diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 9a309c348e..c9335f39fa 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -381,6 +381,7 @@ OBJS-$(CONFIG_HQ_HQA_DECODER)          += hq_hqa.o hq_hqadata.o hq_hqadsp.o \
 OBJS-$(CONFIG_HQX_DECODER)             += hqx.o hqxvlc.o hqxdsp.o canopus.o
 OBJS-$(CONFIG_HUFFYUV_DECODER)         += huffyuv.o huffyuvdec.o
 OBJS-$(CONFIG_HUFFYUV_ENCODER)         += huffyuv.o huffyuvenc.o
+OBJS-$(CONFIG_HYMT_DECODER)            += huffyuv.o huffyuvdec.o
 OBJS-$(CONFIG_IDCIN_DECODER)           += idcinvideo.o
 OBJS-$(CONFIG_IDF_DECODER)             += bintext.o cga_data.o
 OBJS-$(CONFIG_IFF_ILBM_DECODER)        += iff.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index b1d1ef26c0..53ab6e0025 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -151,6 +151,7 @@ extern AVCodec ff_hq_hqa_decoder;
 extern AVCodec ff_hqx_decoder;
 extern AVCodec ff_huffyuv_encoder;
 extern AVCodec ff_huffyuv_decoder;
+extern AVCodec ff_hymt_decoder;
 extern AVCodec ff_idcin_decoder;
 extern AVCodec ff_iff_ilbm_decoder;
 extern AVCodec ff_imm4_decoder;
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 2a4be2ca4f..d428be4741 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -449,6 +449,7 @@ enum AVCodecID {
     AV_CODEC_ID_FITS,
     AV_CODEC_ID_IMM4,
     AV_CODEC_ID_PROSUMER,
+    AV_CODEC_ID_HYMT,
 
     /* various PCM "codecs" */
     AV_CODEC_ID_FIRST_AUDIO = 0x10000,     ///< A dummy id pointing at the start of audio codecs
diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
index e611183599..362dc253c2 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -1668,6 +1668,13 @@ static const AVCodecDescriptor codec_descriptors[] = {
         .long_name = NULL_IF_CONFIG_SMALL("Brooktree ProSumer Video"),
         .props     = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSY,
     },
+    {
+        .id        = AV_CODEC_ID_HYMT,
+        .type      = AVMEDIA_TYPE_VIDEO,
+        .name      = "hymt",
+        .long_name = NULL_IF_CONFIG_SMALL("HuffYUV MT"),
+        .props     = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSLESS,
+    },
 
     /* various PCM "codecs" */
     {
diff --git a/libavcodec/huffyuvdec.c b/libavcodec/huffyuvdec.c
index 66357bfb40..b5b65510ed 100644
--- a/libavcodec/huffyuvdec.c
+++ b/libavcodec/huffyuvdec.c
@@ -905,54 +905,23 @@ static void add_median_prediction(HYuvContext *s, uint8_t *dst, const uint8_t *s
         s->hdsp.add_hfyu_median_pred_int16((uint16_t *)dst, (const uint16_t *)src, (const uint16_t *)diff, s->n-1, w, left, left_top);
     }
 }
-static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
-                        AVPacket *avpkt)
+
+static int decode_slice(AVCodecContext *avctx, AVFrame *p, int height,
+                        int buf_size, int y_offset)
 {
-    const uint8_t *buf = avpkt->data;
-    int buf_size       = avpkt->size;
     HYuvContext *s = avctx->priv_data;
+    int fake_ystride, fake_ustride, fake_vstride;
     const int width  = s->width;
     const int width2 = s->width >> 1;
-    const int height = s->height;
-    int fake_ystride, fake_ustride, fake_vstride;
-    ThreadFrame frame = { .f = data };
-    AVFrame *const p = data;
-    int table_size = 0, ret;
-
-    if (buf_size < (width * height + 7)/8)
-        return AVERROR_INVALIDDATA;
-
-    av_fast_padded_malloc(&s->bitstream_buffer,
-                   &s->bitstream_buffer_size,
-                   buf_size);
-    if (!s->bitstream_buffer)
-        return AVERROR(ENOMEM);
-
-    s->bdsp.bswap_buf((uint32_t *) s->bitstream_buffer,
-                      (const uint32_t *) buf, buf_size / 4);
-
-    if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
-        return ret;
-
-    if (s->context) {
-        table_size = read_huffman_tables(s, s->bitstream_buffer, buf_size);
-        if (table_size < 0)
-            return table_size;
-    }
-
-    if ((unsigned) (buf_size - table_size) >= INT_MAX / 8)
-        return AVERROR_INVALIDDATA;
+    int ret;
 
-    if ((ret = init_get_bits(&s->gb, s->bitstream_buffer + table_size,
-                             (buf_size - table_size) * 8)) < 0)
+    if ((ret = init_get_bits8(&s->gb, s->bitstream_buffer, buf_size)) < 0)
         return ret;
 
     fake_ystride = s->interlaced ? p->linesize[0] * 2 : p->linesize[0];
     fake_ustride = s->interlaced ? p->linesize[1] * 2 : p->linesize[1];
     fake_vstride = s->interlaced ? p->linesize[2] * 2 : p->linesize[2];
 
