diff --git a/doc/multithreading.txt b/doc/multithreading.txt
index 5b9dcb0bfc..4f645dc147 100644
--- a/doc/multithreading.txt
+++ b/doc/multithreading.txt
@@ -51,9 +51,6 @@ the decode process starts. Call ff_thread_finish_setup() afterwards. If
 some code can't be moved, have update_thread_context() run it in the next
 thread.
 
-If the codec allocates writable tables in its init(), add an init_thread_copy()
-which re-allocates them for other threads.
-
 Add AV_CODEC_CAP_FRAME_THREADS to the codec capabilities. There will be very little
 speed gain at this point but it should work.
 
diff --git a/libavcodec/aic.c b/libavcodec/aic.c
index 956d71fcff..f027fa99ef 100644
--- a/libavcodec/aic.c
+++ b/libavcodec/aic.c
@@ -504,6 +504,5 @@ AVCodec ff_aic_decoder = {
     .close          = aic_decode_close,
     .decode         = aic_decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(aic_decode_init),
     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
 };
diff --git a/libavcodec/alac.c b/libavcodec/alac.c
index ea5ab182f9..c8c04223a0 100644
--- a/libavcodec/alac.c
+++ b/libavcodec/alac.c
@@ -601,15 +601,6 @@ static av_cold int alac_decode_init(AVCodecContext * avctx)
     return 0;
 }
 
-#if HAVE_THREADS
-static int init_thread_copy(AVCodecContext *avctx)
-{
-    ALACContext *alac = avctx->priv_data;
-    alac->avctx = avctx;
-    return allocate_buffers(alac);
-}
-#endif
-
 static const AVOption options[] = {
     { "extra_bits_bug", "Force non-standard decoding process",
       offsetof(ALACContext, extra_bit_bug), AV_OPT_TYPE_BOOL, { .i64 = 0 },
@@ -633,7 +624,6 @@ AVCodec ff_alac_decoder = {
     .init           = alac_decode_init,
     .close          = alac_decode_close,
     .decode         = alac_decode_frame,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(init_thread_copy),
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
     .priv_class     = &alac_class
 };
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 6da0d02a61..55151a0b71 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -2634,12 +2634,6 @@ typedef struct AVCodec {
      * @name Frame-level threading support functions
      * @{
      */
-    /**
-     * If defined, called on thread contexts when they are created.
-     * If the codec allocates writable tables in init(), re-allocate them here.
-     * priv_data will be set to a copy of the original.
-     */
-    int (*init_thread_copy)(AVCodecContext *);
     /**
      * Copy necessary context variables from a previous thread context to the current one.
      * If not defined, the next thread will start automatically; otherwise, the codec
diff --git a/libavcodec/cfhd.c b/libavcodec/cfhd.c
index b4d6b25cbc..7956367b49 100644
--- a/libavcodec/cfhd.c
+++ b/libavcodec/cfhd.c
@@ -1039,10 +1039,8 @@ static av_cold int cfhd_close(AVCodecContext *avctx)
 
     free_buffers(s);
 
-    if (!avctx->internal->is_copy) {
-        ff_free_vlc(&s->vlc_9);
-        ff_free_vlc(&s->vlc_18);
-    }
+    ff_free_vlc(&s->vlc_9);
+    ff_free_vlc(&s->vlc_18);
 
     return 0;
 }
diff --git a/libavcodec/cllc.c b/libavcodec/cllc.c
index af0f6da2e9..1f2c98ef73 100644
--- a/libavcodec/cllc.c
+++ b/libavcodec/cllc.c
@@ -483,19 +483,6 @@ static int cllc_decode_frame(AVCodecContext *avctx, void *data,
     return avpkt->size;
 }
 
-#if HAVE_THREADS
-static int cllc_init_thread_copy(AVCodecContext *avctx)
-{
-    CLLCContext *ctx = avctx->priv_data;
-
-    ctx->avctx            = avctx;
-    ctx->swapped_buf      = NULL;
-    ctx->swapped_buf_size = 0;
-
-    return 0;
-}
-#endif
-
 static av_cold int cllc_decode_close(AVCodecContext *avctx)
 {
     CLLCContext *ctx = avctx->priv_data;
@@ -526,7 +513,6 @@ AVCodec ff_cllc_decoder = {
     .id             = AV_CODEC_ID_CLLC,
     .priv_data_size = sizeof(CLLCContext),
     .init           = cllc_decode_init,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(cllc_init_thread_copy),
     .decode         = cllc_decode_frame,
     .close          = cllc_decode_close,
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
diff --git a/libavcodec/dnxhddec.c b/libavcodec/dnxhddec.c
index f7585458b9..e5d01e2e71 100644
--- a/libavcodec/dnxhddec.c
+++ b/libavcodec/dnxhddec.c
@@ -144,21 +144,6 @@ static int dnxhd_init_vlc(DNXHDContext *ctx, uint32_t cid, int bitdepth)
     return 0;
 }
 
-static av_cold int dnxhd_decode_init_thread_copy(AVCodecContext *avctx)
-{
-    DNXHDContext *ctx = avctx->priv_data;
-
-    ctx->avctx = avctx;
-    // make sure VLC tables will be loaded when cid is parsed
-    ctx->cid = -1;
-
-    ctx->rows = av_mallocz_array(avctx->thread_count, sizeof(RowContext));
-    if (!ctx->rows)
-        return AVERROR(ENOMEM);
-
-    return 0;
-}
-
 static int dnxhd_get_profile(int cid)
 {
     switch(cid) {
@@ -740,6 +725,5 @@ AVCodec ff_dnxhd_decoder = {
     .decode         = dnxhd_decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS |
                       AV_CODEC_CAP_SLICE_THREADS,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(dnxhd_decode_init_thread_copy),
     .profiles       = NULL_IF_CONFIG_SMALL(ff_dnxhd_profiles),
 };
diff --git a/libavcodec/exr.c b/libavcodec/exr.c
index 1db30a1ae0..73419eadb1 100644
--- a/libavcodec/exr.c
+++ b/libavcodec/exr.c
@@ -1863,20 +1863,6 @@ static av_cold int decode_init(AVCodecContext *avctx)
     return 0;
 }
 
