Merge commit '728d90a0c1973661a9e73da697bf4f90c9d19577'

* commit '728d90a0c1973661a9e73da697bf4f90c9d19577':
  h264: decouple h264_sei from the h264 decoder

Main changes:

- SEI decoding doesn't have access to the debug flag in the codec context so a
  few logging are dropped.

- naming of quincunx_sampling_flag and frame_packing_arrangement_type are kept
  as they are in FFmpeg instead of respectively quincunx_subsampling and
  arrangement_type used in Libav because the former match the specifications.

- don't reset the x264 build info once read in order to fix
  fate-h264-lossless (change by Hendrik)

- H264Context.has_recovery_point and deprecated
  AVCodecContext.dtg_active_format are set after ff_h264_sei_decode()
  based on the SEI state since ff_h264_sei_decode() doesn't have access
  to H264Context anymore.

- frame_packing_arrangement_type is not checked against <= 0 in
  decode_postinit() since it is always read as a positive value with
  get_bits(). This fixes a -Wtype-limits warning by GCC spotted by
  Michael.

Side Notes:

- tested that ffprobe on the file from ticket #3652 still returns 4
  keyframes
- tested that playback from ticket #3063 still works

Merged-by: Clément Bœsch <clement@stupeflix.com>
Signed-off-by: Hendrik Leppkes <h.leppkes@gmail.com>

8 files changed, 407 insertions, 387 deletions

diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index 795e5999cf..831d91880e 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -430,17 +430,17 @@ static int h264_init_context(AVCodecContext *avctx, H264Context *h)
     h->workaround_bugs       = avctx->workaround_bugs;
     h->flags                 = avctx->flags;
     h->poc.prev_poc_msb      = 1 << 16;
-    h->x264_build            = -1;
     h->recovery_frame        = -1;
     h->frame_recovered       = 0;
     h->poc.prev_frame_num    = -1;
-    h->sei_fpa.frame_packing_arrangement_cancel_flag = -1;
+    h->sei.frame_packing.frame_packing_arrangement_cancel_flag = -1;
+    h->sei.unregistered.x264_build = -1;
 
     h->next_outputed_poc = INT_MIN;
     for (i = 0; i < MAX_DELAYED_PIC_COUNT; i++)
         h->last_pocs[i] = INT_MIN;
 
-    ff_h264_reset_sei(h);
+    ff_h264_sei_uninit(&h->sei);
 
     avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
 
@@ -594,7 +594,8 @@ static void decode_postinit(H264Context *h, int setup_finished)
      * decoding process if it exists. */
 
     if (sps->pic_struct_present_flag) {
-        switch (h->sei_pic_struct) {
+        H264SEIPictureTiming *pt = &h->sei.picture_timing;
+        switch (pt->pic_struct) {
         case SEI_PIC_STRUCT_FRAME:
             break;
         case SEI_PIC_STRUCT_TOP_FIELD:
@@ -624,9 +625,9 @@ static void decode_postinit(H264Context *h, int setup_finished)
             break;
         }
 
-        if ((h->sei_ct_type & 3) &&
-            h->sei_pic_struct <= SEI_PIC_STRUCT_BOTTOM_TOP)
-            cur->f->interlaced_frame = (h->sei_ct_type & (1 << 1)) != 0;
+        if ((pt->ct_type & 3) &&
+            pt->pic_struct <= SEI_PIC_STRUCT_BOTTOM_TOP)
+            cur->f->interlaced_frame = (pt->ct_type & (1 << 1)) != 0;
     } else {
         /* Derive interlacing flag from used decoding process. */
         cur->f->interlaced_frame = FIELD_OR_MBAFF_PICTURE(h);
@@ -640,8 +641,8 @@ static void decode_postinit(H264Context *h, int setup_finished)
         if (sps->pic_struct_present_flag) {
             /* Use picture timing SEI information. Even if it is a
              * information of a past frame, better than nothing. */
-            if (h->sei_pic_struct == SEI_PIC_STRUCT_TOP_BOTTOM ||
-                h->sei_pic_struct == SEI_PIC_STRUCT_TOP_BOTTOM_TOP)
+            if (h->sei.picture_timing.pic_struct == SEI_PIC_STRUCT_TOP_BOTTOM ||
+                h->sei.picture_timing.pic_struct == SEI_PIC_STRUCT_TOP_BOTTOM_TOP)
                 cur->f->top_field_first = 1;
             else
                 cur->f->top_field_first = 0;
@@ -655,14 +656,14 @@ static void decode_postinit(H264Context *h, int setup_finished)
         }
     }
 
-    if (h->sei_frame_packing_present &&
-        h->frame_packing_arrangement_type >= 0 &&
-        h->frame_packing_arrangement_type <= 6 &&
-        h->content_interpretation_type > 0 &&
-        h->content_interpretation_type < 3) {
+    if (h->sei.frame_packing.present &&
+        h->sei.frame_packing.frame_packing_arrangement_type <= 6 &&
+        h->sei.frame_packing.content_interpretation_type > 0 &&
+        h->sei.frame_packing.content_interpretation_type < 3) {
+        H264SEIFramePacking *fp = &h->sei.frame_packing;
         AVStereo3D *stereo = av_stereo3d_create_side_data(cur->f);
         if (stereo) {
-        switch (h->frame_packing_arrangement_type) {
+        switch (fp->frame_packing_arrangement_type) {
         case 0:
             stereo->type = AV_STEREO3D_CHECKERBOARD;
             break;
@@ -673,7 +674,7 @@ static void decode_postinit(H264Context *h, int setup_finished)
             stereo->type = AV_STEREO3D_LINES;
             break;
         case 3:
-            if (h->quincunx_subsampling)
+            if (fp->quincunx_sampling_flag)
                 stereo->type = AV_STEREO3D_SIDEBYSIDE_QUINCUNX;
             else
                 stereo->type = AV_STEREO3D_SIDEBYSIDE;
@@ -689,42 +690,46 @@ static void decode_postinit(H264Context *h, int setup_finished)
             break;
         }
 
-        if (h->content_interpretation_type == 2)
+        if (fp->content_interpretation_type == 2)
             stereo->flags = AV_STEREO3D_FLAG_INVERT;
         }
     }
 
-    if (h->sei_display_orientation_present &&
-        (h->sei_anticlockwise_rotation || h->sei_hflip || h->sei_vflip)) {
-        double angle = h->sei_anticlockwise_rotation * 360 / (double) (1 << 16);
+    if (h->sei.display_orientation.present &&
+        (h->sei.display_orientation.anticlockwise_rotation ||
+         h->sei.display_orientation.hflip ||
+         h->sei.display_orientation.vflip)) {
+        H264SEIDisplayOrientation *o = &h->sei.display_orientation;
+        double angle = o->anticlockwise_rotation * 360 / (double) (1 << 16);
         AVFrameSideData *rotation = av_frame_new_side_data(cur->f,
                                                            AV_FRAME_DATA_DISPLAYMATRIX,
                                                            sizeof(int32_t) * 9);
         if (rotation) {
             av_display_rotation_set((int32_t *)rotation->data, angle);
             av_display_matrix_flip((int32_t *)rotation->data,
-                                   h->sei_hflip, h->sei_vflip);
+                                   o->hflip, o->vflip);
         }
     }
 
-    if (h->sei_reguserdata_afd_present) {
+    if (h->sei.afd.present) {
         AVFrameSideData *sd = av_frame_new_side_data(cur->f, AV_FRAME_DATA_AFD,
                                                      sizeof(uint8_t));
 
         if (sd) {
-            *sd->data = h->active_format_description;
-            h->sei_reguserdata_afd_present = 0;
+            *sd->data = h->sei.afd.active_format_description;
+            h->sei.afd.present = 0;
         }
     }
 
-    if (h->a53_caption) {
+    if (h->sei.a53_caption.a53_caption) {
+        H264SEIA53Caption *a53 = &h->sei.a53_caption;
         AVFrameSideData *sd = av_frame_new_side_data(cur->f,
                                                      AV_FRAME_DATA_A53_CC,
-                                                     h->a53_caption_size);
+                                                     a53->a53_caption_size);
         if (sd)
-            memcpy(sd->data, h->a53_caption, h->a53_caption_size);
-        av_freep(&h->a53_caption);
-        h->a53_caption_size = 0;
+            memcpy(sd->data, a53->a53_caption, a53->a53_caption_size);
+        av_freep(&a53->a53_caption);
+        a53->a53_caption_size = 0;
         h->avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;
     }
 
