avcodec/mpegpicture: Move mb_var, mc_mb_var and mb_mean to MpegEncCtx

These tables are only used by encoders and only for the current picture;
ergo they need not be put into the picture at all, but rather into
the encoder's context. They also don't need to be refcounted,
because there is only one owner.

In contrast to this, the earlier code refcounts them which
incurs unnecessary overhead. These references are not unreferenced
in ff_mpeg_unref_picture() (they are kept in order to have something
like a buffer pool), so that several buffers are kept at the same
time, although only one is needed, thereby wasting memory.

The code also propagates references to other pictures not part of
the pictures array (namely the copy of the current/next/last picture
in the MpegEncContext which get references of their own). These
references are not unreferenced in ff_mpeg_unref_picture() (the
buffers are probably kept in order to have something like a pool),
yet if the current picture is a B-frame, it gets unreferenced
at the end of ff_mpv_encode_picture() and its slot in the picture
array will therefore be reused the next time; but the copy of the
current picture also still has its references and therefore
these buffers will be made duplicated in order to make them writable
in the next call to ff_mpv_encode_picture(). This is of course
unnecessary.

Finally, ff_find_unused_picture() is supposed to just return
any unused picture and the code is supposed to work with it;
yet for the vsynth*-mpeg4-adap tests the result depends upon
the content of these buffers; given that this patchset
changes the content of these buffers (the initial content is now
the state of these buffers after encoding the last frame;
before this patch the buffers used came from the last picture
that occupied the same slot in the picture array) their ref-files
needed to be changed. This points to a bug somewhere (if one removes
the initialization, one gets uninitialized reads in
adaptive_quantization in ratecontrol.c).

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

7 files changed, 34 insertions, 55 deletions

diff --git a/libavcodec/motion_est.c b/libavcodec/motion_est.c
index 29ab41dc8c..d17ffe42b4 100644
--- a/libavcodec/motion_est.c
+++ b/libavcodec/motion_est.c
@@ -895,7 +895,6 @@ void ff_estimate_p_frame_motion(MpegEncContext * s,
     int P[10][2];
     const int shift= 1+s->quarter_sample;
     int mb_type=0;
-    Picture * const pic= &s->current_picture;
 
     init_ref(c, s->new_picture->data, s->last_picture.f->data, NULL, 16*mb_x, 16*mb_y, 0);
 
@@ -917,8 +916,8 @@ void ff_estimate_p_frame_motion(MpegEncContext * s,
     varc = s->mpvencdsp.pix_norm1(pix, s->linesize) -
            (((unsigned) sum * sum) >> 8) + 500;
 
-    pic->mb_mean[s->mb_stride * mb_y + mb_x] = (sum+128)>>8;
-    pic->mb_var [s->mb_stride * mb_y + mb_x] = (varc+128)>>8;
+    s->mb_mean[s->mb_stride * mb_y + mb_x] = (sum+128)>>8;
+    s->mb_var [s->mb_stride * mb_y + mb_x] = (varc+128)>>8;
     c->mb_var_sum_temp += (varc+128)>>8;
 
     if (s->motion_est != FF_ME_ZERO) {
@@ -965,7 +964,7 @@ void ff_estimate_p_frame_motion(MpegEncContext * s,
 
     vard = s->mecc.sse[0](NULL, pix, ppix, s->linesize, 16);
 
-    pic->mc_mb_var[s->mb_stride * mb_y + mb_x] = (vard+128)>>8;
+    s->mc_mb_var[s->mb_stride * mb_y + mb_x] = (vard+128)>>8;
     c->mc_mb_var_sum_temp += (vard+128)>>8;
 
     if (c->avctx->mb_decision > FF_MB_DECISION_SIMPLE) {
@@ -1509,7 +1508,7 @@ void ff_estimate_b_frame_motion(MpegEncContext * s,
 
         score= ((unsigned)(score*score + 128*256))>>16;
         c->mc_mb_var_sum_temp += score;
-        s->current_picture.mc_mb_var[mb_y*s->mb_stride + mb_x] = score; //FIXME use SSE
+        s->mc_mb_var[mb_y*s->mb_stride + mb_x] = score; //FIXME use SSE
         s->mb_type[mb_y*s->mb_stride + mb_x]= CANDIDATE_MB_TYPE_DIRECT0;
 
         return;
@@ -1574,7 +1573,7 @@ void ff_estimate_b_frame_motion(MpegEncContext * s,
 
