diff --git a/media/ffvpx/libavcodec/avcodec.h b/media/ffvpx/libavcodec/avcodec.h
index 18c3e3ea1e..771d59d726 100644
--- a/media/ffvpx/libavcodec/avcodec.h
+++ b/media/ffvpx/libavcodec/avcodec.h
@@ -1574,7 +1574,7 @@ enum AVPacketSideDataType {
     AV_PKT_DATA_METADATA_UPDATE,
 
     /**
-     * MPEGTS stream ID, this is required to pass the stream ID
+     * MPEGTS stream ID as uint8_t, this is required to pass the stream ID
      * information from the demuxer to the corresponding muxer.
      */
     AV_PKT_DATA_MPEGTS_STREAM_ID,
diff --git a/media/ffvpx/libavcodec/error_resilience.c b/media/ffvpx/libavcodec/error_resilience.c
index d7f94c10c2..8f67542baf 100644
--- a/media/ffvpx/libavcodec/error_resilience.c
+++ b/media/ffvpx/libavcodec/error_resilience.c
@@ -438,7 +438,7 @@ static void guess_mv(ERContext *s)
     }
 
     if ((!(s->avctx->error_concealment&FF_EC_GUESS_MVS)) ||
-        num_avail <= mb_width / 2) {
+        num_avail <= FFMAX(mb_width, mb_height) / 2) {
         for (mb_y = 0; mb_y < mb_height; mb_y++) {
             for (mb_x = 0; mb_x < s->mb_width; mb_x++) {
                 const int mb_xy = mb_x + mb_y * s->mb_stride;
diff --git a/media/ffvpx/libavcodec/h264_direct.c b/media/ffvpx/libavcodec/h264_direct.c
index a7a107c8c2..3825996762 100644
--- a/media/ffvpx/libavcodec/h264_direct.c
+++ b/media/ffvpx/libavcodec/h264_direct.c
@@ -156,8 +156,8 @@ void ff_h264_direct_ref_list_init(const H264Context *const h, H264SliceContext *
             av_log(h->avctx, AV_LOG_ERROR, "co located POCs unavailable\n");
             sl->col_parity = 1;
         } else
-        sl->col_parity = (FFABS(col_poc[0] - cur_poc) >=
-                          FFABS(col_poc[1] - cur_poc));
+            sl->col_parity = (FFABS(col_poc[0] - (int64_t)cur_poc) >=
+                              FFABS(col_poc[1] - (int64_t)cur_poc));
         ref1sidx =
         sidx     = sl->col_parity;
     // FL -> FL & differ parity
diff --git a/media/ffvpx/libavcodec/h264_slice.c b/media/ffvpx/libavcodec/h264_slice.c
index f55cdf51f9..c9c475d73c 100644
--- a/media/ffvpx/libavcodec/h264_slice.c
+++ b/media/ffvpx/libavcodec/h264_slice.c
@@ -672,7 +672,7 @@ static void implicit_weight_table(const H264Context *h, H264SliceContext *sl, in
             cur_poc = h->cur_pic_ptr->field_poc[h->picture_structure - 1];
         }
         if (sl->ref_count[0] == 1 && sl->ref_count[1] == 1 && !FRAME_MBAFF(h) &&
-            sl->ref_list[0][0].poc + (int64_t)sl->ref_list[1][0].poc == 2 * cur_poc) {
+            sl->ref_list[0][0].poc + (int64_t)sl->ref_list[1][0].poc == 2LL * cur_poc) {
             sl->pwt.use_weight        = 0;
             sl->pwt.use_weight_chroma = 0;
             return;
diff --git a/media/ffvpx/libavcodec/hevcdec.c b/media/ffvpx/libavcodec/hevcdec.c
index 89b121d2f0..2412bd0a97 100644
--- a/media/ffvpx/libavcodec/hevcdec.c
+++ b/media/ffvpx/libavcodec/hevcdec.c
@@ -472,6 +472,11 @@ static int hls_slice_header(HEVCContext *s)
 