@@ -859,7 +864,7 @@ void ff_h264_flush_change(H264Context *h)
     ff_h264_unref_picture(h, &h->last_pic_for_ec);
 
     h->first_field = 0;
-    ff_h264_reset_sei(h);
+    ff_h264_sei_uninit(&h->sei);
     h->recovery_frame = -1;
     h->frame_recovered = 0;
     h->current_slice = 0;
@@ -1005,7 +1010,7 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size,
         h->current_slice = 0;
         if (!h->first_field)
             h->cur_pic_ptr = NULL;
-        ff_h264_reset_sei(h);
+        ff_h264_sei_uninit(&h->sei);
     }
 
     if (h->nal_length_size == 4) {
@@ -1096,13 +1101,15 @@ again:
             if ((err = ff_h264_decode_slice_header(h, sl)))
                 break;
 
-            if (h->sei_recovery_frame_cnt >= 0) {
-                if (h->poc.frame_num != h->sei_recovery_frame_cnt || sl->slice_type_nos != AV_PICTURE_TYPE_I)
+            if (h->sei.recovery_point.recovery_frame_cnt >= 0) {
+                const int sei_recovery_frame_cnt = h->sei.recovery_point.recovery_frame_cnt;
+
+                if (h->poc.frame_num != sei_recovery_frame_cnt || sl->slice_type_nos != AV_PICTURE_TYPE_I)
                     h->valid_recovery_point = 1;
 
                 if (   h->recovery_frame < 0
-                    || av_mod_uintp2(h->recovery_frame - h->poc.frame_num, h->ps.sps->log2_max_frame_num) > h->sei_recovery_frame_cnt) {
-                    h->recovery_frame = av_mod_uintp2(h->poc.frame_num + h->sei_recovery_frame_cnt, h->ps.sps->log2_max_frame_num);
+                    || av_mod_uintp2(h->recovery_frame - h->poc.frame_num, h->ps.sps->log2_max_frame_num) > sei_recovery_frame_cnt) {
+                    h->recovery_frame = av_mod_uintp2(h->poc.frame_num + sei_recovery_frame_cnt, h->ps.sps->log2_max_frame_num);
 
                     if (!h->valid_recovery_point)
                         h->recovery_frame = h->poc.frame_num;
@@ -1167,10 +1174,15 @@ again:
             avpriv_request_sample(avctx, "data partitioning");
             break;
         case NAL_SEI:
-            h->gb = nal->gb;
-            ret = ff_h264_decode_sei(h);
+            ret = ff_h264_sei_decode(&h->sei, &nal->gb, &h->ps, avctx);
+            h->has_recovery_point = h->has_recovery_point || h->sei.recovery_point.recovery_frame_cnt != -1;
             if (avctx->debug & FF_DEBUG_GREEN_MD)
-                debug_green_metadata(&h->sei_green_metadata, h->avctx);
+                debug_green_metadata(&h->sei.green_metadata, h->avctx);
+#if FF_API_AFD
+FF_DISABLE_DEPRECATION_WARNINGS
+            h->avctx->dtg_active_format = h->sei.afd.active_format_description;
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif /* FF_API_AFD */
             if (ret < 0 && (h->avctx->err_recognition & AV_EF_EXPLODE))
                 goto end;
             break;
@@ -1314,7 +1326,7 @@ static int output_frame(H264Context *h, AVFrame *dst, H264Picture *srcp)
     if (ret < 0)
         return ret;
 
-    av_dict_set(&dst->metadata, "stereo_mode", ff_h264_sei_stereo_mode(h), 0);
+    av_dict_set(&dst->metadata, "stereo_mode", ff_h264_sei_stereo_mode(&h->sei.frame_packing), 0);
 
     h->backup_width   = h->avctx->width;
     h->backup_height  = h->avctx->height;
@@ -1532,8 +1544,7 @@ av_cold void ff_h264_free_context(H264Context *h)
     av_freep(&h->slice_ctx);
     h->nb_slice_ctx = 0;
 
-    h->a53_caption_size = 0;
-    av_freep(&h->a53_caption);
+    ff_h264_sei_uninit(&h->sei);
 
     for (i = 0; i < MAX_SPS_COUNT; i++)
         av_buffer_unref(&h->ps.sps_list[i]);
diff --git a/libavcodec/h264.h b/libavcodec/h264.h
index b156805128..ba6f43c6a2 100644
--- a/libavcodec/h264.h
+++ b/libavcodec/h264.h
@@ -35,6 +35,7 @@
 #include "error_resilience.h"
 #include "get_bits.h"
 #include "h264_parse.h"
+#include "h264_sei.h"
 #include "h2645_parse.h"
 #include "h264chroma.h"
 #include "h264dsp.h"
@@ -131,48 +132,6 @@ enum {
 };
 
 /**
- * SEI message types
- */
-typedef enum {
-    SEI_TYPE_BUFFERING_PERIOD       = 0,   ///< buffering period (H.264, D.1.1)
-    SEI_TYPE_PIC_TIMING             = 1,   ///< picture timing
-    SEI_TYPE_USER_DATA_REGISTERED   = 4,   ///< registered user data as specified by Rec. ITU-T T.35
-    SEI_TYPE_USER_DATA_UNREGISTERED = 5,   ///< unregistered user data
-    SEI_TYPE_RECOVERY_POINT         = 6,   ///< recovery point (frame # to decoder sync)
-    SEI_TYPE_FRAME_PACKING          = 45,  ///< frame packing arrangement
-    SEI_TYPE_DISPLAY_ORIENTATION    = 47,  ///< display orientation
-    SEI_TYPE_GREEN_METADATA         = 56   ///< GreenMPEG information
-} SEI_Type;
-
-/**
- * pic_struct in picture timing SEI message
- */
-typedef enum {
-    SEI_PIC_STRUCT_FRAME             = 0, ///<  0: %frame
-    SEI_PIC_STRUCT_TOP_FIELD         = 1, ///<  1: top field
-    SEI_PIC_STRUCT_BOTTOM_FIELD      = 2, ///<  2: bottom field
-    SEI_PIC_STRUCT_TOP_BOTTOM        = 3, ///<  3: top field, bottom field, in that order
-    SEI_PIC_STRUCT_BOTTOM_TOP        = 4, ///<  4: bottom field, top field, in that order
-    SEI_PIC_STRUCT_TOP_BOTTOM_TOP    = 5, ///<  5: top field, bottom field, top field repeated, in that order
-    SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM = 6, ///<  6: bottom field, top field, bottom field repeated, in that order
-    SEI_PIC_STRUCT_FRAME_DOUBLING    = 7, ///<  7: %frame doubling
-    SEI_PIC_STRUCT_FRAME_TRIPLING    = 8  ///<  8: %frame tripling
-} SEI_PicStructType;
-
-/**
- * frame_packing_arrangement types
- */
-typedef enum {
-    SEI_FPA_TYPE_CHECKERBOARD        = 0,
-    SEI_FPA_TYPE_INTERLEAVE_COLUMN   = 1,
-    SEI_FPA_TYPE_INTERLEAVE_ROW      = 2,
-    SEI_FPA_TYPE_SIDE_BY_SIDE        = 3,
-    SEI_FPA_TYPE_TOP_BOTTOM          = 4,
-    SEI_FPA_TYPE_INTERLEAVE_TEMPORAL = 5,
-    SEI_FPA_TYPE_2D                  = 6,
-} SEI_FpaType;
-
-/**
  * Sequence parameter set
  */
 typedef struct SPS {
@@ -281,34 +240,6 @@ typedef struct H264ParamSets {
 } H264ParamSets;
 
