diff --git a/libavcodec/magicyuv.c b/libavcodec/magicyuv.c
index 539da54c2f..3573db0f0a 100644
--- a/libavcodec/magicyuv.c
+++ b/libavcodec/magicyuv.c
@@ -73,12 +73,16 @@ typedef struct MagicYUVContext {
     int (*magy_decode_slice)(AVCodecContext *avctx, void *tdata,
                              int j, int threadnr);
     LLVidDSPContext   llviddsp;
+    HuffEntry         he[1 << 14];
+    uint8_t           len[1 << 14];
 } MagicYUVContext;
 
-static int huff_build(const uint8_t len[], uint16_t codes_pos[33],
+static int huff_build(AVCodecContext *avctx,
+                      const uint8_t len[], uint16_t codes_pos[33],
                       VLC *vlc, VLC_MULTI *multi, int nb_elems, void *logctx)
 {
-    HuffEntry he[4096];
+    MagicYUVContext *s = avctx->priv_data;
+    HuffEntry *he = s->he;
 
     for (int i = 31; i > 0; i--)
         codes_pos[i] += codes_pos[i + 1];
@@ -381,7 +385,7 @@ static int build_huffman(AVCodecContext *avctx, const uint8_t *table,
 {
     MagicYUVContext *s = avctx->priv_data;
     GetByteContext gb;
-    uint8_t len[4096];
+    uint8_t *len = s->len;
     uint16_t length_count[33] = { 0 };
     int i = 0, j = 0, k;
 
@@ -409,7 +413,7 @@ static int build_huffman(AVCodecContext *avctx, const uint8_t *table,
 
         if (j == max) {
             j = 0;
-            if (huff_build(len, length_count, &s->vlc[i], &s->multi[i], max, avctx)) {
+            if (huff_build(avctx, len, length_count, &s->vlc[i], &s->multi[i], max, avctx)) {
                 av_log(avctx, AV_LOG_ERROR, "Cannot build Huffman codes\n");
                 return AVERROR_INVALIDDATA;
             }
@@ -526,6 +530,16 @@ static int magy_decode_frame(AVCodecContext *avctx, AVFrame *p,
         s->decorrelate = 1;
         s->bps = 12;
         break;
+    case 0x71:
+        avctx->pix_fmt = AV_PIX_FMT_GBRP14;
+        s->decorrelate = 1;
+        s->bps = 14;
+        break;
+    case 0x72:
+        avctx->pix_fmt = AV_PIX_FMT_GBRAP14;
+        s->decorrelate = 1;
+        s->bps = 14;
+        break;
     case 0x73:
         avctx->pix_fmt = AV_PIX_FMT_GRAY10;
         s->bps = 10;
@@ -653,7 +667,9 @@ static int magy_decode_frame(AVCodecContext *avctx, AVFrame *p,
         avctx->pix_fmt == AV_PIX_FMT_GBRP10 ||
         avctx->pix_fmt == AV_PIX_FMT_GBRAP10||
         avctx->pix_fmt == AV_PIX_FMT_GBRAP12||
-        avctx->pix_fmt == AV_PIX_FMT_GBRP12) {
+        avctx->pix_fmt == AV_PIX_FMT_GBRAP14||
+        avctx->pix_fmt == AV_PIX_FMT_GBRP12||
+        avctx->pix_fmt == AV_PIX_FMT_GBRP14) {
         FFSWAP(uint8_t*, p->data[0], p->data[1]);
         FFSWAP(int, p->linesize[0], p->linesize[1]);
     } else {
diff --git a/libavformat/isom_tags.c b/libavformat/isom_tags.c
index 4738171a9c..4e0727bb45 100644
--- a/libavformat/isom_tags.c
+++ b/libavformat/isom_tags.c
@@ -260,6 +260,8 @@ const AVCodecTag ff_codec_movvideo_tags[] = {
     { AV_CODEC_ID_MAGICYUV, MKTAG('M', '8', 'Y', 'A') },
     { AV_CODEC_ID_MAGICYUV, MKTAG('M', '2', 'R', 'A') },
     { AV_CODEC_ID_MAGICYUV, MKTAG('M', '2', 'R', 'G') },
+    { AV_CODEC_ID_MAGICYUV, MKTAG('M', '4', 'R', 'A') },
+    { AV_CODEC_ID_MAGICYUV, MKTAG('M', '4', 'R', 'G') },
 
     { AV_CODEC_ID_SHEERVIDEO, MKTAG('S', 'h', 'r', '0') },
     { AV_CODEC_ID_SHEERVIDEO, MKTAG('S', 'h', 'r', '1') },
diff --git a/libavformat/riff.c b/libavformat/riff.c
index 97708df6e3..51d23b290e 100644
--- a/libavformat/riff.c
+++ b/libavformat/riff.c
@@ -463,6 +463,8 @@ const AVCodecTag ff_codec_bmp_tags[] = {
     { AV_CODEC_ID_MAGICYUV,     MKTAG('M', '0', 'Y', '4') },
     { AV_CODEC_ID_MAGICYUV,     MKTAG('M', '2', 'R', 'A') },
     { AV_CODEC_ID_MAGICYUV,     MKTAG('M', '2', 'R', 'G') },
+    { AV_CODEC_ID_MAGICYUV,     MKTAG('M', '4', 'R', 'A') },
+    { AV_CODEC_ID_MAGICYUV,     MKTAG('M', '4', 'R', 'G') },
     { AV_CODEC_ID_YLC,          MKTAG('Y', 'L', 'C', '0') },
     { AV_CODEC_ID_SPEEDHQ,      MKTAG('S', 'H', 'Q', '0') },
     { AV_CODEC_ID_SPEEDHQ,      MKTAG('S', 'H', 'Q', '1') },