-    s->last_slice_end = 0;
-
     if (s->version > 2) {
         int plane;
         for(plane = 0; plane < 1 + 2*s->chroma + s->alpha; plane++) {
@@ -1034,31 +1003,31 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
             return AVERROR_PATCHWELCOME;
         } else {
             leftv         =
-            p->data[2][0] = get_bits(&s->gb, 8);
+            p->data[2][0 + y_offset * p->linesize[2]] = get_bits(&s->gb, 8);
             lefty         =
-            p->data[0][1] = get_bits(&s->gb, 8);
+            p->data[0][1 + y_offset * p->linesize[0]] = get_bits(&s->gb, 8);
             leftu         =
-            p->data[1][0] = get_bits(&s->gb, 8);
-            p->data[0][0] = get_bits(&s->gb, 8);
+            p->data[1][0 + y_offset * p->linesize[1]] = get_bits(&s->gb, 8);
+            p->data[0][0 + y_offset * p->linesize[0]] = get_bits(&s->gb, 8);
 
             switch (s->predictor) {
             case LEFT:
             case PLANE:
                 decode_422_bitstream(s, width - 2);
-                lefty = s->llviddsp.add_left_pred(p->data[0] + 2, s->temp[0],
+                lefty = s->llviddsp.add_left_pred(p->data[0] + p->linesize[0] * y_offset + 2, s->temp[0],
                                                    width - 2, lefty);
                 if (!(s->flags & AV_CODEC_FLAG_GRAY)) {
-                    leftu = s->llviddsp.add_left_pred(p->data[1] + 1, s->temp[1], width2 - 1, leftu);
-                    leftv = s->llviddsp.add_left_pred(p->data[2] + 1, s->temp[2], width2 - 1, leftv);
+                    leftu = s->llviddsp.add_left_pred(p->data[1] + p->linesize[1] * y_offset + 1, s->temp[1], width2 - 1, leftu);
+                    leftv = s->llviddsp.add_left_pred(p->data[2] + p->linesize[2] * y_offset + 1, s->temp[2], width2 - 1, leftv);
                 }
 
-                for (cy = y = 1; y < s->height; y++, cy++) {
+                for (cy = y = 1; y < height; y++, cy++) {
                     uint8_t *ydst, *udst, *vdst;
 
                     if (s->bitstream_bpp == 12) {
                         decode_gray_bitstream(s, width);
 
-                        ydst = p->data[0] + p->linesize[0] * y;
+                        ydst = p->data[0] + p->linesize[0] * (y + y_offset);
 
                         lefty = s->llviddsp.add_left_pred(ydst, s->temp[0],
                                                            width, lefty);
@@ -1067,15 +1036,15 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
                                 s->llviddsp.add_bytes(ydst, ydst - fake_ystride, width);
                         }
                         y++;
-                        if (y >= s->height)
+                        if (y >= height)
                             break;
                     }
 
                     draw_slice(s, p, y);
 
-                    ydst = p->data[0] + p->linesize[0] * y;
-                    udst = p->data[1] + p->linesize[1] * cy;
-                    vdst = p->data[2] + p->linesize[2] * cy;
+                    ydst = p->data[0] + p->linesize[0] * (y  + y_offset);
+                    udst = p->data[1] + p->linesize[1] * (cy + y_offset);
+                    vdst = p->data[2] + p->linesize[2] * (cy + y_offset);
 
                     decode_422_bitstream(s, width);
                     lefty = s->llviddsp.add_left_pred(ydst, s->temp[0],
@@ -1185,7 +1154,7 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
     } else {
         int y;
         uint8_t left[4];
-        const int last_line = (height - 1) * p->linesize[0];
+        const int last_line = (y_offset + height - 1) * p->linesize[0];
 
         if (s->bitstream_bpp == 32) {
             left[A] = p->data[0][last_line + A] = get_bits(&s->gb, 8);
@@ -1208,17 +1177,17 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
                 s->hdsp.add_hfyu_left_pred_bgr32(p->data[0] + last_line + 4,
                                                  s->temp[0], width - 1, left);
 
-                for (y = s->height - 2; y >= 0; y--) { // Yes it is stored upside down.
+                for (y = height - 2; y >= 0; y--) { // Yes it is stored upside down.
                     decode_bgr_bitstream(s, width);
 