 /**
- * Frame Packing Arrangement Type
- */
-typedef struct FPA {
-    int         frame_packing_arrangement_id;
-    int         frame_packing_arrangement_cancel_flag; ///< is previous arrangement canceled, -1 if never received
-    SEI_FpaType frame_packing_arrangement_type;
-    int         frame_packing_arrangement_repetition_period;
-    int         content_interpretation_type;
-    int         quincunx_sampling_flag;
-} FPA;
-
-/**
- * Green MetaData Information Type
- */
-typedef struct H264SEIGreenMetaData {
-    uint8_t green_metadata_type;
-    uint8_t period_type;
-    uint16_t num_seconds;
-    uint16_t num_pictures;
-    uint8_t percent_non_zero_macroblocks;
-    uint8_t percent_intra_coded_macroblocks;
-    uint8_t percent_six_tap_filtering;
-    uint8_t percent_alpha_point_deblocking_instance;
-    uint8_t xsd_metric_type;
-    uint16_t xsd_metric_value;
-} H264SEIGreenMetaData;
-
-/**
  * Memory management control operation opcode.
  */
 typedef enum MMCOOpcode {
@@ -622,8 +553,6 @@ typedef struct H264Context {
     uint8_t field_scan8x8_q0[64];
     uint8_t field_scan8x8_cavlc_q0[64];
 
-    int x264_build;
-
     int mb_y;
     int mb_height, mb_width;
     int mb_stride;
@@ -708,11 +637,6 @@ typedef struct H264Context {
     /** @} */
 
     /**
-     * pic_struct in picture timing SEI message
-     */
-    SEI_PicStructType sei_pic_struct;
-
-    /**
      * Complement sei_pic_struct
      * SEI_PIC_STRUCT_TOP_BOTTOM and SEI_PIC_STRUCT_BOTTOM_TOP indicate interlaced frames.
      * However, soft telecined frames may have these values.
@@ -721,61 +645,10 @@ typedef struct H264Context {
     int prev_interlaced_frame;
 
     /**
-     * frame_packing_arrangment SEI message
-     */
-    int sei_frame_packing_present;
-    int frame_packing_arrangement_type;
-    int content_interpretation_type;
-    int quincunx_subsampling;
-
-    /**
-     * display orientation SEI message
-     */
-    int sei_display_orientation_present;
-    int sei_anticlockwise_rotation;
-    int sei_hflip, sei_vflip;
-
-    /**
-     * User data registered by Rec. ITU-T T.35 SEI
-     */
-    int sei_reguserdata_afd_present;
-    uint8_t active_format_description;
-    int a53_caption_size;
-    uint8_t *a53_caption;
-
-    /**
-     * Bit set of clock types for fields/frames in picture timing SEI message.
-     * For each found ct_type, appropriate bit is set (e.g., bit 1 for
-     * interlaced).
-     */
-    int sei_ct_type;
-
-    /**
-     * dpb_output_delay in picture timing SEI message, see H.264 C.2.2
-     */
-    int sei_dpb_output_delay;
-
-    /**
-     * cpb_removal_delay in picture timing SEI message, see H.264 C.1.2
-     */
-    int sei_cpb_removal_delay;
-
-    /**
-     * recovery_frame_cnt from SEI message
-     *
-     * Set to -1 if no recovery point SEI message found or to number of frames
-     * before playback synchronizes. Frames having recovery point are key
-     * frames.
-     */
-    int sei_recovery_frame_cnt;
-
-    /**
      * Are the SEI recovery points looking valid.
      */
     int valid_recovery_point;
 
-    FPA sei_fpa;
-
     /**
      * recovery_frame is the frame_num at which the next frame should
      * be fully constructed.
@@ -807,10 +680,6 @@ typedef struct H264Context {
      * slices) anymore */
     int setup_finished;
 
-    // Timestamp stuff
-    int sei_buffering_period_present;   ///< Buffering period SEI flag
-    int initial_cpb_removal_delay[32];  ///< Initial timestamps for CPBs
-
     int cur_chroma_format_idc;
     int cur_bit_depth_luma;
     int16_t slice_row[MAX_SLICES]; ///< to detect when MAX_SLICES is too low
@@ -821,6 +690,8 @@ typedef struct H264Context {
 
     int enable_er;
 
+    H264SEIContext sei;
+
     AVBufferPool *qscale_table_pool;
     AVBufferPool *mb_type_pool;
     AVBufferPool *motion_val_pool;
@@ -830,19 +701,11 @@ typedef struct H264Context {
     qpel_mc_func (*qpel_put)[16];
     qpel_mc_func (*qpel_avg)[16];
 
-    /*Green Metadata */
-    H264SEIGreenMetaData sei_green_metadata;
-
 } H264Context;
 
 extern const uint16_t ff_h264_mb_sizes[4];
 
 /**
- * Decode SEI
- */
-int ff_h264_decode_sei(H264Context *h);
-
-/**
  * Decode SPS
  */
 int ff_h264_decode_seq_parameter_set(GetBitContext *gb, AVCodecContext *avctx,
@@ -921,19 +784,6 @@ void ff_h264_filter_mb(const H264Context *h, H264SliceContext *sl, int mb_x, int
                        uint8_t *img_y, uint8_t *img_cb, uint8_t *img_cr,
                        unsigned int linesize, unsigned int uvlinesize);
 
-/**
- * Reset SEI values at the beginning of the frame.
- *
- * @param h H.264 context.
- */
-void ff_h264_reset_sei(H264Context *h);
-
-/**
- * Get stereo_mode string from the h264 frame_packing_arrangement
- * @param h H.264 context.
- */
-const char* ff_h264_sei_stereo_mode(H264Context *h);
-
 /*
  * o-o o-o
  *  / / /
diff --git a/libavcodec/h264_direct.c b/libavcodec/h264_direct.c
index 0b3c02568a..9da6745120 100644
--- a/libavcodec/h264_direct.c
+++ b/libavcodec/h264_direct.c
@@ -395,7 +395,7 @@ single_col:
              (l1ref0[0] < 0 && !l1ref1[0] &&
               FFABS(l1mv1[0][0]) <= 1 &&
               FFABS(l1mv1[0][1]) <= 1 &&
-              h->x264_build > 33U))) {
+              h->sei.unregistered.x264_build > 33U))) {
             a = b = 0;
             if (ref[0] > 0)
                 a = mv[0];
@@ -430,7 +430,7 @@ single_col:
                 (l1ref0[i8] == 0 ||
                  (l1ref0[i8] < 0 &&
                   l1ref1[i8] == 0 &&
-                  h->x264_build > 33U))) {
+                  h->sei.unregistered.x264_build > 33U))) {
                 const int16_t (*l1mv)[2] = l1ref0[i8] == 0 ? l1mv0 : l1mv1;
                 if (IS_SUB_8X8(sub_mb_type)) {
                     const int16_t *mv_col = l1mv[x8 * 3 + y8 * 3 * b4_stride];
diff --git a/libavcodec/h264_mb.c b/libavcodec/h264_mb.c
index 75535adb95..c9fdf7a71f 100644
--- a/libavcodec/h264_mb.c
+++ b/libavcodec/h264_mb.c
@@ -636,7 +636,7 @@ static av_always_inline void hl_decode_mb_predict_luma(const H264Context *h,
                 uint8_t *const ptr = dest_y + block_offset[i];
                 const int dir      = sl->intra4x4_pred_mode_cache[scan8[i]];
                 if (transform_bypass && h->ps.sps->profile_idc == 244 && dir <= 1) {
-                    if (h->x264_build != -1) {
+                    if (h->sei.unregistered.x264_build != -1) {
                         h->hpc.pred8x8l_add[dir](ptr, sl->mb + (i * 16 + p * 256 << pixel_shift), linesize);
                     } else
                         h->hpc.pred8x8l_filter_add[dir](ptr, sl->mb + (i * 16 + p * 256 << pixel_shift),
diff --git a/libavcodec/h264_parser.c b/libavcodec/h264_parser.c
index e0977ea785..9fccdc98bc 100644
--- a/libavcodec/h264_parser.c
+++ b/libavcodec/h264_parser.c
@@ -39,6 +39,7 @@
 #include "get_bits.h"
 #include "golomb.h"
 #include "h264.h"
+#include "h264_sei.h"
 #include "h264data.h"
 #include "internal.h"
 #include "mpegutils.h"
@@ -50,6 +51,7 @@ typedef struct H264ParseContext {
     H264ParamSets ps;
     H264DSPContext h264dsp;
     H264POCContext poc;
+    H264SEIContext sei;
     int got_first;
 } H264ParseContext;
 