     // Coded parameters
     sh->first_slice_in_pic_flag = get_bits1(gb);
+    if (s->ref && sh->first_slice_in_pic_flag) {
+        av_log(s->avctx, AV_LOG_ERROR, "Two slices reporting being the first in the same frame.\n");
+        return 1; // This slice will be skiped later, do not corrupt state
+    }
+
     if ((IS_IDR(s) || IS_BLA(s)) && sh->first_slice_in_pic_flag) {
         s->seq_decode = (s->seq_decode + 1) & 0xff;
         s->max_ra     = INT_MAX;
@@ -2862,6 +2867,11 @@ static int decode_nal_unit(HEVCContext *s, const H2645NAL *nal)
         ret = hls_slice_header(s);
         if (ret < 0)
             return ret;
+        if (ret == 1) {
+            ret = AVERROR_INVALIDDATA;
+            goto fail;
+        }
+
 
         if (s->sh.first_slice_in_pic_flag) {
             if (s->max_ra == INT_MAX) {
diff --git a/media/ffvpx/libavcodec/mpegaudio_parser.c b/media/ffvpx/libavcodec/mpegaudio_parser.c
index a072851ecf..04400a44e7 100644
--- a/media/ffvpx/libavcodec/mpegaudio_parser.c
+++ b/media/ffvpx/libavcodec/mpegaudio_parser.c
@@ -100,7 +100,7 @@ static int mpegaudio_parse(AVCodecParserContext *s1,
                             "MP3ADU full parser");
                         *poutbuf = NULL;
                         *poutbuf_size = 0;
-                        return 0; /* parsers must not return error codes */
+                        return buf_size; /* parsers must not return error codes */
                     }
 
                     break;
diff --git a/media/ffvpx/libavutil/imgutils.c b/media/ffvpx/libavutil/imgutils.c
index 5005178804..4f3cf86dca 100644
--- a/media/ffvpx/libavutil/imgutils.c
+++ b/media/ffvpx/libavutil/imgutils.c
@@ -499,7 +499,6 @@ int av_image_copy_to_buffer(uint8_t *dst, int dst_size,
 static void memset_bytes(uint8_t *dst, size_t dst_size, uint8_t *clear,
                          size_t clear_size)
 {
-    size_t pos = 0;
     int same = 1;
     int i;
 
@@ -519,28 +518,12 @@ static void memset_bytes(uint8_t *dst, size_t dst_size, uint8_t *clear,
     if (clear_size == 1) {
         memset(dst, clear[0], dst_size);
         dst_size = 0;
-    } else if (clear_size == 2) {
-        uint16_t val = AV_RN16(clear);
-        for (; dst_size >= 2; dst_size -= 2) {
-            AV_WN16(dst, val);
-            dst += 2;
-        }
-    } else if (clear_size == 4) {
-        uint32_t val = AV_RN32(clear);
-        for (; dst_size >= 4; dst_size -= 4) {
-            AV_WN32(dst, val);
-            dst += 4;
-        }
-    } else if (clear_size == 8) {
-        uint32_t val = AV_RN64(clear);
-        for (; dst_size >= 8; dst_size -= 8) {
-            AV_WN64(dst, val);
-            dst += 8;
-        }
+    } else {
+        if (clear_size > dst_size)
+            clear_size = dst_size;
+        memcpy(dst, clear, clear_size);
+        av_memcpy_backptr(dst + clear_size, clear_size, dst_size - clear_size);
     }
-
-    for (; dst_size; dst_size--)
-        *dst++ = clear[pos++ % clear_size];
 }
 
 // Maximum size in bytes of a plane element (usually a pixel, or multiple pixels
diff --git a/media/ffvpx/libavutil/mem.c b/media/ffvpx/libavutil/mem.c
index 36740f1154..4f7ac75df1 100644
--- a/media/ffvpx/libavutil/mem.c
+++ b/media/ffvpx/libavutil/mem.c
@@ -385,6 +385,18 @@ static void fill32(uint8_t *dst, int len)
 {
     uint32_t v = AV_RN32(dst - 4);
 
+#if HAVE_FAST_64BIT
+    uint64_t v2= v + ((uint64_t)v<<32);
+    while (len >= 32) {
+        AV_WN64(dst   , v2);
+        AV_WN64(dst+ 8, v2);
+        AV_WN64(dst+16, v2);
+        AV_WN64(dst+24, v2);
+        dst += 32;
+        len -= 32;
+    }
+#endif
+
     while (len >= 4) {
         AV_WN32(dst, v);
         dst += 4;