         score= ((unsigned)(score*score + 128*256))>>16;
         c->mc_mb_var_sum_temp += score;
-        s->current_picture.mc_mb_var[mb_y*s->mb_stride + mb_x] = score; //FIXME use SSE
+        s->mc_mb_var[mb_y*s->mb_stride + mb_x] = score; //FIXME use SSE
     }
 
     if(c->avctx->mb_decision > FF_MB_DECISION_SIMPLE){
@@ -1629,7 +1628,8 @@ int ff_get_best_fcode(MpegEncContext * s, const int16_t (*mv_table)[2], int type
                         continue;
 
                     for(j=0; j<fcode && j<8; j++){
-                        if(s->pict_type==AV_PICTURE_TYPE_B || s->current_picture.mc_mb_var[xy] < s->current_picture.mb_var[xy])
+                        if (s->pict_type == AV_PICTURE_TYPE_B ||
+                            s->mc_mb_var[xy] < s->mb_var[xy])
                             score[j]-= 170;
                     }
                 }
diff --git a/libavcodec/mpegpicture.c b/libavcodec/mpegpicture.c
index aaa1df0bd8..f32f8d061b 100644
--- a/libavcodec/mpegpicture.c
+++ b/libavcodec/mpegpicture.c
@@ -37,9 +37,6 @@ static void av_noinline free_picture_tables(Picture *pic)
     pic->alloc_mb_width  =
     pic->alloc_mb_height = 0;
 
-    av_buffer_unref(&pic->mb_var_buf);
-    av_buffer_unref(&pic->mc_mb_var_buf);
-    av_buffer_unref(&pic->mb_mean_buf);
     av_buffer_unref(&pic->mbskip_table_buf);
     av_buffer_unref(&pic->qscale_table_buf);
     av_buffer_unref(&pic->mb_type_buf);
@@ -60,9 +57,6 @@ do {\
     return ret;\
 } while (0)
 
-    MAKE_WRITABLE(mb_var_buf);
-    MAKE_WRITABLE(mc_mb_var_buf);
-    MAKE_WRITABLE(mb_mean_buf);
     MAKE_WRITABLE(mbskip_table_buf);
     MAKE_WRITABLE(qscale_table_buf);
     MAKE_WRITABLE(mb_type_buf);
@@ -218,14 +212,6 @@ static int alloc_picture_tables(AVCodecContext *avctx, Picture *pic, int encodin
     if (!pic->mbskip_table_buf || !pic->qscale_table_buf || !pic->mb_type_buf)
         return AVERROR(ENOMEM);
 
-    if (encoding) {
-        pic->mb_var_buf    = av_buffer_allocz(mb_array_size * sizeof(int16_t));
-        pic->mc_mb_var_buf = av_buffer_allocz(mb_array_size * sizeof(int16_t));
-        pic->mb_mean_buf   = av_buffer_allocz(mb_array_size);
-        if (!pic->mb_var_buf || !pic->mc_mb_var_buf || !pic->mb_mean_buf)
-            return AVERROR(ENOMEM);
-    }
-
     if (out_format == FMT_H263 || encoding ||
         (avctx->export_side_data & AV_CODEC_EXPORT_DATA_MVS)) {
         int mv_size        = 2 * (b8_array_size + 4) * sizeof(int16_t);
@@ -285,12 +271,6 @@ int ff_alloc_picture(AVCodecContext *avctx, Picture *pic, MotionEstContext *me,
     if (ret < 0)
         goto fail;
 
-    if (encoding) {
-        pic->mb_var    = (uint16_t*)pic->mb_var_buf->data;
-        pic->mc_mb_var = (uint16_t*)pic->mc_mb_var_buf->data;
-        pic->mb_mean   = pic->mb_mean_buf->data;
-    }
-
     pic->mbskip_table = pic->mbskip_table_buf->data;
     pic->qscale_table = pic->qscale_table_buf->data + 2 * mb_stride + 1;
     pic->mb_type      = (uint32_t*)pic->mb_type_buf->data + 2 * mb_stride + 1;
@@ -316,7 +296,7 @@ fail:
  */
 void ff_mpeg_unref_picture(AVCodecContext *avctx, Picture *pic)
 {
-    int off = offsetof(Picture, mb_mean) + sizeof(pic->mb_mean);
+    int off = offsetof(Picture, hwaccel_priv_buf) + sizeof(pic->hwaccel_priv_buf);
 
     pic->tf.f = pic->f;
     /* WM Image / Screen codecs allocate internal buffers with different
@@ -340,10 +320,7 @@ int ff_update_picture_tables(Picture *dst, const Picture *src)
 {
     int i, ret;
 