-#if HAVE_THREADS
-static int decode_init_thread_copy(AVCodecContext *avctx)
-{
-    EXRContext *s = avctx->priv_data;
-
-    // allocate thread data, used for non EXR_RAW compression types
-    s->thread_data = av_mallocz_array(avctx->thread_count, sizeof(EXRThreadData));
-    if (!s->thread_data)
-        return AVERROR_INVALIDDATA;
-
-    return 0;
-}
-#endif
-
 static av_cold int decode_end(AVCodecContext *avctx)
 {
     EXRContext *s = avctx->priv_data;
@@ -1956,7 +1942,6 @@ AVCodec ff_exr_decoder = {
     .id               = AV_CODEC_ID_EXR,
     .priv_data_size   = sizeof(EXRContext),
     .init             = decode_init,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(decode_init_thread_copy),
     .close            = decode_end,
     .decode           = decode_frame,
     .capabilities     = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS |
diff --git a/libavcodec/ffv1dec.c b/libavcodec/ffv1dec.c
index 2ffd3ef991..c704373cfe 100644
--- a/libavcodec/ffv1dec.c
+++ b/libavcodec/ffv1dec.c
@@ -977,34 +977,6 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPac
     return buf_size;
 }
 
-#if HAVE_THREADS
-static int init_thread_copy(AVCodecContext *avctx)
-{
-    FFV1Context *f = avctx->priv_data;
-    int i, ret;
-
-    f->picture.f      = NULL;
-    f->last_picture.f = NULL;
-    f->sample_buffer  = NULL;
-    f->max_slice_count = 0;
-    f->slice_count = 0;
-
-    for (i = 0; i < f->quant_table_count; i++) {
-        av_assert0(f->version > 1);
-        f->initial_states[i] = av_memdup(f->initial_states[i],
-                                         f->context_count[i] * sizeof(*f->initial_states[i]));
-    }
-
-    f->picture.f      = av_frame_alloc();
-    f->last_picture.f = av_frame_alloc();
-
-    if ((ret = ff_ffv1_init_slice_contexts(f)) < 0)
-        return ret;
-
-    return 0;
-}
-#endif
-
 static void copy_fields(FFV1Context *fsdst, FFV1Context *fssrc, FFV1Context *fsrc)
 {
     fsdst->version             = fsrc->version;
@@ -1088,7 +1060,6 @@ AVCodec ff_ffv1_decoder = {
     .init           = decode_init,
     .close          = ff_ffv1_close,
     .decode         = decode_frame,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(init_thread_copy),
     .update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context),
     .capabilities   = AV_CODEC_CAP_DR1 /*| AV_CODEC_CAP_DRAW_HORIZ_BAND*/ |
                       AV_CODEC_CAP_FRAME_THREADS | AV_CODEC_CAP_SLICE_THREADS,
diff --git a/libavcodec/flacdec.c b/libavcodec/flacdec.c
index c8eb456049..fb27e8e6d4 100644
--- a/libavcodec/flacdec.c
+++ b/libavcodec/flacdec.c
@@ -639,19 +639,6 @@ static int flac_decode_frame(AVCodecContext *avctx, void *data,
     return bytes_read;
 }
 
-#if HAVE_THREADS
-static int init_thread_copy(AVCodecContext *avctx)
-{
-    FLACContext *s = avctx->priv_data;
-    s->decoded_buffer = NULL;
-    s->decoded_buffer_size = 0;
-    s->avctx = avctx;
-    if (s->flac_stream_info.max_blocksize)
-        return allocate_buffers(s);
-    return 0;
-}
-#endif
-
 static av_cold int flac_decode_close(AVCodecContext *avctx)
 {
     FLACContext *s = avctx->priv_data;
@@ -682,7 +669,6 @@ AVCodec ff_flac_decoder = {
     .init           = flac_decode_init,
     .close          = flac_decode_close,
     .decode         = flac_decode_frame,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(init_thread_copy),
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16,
                                                       AV_SAMPLE_FMT_S16P,
diff --git a/libavcodec/h264dec.c b/libavcodec/h264dec.c
index defe514828..b6c51ed1e2 100644
--- a/libavcodec/h264dec.c
+++ b/libavcodec/h264dec.c
@@ -409,13 +409,15 @@ static av_cold int h264_decode_init(AVCodecContext *avctx)
     }
     avctx->ticks_per_frame = 2;
 
-    if (avctx->extradata_size > 0 && avctx->extradata) {
-        ret = ff_h264_decode_extradata(avctx->extradata, avctx->extradata_size,
-                                       &h->ps, &h->is_avc, &h->nal_length_size,
-                                       avctx->err_recognition, avctx);
-        if (ret < 0) {
-            h264_decode_end(avctx);
-            return ret;
+    if (!avctx->internal->is_copy) {
+        if (avctx->extradata_size > 0 && avctx->extradata) {
+            ret = ff_h264_decode_extradata(avctx->extradata, avctx->extradata_size,
+                                           &h->ps, &h->is_avc, &h->nal_length_size,
+                                           avctx->err_recognition, avctx);
+            if (ret < 0) {
+                h264_decode_end(avctx);
+                return ret;
+            }
         }
     }
 
@@ -438,27 +440,6 @@ static av_cold int h264_decode_init(AVCodecContext *avctx)
     return 0;
 }
 
