lavc: Move brd_scale to codec private options

This option is only used by mpegvideoenc,
It is a very codec-specific option, so deprecate the global variant.
Set proper limits to the maximum allowed values.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

libavcodec/avcodec.h

@@ -1958,12 +1958,11 @@ typedef struct AVCodecContext {
      */
     int bidir_refine;
 
-    /**
-     *
-     * - encoding: Set by user.
-     * - decoding: unused
-     */
+#if FF_API_PRIVATE_OPT
+    /** @deprecated use encoder private options instead */
+    attribute_deprecated
     int brd_scale;
+#endif
 
     /**
      * minimum GOP size

libavcodec/mpegvideo.h

@@ -444,6 +444,7 @@ typedef struct MpegEncContext {
     int top_field_first;
     int concealment_motion_vectors;
     int q_scale_type;
+    int brd_scale;
     int intra_vlc_format;
     int alternate_scan;
     int repeat_first_field;
@@ -577,6 +578,7 @@ typedef struct MpegEncContext {
 { "xone", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FF_ME_XONE }, 0, 0, FF_MPV_OPT_FLAGS, "motion_est" }, \
 {"b_strategy", "Strategy to choose between I/P/B-frames",           FF_MPV_OFFSET(b_frame_strategy), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 2, FF_MPV_OPT_FLAGS }, \
 {"b_sensitivity", "Adjust sensitivity of b_frame_strategy 1",       FF_MPV_OFFSET(b_sensitivity), AV_OPT_TYPE_INT, {.i64 = 40 }, 1, INT_MAX, FF_MPV_OPT_FLAGS }, \
+{"brd_scale", "Downscale frames for dynamic B-frame decision",      FF_MPV_OFFSET(brd_scale), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 3, FF_MPV_OPT_FLAGS }, \
 
 extern const AVOption ff_mpv_generic_options[];
 

libavcodec/mpegvideo_enc.c

@@ -876,6 +876,13 @@ FF_ENABLE_DEPRECATION_WARNINGS
     FF_ENABLE_DEPRECATION_WARNINGS
 #endif
 
+#if FF_API_PRIVATE_OPT
+    FF_DISABLE_DEPRECATION_WARNINGS
+    if (avctx->brd_scale)
+        s->brd_scale = avctx->brd_scale;
+    FF_ENABLE_DEPRECATION_WARNINGS
+#endif
+
     if (s->b_frame_strategy == 2) {
         for (i = 0; i < s->max_b_frames + 2; i++) {
             s->tmp_frames[i] = av_frame_alloc();
@@ -883,8 +890,8 @@ FF_ENABLE_DEPRECATION_WARNINGS
                 return AVERROR(ENOMEM);
 
             s->tmp_frames[i]->format = AV_PIX_FMT_YUV420P;
-            s->tmp_frames[i]->width  = s->width  >> avctx->brd_scale;
-            s->tmp_frames[i]->height = s->height >> avctx->brd_scale;
+            s->tmp_frames[i]->width  = s->width  >> s->brd_scale;
+            s->tmp_frames[i]->height = s->height >> s->brd_scale;
 
             ret = av_frame_get_buffer(s->tmp_frames[i], 32);
             if (ret < 0)
@@ -1182,7 +1189,7 @@ static int estimate_best_b_count(MpegEncContext *s)
 {
     AVCodec *codec    = avcodec_find_encoder(s->avctx->codec_id);
     AVCodecContext *c = avcodec_alloc_context3(NULL);
-    const int scale = s->avctx->brd_scale;
+    const int scale = s->brd_scale;
     int i, j, out_size, p_lambda, b_lambda, lambda2;
     int64_t best_rd  = INT64_MAX;
     int best_b_count = -1;

libavcodec/options_table.h

@@ -383,7 +383,9 @@ static const AVOption avcodec_options[] = {
 {"nokey"           , NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVDISCARD_NONKEY  }, INT_MIN, INT_MAX, V|D, "avdiscard"},
 {"all"             , NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVDISCARD_ALL     }, INT_MIN, INT_MAX, V|D, "avdiscard"},
 {"bidir_refine", "refine the two motion vectors used in bidirectional macroblocks", OFFSET(bidir_refine), AV_OPT_TYPE_INT, {.i64 = 1 }, 0, 4, V|E},
+#if FF_API_PRIVATE_OPT
 {"brd_scale", "downscale frames for dynamic B-frame decision", OFFSET(brd_scale), AV_OPT_TYPE_INT, {.i64 = DEFAULT }, 0, 10, V|E},
+#endif
 {"keyint_min", "minimum interval between IDR-frames (x264)", OFFSET(keyint_min), AV_OPT_TYPE_INT, {.i64 = 25 }, INT_MIN, INT_MAX, V|E},
 {"refs", "reference frames to consider for motion compensation", OFFSET(refs), AV_OPT_TYPE_INT, {.i64 = 1 }, INT_MIN, INT_MAX, V|E},
 {"chromaoffset", "chroma QP offset from luma", OFFSET(chromaoffset), AV_OPT_TYPE_INT, {.i64 = DEFAULT }, INT_MIN, INT_MAX, V|E},