-    ret  = av_buffer_replace(&dst->mb_var_buf,       src->mb_var_buf);
-    ret |= av_buffer_replace(&dst->mc_mb_var_buf,    src->mc_mb_var_buf);
-    ret |= av_buffer_replace(&dst->mb_mean_buf,      src->mb_mean_buf);
-    ret |= av_buffer_replace(&dst->mbskip_table_buf, src->mbskip_table_buf);
+    ret  = av_buffer_replace(&dst->mbskip_table_buf, src->mbskip_table_buf);
     ret |= av_buffer_replace(&dst->qscale_table_buf, src->qscale_table_buf);
     ret |= av_buffer_replace(&dst->mb_type_buf,      src->mb_type_buf);
     for (i = 0; i < 2; i++) {
@@ -356,9 +333,6 @@ int ff_update_picture_tables(Picture *dst, const Picture *src)
         return ret;
     }
 
-    dst->mb_var        = src->mb_var;
-    dst->mc_mb_var     = src->mc_mb_var;
-    dst->mb_mean       = src->mb_mean;
     dst->mbskip_table  = src->mbskip_table;
     dst->qscale_table  = src->qscale_table;
     dst->mb_type       = src->mb_type;
diff --git a/libavcodec/mpegpicture.h b/libavcodec/mpegpicture.h
index 0671bbae8e..62589595d0 100644
--- a/libavcodec/mpegpicture.h
+++ b/libavcodec/mpegpicture.h
@@ -62,19 +62,10 @@ typedef struct Picture {
     AVBufferRef *ref_index_buf[2];
     int8_t *ref_index[2];
 
-    AVBufferRef *mb_var_buf;
-    uint16_t *mb_var;           ///< Table for MB variances
-
-    AVBufferRef *mc_mb_var_buf;
-    uint16_t *mc_mb_var;        ///< Table for motion compensated MB variances
-
     int alloc_mb_width;         ///< mb_width used to allocate tables
     int alloc_mb_height;        ///< mb_height used to allocate tables
     int alloc_mb_stride;        ///< mb_stride used to allocate tables
 
-    AVBufferRef *mb_mean_buf;
-    uint8_t *mb_mean;           ///< Table for MB luminance
-
     AVBufferRef *hwaccel_priv_buf;
     void *hwaccel_picture_private; ///< Hardware accelerator private data
 
diff --git a/libavcodec/mpegvideo.h b/libavcodec/mpegvideo.h
index b1b2727535..47619c1976 100644
--- a/libavcodec/mpegvideo.h
+++ b/libavcodec/mpegvideo.h
@@ -235,6 +235,12 @@ typedef struct MpegEncContext {
     int16_t (*b_field_mv_table[2][2][2])[2];///< MV table (4MV per MB) interlaced B-frame encoding
     uint8_t (*p_field_select_table[2]);  ///< Only the first element is allocated
     uint8_t (*b_field_select_table[2][2]); ///< Only the first element is allocated
+
+    /* The following three arrays are encoder-only */
+    uint16_t *mb_var;           ///< Table for MB variances
+    uint16_t *mc_mb_var;        ///< Table for motion compensated MB variances
+    uint8_t *mb_mean;           ///< Table for MB luminance
+
     int motion_est;                      ///< ME algorithm
     int me_penalty_compensation;
     int me_pre;                          ///< prepass for motion estimation
diff --git a/libavcodec/mpegvideo_enc.c b/libavcodec/mpegvideo_enc.c
index 0ca004ee39..a34fb66eac 100644
--- a/libavcodec/mpegvideo_enc.c
+++ b/libavcodec/mpegvideo_enc.c
@@ -313,6 +313,7 @@ av_cold int ff_mpv_encode_init(AVCodecContext *avctx)
     MpegEncContext *s = avctx->priv_data;
     AVCPBProperties *cpb_props;
     int i, ret;
+    int mb_array_size;
 
     mpv_encode_defaults(s);
 
@@ -823,6 +824,12 @@ av_cold int ff_mpv_encode_init(AVCodecContext *avctx)
         !FF_ALLOCZ_TYPED_ARRAY(s->reordered_input_picture, MAX_PICTURE_COUNT))
         return AVERROR(ENOMEM);
 