-#if HAVE_THREADS
-static int decode_init_thread_copy(AVCodecContext *avctx)
-{
-    H264Context *h = avctx->priv_data;
-    int ret;
-
-    if (!avctx->internal->is_copy)
-        return 0;
-
-    memset(h, 0, sizeof(*h));
-
-    ret = h264_init_context(avctx, h);
-    if (ret < 0)
-        return ret;
-
-    h->context_initialized = 0;
-
-    return 0;
-}
-#endif
-
 /**
  * instantaneous decoder refresh.
  */
@@ -1081,7 +1062,6 @@ AVCodec ff_h264_decoder = {
     .caps_internal         = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_EXPORTS_CROPPING |
                              FF_CODEC_CAP_ALLOCATE_PROGRESS,
     .flush                 = flush_dpb,
-    .init_thread_copy      = ONLY_IF_THREADS_ENABLED(decode_init_thread_copy),
     .update_thread_context = ONLY_IF_THREADS_ENABLED(ff_h264_update_thread_context),
     .profiles              = NULL_IF_CONFIG_SMALL(ff_h264_profiles),
     .priv_class            = &h264_class,
diff --git a/libavcodec/hevcdec.c b/libavcodec/hevcdec.c
index 58689a4370..36be83948e 100644
--- a/libavcodec/hevcdec.c
+++ b/libavcodec/hevcdec.c
@@ -3506,11 +3506,13 @@ static av_cold int hevc_decode_init(AVCodecContext *avctx)
     else
         s->threads_number = 1;
 
-    if (avctx->extradata_size > 0 && avctx->extradata) {
-        ret = hevc_decode_extradata(s, avctx->extradata, avctx->extradata_size, 1);
-        if (ret < 0) {
-            hevc_decode_free(avctx);
-            return ret;
+    if (!avctx->internal->is_copy) {
+        if (avctx->extradata_size > 0 && avctx->extradata) {
+            ret = hevc_decode_extradata(s, avctx->extradata, avctx->extradata_size, 1);
+            if (ret < 0) {
+                hevc_decode_free(avctx);
+                return ret;
+            }
         }
     }
 
@@ -3522,22 +3524,6 @@ static av_cold int hevc_decode_init(AVCodecContext *avctx)
     return 0;
 }
 
-#if HAVE_THREADS
-static av_cold int hevc_init_thread_copy(AVCodecContext *avctx)
-{
-    HEVCContext *s = avctx->priv_data;
-    int ret;
-
-    memset(s, 0, sizeof(*s));
-
-    ret = hevc_init_context(avctx);
-    if (ret < 0)
-        return ret;
-
-    return 0;
-}
-#endif
-
 static void hevc_decode_flush(AVCodecContext *avctx)
 {
     HEVCContext *s = avctx->priv_data;
@@ -3577,7 +3563,6 @@ AVCodec ff_hevc_decoder = {
     .decode                = hevc_decode_frame,
     .flush                 = hevc_decode_flush,
     .update_thread_context = ONLY_IF_THREADS_ENABLED(hevc_update_thread_context),
-    .init_thread_copy      = ONLY_IF_THREADS_ENABLED(hevc_init_thread_copy),
     .capabilities          = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY |
                              AV_CODEC_CAP_SLICE_THREADS | AV_CODEC_CAP_FRAME_THREADS,
     .caps_internal         = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_EXPORTS_CROPPING |
diff --git a/libavcodec/hqx.c b/libavcodec/hqx.c
index 39404d24e5..e2b895ac40 100644
--- a/libavcodec/hqx.c
+++ b/libavcodec/hqx.c
@@ -520,9 +520,6 @@ static av_cold int hqx_decode_close(AVCodecContext *avctx)
     int i;
     HQXContext *ctx = avctx->priv_data;
 
-    if (avctx->internal->is_copy)
-        return 0;
-
     ff_free_vlc(&ctx->cbp_vlc);
     for (i = 0; i < 3; i++) {
         ff_free_vlc(&ctx->dc_vlc[i]);
diff --git a/libavcodec/huffyuvdec.c b/libavcodec/huffyuvdec.c
index 46dcfa8235..0ee7ec3917 100644
--- a/libavcodec/huffyuvdec.c
+++ b/libavcodec/huffyuvdec.c
@@ -570,35 +570,6 @@ static av_cold int decode_init(AVCodecContext *avctx)
     return ret;
 }
 
-#if HAVE_THREADS
-static av_cold int decode_init_thread_copy(AVCodecContext *avctx)
-{
-    HYuvContext *s = avctx->priv_data;
-    int i, ret;
-
-    s->avctx = avctx;
-
-    if ((ret = ff_huffyuv_alloc_temp(s)) < 0) {
-        ff_huffyuv_common_end(s);
-        return ret;
-    }
-
-    for (i = 0; i < 8; i++)
-        s->vlc[i].table = NULL;
-
-    if (s->version >= 2) {
-        if ((ret = read_huffman_tables(s, avctx->extradata + 4,
-                                       avctx->extradata_size)) < 0)
-            return ret;
-    } else {
-        if ((ret = read_old_huffman_tables(s)) < 0)
-            return ret;
-    }
-
-    return 0;
-}
-#endif
-
 /** Subset of GET_VLC for use in hand-roller VLC code */
 #define VLC_INTERN(dst, table, gb, name, bits, max_depth)   \
     code = table[index][0];                                 \
@@ -1302,7 +1273,6 @@ AVCodec ff_huffyuv_decoder = {
     .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),
 };
 
 #if CONFIG_FFVHUFF_DECODER
@@ -1317,7 +1287,6 @@ AVCodec ff_ffvhuff_decoder = {
     .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_FFVHUFF_DECODER */
 
@@ -1333,6 +1302,5 @@ AVCodec ff_hymt_decoder = {
     .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/libavcodec/lagarith.c b/libavcodec/lagarith.c
index 0a45812bc1..d81e55cf4c 100644
--- a/libavcodec/lagarith.c
+++ b/libavcodec/lagarith.c
@@ -712,16 +712,6 @@ static av_cold int lag_decode_init(AVCodecContext *avctx)
     return 0;
 }
 