@@ -249,8 +251,8 @@ static inline int parse_nal_units(AVCodecParserContext *s,
     s->picture_structure = AV_PICTURE_STRUCTURE_UNKNOWN;
 
     h->avctx = avctx;
-    ff_h264_reset_sei(h);
-    h->sei_fpa.frame_packing_arrangement_cancel_flag = -1;
+    ff_h264_sei_uninit(&p->sei);
+    h->sei.frame_packing.frame_packing_arrangement_cancel_flag = -1;
 
     if (!buf_size)
         return 0;
@@ -318,12 +320,7 @@ static inline int parse_nal_units(AVCodecParserContext *s,
                                                  nal.size_bits);
             break;
         case NAL_SEI:
-            {
-                H264ParamSets ps = h->ps;
-                h->ps = p->ps;
-                ff_h264_decode_sei(h);
-                h->ps = ps;
-            }
+            ff_h264_sei_decode(&p->sei, &nal.gb, &p->ps, avctx);
             break;
         case NAL_IDR_SLICE:
             s->key_frame = 1;
@@ -337,7 +334,7 @@ static inline int parse_nal_units(AVCodecParserContext *s,
             get_ue_golomb_long(&nal.gb);  // skip first_mb_in_slice
             slice_type   = get_ue_golomb_31(&nal.gb);
             s->pict_type = ff_h264_golomb_to_pict_type[slice_type % 5];
-            if (h->sei_recovery_frame_cnt >= 0) {
+            if (p->sei.recovery_point.recovery_frame_cnt >= 0) {
                 /* key frame, since recovery_frame_cnt is set */
                 s->key_frame = 1;
             }
@@ -462,7 +459,7 @@ static inline int parse_nal_units(AVCodecParserContext *s,
             }
 
             if (sps->pic_struct_present_flag) {
-                switch (h->sei_pic_struct) {
+                switch (p->sei.picture_timing.pic_struct) {
                 case SEI_PIC_STRUCT_TOP_FIELD:
                 case SEI_PIC_STRUCT_BOTTOM_FIELD:
                     s->repeat_pict = 0;
@@ -493,7 +490,7 @@ static inline int parse_nal_units(AVCodecParserContext *s,
             if (h->picture_structure == PICT_FRAME) {
                 s->picture_structure = AV_PICTURE_STRUCTURE_FRAME;
                 if (sps->pic_struct_present_flag) {
-                    switch (h->sei_pic_struct) {
+                    switch (p->sei.picture_timing.pic_struct) {
                     case SEI_PIC_STRUCT_TOP_BOTTOM:
                     case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
                         s->field_order = AV_FIELD_TT;
@@ -603,10 +600,10 @@ static int h264_parse(AVCodecParserContext *s,
 
     if (avctx->framerate.num)
         avctx->time_base = av_inv_q(av_mul_q(avctx->framerate, (AVRational){avctx->ticks_per_frame, 1}));
-    if (h->sei_cpb_removal_delay >= 0) {
-        s->dts_sync_point    = h->sei_buffering_period_present;
-        s->dts_ref_dts_delta = h->sei_cpb_removal_delay;
-        s->pts_dts_delta     = h->sei_dpb_output_delay;
+    if (p->sei.picture_timing.cpb_removal_delay >= 0) {
+        s->dts_sync_point    = p->sei.buffering_period.present;
+        s->dts_ref_dts_delta = p->sei.picture_timing.cpb_removal_delay;
+        s->pts_dts_delta     = p->sei.picture_timing.dpb_output_delay;
     } else {
         s->dts_sync_point    = INT_MIN;
         s->dts_ref_dts_delta = INT_MIN;
@@ -669,6 +666,8 @@ static void h264_close(AVCodecParserContext *s)
     av_freep(&pc->buffer);
     ff_h264_free_context(h);
 
+    ff_h264_sei_uninit(&p->sei);
+
     for (i = 0; i < FF_ARRAY_ELEMS(p->ps.sps_list); i++)
         av_buffer_unref(&p->ps.sps_list[i]);
 
diff --git a/libavcodec/h264_sei.c b/libavcodec/h264_sei.c
index 8fcaa61067..d0596dcb81 100644
--- a/libavcodec/h264_sei.c
+++ b/libavcodec/h264_sei.c
@@ -26,124 +26,124 @@
  */
 
 #include "avcodec.h"
+#include "get_bits.h"
 #include "golomb.h"
 #include "h264.h"
+#include "h264_sei.h"
 #include "internal.h"
 
 static const uint8_t sei_num_clock_ts_table[9] = {
     1, 1, 1, 2, 2, 3, 3, 2, 3
 };
 
-void ff_h264_reset_sei(H264Context *h)
+void ff_h264_sei_uninit(H264SEIContext *h)
 {
-    h->sei_recovery_frame_cnt       = -1;
-    h->sei_dpb_output_delay         =  0;
-    h->sei_cpb_removal_delay        = -1;
-    h->sei_buffering_period_present =  0;
-    h->sei_frame_packing_present    =  0;
-    h->sei_display_orientation_present = 0;
-    h->sei_reguserdata_afd_present  =  0;
-
-    h->a53_caption_size = 0;
-    av_freep(&h->a53_caption);
+    h->recovery_point.recovery_frame_cnt = -1;
+
+    h->picture_timing.dpb_output_delay  = 0;
+    h->picture_timing.cpb_removal_delay = -1;
+
+    h->buffering_period.present    = 0;
+    h->frame_packing.present       = 0;
+    h->display_orientation.present = 0;
+    h->afd.present                 =  0;
+
+    h->a53_caption.a53_caption_size = 0;
+    av_freep(&h->a53_caption.a53_caption);
 }
 
-static int decode_picture_timing(H264Context *h)
+static int decode_picture_timing(H264SEIPictureTiming *h, GetBitContext *gb,
+                                 const H264ParamSets *ps, void *logctx)
 {
-    const SPS *sps = h->ps.sps;
     int i;
+    const SPS *sps = ps->sps;
 
     for (i = 0; i<MAX_SPS_COUNT; i++)
-        if ((!sps || !sps->log2_max_frame_num) && h->ps.sps_list[i])
-            sps = (const SPS *)h->ps.sps_list[i]->data;
+        if ((!sps || !sps->log2_max_frame_num) && ps->sps_list[i])
+            sps = (const SPS *)ps->sps_list[i]->data;
 
     if (!sps) {
-        av_log(h->avctx, AV_LOG_ERROR, "SPS unavailable in decode_picture_timing\n");
+        av_log(logctx, AV_LOG_ERROR, "SPS unavailable in decode_picture_timing\n");
         return 0;
     }
 
-    if (sps->nal_hrd_parameters_present_flag || sps->vcl_hrd_parameters_present_flag) {
-        h->sei_cpb_removal_delay = get_bits_long(&h->gb,
-                                                 sps->cpb_removal_delay_length);
-        h->sei_dpb_output_delay  = get_bits_long(&h->gb,
-                                                 sps->dpb_output_delay_length);
+    if (sps->nal_hrd_parameters_present_flag ||
+        sps->vcl_hrd_parameters_present_flag) {
+        h->cpb_removal_delay = get_bits_long(gb, sps->cpb_removal_delay_length);
+        h->dpb_output_delay  = get_bits_long(gb, sps->dpb_output_delay_length);
     }
     if (sps->pic_struct_present_flag) {
         unsigned int i, num_clock_ts;
 
-        h->sei_pic_struct = get_bits(&h->gb, 4);
-        h->sei_ct_type    = 0;
+        h->pic_struct = get_bits(gb, 4);
+        h->ct_type    = 0;
 
-        if (h->sei_pic_struct > SEI_PIC_STRUCT_FRAME_TRIPLING)
+        if (h->pic_struct > SEI_PIC_STRUCT_FRAME_TRIPLING)
             return AVERROR_INVALIDDATA;
 
-        num_clock_ts = sei_num_clock_ts_table[h->sei_pic_struct];
+        num_clock_ts = sei_num_clock_ts_table[h->pic_struct];
 
         for (i = 0; i < num_clock_ts; i++) {
-            if (get_bits(&h->gb, 1)) {                /* clock_timestamp_flag */
+            if (get_bits(gb, 1)) {                /* clock_timestamp_flag */
                 unsigned int full_timestamp_flag;
 
