From eccc03c8fbc603a0a3257df66f0705f74fe2581a Mon Sep 17 00:00:00 2001
From: Mark Thompson <sw@jkqxz.net>
Date: Sun, 11 Feb 2018 17:33:15 +0000
Subject: [PATCH] cbs_h264: Add support for filler NAL units

---
 libavcodec/cbs_h264.h                 |  6 ++++++
 libavcodec/cbs_h2645.c                | 21 +++++++++++++++++++
 libavcodec/cbs_h264_syntax_template.c | 29 +++++++++++++++++++++++++++
 3 files changed, 56 insertions(+)

diff --git a/libavcodec/cbs_h264.h b/libavcodec/cbs_h264.h
index a59b7be1be..5a7dc27698 100644
--- a/libavcodec/cbs_h264.h
+++ b/libavcodec/cbs_h264.h
@@ -408,6 +408,12 @@ typedef struct H264RawSlice {
     AVBufferRef *data_ref;
 } H264RawSlice;
 
+typedef struct H264RawFiller {
+    H264RawNALUnitHeader nal_unit_header;
+
+    uint32_t filler_size;
+} H264RawFiller;
+
 
 typedef struct CodedBitstreamH264Context {
     // Reader/writer context in common with the H.265 implementation.
diff --git a/libavcodec/cbs_h2645.c b/libavcodec/cbs_h2645.c
index ebc02361d0..d6131a13e5 100644
--- a/libavcodec/cbs_h2645.c
+++ b/libavcodec/cbs_h2645.c
@@ -815,6 +815,19 @@ static int cbs_h264_read_nal_unit(CodedBitstreamContext *ctx,
         }
         break;
 
+    case H264_NAL_FILLER_DATA:
+        {
+            err = ff_cbs_alloc_unit_content(ctx, unit,
+                                            sizeof(H264RawFiller), NULL);
+            if (err < 0)
+                return err;
+
+            err = cbs_h264_read_filler(ctx, &bc, unit->content);
+            if (err < 0)
+                return err;
+        }
+        break;
+
     default:
         return AVERROR(ENOSYS);
     }
@@ -1070,6 +1083,14 @@ static int cbs_h264_write_nal_unit(CodedBitstreamContext *ctx,
         }
         break;
 
+    case H264_NAL_FILLER_DATA:
+        {
+            err = cbs_h264_write_filler(ctx, pbc, unit->content);
+            if (err < 0)
+                return err;
+        }
+        break;
+
     default:
         av_log(ctx->log_ctx, AV_LOG_ERROR, "Write unimplemented for "
                "NAL unit type %"PRIu32".\n", unit->type);
diff --git a/libavcodec/cbs_h264_syntax_template.c b/libavcodec/cbs_h264_syntax_template.c
index 29e9735987..1aa7888584 100644
--- a/libavcodec/cbs_h264_syntax_template.c
+++ b/libavcodec/cbs_h264_syntax_template.c
@@ -1247,3 +1247,32 @@ static int FUNC(slice_header)(CodedBitstreamContext *ctx, RWContext *rw,
 
     return 0;
 }
+
+static int FUNC(filler)(CodedBitstreamContext *ctx, RWContext *rw,
+                        H264RawFiller *current)
+{
+    av_unused int ff_byte = 0xff;
+    int err;
+
+    HEADER("Filler Data");
+
+    CHECK(FUNC(nal_unit_header)(ctx, rw, &current->nal_unit_header,
+                                1 << H264_NAL_FILLER_DATA));
+
+#ifdef READ
+    while (bitstream_peek(rw, 8) == 0xff) {
+        xu(8, ff_byte, ff_byte, 0xff, 0xff);
+        ++current->filler_size;
+    }
+#else
+    {
+        uint32_t i;
+        for (i = 0; i < current->filler_size; i++)
+            xu(8, ff_byte, ff_byte, 0xff, 0xff);
+    }
+#endif
+
+    CHECK(FUNC(rbsp_trailing_bits)(ctx, rw));
+
+    return 0;
+}