_plane_flag || sps->chroma_format_idc == 0) {
         crop_unit_x = 1;
         crop_unit_y = 2 - sps->frame_mbs_only_flag;
     } else {
         crop_unit_x = 1 + (sps->chroma_format_idc < 3);
         crop_unit_y = (1 + (sps->chroma_format_idc < 2)) *
                        (2 - sps->frame_mbs_only_flag);
     }
 #define CROP(border, unit) do { \
         if (ctx->crop_ ## border >= 0) { \
             if (ctx->crop_ ## border % unit != 0) { \
                 av_log(bsf, AV_LOG_ERROR, "Invalid value for crop_%s: " \
                        "must be a multiple of %d.\n", #border, unit); \
                 return AVERROR(EINVAL); \
             } \
             sps->frame_crop_ ## border ## _offset = \
                   ctx->crop_ ## border / unit; \
             sps->frame_cropping_flag = 1; \
         } \
     } while (0)
     CROP(left,   crop_unit_x);
     CROP(right,  crop_unit_x);
     CROP(top,    crop_unit_y);
     CROP(bottom, crop_unit_y);
 #undef CROP
 
     if (need_vui)
         sps->vui_parameters_present_flag = 1;
 
     return 0;
 }
 
 static int h264_metadata_filter(AVBSFContext *bsf, AVPacket *out)
 {
     H264MetadataContext *ctx = bsf->priv_data;
     AVPacket *in = NULL;
     CodedBitstreamFragment *au = &ctx->access_unit;
     int err, i, j, has_sps;

     uint8_t *displaymatrix_side_data = NULL;
     size_t displaymatrix_side_data_size = 0;

 
     err = ff_bsf_get_packet(bsf, &in);
     if (err < 0)

         return err;

 
     err = ff_cbs_read_packet(ctx->cbc, au, in);
     if (err < 0) {
         av_log(bsf, AV_LOG_ERROR, "Failed to read packet.\n");
         goto fail;
     }
 
     if (au->nb_units == 0) {
         av_log(bsf, AV_LOG_ERROR, "No NAL units in packet.\n");
         err = AVERROR_INVALIDDATA;
         goto fail;
     }
 
     // If an AUD is present, it must be the first NAL unit.
     if (au->units[0].type == H264_NAL_AUD) {
         if (ctx->aud == REMOVE)
             ff_cbs_delete_unit(ctx->cbc, au, 0);
     } else {
         if (ctx->aud == INSERT) {
             static const int primary_pic_type_table[] = {
                 0x084, // 2, 7
                 0x0a5, // 0, 2, 5, 7
                 0x0e7, // 0, 1, 2, 5, 6, 7
                 0x210, // 4, 9
                 0x318, // 3, 4, 8, 9
                 0x294, // 2, 4, 7, 9
                 0x3bd, // 0, 2, 3, 4, 5, 7, 8, 9
                 0x3ff, // 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
             };
             int primary_pic_type_mask = 0xff;

             H264RawAUD aud = {
                 .nal_unit_header.nal_unit_type = H264_NAL_AUD,
             };

 
             for (i = 0; i < au->nb_units; i++) {
                 if (au->units[i].type == H264_NAL_SLICE ||
                     au->units[i].type == H264_NAL_IDR_SLICE) {
                     H264RawSlice *slice = au->units[i].content;
                     for (j = 0; j < FF_ARRAY_ELEMS(primary_pic_type_table); j++) {
                          if (!(primary_pic_type_table[j] &
                                (1 << slice->header.slice_type)))
                              primary_pic_type_mask &= ~(1 << j);
                     }
                 }
             }
             for (j = 0; j < FF_ARRAY_ELEMS(primary_pic_type_table); j++)
                 if (primary_pic_type_mask & (1 << j))
                     break;
             if (j >= FF_ARRAY_ELEMS(primary_pic_type_table)) {
                 av_log(bsf, AV_LOG_ERROR, "No usable primary_pic_type: "
                        "invalid slice types?\n");
                 err = AVERROR_INVALIDDATA;
                 goto fail;
             }
 

             aud.primary_pic_type = j;

 
             err = ff_cbs_insert_unit_content(ctx->cbc, au,

                                              0, H264_NAL_AUD, &aud, NULL);

             if (err < 0) {
                 av_log(bsf, AV_LOG_ERROR, "Failed to insert AUD.\n");
                 goto fail;
             }
         }
     }
 
     has_sps = 0;
     for (i = 0; i < au->nb_units; i++) {
         if (au->units[i].type == H264_NAL_SPS) {
             err = h264_metadata_update_sps(bsf, au->units[i].content);
             if (err < 0)
                 goto fail;
             has_sps = 1;
         }
     }
 