-                h->sei_ct_type |= 1 << get_bits(&h->gb, 2);
-                skip_bits(&h->gb, 1);                 /* nuit_field_based_flag */
-                skip_bits(&h->gb, 5);                 /* counting_type */
-                full_timestamp_flag = get_bits(&h->gb, 1);
-                skip_bits(&h->gb, 1);                 /* discontinuity_flag */
-                skip_bits(&h->gb, 1);                 /* cnt_dropped_flag */
-                skip_bits(&h->gb, 8);                 /* n_frames */
+                h->ct_type |= 1 << get_bits(gb, 2);
+                skip_bits(gb, 1);                 /* nuit_field_based_flag */
+                skip_bits(gb, 5);                 /* counting_type */
+                full_timestamp_flag = get_bits(gb, 1);
+                skip_bits(gb, 1);                 /* discontinuity_flag */
+                skip_bits(gb, 1);                 /* cnt_dropped_flag */
+                skip_bits(gb, 8);                 /* n_frames */
                 if (full_timestamp_flag) {
-                    skip_bits(&h->gb, 6);             /* seconds_value 0..59 */
-                    skip_bits(&h->gb, 6);             /* minutes_value 0..59 */
-                    skip_bits(&h->gb, 5);             /* hours_value 0..23 */
+                    skip_bits(gb, 6);             /* seconds_value 0..59 */
+                    skip_bits(gb, 6);             /* minutes_value 0..59 */
+                    skip_bits(gb, 5);             /* hours_value 0..23 */
                 } else {
-                    if (get_bits(&h->gb, 1)) {        /* seconds_flag */
-                        skip_bits(&h->gb, 6);         /* seconds_value range 0..59 */
-                        if (get_bits(&h->gb, 1)) {    /* minutes_flag */
-                            skip_bits(&h->gb, 6);     /* minutes_value 0..59 */
-                            if (get_bits(&h->gb, 1))  /* hours_flag */
-                                skip_bits(&h->gb, 5); /* hours_value 0..23 */
+                    if (get_bits(gb, 1)) {        /* seconds_flag */
+                        skip_bits(gb, 6);         /* seconds_value range 0..59 */
+                        if (get_bits(gb, 1)) {    /* minutes_flag */
+                            skip_bits(gb, 6);     /* minutes_value 0..59 */
+                            if (get_bits(gb, 1))  /* hours_flag */
+                                skip_bits(gb, 5); /* hours_value 0..23 */
                         }
                     }
                 }
                 if (sps->time_offset_length > 0)
-                    skip_bits(&h->gb,
+                    skip_bits(gb,
                               sps->time_offset_length); /* time_offset */
             }
         }
 
-        if (h->avctx->debug & FF_DEBUG_PICT_INFO)
-            av_log(h->avctx, AV_LOG_DEBUG, "ct_type:%X pic_struct:%d\n",
-                   h->sei_ct_type, h->sei_pic_struct);
+        av_log(logctx, AV_LOG_DEBUG, "ct_type:%X pic_struct:%d\n",
+               h->ct_type, h->pic_struct);
     }
     return 0;
 }
 
-static int decode_registered_user_data_afd(H264Context *h, int size)
+static int decode_registered_user_data_afd(H264SEIAFD *h, GetBitContext *gb, int size)
 {
     int flag;
 
     if (size-- < 1)
         return AVERROR_INVALIDDATA;
-    skip_bits(&h->gb, 1);               // 0
-    flag = get_bits(&h->gb, 1);         // active_format_flag
-    skip_bits(&h->gb, 6);               // reserved
+    skip_bits(gb, 1);               // 0
+    flag = get_bits(gb, 1);         // active_format_flag
+    skip_bits(gb, 6);               // reserved
 
     if (flag) {
         if (size-- < 1)
             return AVERROR_INVALIDDATA;
-        skip_bits(&h->gb, 4);           // reserved
-        h->active_format_description   = get_bits(&h->gb, 4);
-        h->sei_reguserdata_afd_present = 1;
-#if FF_API_AFD
-FF_DISABLE_DEPRECATION_WARNINGS
-        h->avctx->dtg_active_format = h->active_format_description;
-FF_ENABLE_DEPRECATION_WARNINGS
-#endif /* FF_API_AFD */
+        skip_bits(gb, 4);           // reserved
+        h->active_format_description = get_bits(gb, 4);
+        h->present                   = 1;
     }
 
     return 0;
 }
 
-static int decode_registered_user_data_closed_caption(H264Context *h, int size)
+static int decode_registered_user_data_closed_caption(H264SEIA53Caption *h,
+                                                     GetBitContext *gb, void *logctx,
+                                                     int size)
 {
     int flag;
     int user_data_type_code;
@@ -152,15 +152,15 @@ static int decode_registered_user_data_closed_caption(H264Context *h, int size)
     if (size < 3)
         return AVERROR(EINVAL);
 
-    user_data_type_code = get_bits(&h->gb, 8);
+    user_data_type_code = get_bits(gb, 8);
     if (user_data_type_code == 0x3) {
-        skip_bits(&h->gb, 1);           // reserved
+        skip_bits(gb, 1);           // reserved
 
-        flag = get_bits(&h->gb, 1);     // process_cc_data_flag
+        flag = get_bits(gb, 1);     // process_cc_data_flag
         if (flag) {
-            skip_bits(&h->gb, 1);       // zero bit
-            cc_count = get_bits(&h->gb, 5);
-            skip_bits(&h->gb, 8);       // reserved
+            skip_bits(gb, 1);       // zero bit
+            cc_count = get_bits(gb, 5);
+            skip_bits(gb, 8);       // reserved
             size -= 2;
 
             if (cc_count && size >= cc_count * 3) {
@@ -177,24 +177,25 @@ static int decode_registered_user_data_closed_caption(H264Context *h, int size)
                     return ret;
 
                 for (i = 0; i < cc_count; i++) {
-                    h->a53_caption[h->a53_caption_size++] = get_bits(&h->gb, 8);
-                    h->a53_caption[h->a53_caption_size++] = get_bits(&h->gb, 8);
-                    h->a53_caption[h->a53_caption_size++] = get_bits(&h->gb, 8);
+                    h->a53_caption[h->a53_caption_size++] = get_bits(gb, 8);
+                    h->a53_caption[h->a53_caption_size++] = get_bits(gb, 8);
+                    h->a53_caption[h->a53_caption_size++] = get_bits(gb, 8);
                 }
 
-                skip_bits(&h->gb, 8);   // marker_bits
+                skip_bits(gb, 8);   // marker_bits
             }
         }
     } else {
         int i;
         for (i = 0; i < size - 1; i++)
-            skip_bits(&h->gb, 8);
+            skip_bits(gb, 8);
     }
 
     return 0;
 }
 
-static int decode_registered_user_data(H264Context *h, int size)
+static int decode_registered_user_data(H264SEIContext *h, GetBitContext *gb,
+                                       void *logctx, int size)
 {
     uint32_t country_code;
     uint32_t user_identifier;
@@ -203,31 +204,33 @@ static int decode_registered_user_data(H264Context *h, int size)
         return AVERROR_INVALIDDATA;
     size -= 7;
 
-    country_code = get_bits(&h->gb, 8); // itu_t_t35_country_code
+    country_code = get_bits(gb, 8); // itu_t_t35_country_code
     if (country_code == 0xFF) {
-        skip_bits(&h->gb, 8);           // itu_t_t35_country_code_extension_byte
+        skip_bits(gb, 8);           // itu_t_t35_country_code_extension_byte
         size--;
     }
 