-                    s->hdsp.add_hfyu_left_pred_bgr32(p->data[0] + p->linesize[0] * y,
+                    s->hdsp.add_hfyu_left_pred_bgr32(p->data[0] + p->linesize[0] * (y + y_offset),
                                                      s->temp[0], width, left);
                     if (s->predictor == PLANE) {
                         if (s->bitstream_bpp != 32)
                             left[A] = 0;
-                        if (y < s->height - 1 - s->interlaced) {
-                            s->llviddsp.add_bytes(p->data[0] + p->linesize[0] * y,
-                                              p->data[0] + p->linesize[0] * y +
+                        if (y < height - 1 - s->interlaced) {
+                            s->llviddsp.add_bytes(p->data[0] + p->linesize[0] * (y + y_offset),
+                                              p->data[0] + p->linesize[0] * (y + y_offset) +
                                               fake_ystride, 4 * width);
                         }
                     }
@@ -1236,7 +1205,82 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
             return AVERROR_PATCHWELCOME;
         }
     }
-    emms_c();
+
+    return 0;
+}
+
+static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
+                        AVPacket *avpkt)
+{
+    const uint8_t *buf = avpkt->data;
+    int buf_size       = avpkt->size;
+    HYuvContext *s = avctx->priv_data;
+    const int width  = s->width;
+    const int height = s->height;
+    ThreadFrame frame = { .f = data };
+    AVFrame *const p = data;
+    int slice, table_size = 0, ret, nb_slices;
+    unsigned slices_info_offset;
+    int slice_height;
+
+    if (buf_size < (width * height + 7)/8)
+        return AVERROR_INVALIDDATA;
+
+    av_fast_padded_malloc(&s->bitstream_buffer,
+                   &s->bitstream_buffer_size,
+                   buf_size);
+    if (!s->bitstream_buffer)
+        return AVERROR(ENOMEM);
+
+    s->bdsp.bswap_buf((uint32_t *) s->bitstream_buffer,
+                      (const uint32_t *) buf, buf_size / 4);
+
+    if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
+        return ret;
+
+    if (s->context) {
+        table_size = read_huffman_tables(s, s->bitstream_buffer, buf_size);
+        if (table_size < 0)
+            return table_size;
+    }
+
+    if ((unsigned) (buf_size - table_size) >= INT_MAX / 8)
+        return AVERROR_INVALIDDATA;
+
+    s->last_slice_end = 0;
+
+    if (avctx->codec_id == AV_CODEC_ID_HYMT &&
+        (buf_size > 32 && AV_RL32(avpkt->data + buf_size - 16) == 0)) {
+        slices_info_offset = AV_RL32(avpkt->data + buf_size - 4);
+        slice_height = AV_RL32(avpkt->data + buf_size - 8);
+        nb_slices = AV_RL32(avpkt->data + buf_size - 12);
+        if (nb_slices * 8LL + slices_info_offset > buf_size - 16)
+            return AVERROR_INVALIDDATA;
+    } else {
+        slice_height = height;
+        nb_slices = 1;
+    }
+
+    for (slice = 0; slice < nb_slices; slice++) {
+        int y_offset, slice_offset, slice_size;
+
+        if (nb_slices > 1) {
+            slice_offset = AV_RL32(avpkt->data + slices_info_offset + slice * 8);
+            slice_size = AV_RL32(avpkt->data + slices_info_offset + slice * 8 + 4);
+            y_offset = height - (slice + 1) * slice_height;
+        } else {
+            y_offset = 0;
+            slice_offset = 0;
+            slice_size = buf_size;
+        }
+        s->bdsp.bswap_buf((uint32_t *)s->bitstream_buffer,
+                          (const uint32_t *)(buf + slice_offset), slice_size / 4);
+
+        ret = decode_slice(avctx, p, slice_height, slice_size, y_offset);
+        emms_c();
+        if (ret < 0)
+            return ret;
+    }
 
     *got_frame = 1;
 
@@ -1272,3 +1316,19 @@ AVCodec ff_ffvhuff_decoder = {
     .init_thread_copy = ONLY_IF_THREADS_ENABLED(decode_init_thread_copy),
 };
 #endif /* CONFIG_FFVHUFF_DECODER */
+
+#if CONFIG_HYMT_DECODER
+AVCodec ff_hymt_decoder = {
+    .name             = "hymt",
+    .long_name        = NULL_IF_CONFIG_SMALL("HuffYUV MT"),
+    .type             = AVMEDIA_TYPE_VIDEO,
+    .id               = AV_CODEC_ID_HYMT,
+    .priv_data_size   = sizeof(HYuvContext),
+    .init             = decode_init,
+    .close            = decode_end,
+    .decode           = decode_frame,
+    .capabilities     = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DRAW_HORIZ_BAND |
+                        AV_CODEC_CAP_FRAME_THREADS,
+    .init_thread_copy = ONLY_IF_THREADS_ENABLED(decode_init_thread_copy),
+};
+#endif /* CONFIG_HYMT_DECODER */
diff --git a/libavformat/riff.c b/libavformat/riff.c
index cf27d0dfd5..7385125bbb 100644
--- a/libavformat/riff.c
+++ b/libavformat/riff.c
@@ -472,6 +472,7 @@ const AVCodecTag ff_codec_bmp_tags[] = {
     { AV_CODEC_ID_SRGC,         MKTAG('S', 'R', 'G', 'C') },
     { AV_CODEC_ID_IMM4,         MKTAG('I', 'M', 'M', '4') },
     { AV_CODEC_ID_PROSUMER,     MKTAG('B', 'T', '2', '0') },
+    { AV_CODEC_ID_HYMT,         MKTAG('H', 'Y', 'M', 'T') },
     { AV_CODEC_ID_NONE,         0 }
 };
 