     // Only insert the SEI in access units containing SPSs, and also

     // unconditionally in the first access unit we ever see.

     if (ctx->sei_user_data && (has_sps || !ctx->done_first_au)) {

         H264RawSEIPayload payload = {
             .payload_type = H264_SEI_TYPE_USER_DATA_UNREGISTERED,
         };
         H264RawSEIUserDataUnregistered *udu =
             &payload.payload.user_data_unregistered;

 
         for (i = j = 0; j < 32 && ctx->sei_user_data[i]; i++) {
             int c, v;
             c = ctx->sei_user_data[i];
             if (c == '-') {
                 continue;
             } else if (av_isxdigit(c)) {
                 c = av_tolower(c);
                 v = (c <= '9' ? c - '0' : c - 'a' + 10);
             } else {
                 goto invalid_user_data;
             }
             if (i & 1)
                 udu->uuid_iso_iec_11578[j / 2] |= v;
             else
                 udu->uuid_iso_iec_11578[j / 2] = v << 4;
             ++j;
         }
         if (j == 32 && ctx->sei_user_data[i] == '+') {

             size_t len = strlen(ctx->sei_user_data + i + 1);
 
             udu->data_ref = av_buffer_alloc(len + 1);
             if (!udu->data_ref) {

                 err = AVERROR(ENOMEM);

                 goto fail;

             }
 

             udu->data        = udu->data_ref->data;
             udu->data_length = len + 1;
             memcpy(udu->data, ctx->sei_user_data + i + 1, len + 1);

             payload.payload_size = 16 + udu->data_length;

             err = ff_cbs_h264_add_sei_message(ctx->cbc, au, &payload);
             if (err < 0) {
                 av_log(bsf, AV_LOG_ERROR, "Failed to add user data SEI "
                        "message to access unit.\n");
                 goto fail;

             }
 
         } else {
         invalid_user_data:
             av_log(bsf, AV_LOG_ERROR, "Invalid user data: "
                    "must be \"UUID+string\".\n");
             err = AVERROR(EINVAL);

             goto fail;

         }
     }
 

     if (ctx->delete_filler) {
         for (i = 0; i < au->nb_units; i++) {
             if (au->units[i].type == H264_NAL_FILLER_DATA) {
                 // Filler NAL units.
                 err = ff_cbs_delete_unit(ctx->cbc, au, i);
                 if (err < 0) {
                     av_log(bsf, AV_LOG_ERROR, "Failed to delete "
                            "filler NAL.\n");
                     goto fail;
                 }
                 --i;
                 continue;
             }
 
             if (au->units[i].type == H264_NAL_SEI) {
                 // Filler SEI messages.
                 H264RawSEI *sei = au->units[i].content;
 
                 for (j = 0; j < sei->payload_count; j++) {
                     if (sei->payload[j].payload_type ==
                         H264_SEI_TYPE_FILLER_PAYLOAD) {
                         err = ff_cbs_h264_delete_sei_message(ctx->cbc, au,
                                                              &au->units[i], j);
                         if (err < 0) {
                             av_log(bsf, AV_LOG_ERROR, "Failed to delete "
                                    "filler SEI message.\n");
                             goto fail;
                         }
                         // Renumbering might have happened, start again at
                         // the same NAL unit position.
                         --i;
                         break;
                     }
                 }
             }
         }
     }
 

     if (ctx->display_orientation != PASS) {
         for (i = 0; i < au->nb_units; i++) {
             H264RawSEI *sei;
             if (au->units[i].type != H264_NAL_SEI)
                 continue;
             sei = au->units[i].content;
 
             for (j = 0; j < sei->payload_count; j++) {
                 H264RawSEIDisplayOrientation *disp;
                 int32_t *matrix;
 
                 if (sei->payload[j].payload_type !=
                     H264_SEI_TYPE_DISPLAY_ORIENTATION)
                     continue;
                 disp = &sei->payload[j].payload.display_orientation;
 