     /* itu_t_t35_payload_byte follows */
-    skip_bits(&h->gb, 8);              // terminal provider code
-    skip_bits(&h->gb, 8);              // terminal provider oriented code
-    user_identifier = get_bits_long(&h->gb, 32);
+    skip_bits(gb, 8);              // terminal provider code
+    skip_bits(gb, 8);              // terminal provider oriented code
+    user_identifier = get_bits_long(gb, 32);
 
     switch (user_identifier) {
         case MKBETAG('D', 'T', 'G', '1'):       // afd_data
-            return decode_registered_user_data_afd(h, size);
+            return decode_registered_user_data_afd(&h->afd, gb, size);
         case MKBETAG('G', 'A', '9', '4'):       // closed captions
-            return decode_registered_user_data_closed_caption(h, size);
+            return decode_registered_user_data_closed_caption(&h->a53_caption, gb,
+                                                              logctx, size);
         default:
-            skip_bits(&h->gb, size * 8);
+            skip_bits(gb, size * 8);
             break;
     }
 
     return 0;
 }
 
-static int decode_unregistered_user_data(H264Context *h, int size)
+static int decode_unregistered_user_data(H264SEIUnregistered *h, GetBitContext *gb,
+                                         void *logctx, int size)
 {
     uint8_t *user_data;
     int e, build, i;
@@ -240,7 +243,7 @@ static int decode_unregistered_user_data(H264Context *h, int size)
         return AVERROR(ENOMEM);
 
     for (i = 0; i < size + 16; i++)
-        user_data[i] = get_bits(&h->gb, 8);
+        user_data[i] = get_bits(gb, 8);
 
     user_data[i] = 0;
     e = sscanf(user_data + 16, "x264 - core %d", &build);
@@ -250,114 +253,100 @@ static int decode_unregistered_user_data(H264Context *h, int size)
         h->x264_build = 67;
 
     if (strlen(user_data + 16) > 0)
-        av_log(h->avctx, AV_LOG_DEBUG, "user data:\"%s\"\n", user_data + 16);
+        av_log(logctx, AV_LOG_DEBUG, "user data:\"%s\"\n", user_data + 16);
 
     av_free(user_data);
     return 0;
 }
 
-static int decode_recovery_point(H264Context *h)
+static int decode_recovery_point(H264SEIRecoveryPoint *h, GetBitContext *gb)
 {
-    h->sei_recovery_frame_cnt = get_ue_golomb_long(&h->gb);
+    h->recovery_frame_cnt = get_ue_golomb_long(gb);
 
     /* 1b exact_match_flag,
      * 1b broken_link_flag,
      * 2b changing_slice_group_idc */
-    skip_bits(&h->gb, 4);
-
-    if (h->avctx->debug & FF_DEBUG_PICT_INFO)
-        av_log(h->avctx, AV_LOG_DEBUG, "sei_recovery_frame_cnt: %d\n", h->sei_recovery_frame_cnt);
-
-    h->has_recovery_point = 1;
+    skip_bits(gb, 4);
 
     return 0;
 }
 
-static int decode_buffering_period(H264Context *h)
+static int decode_buffering_period(H264SEIBufferingPeriod *h, GetBitContext *gb,
+                                   const H264ParamSets *ps, void *logctx)
 {
     unsigned int sps_id;
     int sched_sel_idx;
     SPS *sps;
 
-    sps_id = get_ue_golomb_31(&h->gb);
-    if (sps_id > 31 || !h->ps.sps_list[sps_id]) {
-        av_log(h->avctx, AV_LOG_ERROR,
+    sps_id = get_ue_golomb_31(gb);
+    if (sps_id > 31 || !ps->sps_list[sps_id]) {
+        av_log(logctx, AV_LOG_ERROR,
                "non-existing SPS %d referenced in buffering period\n", sps_id);
         return AVERROR_INVALIDDATA;
     }
-    sps = (SPS*)h->ps.sps_list[sps_id]->data;
+    sps = (SPS*)ps->sps_list[sps_id]->data;
 
     // NOTE: This is really so duplicated in the standard... See H.264, D.1.1
     if (sps->nal_hrd_parameters_present_flag) {
         for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
             h->initial_cpb_removal_delay[sched_sel_idx] =
-                get_bits_long(&h->gb, sps->initial_cpb_removal_delay_length);
+                get_bits_long(gb, sps->initial_cpb_removal_delay_length);
             // initial_cpb_removal_delay_offset
-            skip_bits(&h->gb, sps->initial_cpb_removal_delay_length);
+            skip_bits(gb, sps->initial_cpb_removal_delay_length);
         }
     }
     if (sps->vcl_hrd_parameters_present_flag) {
         for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
             h->initial_cpb_removal_delay[sched_sel_idx] =
-                get_bits_long(&h->gb, sps->initial_cpb_removal_delay_length);
+                get_bits_long(gb, sps->initial_cpb_removal_delay_length);
             // initial_cpb_removal_delay_offset
-            skip_bits(&h->gb, sps->initial_cpb_removal_delay_length);
+            skip_bits(gb, sps->initial_cpb_removal_delay_length);
         }
     }
 
-    h->sei_buffering_period_present = 1;
+    h->present = 1;
     return 0;
 }
 
-static int decode_frame_packing_arrangement(H264Context *h)
+static int decode_frame_packing_arrangement(H264SEIFramePacking *h,
+                                            GetBitContext *gb)
 {
-    h->sei_fpa.frame_packing_arrangement_id          = get_ue_golomb_long(&h->gb);
-    h->sei_fpa.frame_packing_arrangement_cancel_flag = get_bits1(&h->gb);
-    h->sei_frame_packing_present = !h->sei_fpa.frame_packing_arrangement_cancel_flag;
-
-    if (h->sei_frame_packing_present) {
-        h->sei_fpa.frame_packing_arrangement_type =
-        h->frame_packing_arrangement_type = get_bits(&h->gb, 7);
-        h->sei_fpa.quincunx_sampling_flag         =
-        h->quincunx_subsampling           = get_bits1(&h->gb);
-        h->sei_fpa.content_interpretation_type    =
-        h->content_interpretation_type    = get_bits(&h->gb, 6);
+    h->frame_packing_arrangement_id          = get_ue_golomb_long(gb);
+    h->frame_packing_arrangement_cancel_flag = get_bits1(gb);
+    h->present = !h->frame_packing_arrangement_cancel_flag;
+
+    if (h->present) {
+        h->frame_packing_arrangement_type = get_bits(gb, 7);
+        h->quincunx_sampling_flag         = get_bits1(gb);
+        h->content_interpretation_type    = get_bits(gb, 6);
 
         // the following skips: spatial_flipping_flag, frame0_flipped_flag,
         // field_views_flag, current_frame_is_frame0_flag,
         // frame0_self_contained_flag, frame1_self_contained_flag
-        skip_bits(&h->gb, 6);
+        skip_bits(gb, 6);
 
-        if (!h->quincunx_subsampling && h->frame_packing_arrangement_type != 5)
-            skip_bits(&h->gb, 16);      // frame[01]_grid_position_[xy]
-        skip_bits(&h->gb, 8);           // frame_packing_arrangement_reserved_byte
-        h->sei_fpa.frame_packing_arrangement_repetition_period = get_ue_golomb_long(&h->gb);
+        if (!h->quincunx_sampling_flag && h->frame_packing_arrangement_type != 5)
+            skip_bits(gb, 16);      // frame[01]_grid_position_[xy]
+        skip_bits(gb, 8);           // frame_packing_arrangement_reserved_byte
+        h->frame_packing_arrangement_repetition_period = get_ue_golomb_long(gb);
     }
-    skip_bits1(&h->gb);                 // frame_packing_arrangement_extension_flag
-
-    if (h->avctx->debug & FF_DEBUG_PICT_INFO)
-        av_log(h->avctx, AV_LOG_DEBUG, "SEI FPA %d %d %d %d %d %d\n",
-                                       h->sei_fpa.frame_packing_arrangement_id,
-                                       h->sei_fpa.frame_packing_arrangement_cancel_flag,
-                                       h->sei_fpa.frame_packing_arrangement_type,
-                                       h->sei_fpa.quincunx_sampling_flag,
-                                       h->sei_fpa.content_interpretation_type,
-                                       h->sei_fpa.frame_packing_arrangement_repetition_period);
+    skip_bits1(gb);                 // frame_packing_arrangement_extension_flag
 
     return 0;
 }
 
-static int decode_display_orientation(H264Context *h)
+static int decode_display_orientation(H264SEIDisplayOrientation *h,
+                                      GetBitContext *gb)
 {
-    h->sei_display_orientation_present = !get_bits1(&h->gb);
+    h->present = !get_bits1(gb);
 
-    if (h->sei_display_orientation_present) {
-        h->sei_hflip = get_bits1(&h->gb);     // hor_flip
-        h->sei_vflip = get_bits1(&h->gb);     // ver_flip
+    if (h->present) {
+        h->hflip = get_bits1(gb);     // hor_flip
+        h->vflip = get_bits1(gb);     // ver_flip
 
