[FFmpeg-devel] [PATCH 1/1] avcodec/mpegutils: add motion_vec debug mode

Chema Gonzalez chemag at gmail.com
Thu Sep 1 03:26:08 EEST 2022


Add a new debug mode ("motion_vec") that prints the values of the
motion vectors (MV).

Note that, in order to give the same weight to MV from bigger
blocks, we may print each MV pair more than once.

Tested:

```
$ ./ffprobe -v quiet -show_frames -debug motion_vec /tmp/in.264 \
    2>&1 >/dev/null
...
[h264 @ ...] nal_unit_type: 1(Coded slice of a non-IDR picture), ...
[h264 @ ...] New frame, type: I
[h264 @ ...]    0    0   0    0   0    0   0    0   0    0   0    0...
[h264 @ ...]    0    0   0    0   0    0   0    0   0    0   0    0...
[h264 @ ...]    0    0   0    0   0    0   0    0   0    0   0    0...
[h264 @ ...]    0    0   0    0   0    0   0    0   0    0   0    0...
[h264 @ ...]    0    0   0    0   0    0   0    0   0    0   0    0...
[h264 @ ...]    0    0   0    0   0    0   0    0   0    0   0    0...
[h264 @ ...]    0    0   0    0   0    0   0    0   0    0   0    0...
[h264 @ ...]    0    0   0    0   0    0   0    0   0    0   0    0...
[h264 @ ...]    0    0   0    0   0    0   0    0   0    0   0    0...
[h264 @ ...] nal_unit_type: 1(Coded slice of a non-IDR picture), ...
[h264 @ ...] nal_unit_type: 1(Coded slice of a non-IDR picture), ...
[h264 @ ...] New frame, type: B
[h264 @ ...]    0    0   0    0   0    0   0    0   0    0   0    0...
[h264 @ ...]    0    0   0    0   0    0   0    0   0    0   0    0...
[h264 @ ...]    0    0   0    0   0    0   0    0   0    0   0    0...
[h264 @ ...]    0    0   0    0   0    0   0    0   0    0   0    0...
[h264 @ ...]    0    0   0    0   0    0   0    0   0    0   0    0...
[h264 @ ...]    0    0   0    0   0    0   0    0   0    0   0    0...
[h264 @ ...]    0    0   0    0   0    0   0    0   0    0   0    0...
[h264 @ ...]    0    0   0    0   0    0   0    0   0    0   0    0...
[h264 @ ...]    0    0   0    0   0    0   0    0   0    0   0    0...
[h264 @ ...] nal_unit_type: 1(Coded slice of a non-IDR picture), ...
...
```
---
 libavcodec/avcodec.h       |  1 +
 libavcodec/mpegutils.c     | 45 +++++++++++++++++++++++++++++++++++++-
 libavcodec/options_table.h |  1 +
 3 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 65c8535359..4287555a31 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -1344,6 +1344,7 @@ typedef struct AVCodecContext {
 #define FF_DEBUG_THREADS     0x00010000
 #define FF_DEBUG_GREEN_MD    0x00800000
 #define FF_DEBUG_NOMC        0x01000000
+#define FF_DEBUG_MOTION_VEC  0x02000000
 
     /**
      * Error recognition; may misdetect some more or less valid parts as errors.
diff --git a/libavcodec/mpegutils.c b/libavcodec/mpegutils.c
index ff9418232b..d0a94784fb 100644
--- a/libavcodec/mpegutils.c
+++ b/libavcodec/mpegutils.c
@@ -246,8 +246,11 @@ 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_SKIP | FF_DEBUG_QP | FF_DEBUG_MB_TYPE | FF_DEBUG_MOTION_VEC)) {
         int x,y;
+        const int mv_sample_log2 = avctx->codec_id == AV_CODEC_ID_H264 || avctx->codec_id == AV_CODEC_ID_SVQ3 ? 2 : 1;
+        const int mv_stride      = (mb_width << mv_sample_log2) +
+                                   (avctx->codec->id == AV_CODEC_ID_H264 ? 0 : 1);
 
