@@ -142,8 +142,16 @@ int ff_frame_thread_encoder_init(AVCodecContext *avctx, AVDictionary *options){

     if (avctx->codec_id == AV_CODEC_ID_HUFFYUV ||

         avctx->codec_id == AV_CODEC_ID_FFVHUFF) {

+        int warn = 0;

+        if (avctx->flags & CODEC_FLAG_PASS1)

+            warn = 1;

+        else if(avctx->context_model > 0) {

+            AVDictionaryEntry *t = av_dict_get(options, "non_deterministic",

+                                               NULL, AV_DICT_MATCH_CASE);

+            warn = !t || !t->value || !atoi(t->value) ? 1 : 0;

+        }

         // huffyuv does not support these with multiple frame threads currently

-        if (avctx->context_model > 0 || (avctx->flags & CODEC_FLAG_PASS1)) {

+        if (warn) {

             av_log(avctx, AV_LOG_WARNING,

                "Forcing thread count to 1 for huffyuv encoding with first pass or context 1\n");

             avctx->thread_count = 1;

@@ -52,6 +52,7 @@ typedef enum Predictor {

 } Predictor;

 typedef struct HYuvContext {

+    AVClass *class;

     AVCodecContext *avctx;

     Predictor predictor;

     GetBitContext gb;

@@ -88,6 +89,7 @@ typedef struct HYuvContext {

     HuffYUVDSPContext hdsp;

     HuffYUVEncDSPContext hencdsp;

     LLVidDSPContext llviddsp;

+    int non_determ; // non-deterministic, multi-threaded encoder allowed

 } HYuvContext;

 void ff_huffyuv_common_init(AVCodecContext *s);

@@ -34,6 +34,7 @@

 #include "huffyuvencdsp.h"

 #include "internal.h"

 #include "put_bits.h"

+#include "libavutil/opt.h"

 #include "libavutil/pixdesc.h"

 static inline void diff_bytes(HYuvContext *s, uint8_t *dst,

@@ -990,6 +991,27 @@ static av_cold int encode_end(AVCodecContext *avctx)

     return 0;

 }

+static const AVOption options[] = {

+    { "non_deterministic", "Allow multithreading for e.g. context=1 at the expense of determinism",

+      offsetof(HYuvContext, non_determ), AV_OPT_TYPE_INT, { .i64 = 1 },

+      0, 1, AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM },

+    { NULL },

+};

+

+static const AVClass normal_class = {

+    .class_name = "huffyuv",

+    .item_name  = av_default_item_name,

+    .option     = options,

+    .version    = LIBAVUTIL_VERSION_INT,

+};

+

+static const AVClass ff_class = {

+    .class_name = "ffvhuff",

+    .item_name  = av_default_item_name,

+    .option     = options,

+    .version    = LIBAVUTIL_VERSION_INT,

+};

+

 AVCodec ff_huffyuv_encoder = {

     .name           = "huffyuv",

     .long_name      = NULL_IF_CONFIG_SMALL("Huffyuv / HuffYUV"),

@@ -1000,6 +1022,7 @@ AVCodec ff_huffyuv_encoder = {

     .encode2        = encode_frame,

     .close          = encode_end,

     .capabilities   = CODEC_CAP_FRAME_THREADS | CODEC_CAP_INTRA_ONLY,

+    .priv_class     = &normal_class,

     .pix_fmts       = (const enum AVPixelFormat[]){

         AV_PIX_FMT_YUV422P, AV_PIX_FMT_RGB24,

         AV_PIX_FMT_RGB32, AV_PIX_FMT_NONE

@@ -1017,6 +1040,7 @@ AVCodec ff_ffvhuff_encoder = {

     .encode2        = encode_frame,

     .close          = encode_end,

     .capabilities   = CODEC_CAP_FRAME_THREADS | CODEC_CAP_INTRA_ONLY,

+    .priv_class     = &ff_class,

     .pix_fmts       = (const enum AVPixelFormat[]){

         AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV411P,

         AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV440P,