-        h->sei_anticlockwise_rotation = get_bits(&h->gb, 16);
-        get_ue_golomb_long(&h->gb);  // display_orientation_repetition_period
-        skip_bits1(&h->gb);          // display_orientation_extension_flag
+        h->anticlockwise_rotation = get_bits(gb, 16);
+        get_ue_golomb_long(gb);       // display_orientation_repetition_period
+        skip_bits1(gb);               // display_orientation_extension_flag
     }
 
     return 0;
@@ -388,107 +377,105 @@ static int decode_green_metadata(H264SEIGreenMetaData *h, GetBitContext *gb)
     return 0;
 }
 
-int ff_h264_decode_sei(H264Context *h)
+int ff_h264_sei_decode(H264SEIContext *h, GetBitContext *gb,
+                       const H264ParamSets *ps, void *logctx)
 {
-    while (get_bits_left(&h->gb) > 16 && show_bits(&h->gb, 16)) {
+    while (get_bits_left(gb) > 16 && show_bits(gb, 16)) {
         int type = 0;
         unsigned size = 0;
         unsigned next;
         int ret  = 0;
 
         do {
-            if (get_bits_left(&h->gb) < 8)
+            if (get_bits_left(gb) < 8)
                 return AVERROR_INVALIDDATA;
-            type += show_bits(&h->gb, 8);
-        } while (get_bits(&h->gb, 8) == 255);
+            type += show_bits(gb, 8);
+        } while (get_bits(gb, 8) == 255);
 
         do {
-            if (get_bits_left(&h->gb) < 8)
+            if (get_bits_left(gb) < 8)
                 return AVERROR_INVALIDDATA;
-            size += show_bits(&h->gb, 8);
-        } while (get_bits(&h->gb, 8) == 255);
-
-        if (h->avctx->debug&FF_DEBUG_STARTCODE)
-            av_log(h->avctx, AV_LOG_DEBUG, "SEI %d len:%d\n", type, size);
+            size += show_bits(gb, 8);
+        } while (get_bits(gb, 8) == 255);
 
-        if (size > get_bits_left(&h->gb) / 8) {
-            av_log(h->avctx, AV_LOG_ERROR, "SEI type %d size %d truncated at %d\n",
-                   type, 8*size, get_bits_left(&h->gb));
+        if (size > get_bits_left(gb) / 8) {
+            av_log(logctx, AV_LOG_ERROR, "SEI type %d size %d truncated at %d\n",
+                   type, 8*size, get_bits_left(gb));
             return AVERROR_INVALIDDATA;
         }
-        next = get_bits_count(&h->gb) + 8 * size;
+        next = get_bits_count(gb) + 8 * size;
 
         switch (type) {
         case SEI_TYPE_PIC_TIMING: // Picture timing SEI
-            ret = decode_picture_timing(h);
+            ret = decode_picture_timing(&h->picture_timing, gb, ps, logctx);
             break;
         case SEI_TYPE_USER_DATA_REGISTERED:
-            ret = decode_registered_user_data(h, size);
+            ret = decode_registered_user_data(h, gb, logctx, size);
             break;
         case SEI_TYPE_USER_DATA_UNREGISTERED:
-            ret = decode_unregistered_user_data(h, size);
+            ret = decode_unregistered_user_data(&h->unregistered, gb, logctx, size);
             break;
         case SEI_TYPE_RECOVERY_POINT:
-            ret = decode_recovery_point(h);
+            ret = decode_recovery_point(&h->recovery_point, gb);
             break;
         case SEI_TYPE_BUFFERING_PERIOD:
-            ret = decode_buffering_period(h);
+            ret = decode_buffering_period(&h->buffering_period, gb, ps, logctx);
             break;
         case SEI_TYPE_FRAME_PACKING:
-            ret = decode_frame_packing_arrangement(h);
+            ret = decode_frame_packing_arrangement(&h->frame_packing, gb);
             break;
         case SEI_TYPE_DISPLAY_ORIENTATION:
-            ret = decode_display_orientation(h);
+            ret = decode_display_orientation(&h->display_orientation, gb);
             break;
         case SEI_TYPE_GREEN_METADATA:
-            ret = decode_green_metadata(&h->sei_green_metadata, &h->gb);
+            ret = decode_green_metadata(&h->green_metadata, gb);
             break;
         default:
-            av_log(h->avctx, AV_LOG_DEBUG, "unknown SEI type %d\n", type);
+            av_log(logctx, AV_LOG_DEBUG, "unknown SEI type %d\n", type);
         }
         if (ret < 0)
             return ret;
 
-        skip_bits_long(&h->gb, next - get_bits_count(&h->gb));
+        skip_bits_long(gb, next - get_bits_count(gb));
 
         // FIXME check bits here
-        align_get_bits(&h->gb);
+        align_get_bits(gb);
     }
 