-#if HAVE_THREADS
-static av_cold int lag_decode_init_thread_copy(AVCodecContext *avctx)
-{
-    LagarithContext *l = avctx->priv_data;
-    l->avctx = avctx;
-
-    return 0;
-}
-#endif
-
 AVCodec ff_lagarith_decoder = {
     .name           = "lagarith",
     .long_name      = NULL_IF_CONFIG_SMALL("Lagarith lossless"),
@@ -729,7 +719,6 @@ AVCodec ff_lagarith_decoder = {
     .id             = AV_CODEC_ID_LAGARITH,
     .priv_data_size = sizeof(LagarithContext),
     .init           = lag_decode_init,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(lag_decode_init_thread_copy),
     .decode         = lag_decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
 };
diff --git a/libavcodec/lcldec.c b/libavcodec/lcldec.c
index 046cdc4f8e..c51083bdf2 100644
--- a/libavcodec/lcldec.c
+++ b/libavcodec/lcldec.c
@@ -622,13 +622,6 @@ static av_cold int decode_init(AVCodecContext *avctx)
     return 0;
 }
 
-#if HAVE_THREADS
-static int init_thread_copy(AVCodecContext *avctx)
-{
-    return decode_init(avctx);
-}
-#endif
-
 static av_cold int decode_end(AVCodecContext *avctx)
 {
     LclDecContext * const c = avctx->priv_data;
@@ -650,7 +643,6 @@ AVCodec ff_mszh_decoder = {
     .id             = AV_CODEC_ID_MSZH,
     .priv_data_size = sizeof(LclDecContext),
     .init           = decode_init,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(init_thread_copy),
     .close          = decode_end,
     .decode         = decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
@@ -666,7 +658,6 @@ AVCodec ff_zlib_decoder = {
     .id             = AV_CODEC_ID_ZLIB,
     .priv_data_size = sizeof(LclDecContext),
     .init           = decode_init,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(init_thread_copy),
     .close          = decode_end,
     .decode         = decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
diff --git a/libavcodec/magicyuv.c b/libavcodec/magicyuv.c
index aacd0d4d7d..5d76274d54 100644
--- a/libavcodec/magicyuv.c
+++ b/libavcodec/magicyuv.c
@@ -749,21 +749,6 @@ static int magy_decode_frame(AVCodecContext *avctx, void *data,
     return avpkt->size;
 }
 
-#if HAVE_THREADS
-static int magy_init_thread_copy(AVCodecContext *avctx)
-{
-    MagicYUVContext *s = avctx->priv_data;
-    int i;
-
-    for (i = 0; i < FF_ARRAY_ELEMS(s->slices); i++) {
-        s->slices[i] = NULL;
-        s->slices_size[i] = 0;
-    }
-
-    return 0;
-}
-#endif
-
 static av_cold int magy_decode_init(AVCodecContext *avctx)
 {
     MagicYUVContext *s = avctx->priv_data;
@@ -792,7 +777,6 @@ AVCodec ff_magicyuv_decoder = {
     .id               = AV_CODEC_ID_MAGICYUV,
     .priv_data_size   = sizeof(MagicYUVContext),
     .init             = magy_decode_init,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(magy_init_thread_copy),
     .close            = magy_decode_end,
     .decode           = magy_decode_frame,
     .capabilities     = AV_CODEC_CAP_DR1 |
diff --git a/libavcodec/mdec.c b/libavcodec/mdec.c
index 330b761279..7e34ec568e 100644
--- a/libavcodec/mdec.c
+++ b/libavcodec/mdec.c
@@ -240,17 +240,6 @@ static av_cold int decode_init(AVCodecContext *avctx)
     return 0;
 }
 
-#if HAVE_THREADS
-static av_cold int decode_init_thread_copy(AVCodecContext *avctx)
-{
-    MDECContext * const a = avctx->priv_data;
-
-    a->avctx           = avctx;
-
-    return 0;
-}
-#endif
-
 static av_cold int decode_end(AVCodecContext *avctx)
 {
     MDECContext * const a = avctx->priv_data;
@@ -271,5 +260,4 @@ AVCodec ff_mdec_decoder = {
     .close            = decode_end,
     .decode           = decode_frame,
     .capabilities     = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(decode_init_thread_copy)
 };
diff --git a/libavcodec/mimic.c b/libavcodec/mimic.c
index 8e3a77a334..2563a49d53 100644
--- a/libavcodec/mimic.c
+++ b/libavcodec/mimic.c
@@ -128,8 +128,7 @@ static av_cold int mimic_decode_end(AVCodecContext *avctx)
         av_frame_free(&ctx->frames[i].f);
     }
 
-    if (!avctx->internal->is_copy)
-        ff_free_vlc(&ctx->vlc);
+    ff_free_vlc(&ctx->vlc);
 
     return 0;
 }
@@ -449,24 +448,6 @@ static int mimic_decode_frame(AVCodecContext *avctx, void *data,
     return buf_size;
 }
 
-#if HAVE_THREADS
-static av_cold int mimic_init_thread_copy(AVCodecContext *avctx)
-{
-    MimicContext *ctx = avctx->priv_data;
-    int i;
-
-    for (i = 0; i < FF_ARRAY_ELEMS(ctx->frames); i++) {
-        ctx->frames[i].f = av_frame_alloc();
-        if (!ctx->frames[i].f) {
-            mimic_decode_end(avctx);
-            return AVERROR(ENOMEM);
-        }
-    }
-
-    return 0;
-}
-#endif
-
 AVCodec ff_mimic_decoder = {
     .name                  = "mimic",
     .long_name             = NULL_IF_CONFIG_SMALL("Mimic"),
@@ -478,6 +459,5 @@ AVCodec ff_mimic_decoder = {
     .decode                = mimic_decode_frame,
     .capabilities          = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
     .update_thread_context = ONLY_IF_THREADS_ENABLED(mimic_decode_update_thread_context),
-    .init_thread_copy      = ONLY_IF_THREADS_ENABLED(mimic_init_thread_copy),
     .caps_internal         = FF_CODEC_CAP_ALLOCATE_PROGRESS,
 };
diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c
index de35b330ad..bfb1f92b33 100644
--- a/libavcodec/mpeg4videodec.c
+++ b/libavcodec/mpeg4videodec.c
@@ -3559,13 +3559,11 @@ static av_cold int decode_end(AVCodecContext *avctx)
     Mpeg4DecContext *ctx = avctx->priv_data;
     int i;
 