+    mb_array_size = s->mb_stride * s->mb_height;
+    if (!FF_ALLOCZ_TYPED_ARRAY(s->mc_mb_var, mb_array_size) ||
+        !FF_ALLOCZ_TYPED_ARRAY(s->mb_var, mb_array_size) ||
+        !(s->mb_mean = av_mallocz(mb_array_size)))
+        return AVERROR(ENOMEM);
+
     if (s->noise_reduction) {
         if (!FF_ALLOCZ_TYPED_ARRAY(s->dct_offset, 2))
             return AVERROR(ENOMEM);
@@ -949,6 +956,9 @@ av_cold int ff_mpv_encode_end(AVCodecContext *avctx)
     av_freep(&s->input_picture);
     av_freep(&s->reordered_input_picture);
     av_freep(&s->dct_offset);
+    av_freep(&s->mb_var);
+    av_freep(&s->mc_mb_var);
+    av_freep(&s->mb_mean);
 
     return 0;
 }
@@ -2235,8 +2245,7 @@ static av_always_inline void encode_mb_internal(MpegEncContext *s,
             }
         }
         /* pre quantization */
-        if (s->current_picture.mc_mb_var[s->mb_stride * mb_y + mb_x] <
-                2 * s->qscale * s->qscale) {
+        if (s->mc_mb_var[s->mb_stride * mb_y + mb_x] < 2 * s->qscale * s->qscale) {
             // FIXME optimize
             if (s->mecc.sad[1](NULL, ptr_y, dest_y, wrap_y, 8) < 20 * s->qscale)
                 skip_dct[0] = 1;
@@ -2648,8 +2657,8 @@ static int mb_var_thread(AVCodecContext *c, void *arg){
             varc = (s->mpvencdsp.pix_norm1(pix, s->linesize) -
                     (((unsigned) sum * sum) >> 8) + 500 + 128) >> 8;
 
-            s->current_picture.mb_var [s->mb_stride * mb_y + mb_x] = varc;
-            s->current_picture.mb_mean[s->mb_stride * mb_y + mb_x] = (sum+128)>>8;
+            s->mb_var [s->mb_stride * mb_y + mb_x] = varc;
+            s->mb_mean[s->mb_stride * mb_y + mb_x] = (sum+128)>>8;
             s->me.mb_var_sum_temp    += varc;
         }
     }
diff --git a/libavcodec/ratecontrol.c b/libavcodec/ratecontrol.c
index a7614d75e2..53930f147b 100644
--- a/libavcodec/ratecontrol.c
+++ b/libavcodec/ratecontrol.c
@@ -751,15 +751,14 @@ static void adaptive_quantization(MpegEncContext *s, double q)
     float *bits_tab                  = s->bits_tab;
     const int qmin                   = s->avctx->mb_lmin;
     const int qmax                   = s->avctx->mb_lmax;
-    Picture *const pic               = &s->current_picture;
     const int mb_width               = s->mb_width;
     const int mb_height              = s->mb_height;
 
     for (i = 0; i < s->mb_num; i++) {
         const int mb_xy = s->mb_index2xy[i];
-        float temp_cplx = sqrt(pic->mc_mb_var[mb_xy]); // FIXME merge in pow()
-        float spat_cplx = sqrt(pic->mb_var[mb_xy]);
-        const int lumi  = pic->mb_mean[mb_xy];
+        float temp_cplx = sqrt(s->mc_mb_var[mb_xy]); // FIXME merge in pow()
+        float spat_cplx = sqrt(s->mb_var[mb_xy]);
+        const int lumi  = s->mb_mean[mb_xy];
         float bits, cplx, factor;
         int mb_x = mb_xy % s->mb_stride;
         int mb_y = mb_xy / s->mb_stride;
diff --git a/libavcodec/svq1enc.c b/libavcodec/svq1enc.c
index e5216a99cd..36bc214d76 100644
--- a/libavcodec/svq1enc.c
+++ b/libavcodec/svq1enc.c
@@ -313,9 +313,9 @@ static int svq1_encode_plane(SVQ1EncContext *s, int plane,
         s->m.mb_type = s->mb_type;
 
         // dummies, to avoid segfaults
-        s->m.current_picture.mb_mean   = (uint8_t *)s->dummy;
-        s->m.current_picture.mb_var    = (uint16_t *)s->dummy;
-        s->m.current_picture.mc_mb_var = (uint16_t *)s->dummy;
+        s->m.mb_mean   = (uint8_t *)s->dummy;
+        s->m.mb_var    = (uint16_t *)s->dummy;
+        s->m.mc_mb_var = (uint16_t *)s->dummy;
         s->m.current_picture.mb_type = s->dummy;
 
         s->m.current_picture.motion_val[0]   = s->motion_val8[plane] + 2;