     return 0;
 }
 
-const char* ff_h264_sei_stereo_mode(H264Context *h)
+const char *ff_h264_sei_stereo_mode(const H264SEIFramePacking *h)
 {
-    if (h->sei_fpa.frame_packing_arrangement_cancel_flag == 0) {
-        switch (h->sei_fpa.frame_packing_arrangement_type) {
+    if (h->frame_packing_arrangement_cancel_flag == 0) {
+        switch (h->frame_packing_arrangement_type) {
             case SEI_FPA_TYPE_CHECKERBOARD:
-                if (h->sei_fpa.content_interpretation_type == 2)
+                if (h->content_interpretation_type == 2)
                     return "checkerboard_rl";
                 else
                     return "checkerboard_lr";
             case SEI_FPA_TYPE_INTERLEAVE_COLUMN:
-                if (h->sei_fpa.content_interpretation_type == 2)
+                if (h->content_interpretation_type == 2)
                     return "col_interleaved_rl";
                 else
                     return "col_interleaved_lr";
             case SEI_FPA_TYPE_INTERLEAVE_ROW:
-                if (h->sei_fpa.content_interpretation_type == 2)
+                if (h->content_interpretation_type == 2)
                     return "row_interleaved_rl";
                 else
                     return "row_interleaved_lr";
             case SEI_FPA_TYPE_SIDE_BY_SIDE:
-                if (h->sei_fpa.content_interpretation_type == 2)
+                if (h->content_interpretation_type == 2)
                     return "right_left";
                 else
                     return "left_right";
             case SEI_FPA_TYPE_TOP_BOTTOM:
-                if (h->sei_fpa.content_interpretation_type == 2)
+                if (h->content_interpretation_type == 2)
                     return "bottom_top";
                 else
                     return "top_bottom";
             case SEI_FPA_TYPE_INTERLEAVE_TEMPORAL:
-                if (h->sei_fpa.content_interpretation_type == 2)
+                if (h->content_interpretation_type == 2)
                     return "block_rl";
                 else
                     return "block_lr";
@@ -496,7 +483,7 @@ const char* ff_h264_sei_stereo_mode(H264Context *h)
             default:
                 return "mono";
         }
-    } else if (h->sei_fpa.frame_packing_arrangement_cancel_flag == 1) {
+    } else if (h->frame_packing_arrangement_cancel_flag == 1) {
         return "mono";
     } else {
         return NULL;
diff --git a/libavcodec/h264_sei.h b/libavcodec/h264_sei.h
new file mode 100644
index 0000000000..91977952ca
--- /dev/null
+++ b/libavcodec/h264_sei.h
@@ -0,0 +1,173 @@
+/*
+ * 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
+ */
+
+#ifndef AVCODEC_H264_SEI_H
+#define AVCODEC_H264_SEI_H
+
+#include "get_bits.h"
+
+/**
+ * SEI message types
+ */
+typedef enum {
+    SEI_TYPE_BUFFERING_PERIOD       = 0,   ///< buffering period (H.264, D.1.1)
+    SEI_TYPE_PIC_TIMING             = 1,   ///< picture timing
+    SEI_TYPE_USER_DATA_REGISTERED   = 4,   ///< registered user data as specified by Rec. ITU-T T.35
+    SEI_TYPE_USER_DATA_UNREGISTERED = 5,   ///< unregistered user data
+    SEI_TYPE_RECOVERY_POINT         = 6,   ///< recovery point (frame # to decoder sync)
+    SEI_TYPE_FRAME_PACKING          = 45,  ///< frame packing arrangement
+    SEI_TYPE_DISPLAY_ORIENTATION    = 47,  ///< display orientation
+    SEI_TYPE_GREEN_METADATA         = 56   ///< GreenMPEG information
+} SEI_Type;
+
+/**
+ * pic_struct in picture timing SEI message
+ */
+typedef enum {
+    SEI_PIC_STRUCT_FRAME             = 0, ///<  0: %frame
+    SEI_PIC_STRUCT_TOP_FIELD         = 1, ///<  1: top field
+    SEI_PIC_STRUCT_BOTTOM_FIELD      = 2, ///<  2: bottom field
+    SEI_PIC_STRUCT_TOP_BOTTOM        = 3, ///<  3: top field, bottom field, in that order
+    SEI_PIC_STRUCT_BOTTOM_TOP        = 4, ///<  4: bottom field, top field, in that order
+    SEI_PIC_STRUCT_TOP_BOTTOM_TOP    = 5, ///<  5: top field, bottom field, top field repeated, in that order
+    SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM = 6, ///<  6: bottom field, top field, bottom field repeated, in that order
+    SEI_PIC_STRUCT_FRAME_DOUBLING    = 7, ///<  7: %frame doubling
+    SEI_PIC_STRUCT_FRAME_TRIPLING    = 8  ///<  8: %frame tripling
+} SEI_PicStructType;
+
+/**
+ * frame_packing_arrangement types
+ */
+typedef enum {
+    SEI_FPA_TYPE_CHECKERBOARD        = 0,
+    SEI_FPA_TYPE_INTERLEAVE_COLUMN   = 1,
+    SEI_FPA_TYPE_INTERLEAVE_ROW      = 2,
+    SEI_FPA_TYPE_SIDE_BY_SIDE        = 3,
+    SEI_FPA_TYPE_TOP_BOTTOM          = 4,
+    SEI_FPA_TYPE_INTERLEAVE_TEMPORAL = 5,
+    SEI_FPA_TYPE_2D                  = 6,
+} SEI_FpaType;
+
+typedef struct H264SEIPictureTiming {
+    SEI_PicStructType pic_struct;
+
+    /**
+     * Bit set of clock types for fields/frames in picture timing SEI message.
+     * For each found ct_type, appropriate bit is set (e.g., bit 1 for
+     * interlaced).
+     */
+    int ct_type;
+
+    /**
+     * dpb_output_delay in picture timing SEI message, see H.264 C.2.2
+     */
+    int dpb_output_delay;
+
+    /**
+     * cpb_removal_delay in picture timing SEI message, see H.264 C.1.2
+     */
+    int cpb_removal_delay;
+} H264SEIPictureTiming;
+
+typedef struct H264SEIAFD {
+    int present;
+    uint8_t active_format_description;
+} H264SEIAFD;
+
+typedef struct H264SEIA53Caption {
+    int a53_caption_size;
+    uint8_t *a53_caption;
+} H264SEIA53Caption;
+
+typedef struct H264SEIUnregistered {
+    int x264_build;
+} H264SEIUnregistered;
+
+typedef struct H264SEIRecoveryPoint {
+    /**
+     * recovery_frame_cnt
+     *
+     * Set to -1 if no recovery point SEI message found or to number of frames
+     * before playback synchronizes. Frames having recovery point are key
+     * frames.
+     */
+    int recovery_frame_cnt;
+} H264SEIRecoveryPoint;
+
+typedef struct H264SEIBufferingPeriod {
+    int present;   ///< Buffering period SEI flag
+    int initial_cpb_removal_delay[32];  ///< Initial timestamps for CPBs
+} H264SEIBufferingPeriod;
+
+typedef struct H264SEIFramePacking {
+    int present;
+    int frame_packing_arrangement_id;
+    int frame_packing_arrangement_cancel_flag;  ///< is previous arrangement canceled, -1 if never received
+    SEI_FpaType frame_packing_arrangement_type;
+    int frame_packing_arrangement_repetition_period;
+    int content_interpretation_type;
+    int quincunx_sampling_flag;
+} H264SEIFramePacking;
+
+typedef struct H264SEIDisplayOrientation {
+    int present;
+    int anticlockwise_rotation;
+    int hflip, vflip;
+} H264SEIDisplayOrientation;
+
+typedef struct H264SEIGreenMetaData {
+    uint8_t green_metadata_type;
+    uint8_t period_type;
+    uint16_t num_seconds;
+    uint16_t num_pictures;
+    uint8_t percent_non_zero_macroblocks;
+    uint8_t percent_intra_coded_macroblocks;
+    uint8_t percent_six_tap_filtering;
+    uint8_t percent_alpha_point_deblocking_instance;
+    uint8_t xsd_metric_type;
+    uint16_t xsd_metric_value;
+} H264SEIGreenMetaData;
+
+typedef struct H264SEIContext {
+    H264SEIPictureTiming picture_timing;
+    H264SEIAFD afd;
+    H264SEIA53Caption a53_caption;
+    H264SEIUnregistered unregistered;
+    H264SEIRecoveryPoint recovery_point;
+    H264SEIBufferingPeriod buffering_period;
+    H264SEIFramePacking frame_packing;
+    H264SEIDisplayOrientation display_orientation;
+    H264SEIGreenMetaData green_metadata;
+} H264SEIContext;
+
+struct H264ParamSets;
+
+int ff_h264_sei_decode(H264SEIContext *h, GetBitContext *gb,
+                       const struct H264ParamSets *ps, void *logctx);
+
+/**
+ * Reset SEI values at the beginning of the frame.
+ */
+void ff_h264_sei_uninit(H264SEIContext *h);
+
+/**
+ * Get stereo_mode string from the h264 frame_packing_arrangement
+ */
+const char *ff_h264_sei_stereo_mode(const H264SEIFramePacking *h);
+
+#endif /* AVCODEC_H264_SEI_H */
diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c
index 25dbf6cb3e..45e076b9c1 100644
--- a/libavcodec/h264_slice.c
+++ b/libavcodec/h264_slice.c
@@ -418,7 +418,7 @@ int ff_h264_update_thread_context(AVCodecContext *dst,
     // extradata/NAL handling
     h->is_avc = h1->is_avc;
     h->nal_length_size = h1->nal_length_size;
-    h->x264_build      = h1->x264_build;
+    h->sei.unregistered.x264_build = h1->sei.unregistered.x264_build;
 
     // POC timing
     copy_fields(h, h1, poc, current_slice);
@@ -486,7 +486,7 @@ static int h264_frame_start(H264Context *h)
     pic->mmco_reset  = 0;
     pic->recovered   = 0;
     pic->invalid_gap = 0;
-    pic->sei_recovery_frame_cnt = h->sei_recovery_frame_cnt;
+    pic->sei_recovery_frame_cnt = h->sei.recovery_point.recovery_frame_cnt;
 
     if ((ret = alloc_picture(h, pic)) < 0)
         return ret;
@@ -913,7 +913,7 @@ static int h264_slice_header_init(H264Context *h)
 
     if (sps->timing_info_present_flag) {
         int64_t den = sps->time_scale;
-        if (h->x264_build < 44U)
+        if (h->sei.unregistered.x264_build < 44U)
             den *= 2;
         av_reduce(&h->avctx->framerate.den, &h->avctx->framerate.num,
                   sps->num_units_in_tick * h->avctx->ticks_per_frame, den, 1 << 30);
@@ -1126,7 +1126,7 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl)
             (h->avctx->skip_frame >= AVDISCARD_NONREF && !h->nal_ref_idc) ||
             (h->avctx->skip_frame >= AVDISCARD_BIDIR  && sl->slice_type_nos == AV_PICTURE_TYPE_B) ||
             (h->avctx->skip_frame >= AVDISCARD_NONINTRA && sl->slice_type_nos != AV_PICTURE_TYPE_I) ||
-            (h->avctx->skip_frame >= AVDISCARD_NONKEY && h->nal_unit_type != NAL_IDR_SLICE && h->sei_recovery_frame_cnt < 0) ||
+            (h->avctx->skip_frame >= AVDISCARD_NONKEY && h->nal_unit_type != NAL_IDR_SLICE && h->sei.recovery_point.recovery_frame_cnt < 0) ||
             h->avctx->skip_frame >= AVDISCARD_ALL) {
             return SLICE_SKIPED;
         }