-    if (!avctx->internal->is_copy) {
-        for (i = 0; i < 12; i++)
-            ff_free_vlc(&ctx->studio_intra_tab[i]);
+    for (i = 0; i < 12; i++)
+        ff_free_vlc(&ctx->studio_intra_tab[i]);
 
-        ff_free_vlc(&ctx->studio_luma_dc);
-        ff_free_vlc(&ctx->studio_chroma_dc);
-    }
+    ff_free_vlc(&ctx->studio_luma_dc);
+    ff_free_vlc(&ctx->studio_chroma_dc);
 
     return ff_h263_decode_end(avctx);
 }
diff --git a/libavcodec/pixlet.c b/libavcodec/pixlet.c
index 03a2cdacc8..7b068b1ce5 100644
--- a/libavcodec/pixlet.c
+++ b/libavcodec/pixlet.c
@@ -675,28 +675,12 @@ static int pixlet_decode_frame(AVCodecContext *avctx, void *data,
     return pktsize;
 }
 
-#if HAVE_THREADS
-static int pixlet_init_thread_copy(AVCodecContext *avctx)
-{
-    PixletContext *ctx = avctx->priv_data;
-
-    ctx->filter[0]  = NULL;
-    ctx->filter[1]  = NULL;
-    ctx->prediction = NULL;
-    ctx->w = 0;
-    ctx->h = 0;
-
-    return 0;
-}
-#endif /* HAVE_THREADS */
-
 AVCodec ff_pixlet_decoder = {
     .name             = "pixlet",
     .long_name        = NULL_IF_CONFIG_SMALL("Apple Pixlet"),
     .type             = AVMEDIA_TYPE_VIDEO,
     .id               = AV_CODEC_ID_PIXLET,
     .init             = pixlet_init,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(pixlet_init_thread_copy),
     .close            = pixlet_close,
     .decode           = pixlet_decode_frame,
     .priv_data_size   = sizeof(PixletContext),
diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index af8608b23b..7e2c19bd57 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -1771,9 +1771,7 @@ static av_cold int png_dec_init(AVCodecContext *avctx)
         return AVERROR(ENOMEM);
     }
 
-    if (!avctx->internal->is_copy) {
-        ff_pngdsp_init(&s->dsp);
-    }
+    ff_pngdsp_init(&s->dsp);
 
     return 0;
 }
@@ -1808,7 +1806,6 @@ AVCodec ff_apng_decoder = {
     .init           = png_dec_init,
     .close          = png_dec_end,
     .decode         = decode_frame_apng,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(png_dec_init),
     .update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context),
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS /*| AV_CODEC_CAP_DRAW_HORIZ_BAND*/,
     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
@@ -1826,7 +1823,6 @@ AVCodec ff_png_decoder = {
     .init           = png_dec_init,
     .close          = png_dec_end,
     .decode         = decode_frame_png,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(png_dec_init),
     .update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context),
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS /*| AV_CODEC_CAP_DRAW_HORIZ_BAND*/,
     .caps_internal  = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM | FF_CODEC_CAP_INIT_THREADSAFE |
diff --git a/libavcodec/proresdec2.c b/libavcodec/proresdec2.c
index 2652a31c81..d5fbfc6711 100644
--- a/libavcodec/proresdec2.c
+++ b/libavcodec/proresdec2.c
@@ -807,17 +807,6 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
     return avpkt->size;
 }
 
-#if HAVE_THREADS
-static int decode_init_thread_copy(AVCodecContext *avctx)
-{
-    ProresContext *ctx = avctx->priv_data;
-
-    ctx->slices = NULL;
-
-    return 0;
-}
-#endif
-
 static av_cold int decode_close(AVCodecContext *avctx)
 {
     ProresContext *ctx = avctx->priv_data;
@@ -834,7 +823,6 @@ AVCodec ff_prores_decoder = {
     .id             = AV_CODEC_ID_PRORES,
     .priv_data_size = sizeof(ProresContext),
     .init           = decode_init,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(decode_init_thread_copy),
     .close          = decode_close,
     .decode         = decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_SLICE_THREADS | AV_CODEC_CAP_FRAME_THREADS,
diff --git a/libavcodec/pthread_frame.c b/libavcodec/pthread_frame.c
index f078790737..69671c90fb 100644
--- a/libavcodec/pthread_frame.c
+++ b/libavcodec/pthread_frame.c
@@ -703,7 +703,10 @@ void ff_frame_thread_free(AVCodecContext *avctx, int thread_count)
         av_freep(&p->released_buffers);
 
         if (i && p->avctx) {
+            if (codec->priv_class)
+                av_opt_free(p->avctx->priv_data);
             av_freep(&p->avctx->priv_data);
+
             av_freep(&p->avctx->slice_offset);
         }
 
@@ -809,28 +812,30 @@ int ff_frame_thread_init(AVCodecContext *avctx)
         copy->internal->thread_ctx = p;
         copy->internal->last_pkt_props = &p->avpkt;
 
-        if (!i) {
-            src = copy;
-
-            if (codec->init)
-                err = codec->init(copy);
-
-            update_context_from_thread(avctx, copy, 1);
-        } else {
-            copy->priv_data = av_malloc(codec->priv_data_size);
+        if (i) {
+            copy->priv_data = av_mallocz(codec->priv_data_size);
             if (!copy->priv_data) {
                 err = AVERROR(ENOMEM);
                 goto error;
             }
-            memcpy(copy->priv_data, src->priv_data, codec->priv_data_size);
-            copy->internal->is_copy = 1;
 
-            if (codec->init_thread_copy)
-                err = codec->init_thread_copy(copy);
+            if (codec->priv_class) {
+                *(const AVClass **)copy->priv_data = codec->priv_class;
+                err = av_opt_copy(copy->priv_data, src->priv_data);
+                if (err < 0)
+                    goto error;
+            }
+            copy->internal->is_copy = 1;
         }
 
+        if (codec->init)
+            err = codec->init(copy);
+
         if (err) goto error;
 