                 if (ctx->display_orientation == REMOVE ||
                     ctx->display_orientation == INSERT) {
                     err = ff_cbs_h264_delete_sei_message(ctx->cbc, au,
                                                          &au->units[i], j);
                     if (err < 0) {
                         av_log(bsf, AV_LOG_ERROR, "Failed to delete "
                                "display orientation SEI message.\n");
                         goto fail;
                     }
                     --i;
                     break;
                 }
 
                 matrix = av_mallocz(9 * sizeof(int32_t));
                 if (!matrix) {
                     err = AVERROR(ENOMEM);
                     goto fail;
                 }
 
                 av_display_rotation_set(matrix,
                                         disp->anticlockwise_rotation *
                                         180.0 / 65536.0);
                 av_display_matrix_flip(matrix, disp->hor_flip, disp->ver_flip);
 

                 // If there are multiple display orientation messages in an
                 // access unit then ignore all but the last one.
                 av_freep(&displaymatrix_side_data);
 

                 displaymatrix_side_data      = (uint8_t*)matrix;
                 displaymatrix_side_data_size = 9 * sizeof(int32_t);
             }
         }
     }
     if (ctx->display_orientation == INSERT) {
         H264RawSEIPayload payload = {
             .payload_type = H264_SEI_TYPE_DISPLAY_ORIENTATION,
         };
         H264RawSEIDisplayOrientation *disp =
             &payload.payload.display_orientation;
         uint8_t *data;
         int size;
         int write = 0;
 
         data = av_packet_get_side_data(in, AV_PKT_DATA_DISPLAYMATRIX, &size);
         if (data && size >= 9 * sizeof(int32_t)) {
             int32_t matrix[9];
             int hflip, vflip;
             double angle;
 
             memcpy(matrix, data, sizeof(matrix));
 
             hflip = vflip = 0;
             if (matrix[0] < 0 && matrix[4] > 0)
                 hflip = 1;
             else if (matrix[0] > 0 && matrix[4] < 0)
                 vflip = 1;
             av_display_matrix_flip(matrix, hflip, vflip);
 
             angle = av_display_rotation_get(matrix);
 
             if (!(angle >= -180.0 && angle <= 180.0 /* also excludes NaN */) ||
                 matrix[2] != 0 || matrix[5] != 0 ||
                 matrix[6] != 0 || matrix[7] != 0) {
                 av_log(bsf, AV_LOG_WARNING, "Input display matrix is not "
                        "representable in H.264 parameters.\n");
             } else {
                 disp->hor_flip = hflip;
                 disp->ver_flip = vflip;
                 disp->anticlockwise_rotation =
                     (uint16_t)rint((angle >= 0.0 ? angle
                                                  : angle + 360.0) *
                                    65536.0 / 360.0);
                 write = 1;
             }
         }
 
         if (has_sps || !ctx->done_first_au) {
             if (!isnan(ctx->rotate)) {
                 disp->anticlockwise_rotation =
                     (uint16_t)rint((ctx->rotate >= 0.0 ? ctx->rotate
                                                        : ctx->rotate + 360.0) *
                                    65536.0 / 360.0);
                 write = 1;
             }
             if (ctx->flip) {
                 disp->hor_flip = !!(ctx->flip & FLIP_HORIZONTAL);
                 disp->ver_flip = !!(ctx->flip & FLIP_VERTICAL);
                 write = 1;
             }
         }
 
         if (write) {
             disp->display_orientation_repetition_period = 1;
 
             err = ff_cbs_h264_add_sei_message(ctx->cbc, au, &payload);
             if (err < 0) {
                 av_log(bsf, AV_LOG_ERROR, "Failed to add display orientation "
                        "SEI message to access unit.\n");
                 goto fail;
             }
         }
     }
 

     err = ff_cbs_write_packet(ctx->cbc, out, au);
     if (err < 0) {
         av_log(bsf, AV_LOG_ERROR, "Failed to write packet.\n");
         goto fail;
     }
 
     err = av_packet_copy_props(out, in);
     if (err < 0)
         goto fail;
 

     if (displaymatrix_side_data) {
         err = av_packet_add_side_data(out, AV_PKT_DATA_DISPLAYMATRIX,
                                       displaymatrix_side_data,
                                       displaymatrix_side_data_size);
         if (err) {
             av_log(bsf, AV_LOG_ERROR, "Failed to attach extracted "
                    "displaymatrix side data to packet.\n");
             goto fail;
         }
         displaymatrix_side_data = NULL;
     }
 
