lavc: Move scenechange_threshold to codec private options

This option is only used by mpegvideoenc, x264, and xavs.
It is a very codec-specific option, so deprecate the global variant.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

libavcodec/avcodec.h

@@ -1872,13 +1872,11 @@ typedef struct AVCodecContext {
      */
     uint16_t *inter_matrix;
 
-    /**
-     * scene change detection threshold
-     * 0 is default, larger means fewer detected scene changes.
-     * - encoding: Set by user.
-     * - decoding: unused
-     */
+#if FF_API_PRIVATE_OPT
+    /** @deprecated use encoder private options instead */
+    attribute_deprecated
     int scenechange_threshold;
+#endif
 
     /**
      * noise reduction strength

libavcodec/libx264.c

@@ -81,6 +81,7 @@ typedef struct X264Context {
     int coder;
     int b_frame_strategy;
     int chroma_offset;
+    int scenechange_threshold;
 
     char *x264_params;
 } X264Context;
@@ -427,8 +428,16 @@ FF_ENABLE_DEPRECATION_WARNINGS
         x4->params.i_keyint_max         = avctx->gop_size;
     if (avctx->max_b_frames >= 0)
         x4->params.i_bframe             = avctx->max_b_frames;
-    if (avctx->scenechange_threshold >= 0)
-        x4->params.i_scenecut_threshold = avctx->scenechange_threshold;
+
+#if FF_API_PRIVATE_OPT
+FF_DISABLE_DEPRECATION_WARNINGS
+    if (avctx->scenechange_threshold)
+        x4->scenechange_threshold = avctx->scenechange_threshold;
+    if (x4->scenechange_threshold >= 0)
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif
+    x4->params.i_scenecut_threshold = x4->scenechange_threshold;
+
     if (avctx->qmin >= 0)
         x4->params.rc.i_qp_min          = avctx->qmin;
     if (avctx->qmax >= 0)
@@ -749,6 +758,7 @@ static const AVOption options[] = {
     { "cabac",            NULL, 0, AV_OPT_TYPE_CONST, { .i64 = 1 },  INT_MIN, INT_MAX, VE, "coder" },
     { "b_strategy",   "Strategy to choose between I/P/B-frames",          OFFSET(b_frame_strategy), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 2, VE },
     { "chromaoffset", "QP difference between chroma and luma",           OFFSET(chroma_offset), AV_OPT_TYPE_INT, { .i64 = 0 }, INT_MIN, INT_MAX, VE },
+    { "sc_threshold", "Scene change threshold",                           OFFSET(scenechange_threshold), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, VE },
 
     { "x264-params",  "Override the x264 configuration using a :-separated list of key=value parameters", OFFSET(x264_params), AV_OPT_TYPE_STRING, { 0 }, 0, 0, VE },
     { NULL },
@@ -765,7 +775,9 @@ static const AVCodecDefault x264_defaults[] = {
     { "qblur",            "-1" },
     { "qcomp",            "-1" },
     { "refs",             "-1" },
+#if FF_API_PRIVATE_OPT
     { "sc_threshold",     "-1" },
+#endif
     { "trellis",          "-1" },
     { "nr",               "-1" },
     { "me_range",         "-1" },

libavcodec/libxavs.c

@@ -58,6 +58,7 @@ typedef struct XavsContext {
     int mixed_refs;
     int b_frame_strategy;
     int chroma_offset;
+    int scenechange_threshold;
 
     int64_t *pts_buffer;
     int out_frame_count;
@@ -330,7 +331,14 @@ FF_ENABLE_DEPRECATION_WARNINGS
     if (x4->params.i_keyint_min > x4->params.i_keyint_max)
         x4->params.i_keyint_min = x4->params.i_keyint_max;
 
-    x4->params.i_scenecut_threshold        = avctx->scenechange_threshold;
+#if FF_API_PRIVATE_OPT
+FF_DISABLE_DEPRECATION_WARNINGS
+    if (avctx->scenechange_threshold)
+        x4->scenechange_threshold = avctx->scenechange_threshold;
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif
+
+    x4->params.i_scenecut_threshold = x4->scenechange_threshold;
 
    // x4->params.b_deblocking_filter       = avctx->flags & AV_CODEC_FLAG_LOOP_FILTER;
 