+        if (!i)
+            update_context_from_thread(avctx, copy, 1);
+
         atomic_init(&p->debug_threads, (copy->debug & FF_DEBUG_THREADS) != 0);
 
         err = AVERROR(pthread_create(&p->thread, NULL, frame_worker_thread, p));
diff --git a/libavcodec/rv30.c b/libavcodec/rv30.c
index 0a63352e6b..36cd5345fd 100644
--- a/libavcodec/rv30.c
+++ b/libavcodec/rv30.c
@@ -304,7 +304,6 @@ AVCodec ff_rv30_decoder = {
         AV_PIX_FMT_YUV420P,
         AV_PIX_FMT_NONE
     },
-    .init_thread_copy      = ONLY_IF_THREADS_ENABLED(ff_rv34_decode_init_thread_copy),
     .update_thread_context = ONLY_IF_THREADS_ENABLED(ff_rv34_decode_update_thread_context),
     .caps_internal         = FF_CODEC_CAP_ALLOCATE_PROGRESS,
 };
diff --git a/libavcodec/rv34.c b/libavcodec/rv34.c
index f877258db6..ec0cd27916 100644
--- a/libavcodec/rv34.c
+++ b/libavcodec/rv34.c
@@ -1529,34 +1529,6 @@ av_cold int ff_rv34_decode_init(AVCodecContext *avctx)
     return 0;
 }
 
-int ff_rv34_decode_init_thread_copy(AVCodecContext *avctx)
-{
-    int err;
-    RV34DecContext *r = avctx->priv_data;
-
-    r->s.avctx = avctx;
-
-    if (avctx->internal->is_copy) {
-        r->tmp_b_block_base = NULL;
-        r->cbp_chroma       = NULL;
-        r->cbp_luma         = NULL;
-        r->deblock_coefs    = NULL;
-        r->intra_types_hist = NULL;
-        r->mb_type          = NULL;
-
-        ff_mpv_idct_init(&r->s);
-
-        if ((err = ff_mpv_common_init(&r->s)) < 0)
-            return err;
-        if ((err = rv34_decoder_alloc(r)) < 0) {
-            ff_mpv_common_end(&r->s);
-            return err;
-        }
-    }
-
-    return 0;
-}
-
 int ff_rv34_decode_update_thread_context(AVCodecContext *dst, const AVCodecContext *src)
 {
     RV34DecContext *r = dst->priv_data, *r1 = src->priv_data;
diff --git a/libavcodec/rv34.h b/libavcodec/rv34.h
index efff94a1d9..1d5522538b 100644
--- a/libavcodec/rv34.h
+++ b/libavcodec/rv34.h
@@ -136,7 +136,6 @@ int ff_rv34_get_start_offset(GetBitContext *gb, int blocks);
 int ff_rv34_decode_init(AVCodecContext *avctx);
 int ff_rv34_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt);
 int ff_rv34_decode_end(AVCodecContext *avctx);
-int ff_rv34_decode_init_thread_copy(AVCodecContext *avctx);
 int ff_rv34_decode_update_thread_context(AVCodecContext *dst, const AVCodecContext *src);
 
 #endif /* AVCODEC_RV34_H */
diff --git a/libavcodec/rv40.c b/libavcodec/rv40.c
index ad15044ee3..462024c81e 100644
--- a/libavcodec/rv40.c
+++ b/libavcodec/rv40.c
@@ -583,7 +583,6 @@ AVCodec ff_rv40_decoder = {
         AV_PIX_FMT_YUV420P,
         AV_PIX_FMT_NONE
     },
-    .init_thread_copy      = ONLY_IF_THREADS_ENABLED(ff_rv34_decode_init_thread_copy),
     .update_thread_context = ONLY_IF_THREADS_ENABLED(ff_rv34_decode_update_thread_context),
     .caps_internal         = FF_CODEC_CAP_ALLOCATE_PROGRESS,
 };
diff --git a/libavcodec/sheervideo.c b/libavcodec/sheervideo.c
index 50c3ebcee7..1a43727a30 100644
--- a/libavcodec/sheervideo.c
+++ b/libavcodec/sheervideo.c
@@ -2063,19 +2063,6 @@ static int decode_frame(AVCodecContext *avctx,
     return avpkt->size;
 }
 
-#if HAVE_THREADS
-static int decode_init_thread_copy(AVCodecContext *avctx)
-{
-    SheerVideoContext *s = avctx->priv_data;
-
-    s->format = 0;
-    memset(&s->vlc[0], 0, sizeof(s->vlc[0]));
-    memset(&s->vlc[1], 0, sizeof(s->vlc[1]));
-
-    return 0;
-}
-#endif
-
 static av_cold int decode_end(AVCodecContext *avctx)
 {
     SheerVideoContext *s = avctx->priv_data;
@@ -2092,7 +2079,6 @@ AVCodec ff_sheervideo_decoder = {
     .type             = AVMEDIA_TYPE_VIDEO,
     .id               = AV_CODEC_ID_SHEERVIDEO,
     .priv_data_size   = sizeof(SheerVideoContext),
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(decode_init_thread_copy),
     .close            = decode_end,
     .decode           = decode_frame,
     .capabilities     = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
diff --git a/libavcodec/takdec.c b/libavcodec/takdec.c
index 8ec87ab509..9fa1cb1f7f 100644
--- a/libavcodec/takdec.c
+++ b/libavcodec/takdec.c
@@ -915,13 +915,6 @@ static int tak_decode_frame(AVCodecContext *avctx, void *data,
 }
 
