From d94dda742c8eab3141197270fb78063ed22442aa Mon Sep 17 00:00:00 2001
From: Mark Thompson <sw@jkqxz.net>
Date: Mon, 7 May 2018 23:33:08 +0100
Subject: [PATCH] cbs_h264: Add support for pan-scan rectangle SEI messages

---
 libavcodec/cbs_h264.h                 | 12 ++++++++++++
 libavcodec/cbs_h2645.c                |  1 +
 libavcodec/cbs_h264_syntax_template.c | 28 +++++++++++++++++++++++++++
 libavcodec/h264_sei.h                 |  1 +
 4 files changed, 42 insertions(+)

diff --git a/libavcodec/cbs_h264.h b/libavcodec/cbs_h264.h
index d953c1f66b..bc1ce1256f 100644
--- a/libavcodec/cbs_h264.h
+++ b/libavcodec/cbs_h264.h
@@ -264,6 +264,17 @@ typedef struct H264RawSEIPicTiming {
     H264RawSEIPicTimestamp timestamp[3];
 } H264RawSEIPicTiming;
 
+typedef struct H264RawSEIPanScanRect {
+    uint32_t pan_scan_rect_id;
+    uint8_t  pan_scan_rect_cancel_flag;
+    uint8_t  pan_scan_cnt_minus1;
+    int32_t  pan_scan_rect_left_offset[3];
+    int32_t  pan_scan_rect_right_offset[3];
+    int32_t  pan_scan_rect_top_offset[3];
+    int32_t  pan_scan_rect_bottom_offset[3];
+    uint16_t pan_scan_rect_repetition_period;
+} H264RawSEIPanScanRect;
+
 typedef struct H264RawSEIUserDataRegistered {
     uint8_t itu_t_t35_country_code;
     uint8_t itu_t_t35_country_code_extension_byte;
@@ -301,6 +312,7 @@ typedef struct H264RawSEIPayload {
     union {
         H264RawSEIBufferingPeriod buffering_period;
         H264RawSEIPicTiming pic_timing;
+        H264RawSEIPanScanRect pan_scan_rect;
         // H264RawSEIFiller filler -> no fields.
         H264RawSEIUserDataRegistered user_data_registered;
         H264RawSEIUserDataUnregistered user_data_unregistered;
diff --git a/libavcodec/cbs_h2645.c b/libavcodec/cbs_h2645.c
index 54f7e93755..76da801959 100644
--- a/libavcodec/cbs_h2645.c
+++ b/libavcodec/cbs_h2645.c
@@ -425,6 +425,7 @@ static void cbs_h264_free_sei_payload(H264RawSEIPayload *payload)
     switch (payload->payload_type) {
     case H264_SEI_TYPE_BUFFERING_PERIOD:
     case H264_SEI_TYPE_PIC_TIMING:
+    case H264_SEI_TYPE_PAN_SCAN_RECT:
     case H264_SEI_TYPE_RECOVERY_POINT:
     case H264_SEI_TYPE_DISPLAY_ORIENTATION:
         break;
diff --git a/libavcodec/cbs_h264_syntax_template.c b/libavcodec/cbs_h264_syntax_template.c
index b789207e33..fb1685e6e6 100644
--- a/libavcodec/cbs_h264_syntax_template.c
+++ b/libavcodec/cbs_h264_syntax_template.c
@@ -626,6 +626,30 @@ static int FUNC(sei_pic_timing)(CodedBitstreamContext *ctx, RWContext *rw,
     return 0;
 }
 
+static int FUNC(sei_pan_scan_rect)(CodedBitstreamContext *ctx, RWContext *rw,
+                                   H264RawSEIPanScanRect *current)
+{
+    int err, i;
+
+    ue(pan_scan_rect_id, 0, UINT32_MAX - 1);
+    flag(pan_scan_rect_cancel_flag);
+
+    if (!current->pan_scan_rect_cancel_flag) {
+        ue(pan_scan_cnt_minus1, 0, 2);
+
+        for (i = 0; i <= current->pan_scan_cnt_minus1; i++) {
+            ses(pan_scan_rect_left_offset[i],   INT32_MIN + 1, INT32_MAX, 1, i);
+            ses(pan_scan_rect_right_offset[i],  INT32_MIN + 1, INT32_MAX, 1, i);
+            ses(pan_scan_rect_top_offset[i],    INT32_MIN + 1, INT32_MAX, 1, i);
+            ses(pan_scan_rect_bottom_offset[i], INT32_MIN + 1, INT32_MAX, 1, i);
+        }
+
+        ue(pan_scan_rect_repetition_period, 0, 16384);
+    }
+
+    return 0;
+}
+
 static int FUNC(sei_user_data_registered)(CodedBitstreamContext *ctx, RWContext *rw,
                                           H264RawSEIUserDataRegistered *current,
                                           uint32_t *payload_size)
@@ -737,6 +761,10 @@ static int FUNC(sei_payload)(CodedBitstreamContext *ctx, RWContext *rw,
         CHECK(FUNC(sei_pic_timing)
               (ctx, rw, &current->payload.pic_timing));
         break;
+    case H264_SEI_TYPE_PAN_SCAN_RECT:
+        CHECK(FUNC(sei_pan_scan_rect)
+              (ctx, rw, &current->payload.pan_scan_rect));
+        break;
     case H264_SEI_TYPE_FILLER_PAYLOAD:
         {
             for (i = 0; i  < current->payload_size; i++)
diff --git a/libavcodec/h264_sei.h b/libavcodec/h264_sei.h
index 9488382b9f..6455f3cec5 100644
--- a/libavcodec/h264_sei.h
+++ b/libavcodec/h264_sei.h
@@ -27,6 +27,7 @@
 typedef enum {
     H264_SEI_TYPE_BUFFERING_PERIOD       = 0,   ///< buffering period (H.264, D.1.1)
     H264_SEI_TYPE_PIC_TIMING             = 1,   ///< picture timing
+    H264_SEI_TYPE_PAN_SCAN_RECT          = 2,   ///< pan-scan rectangle
     H264_SEI_TYPE_FILLER_PAYLOAD         = 3,   ///< filler data
     H264_SEI_TYPE_USER_DATA_REGISTERED   = 4,   ///< registered user data as specified by Rec. ITU-T T.35
     H264_SEI_TYPE_USER_DATA_UNREGISTERED = 5,   ///< unregistered user data