     ctx->done_first_au = 1;
 

     err = 0;
 fail:
     ff_cbs_fragment_uninit(ctx->cbc, au);

     av_freep(&displaymatrix_side_data);

     if (err < 0)
         av_packet_unref(out);

     av_packet_free(&in);
 
     return err;
 }
 
 static int h264_metadata_init(AVBSFContext *bsf)
 {
     H264MetadataContext *ctx = bsf->priv_data;
     CodedBitstreamFragment *au = &ctx->access_unit;
     int err, i;
 
     err = ff_cbs_init(&ctx->cbc, AV_CODEC_ID_H264, bsf);
     if (err < 0)
         return err;
 
     if (bsf->par_in->extradata) {
         err = ff_cbs_read_extradata(ctx->cbc, au, bsf->par_in);
         if (err < 0) {
             av_log(bsf, AV_LOG_ERROR, "Failed to read extradata.\n");
             goto fail;
         }
 
         for (i = 0; i < au->nb_units; i++) {
             if (au->units[i].type == H264_NAL_SPS) {
                 err = h264_metadata_update_sps(bsf, au->units[i].content);
                 if (err < 0)
                     goto fail;
             }
         }
 
         err = ff_cbs_write_extradata(ctx->cbc, bsf->par_out, au);
         if (err < 0) {
             av_log(bsf, AV_LOG_ERROR, "Failed to write extradata.\n");
             goto fail;
         }
     }
 
     err = 0;
 fail:
     ff_cbs_fragment_uninit(ctx->cbc, au);
     return err;
 }
 
 static void h264_metadata_close(AVBSFContext *bsf)
 {
     H264MetadataContext *ctx = bsf->priv_data;
     ff_cbs_close(&ctx->cbc);
 }
 
 #define OFFSET(x) offsetof(H264MetadataContext, x)

 #define FLAGS (AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_BSF_PARAM)

 static const AVOption h264_metadata_options[] = {
     { "aud", "Access Unit Delimiter NAL units",
         OFFSET(aud), AV_OPT_TYPE_INT,

         { .i64 = PASS }, PASS, REMOVE, FLAGS, "aud" },
     { "pass",   NULL, 0, AV_OPT_TYPE_CONST,
         { .i64 = PASS   }, .flags = FLAGS, .unit = "aud" },
     { "insert", NULL, 0, AV_OPT_TYPE_CONST,
         { .i64 = INSERT }, .flags = FLAGS, .unit = "aud" },
     { "remove", NULL, 0, AV_OPT_TYPE_CONST,
         { .i64 = REMOVE }, .flags = FLAGS, .unit = "aud" },

 
     { "sample_aspect_ratio", "Set sample aspect ratio (table E-1)",
         OFFSET(sample_aspect_ratio), AV_OPT_TYPE_RATIONAL,

         { .dbl = 0.0 }, 0, 65535, FLAGS },

 
     { "video_format", "Set video format (table E-2)",
         OFFSET(video_format), AV_OPT_TYPE_INT,

         { .i64 = -1 }, -1, 7, FLAGS},

     { "video_full_range_flag", "Set video full range flag",
         OFFSET(video_full_range_flag), AV_OPT_TYPE_INT,

         { .i64 = -1 }, -1, 1, FLAGS },

     { "colour_primaries", "Set colour primaries (table E-3)",
         OFFSET(colour_primaries), AV_OPT_TYPE_INT,

         { .i64 = -1 }, -1, 255, FLAGS },

     { "transfer_characteristics", "Set transfer characteristics (table E-4)",
         OFFSET(transfer_characteristics), AV_OPT_TYPE_INT,

         { .i64 = -1 }, -1, 255, FLAGS },

     { "matrix_coefficients", "Set matrix coefficients (table E-5)",
         OFFSET(matrix_coefficients), AV_OPT_TYPE_INT,

         { .i64 = -1 }, -1, 255, FLAGS },

 
     { "chroma_sample_loc_type", "Set chroma sample location type (figure E-1)",
         OFFSET(chroma_sample_loc_type), AV_OPT_TYPE_INT,