 #if HAVE_THREADS
-static int init_thread_copy(AVCodecContext *avctx)
-{
-    TAKDecContext *s = avctx->priv_data;
-    s->avctx = avctx;
-    return 0;
-}
-
 static int update_thread_context(AVCodecContext *dst,
                                  const AVCodecContext *src)
 {
@@ -953,7 +946,6 @@ AVCodec ff_tak_decoder = {
     .init             = tak_decode_init,
     .close            = tak_decode_close,
     .decode           = tak_decode_frame,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(init_thread_copy),
     .update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context),
     .capabilities     = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
     .sample_fmts      = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P,
diff --git a/libavcodec/tiff.c b/libavcodec/tiff.c
index e8357114de..3b5985ed1e 100644
--- a/libavcodec/tiff.c
+++ b/libavcodec/tiff.c
@@ -2165,7 +2165,6 @@ AVCodec ff_tiff_decoder = {
     .init           = tiff_init,
     .close          = tiff_end,
     .decode         = decode_frame,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(tiff_init),
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
     .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
     .priv_class     = &tiff_decoder_class,
diff --git a/libavcodec/tta.c b/libavcodec/tta.c
index 3fbee06987..e68e4fbb36 100644
--- a/libavcodec/tta.c
+++ b/libavcodec/tta.c
@@ -389,13 +389,6 @@ error:
     return ret;
 }
 
-static int init_thread_copy(AVCodecContext *avctx)
-{
-    TTAContext *s = avctx->priv_data;
-    s->avctx = avctx;
-    return allocate_buffers(avctx);
-}
-
 static av_cold int tta_decode_close(AVCodecContext *avctx) {
     TTAContext *s = avctx->priv_data;
 
@@ -430,7 +423,6 @@ AVCodec ff_tta_decoder = {
     .init           = tta_decode_init,
     .close          = tta_decode_close,
     .decode         = tta_decode_frame,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(init_thread_copy),
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
     .priv_class     = &tta_decoder_class,
 };
diff --git a/libavcodec/vble.c b/libavcodec/vble.c
index c25ee98697..c48c13127a 100644
--- a/libavcodec/vble.c
+++ b/libavcodec/vble.c
@@ -214,6 +214,5 @@ AVCodec ff_vble_decoder = {
     .close          = vble_decode_close,
     .decode         = vble_decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(vble_decode_init),
     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
 };
diff --git a/libavcodec/vp3.c b/libavcodec/vp3.c
index b80a2e1c9d..c45bed8f85 100644
--- a/libavcodec/vp3.c
+++ b/libavcodec/vp3.c
@@ -347,9 +347,6 @@ static av_cold int vp3_decode_end(AVCodecContext *avctx)
     av_frame_free(&s->last_frame.f);
     av_frame_free(&s->golden_frame.f);
 
-    if (avctx->internal->is_copy)
-        return 0;
-
     for (i = 0; i < 16; i++) {
         ff_free_vlc(&s->dc_vlc[i]);
         ff_free_vlc(&s->ac_vlc_1[i]);
@@ -2601,23 +2598,6 @@ static int vp3_update_thread_context(AVCodecContext *dst, const AVCodecContext *
     }
 
     if (s != s1) {
-        if (!s->current_frame.f)
-            return AVERROR(ENOMEM);
-        // init tables if the first frame hasn't been decoded
-        if (!s->current_frame.f->data[0]) {
-            int y_fragment_count, c_fragment_count;
-            s->avctx = dst;
-            err = allocate_tables(dst);
-            if (err)
-                return err;
-            y_fragment_count = s->fragment_width[0] * s->fragment_height[0];
-            c_fragment_count = s->fragment_width[1] * s->fragment_height[1];
-            memcpy(s->motion_val[0], s1->motion_val[0],
-                   y_fragment_count * sizeof(*s->motion_val[0]));
-            memcpy(s->motion_val[1], s1->motion_val[1],
-                   c_fragment_count * sizeof(*s->motion_val[1]));
-        }
-
         // copy previous frame data
         if ((err = ref_frames(s, s1)) < 0)
             return err;
@@ -2927,28 +2907,6 @@ static int read_huffman_tree(AVCodecContext *avctx, GetBitContext *gb)
     return 0;
 }
 
-#if HAVE_THREADS
-static int vp3_init_thread_copy(AVCodecContext *avctx)
-{
-    Vp3DecodeContext *s = avctx->priv_data;
-
-    s->superblock_coding      = NULL;
-    s->all_fragments          = NULL;
-    s->coded_fragment_list[0] = NULL;
-    s-> kf_coded_fragment_list= NULL;
-    s->nkf_coded_fragment_list= NULL;
-    s->dct_tokens_base        = NULL;
-    s->superblock_fragments   = NULL;
-    s->macroblock_coding      = NULL;
-    s->motion_val[0]          = NULL;
-    s->motion_val[1]          = NULL;
-    s->edge_emu_buffer        = NULL;
-    s->dc_pred_row            = NULL;
-
-    return init_frames(s);
-}
-#endif
-
 #if CONFIG_THEORA_DECODER
 static const enum AVPixelFormat theora_pix_fmts[4] = {
     AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV444P
@@ -3262,7 +3220,6 @@ AVCodec ff_theora_decoder = {
     .capabilities          = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DRAW_HORIZ_BAND |
                              AV_CODEC_CAP_FRAME_THREADS,
     .flush                 = vp3_decode_flush,
-    .init_thread_copy      = ONLY_IF_THREADS_ENABLED(vp3_init_thread_copy),
     .update_thread_context = ONLY_IF_THREADS_ENABLED(vp3_update_thread_context),
     .caps_internal         = FF_CODEC_CAP_EXPORTS_CROPPING | FF_CODEC_CAP_ALLOCATE_PROGRESS,
 };
@@ -3280,7 +3237,6 @@ AVCodec ff_vp3_decoder = {
     .capabilities          = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DRAW_HORIZ_BAND |
                              AV_CODEC_CAP_FRAME_THREADS,
     .flush                 = vp3_decode_flush,
-    .init_thread_copy      = ONLY_IF_THREADS_ENABLED(vp3_init_thread_copy),
     .update_thread_context = ONLY_IF_THREADS_ENABLED(vp3_update_thread_context),
     .caps_internal         = FF_CODEC_CAP_ALLOCATE_PROGRESS,
 };
@@ -3298,7 +3254,6 @@ AVCodec ff_vp4_decoder = {
     .capabilities          = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DRAW_HORIZ_BAND |
                              AV_CODEC_CAP_FRAME_THREADS,
     .flush                 = vp3_decode_flush,
-    .init_thread_copy      = ONLY_IF_THREADS_ENABLED(vp3_init_thread_copy),
     .update_thread_context = ONLY_IF_THREADS_ENABLED(vp3_update_thread_context),
     .caps_internal         = FF_CODEC_CAP_ALLOCATE_PROGRESS,
 };
diff --git a/libavcodec/vp8.c b/libavcodec/vp8.c
index 81da0422be..1794d6d031 100644
--- a/libavcodec/vp8.c
+++ b/libavcodec/vp8.c
@@ -2894,21 +2894,6 @@ av_cold int ff_vp8_decode_init(AVCodecContext *avctx)
 