         av_log(avctx, AV_LOG_DEBUG, "New frame, type: %c\n",
                av_get_picture_type_char(pict->pict_type));
@@ -271,6 +274,46 @@ void ff_print_debug_info2(AVCodecContext *avctx, AVFrame *pict,
                            get_segmentation_char(mb_type),
                            get_interlacement_char(mb_type));
                 }
+                if (avctx->debug & FF_DEBUG_MOTION_VEC) {
+                    int i, direction, mb_type = mbtype_table[x + y * mb_stride];
+                    if (IS_8X8(mb_type)) {
+                        for (i = 0; i < 4; i++) {
+                            int xy = (x * 2 + (i & 1) +
+                                      (y * 2 + (i >> 1)) * mv_stride) << (mv_sample_log2 - 1);
+                            int mx = motion_val[direction][xy][0];
+                            int my = motion_val[direction][xy][1];
+                            av_log(avctx, AV_LOG_DEBUG, "%4d %4d", mx, my);
+                        }
+                    } else if (IS_16X8(mb_type)) {
+                        for (i = 0; i < 2; i++) {
+                            int xy = (x * 2 + (y * 2 + i) * mv_stride) << (mv_sample_log2 - 1);
+                            int mx = motion_val[direction][xy][0];
+                            int my = motion_val[direction][xy][1];
+                            if (IS_INTERLACED(mb_type))
+                                my *= 2;
+                            av_log(avctx, AV_LOG_DEBUG, "%4d %4d", mx, my);
+                            av_log(avctx, AV_LOG_DEBUG, "%4d %4d", mx, my);
+                        }
+                    } else if (IS_8X16(mb_type)) {
+                        for (i = 0; i < 2; i++) {
+                            int xy = (x * 2 + i + y * 2 * mv_stride) << (mv_sample_log2 - 1);
+                            int mx = motion_val[direction][xy][0];
+                            int my = motion_val[direction][xy][1];
+                            if (IS_INTERLACED(mb_type))
+                                my *= 2;
+                            av_log(avctx, AV_LOG_DEBUG, "%4d %4d", mx, my);
+                            av_log(avctx, AV_LOG_DEBUG, "%4d %4d", mx, my);
+                        }
+                    } else {
+                        int xy = (x + y * mv_stride) << mv_sample_log2;
+                        int mx = motion_val[direction][xy][0];
+                        int my = motion_val[direction][xy][1];
+                        av_log(avctx, AV_LOG_DEBUG, "%4d %4d", mx, my);
+                        av_log(avctx, AV_LOG_DEBUG, "%4d %4d", mx, my);
+                        av_log(avctx, AV_LOG_DEBUG, "%4d %4d", mx, my);
+                        av_log(avctx, AV_LOG_DEBUG, "%4d %4d", mx, my);
+                    }
+                }
             }
             av_log(avctx, AV_LOG_DEBUG, "\n");
         }
diff --git a/libavcodec/options_table.h b/libavcodec/options_table.h
index cd02f5096f..0d100069e1 100644
--- a/libavcodec/options_table.h
+++ b/libavcodec/options_table.h
@@ -198,6 +198,7 @@ static const AVOption avcodec_options[] = {
 {"startcode", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_DEBUG_STARTCODE }, INT_MIN, INT_MAX, V|D, "debug"},
 {"er", "error recognition", 0, AV_OPT_TYPE_CONST, {.i64 = FF_DEBUG_ER }, INT_MIN, INT_MAX, V|D, "debug"},
 {"mmco", "memory management control operations (H.264)", 0, AV_OPT_TYPE_CONST, {.i64 = FF_DEBUG_MMCO }, INT_MIN, INT_MAX, V|D, "debug"},
+{"motion_vec", "macroblock (MB) motion vector values", 0, AV_OPT_TYPE_CONST, {.i64 = FF_DEBUG_MOTION_VEC }, INT_MIN, INT_MAX, V|D, "debug"},
 {"bugs", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_DEBUG_BUGS }, INT_MIN, INT_MAX, V|D, "debug"},
 {"buffers", "picture buffer allocations", 0, AV_OPT_TYPE_CONST, {.i64 = FF_DEBUG_BUFFERS }, INT_MIN, INT_MAX, V|D, "debug"},
 {"thread_ops", "threading operations", 0, AV_OPT_TYPE_CONST, {.i64 = FF_DEBUG_THREADS }, INT_MIN, INT_MAX, V|A|D, "debug"},
-- 
2.37.2



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