         { .i64 = -1 }, -1, 6, FLAGS },

 
     { "tick_rate", "Set VUI tick rate (num_units_in_tick / time_scale)",
         OFFSET(tick_rate), AV_OPT_TYPE_RATIONAL,

         { .dbl = 0.0 }, 0, UINT_MAX, FLAGS },

     { "fixed_frame_rate_flag", "Set VUI fixed frame rate flag",
         OFFSET(fixed_frame_rate_flag), AV_OPT_TYPE_INT,

         { .i64 = -1 }, -1, 1, FLAGS },

 
     { "crop_left", "Set left border crop offset",
         OFFSET(crop_left), AV_OPT_TYPE_INT,

         { .i64 = -1 }, -1, H264_MAX_WIDTH, FLAGS },

     { "crop_right", "Set right border crop offset",
         OFFSET(crop_right), AV_OPT_TYPE_INT,

         { .i64 = -1 }, -1, H264_MAX_WIDTH, FLAGS },

     { "crop_top", "Set top border crop offset",
         OFFSET(crop_top), AV_OPT_TYPE_INT,

         { .i64 = -1 }, -1, H264_MAX_HEIGHT, FLAGS },

     { "crop_bottom", "Set bottom border crop offset",
         OFFSET(crop_bottom), AV_OPT_TYPE_INT,

         { .i64 = -1 }, -1, H264_MAX_HEIGHT, FLAGS },

 
     { "sei_user_data", "Insert SEI user data (UUID+string)",

         OFFSET(sei_user_data), AV_OPT_TYPE_STRING, { .str = NULL }, .flags = FLAGS },

     { "delete_filler", "Delete all filler (both NAL and SEI)",

         OFFSET(delete_filler), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, FLAGS},

     { "display_orientation", "Display orientation SEI",
         OFFSET(display_orientation), AV_OPT_TYPE_INT,

         { .i64 = PASS }, PASS, EXTRACT, FLAGS, "disp_or" },
     { "pass",    NULL, 0, AV_OPT_TYPE_CONST,
         { .i64 = PASS    }, .flags = FLAGS, .unit = "disp_or" },
     { "insert",  NULL, 0, AV_OPT_TYPE_CONST,
         { .i64 = INSERT  }, .flags = FLAGS, .unit = "disp_or" },
     { "remove",  NULL, 0, AV_OPT_TYPE_CONST,
         { .i64 = REMOVE  }, .flags = FLAGS, .unit = "disp_or" },
     { "extract", NULL, 0, AV_OPT_TYPE_CONST,
         { .i64 = EXTRACT }, .flags = FLAGS, .unit = "disp_or" },

 
     { "rotate", "Set rotation in display orientation SEI (anticlockwise angle in degrees)",
         OFFSET(rotate), AV_OPT_TYPE_DOUBLE,

         { .dbl = NAN }, -360.0, +360.0, FLAGS },

     { "flip", "Set flip in display orientation SEI",
         OFFSET(flip), AV_OPT_TYPE_FLAGS,

         { .i64 = 0 }, 0, FLIP_HORIZONTAL | FLIP_VERTICAL, FLAGS, "flip" },

     { "horizontal", "Set hor_flip",

         0, AV_OPT_TYPE_CONST,
         { .i64 = FLIP_HORIZONTAL }, .flags = FLAGS, .unit = "flip" },

     { "vertical",   "Set ver_flip",

         0, AV_OPT_TYPE_CONST,
         { .i64 = FLIP_VERTICAL },   .flags = FLAGS, .unit = "flip" },

     { NULL }
 };
 
 static const AVClass h264_metadata_class = {
     .class_name = "h264_metadata_bsf",
     .item_name  = av_default_item_name,
     .option     = h264_metadata_options,

     .version    = LIBAVUTIL_VERSION_INT,

 };
 
 static const enum AVCodecID h264_metadata_codec_ids[] = {
     AV_CODEC_ID_H264, AV_CODEC_ID_NONE,
 };
 
 const AVBitStreamFilter ff_h264_metadata_bsf = {
     .name           = "h264_metadata",
     .priv_data_size = sizeof(H264MetadataContext),
     .priv_class     = &h264_metadata_class,
     .init           = &h264_metadata_init,
     .close          = &h264_metadata_close,
     .filter         = &h264_metadata_filter,
     .codec_ids      = h264_metadata_codec_ids,
 };