[FFmpeg-devel] [PATCH 37/57] avcodec/mpegutils: Don't output wrong mb skip values

Andreas Rheinhardt andreas.rheinhardt at outlook.com
Wed Jun 12 16:48:33 EEST 2024


The earlier code had two problems:
1. For reference frames that are not directly output (happens unless
low_delay is set), the mb skip values referred to the next reference
frame to be decoded.
2. For non-reference frames, every macroblock was always considered
skipped.
This makes the output (worse than) useless; that no one ever
complained about this shows that this feature is not really used.
It is therefore removed.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
---
 libavcodec/h264dec.c       |  2 +-
 libavcodec/mpegutils.c     | 12 ++----------
 libavcodec/mpegutils.h     |  2 +-
 libavcodec/mpegvideo_dec.c |  2 +-
 4 files changed, 5 insertions(+), 13 deletions(-)

diff --git a/libavcodec/h264dec.c b/libavcodec/h264dec.c
index fd23e367b4..c77d8f42db 100644
--- a/libavcodec/h264dec.c
+++ b/libavcodec/h264dec.c
@@ -979,7 +979,7 @@ static int finalize_frame(H264Context *h, AVFrame *dst, H264Picture *out, int *g
         *got_frame = 1;
 
         if (CONFIG_MPEGVIDEODEC) {
-            ff_print_debug_info2(h->avctx, dst, NULL,
+            ff_print_debug_info2(h->avctx, dst,
                                  out->mb_type,
                                  out->qscale_table,
                                  out->motion_val,
diff --git a/libavcodec/mpegutils.c b/libavcodec/mpegutils.c
index a53996852f..73b6650b70 100644
--- a/libavcodec/mpegutils.c
+++ b/libavcodec/mpegutils.c
@@ -153,7 +153,7 @@ static char get_interlacement_char(int mb_type)
 }
 
 void ff_print_debug_info2(AVCodecContext *avctx, AVFrame *pict,
-                          const uint8_t *mbskip_table, const uint32_t *mbtype_table,
+                          const uint32_t *mbtype_table,
                           const int8_t *qscale_table, int16_t (*const motion_val[2])[2],
                           int mb_width, int mb_height, int mb_stride, int quarter_sample)
 {
@@ -248,7 +248,7 @@ void ff_print_debug_info2(AVCodecContext *avctx, AVFrame *pict,
         return;
 
 
-    if (avctx->debug & (FF_DEBUG_SKIP | FF_DEBUG_QP | FF_DEBUG_MB_TYPE)) {
+    if (avctx->debug & (FF_DEBUG_QP | FF_DEBUG_MB_TYPE)) {
         int x,y;
         AVBPrint buf;
         int n;
@@ -267,8 +267,6 @@ void ff_print_debug_info2(AVCodecContext *avctx, AVFrame *pict,
         av_bprint_chars(&buf, ' ', margin_left);
 
         n = 0;
-        if (avctx->debug & FF_DEBUG_SKIP)
-            n++;
         if (avctx->debug & FF_DEBUG_QP)
             n += 2;
         if (avctx->debug & FF_DEBUG_MB_TYPE)
@@ -284,12 +282,6 @@ void ff_print_debug_info2(AVCodecContext *avctx, AVFrame *pict,
             for (x = 0; x < mb_width; x++) {
                 if (x == 0)
                     av_bprintf(&buf, "%*d ", margin_left - 1, y << 4);
-                if (avctx->debug & FF_DEBUG_SKIP) {
-                    int count = mbskip_table ? mbskip_table[x + y * mb_stride] : 0;
-                    if (count > 9)
-                        count = 9;
-                    av_bprintf(&buf, "%1d", count);
-                }
                 if (avctx->debug & FF_DEBUG_QP) {
                     av_bprintf(&buf, "%2d", qscale_table[x + y * mb_stride]);
                 }
diff --git a/libavcodec/mpegutils.h b/libavcodec/mpegutils.h
index 43075191c6..64e69c7746 100644
--- a/libavcodec/mpegutils.h
+++ b/libavcodec/mpegutils.h
@@ -106,7 +106,7 @@ void ff_draw_horiz_band(AVCodecContext *avctx, const AVFrame *cur, const AVFrame
  * Print debugging info for the given picture.
  */
 void ff_print_debug_info2(AVCodecContext *avctx, AVFrame *pict,
-                          const uint8_t *mbskip_table, const uint32_t *mbtype_table,
+                          const uint32_t *mbtype_table,
                           const int8_t *qscale_table, int16_t (*const motion_val[2])[2],
                           int mb_width, int mb_height, int mb_stride, int quarter_sample);
 
diff --git a/libavcodec/mpegvideo_dec.c b/libavcodec/mpegvideo_dec.c
index e95b5a0940..4e279d9fa8 100644
--- a/libavcodec/mpegvideo_dec.c
+++ b/libavcodec/mpegvideo_dec.c
@@ -408,7 +408,7 @@ void ff_mpv_frame_end(MpegEncContext *s)
 
 void ff_print_debug_info(const MpegEncContext *s, const MPVPicture *p, AVFrame *pict)
 {
-    ff_print_debug_info2(s->avctx, pict, s->mbskip_table, p->mb_type,
+    ff_print_debug_info2(s->avctx, pict, p->mb_type,
                          p->qscale_table, p->motion_val,
                          s->mb_width, s->mb_height, s->mb_stride, s->quarter_sample);
 }
-- 
2.40.1



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