@@ -458,6 +466,7 @@ static const AVOption options[] = {
     { "tesa",          NULL,      0,    AV_OPT_TYPE_CONST, { .i64 = XAVS_ME_TESA },              INT_MIN, INT_MAX, VE, "motion-est" },
     { "b_strategy",    "Strategy to choose between I/P/B-frames",         OFFSET(b_frame_strategy), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 2, VE},
     { "chromaoffset", "QP difference between chroma and luma",           OFFSET(chroma_offset), AV_OPT_TYPE_INT, {.i64 = 0 }, INT_MIN, INT_MAX, VE},
+    { "sc_threshold", "Scene change threshold",                           OFFSET(scenechange_threshold), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, VE},
 
     { NULL },
 };

libavcodec/mpegvideo.h

@@ -534,6 +534,8 @@ typedef struct MpegEncContext {
     int frame_skip_factor;
     int frame_skip_exp;
     int frame_skip_cmp;
+
+    int scenechange_threshold;
 } MpegEncContext;
 
 /* mpegvideo_enc common options */
@@ -606,6 +608,7 @@ FF_MPV_OPT_CMP_FUNC, \
 {"skip_factor", "Frame skip factor",                                FF_MPV_OFFSET(frame_skip_factor), AV_OPT_TYPE_INT, {.i64 = 0 }, INT_MIN, INT_MAX, FF_MPV_OPT_FLAGS }, \
 {"skip_exp", "Frame skip exponent",                                 FF_MPV_OFFSET(frame_skip_exp), AV_OPT_TYPE_INT, {.i64 = 0 }, INT_MIN, INT_MAX, FF_MPV_OPT_FLAGS }, \
 {"skip_cmp", "Frame skip compare function",                         FF_MPV_OFFSET(frame_skip_cmp), AV_OPT_TYPE_INT, {.i64 = FF_CMP_DCTMAX }, INT_MIN, INT_MAX, FF_MPV_OPT_FLAGS, "cmp_func" }, \
+{"sc_threshold", "Scene change threshold",                          FF_MPV_OFFSET(scenechange_threshold), AV_OPT_TYPE_INT, {.i64 = 0 }, INT_MIN, INT_MAX, FF_MPV_OPT_FLAGS }, \
 
 extern const AVOption ff_mpv_generic_options[];
 

libavcodec/mpegvideo_enc.c

@@ -468,7 +468,14 @@ FF_ENABLE_DEPRECATION_WARNINGS
         return -1;
     }
 
-    if (s->avctx->scenechange_threshold < 1000000000 &&
+#if FF_API_PRIVATE_OPT
+FF_DISABLE_DEPRECATION_WARNINGS
+    if (avctx->scenechange_threshold)
+        s->scenechange_threshold = avctx->scenechange_threshold;
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif
+
+    if (s->scenechange_threshold < 1000000000 &&
         (s->avctx->flags & AV_CODEC_FLAG_CLOSED_GOP)) {
         av_log(avctx, AV_LOG_ERROR,
                "closed gop with scene change detection are not supported yet, "
@@ -3453,7 +3460,8 @@ static int encode_picture(MpegEncContext *s, int picture_number)
     s->current_picture.   mb_var_sum= s->current_picture_ptr->   mb_var_sum= s->me.   mb_var_sum_temp;
     emms_c();
 
-    if(s->me.scene_change_score > s->avctx->scenechange_threshold && s->pict_type == AV_PICTURE_TYPE_P){
+    if (s->me.scene_change_score > s->scenechange_threshold &&
+        s->pict_type == AV_PICTURE_TYPE_P) {
         s->pict_type= AV_PICTURE_TYPE_I;
         for(i=0; i<s->mb_stride*s->mb_height; i++)
             s->mb_type[i]= CANDIDATE_MB_TYPE_INTRA;

libavcodec/options_table.h

@@ -323,7 +323,9 @@ static const AVOption avcodec_options[] = {
 #if FF_API_STREAM_CODEC_TAG
 {"stream_codec_tag", NULL, OFFSET(stream_codec_tag), AV_OPT_TYPE_INT, {.i64 = DEFAULT }, INT_MIN, INT_MAX},
 #endif
+#if FF_API_PRIVATE_OPT
 {"sc_threshold", "scene change threshold", OFFSET(scenechange_threshold), AV_OPT_TYPE_INT, {.i64 = DEFAULT }, INT_MIN, INT_MAX, V|E},
+#endif
 #if FF_API_MPV_OPT
 {"lmin", "deprecated, use encoder private options instead", OFFSET(lmin), AV_OPT_TYPE_INT, {.i64 =  0 }, 0, INT_MAX, V|E},
 {"lmax", "deprecated, use encoder private options instead", OFFSET(lmax), AV_OPT_TYPE_INT, {.i64 =  0 }, 0, INT_MAX, V|E},