 #if CONFIG_VP8_DECODER
 #if HAVE_THREADS
-static av_cold int vp8_decode_init_thread_copy(AVCodecContext *avctx)
-{
-    VP8Context *s = avctx->priv_data;
-    int ret;
-
-    s->avctx = avctx;
-
-    if ((ret = vp8_init_frames(s)) < 0) {
-        ff_vp8_decode_free(avctx);
-        return ret;
-    }
-
-    return 0;
-}
-
 #define REBASE(pic) ((pic) ? (pic) - &s_src->frames[0] + &s->frames[0] : NULL)
 
 static int vp8_decode_update_thread_context(AVCodecContext *dst,
@@ -2976,7 +2961,6 @@ AVCodec ff_vp8_decoder = {
     .capabilities          = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS |
                              AV_CODEC_CAP_SLICE_THREADS,
     .flush                 = vp8_decode_flush,
-    .init_thread_copy      = ONLY_IF_THREADS_ENABLED(vp8_decode_init_thread_copy),
     .update_thread_context = ONLY_IF_THREADS_ENABLED(vp8_decode_update_thread_context),
     .hw_configs            = (const AVCodecHWConfigInternal*[]) {
 #if CONFIG_VP8_VAAPI_HWACCEL
diff --git a/libavcodec/vp9.c b/libavcodec/vp9.c
index e47ed4e04e..2a3a4555b9 100644
--- a/libavcodec/vp9.c
+++ b/libavcodec/vp9.c
@@ -1748,11 +1748,6 @@ static av_cold int vp9_decode_init(AVCodecContext *avctx)
 }
 
 #if HAVE_THREADS
-static av_cold int vp9_decode_init_thread_copy(AVCodecContext *avctx)
-{
-    return init_frames(avctx);
-}
-
 static int vp9_decode_update_thread_context(AVCodecContext *dst, const AVCodecContext *src)
 {
     int i, ret;
@@ -1812,7 +1807,6 @@ AVCodec ff_vp9_decoder = {
     .caps_internal         = FF_CODEC_CAP_SLICE_THREAD_HAS_MF |
                              FF_CODEC_CAP_ALLOCATE_PROGRESS,
     .flush                 = vp9_decode_flush,
-    .init_thread_copy      = ONLY_IF_THREADS_ENABLED(vp9_decode_init_thread_copy),
     .update_thread_context = ONLY_IF_THREADS_ENABLED(vp9_decode_update_thread_context),
     .profiles              = NULL_IF_CONFIG_SMALL(ff_vp9_profiles),
     .bsfs                  = "vp9_superframe_split",
diff --git a/libavcodec/wavpack.c b/libavcodec/wavpack.c
index 20884805ab..58ab561a15 100644
--- a/libavcodec/wavpack.c
+++ b/libavcodec/wavpack.c
@@ -1009,20 +1009,6 @@ static int wv_dsd_reset(WavpackContext *s, int channels)
 }
 
 #if HAVE_THREADS
-static int init_thread_copy(AVCodecContext *avctx)
-{
-    WavpackContext *s = avctx->priv_data;
-    s->avctx = avctx;
-
-    s->curr_frame.f = av_frame_alloc();
-    s->prev_frame.f = av_frame_alloc();
-
-    if (!s->curr_frame.f || !s->prev_frame.f)
-        return AVERROR(ENOMEM);
-
-    return 0;
-}
-
 static int update_thread_context(AVCodecContext *dst, const AVCodecContext *src)
 {
     WavpackContext *fsrc = src->priv_data;
@@ -1714,7 +1700,6 @@ AVCodec ff_wavpack_decoder = {
     .close          = wavpack_decode_end,
     .decode         = wavpack_decode_frame,
     .flush          = wavpack_decode_flush,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(init_thread_copy),
     .update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context),
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS |
                       AV_CODEC_CAP_SLICE_THREADS,
diff --git a/libavcodec/ylc.c b/libavcodec/ylc.c
index 11333222b9..2afe3fc9d5 100644
--- a/libavcodec/ylc.c
+++ b/libavcodec/ylc.c
@@ -453,24 +453,6 @@ static int decode_frame(AVCodecContext *avctx,
     return avpkt->size;
 }
 
-#if HAVE_THREADS
-static int init_thread_copy(AVCodecContext *avctx)
-{
-    YLCContext *s = avctx->priv_data;
-
-    memset(&s->vlc[0], 0, sizeof(VLC));
-    memset(&s->vlc[1], 0, sizeof(VLC));
-    memset(&s->vlc[2], 0, sizeof(VLC));
-    memset(&s->vlc[3], 0, sizeof(VLC));
-    s->table_bits = NULL;
-    s->table_bits_size = 0;
-    s->bitstream_bits = NULL;
-    s->bitstream_bits_size = 0;
-
-    return 0;
-}
-#endif
-
 static av_cold int decode_end(AVCodecContext *avctx)
 {
     YLCContext *s = avctx->priv_data;
@@ -494,7 +476,6 @@ AVCodec ff_ylc_decoder = {
     .id             = AV_CODEC_ID_YLC,
     .priv_data_size = sizeof(YLCContext),
     .init           = decode_init,
-    .init_thread_copy = ONLY_IF_THREADS_ENABLED(init_thread_copy),
     .close          = decode_end,
     .decode         = decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,