[FFmpeg-devel] [PATCH v4 1/2] fftools/ffmpeg_filter, ffplay: Add flip support to rotation

Jun Li junli1026 at gmail.com
Wed May 8 09:24:07 EEST 2019


Current implemantion for autoratation does not support flip.
That is, if the matrix contains flip info, the API get_rotation
only reflects partial information. This change is for adding
support for hflip (vflip can be achieved by rotation+hflip).
---
 fftools/cmdutils.c        |  4 ++--
 fftools/cmdutils.h        |  2 +-
 fftools/ffmpeg_filter.c   | 31 ++++++++++++++++++++++++++-----
 fftools/ffplay.c          | 22 ++++++++++++++++++----
 libavutil/display.c       | 14 ++++++++++++++
 libavutil/display.h       | 14 ++++++++++++++
 libavutil/tests/display.c |  8 ++++++++
 tests/ref/fate/display    |  4 ++++
 8 files changed, 87 insertions(+), 12 deletions(-)

diff --git a/fftools/cmdutils.c b/fftools/cmdutils.c
index 9cfbc45c2b..1235a3dd7b 100644
--- a/fftools/cmdutils.c
+++ b/fftools/cmdutils.c
@@ -2172,13 +2172,13 @@ void *grow_array(void *array, int elem_size, int *size, int new_size)
     return array;
 }
 
-double get_rotation(AVStream *st)
+double get_rotation_hflip(AVStream *st, int* hflip)
 {
     uint8_t* displaymatrix = av_stream_get_side_data(st,
                                                      AV_PKT_DATA_DISPLAYMATRIX, NULL);
     double theta = 0;
     if (displaymatrix)
-        theta = -av_display_rotation_get((int32_t*) displaymatrix);
+        theta = -av_display_rotation_hflip_get((int32_t*) displaymatrix, hflip);
 
     theta -= 360*floor(theta/360 + 0.9/360);
 
diff --git a/fftools/cmdutils.h b/fftools/cmdutils.h
index 6e2e0a2acb..0349d1bea7 100644
--- a/fftools/cmdutils.h
+++ b/fftools/cmdutils.h
@@ -643,6 +643,6 @@ void *grow_array(void *array, int elem_size, int *size, int new_size);
     char name[128];\
     av_get_channel_layout_string(name, sizeof(name), 0, ch_layout);
 
-double get_rotation(AVStream *st);
+double get_rotation_hflip(AVStream *st, int* hflip);
 
 #endif /* FFTOOLS_CMDUTILS_H */
diff --git a/fftools/ffmpeg_filter.c b/fftools/ffmpeg_filter.c
index 72838de1e2..b000958015 100644
--- a/fftools/ffmpeg_filter.c
+++ b/fftools/ffmpeg_filter.c
@@ -807,22 +807,43 @@ static int configure_input_video_filter(FilterGraph *fg, InputFilter *ifilter,
     last_filter = ifilter->filter;
 
     if (ist->autorotate) {
-        double theta = get_rotation(ist->st);
+        int hflip = 0;
+        double theta = get_rotation_hflip(ist->st, &hflip);
 
-        if (fabs(theta - 90) < 1.0) {
+        if (fabs(theta) < 1.0) {
+            if (hflip)
+                ret = insert_filter(&last_filter, &pad_idx, "hflip", NULL);
+        } else if (fabs(theta - 90) < 1.0) {
             ret = insert_filter(&last_filter, &pad_idx, "transpose", "clock");
-        } else if (fabs(theta - 180) < 1.0) {
-            ret = insert_filter(&last_filter, &pad_idx, "hflip", NULL);
             if (ret < 0)
                 return ret;
-            ret = insert_filter(&last_filter, &pad_idx, "vflip", NULL);
+            if (hflip)
+                ret = insert_filter(&last_filter, &pad_idx, "hflip", NULL);
+        } else if (fabs(theta - 180) < 1.0) {
+            if (hflip) { // rotate 180 and hflip equals vflip
+                ret = insert_filter(&last_filter, &pad_idx, "vflip", NULL);
+            } else {
+                ret = insert_filter(&last_filter, &pad_idx, "hflip", NULL);
+                if (ret < 0)
+                    return ret;
+                ret = insert_filter(&last_filter, &pad_idx, "vflip", NULL);
+            }
         } else if (fabs(theta - 270) < 1.0) {
             ret = insert_filter(&last_filter, &pad_idx, "transpose", "cclock");
+            if (ret < 0)
+                return ret;
+            if (hflip)
+                ret = insert_filter(&last_filter, &pad_idx, "hflip", NULL);
         } else if (fabs(theta) > 1.0) {
             char rotate_buf[64];
             snprintf(rotate_buf, sizeof(rotate_buf), "%f*PI/180", theta);
             ret = insert_filter(&last_filter, &pad_idx, "rotate", rotate_buf);
+            if (ret < 0)
+                return ret;
+            if (hflip)
+                ret = insert_filter(&last_filter, &pad_idx, "hflip", NULL);
         }
+
         if (ret < 0)
             return ret;
     }
diff --git a/fftools/ffplay.c b/fftools/ffplay.c
index 8f050e16e6..2c77612193 100644
--- a/fftools/ffplay.c
+++ b/fftools/ffplay.c
@@ -1914,19 +1914,33 @@ static int configure_video_filters(AVFilterGraph *graph, VideoState *is, const c
 } while (0)
 
     if (autorotate) {
-        double theta  = get_rotation(is->video_st);
+        int hflip;
+        double theta  = get_rotation_hflip(is->video_st, &hflip);
 
-        if (fabs(theta - 90) < 1.0) {
+        if (fabs(theta) < 1.0) {
+            if (hflip)
+                INSERT_FILT("hflip", NULL);
+        } else if (fabs(theta - 90) < 1.0) {
             INSERT_FILT("transpose", "clock");
+            if (hflip)
+                INSERT_FILT("hflip", NULL);
         } else if (fabs(theta - 180) < 1.0) {
-            INSERT_FILT("hflip", NULL);
-            INSERT_FILT("vflip", NULL);
+            if (hflip) { // rotate 180 and hflip equals vflip
+                INSERT_FILT("vflip", NULL);
+            } else {
+                INSERT_FILT("hflip", NULL);
+                INSERT_FILT("vflip", NULL);
+            }
         } else if (fabs(theta - 270) < 1.0) {
             INSERT_FILT("transpose", "cclock");
+            if (hflip)
+                INSERT_FILT("hflip", NULL);
         } else if (fabs(theta) > 1.0) {
             char rotate_buf[64];
             snprintf(rotate_buf, sizeof(rotate_buf), "%f*PI/180", theta);
             INSERT_FILT("rotate", rotate_buf);
+            if (hflip)
+                INSERT_FILT("hflip", NULL);
         }
     }
 
diff --git a/libavutil/display.c b/libavutil/display.c
index a0076e067b..855de4a006 100644
--- a/libavutil/display.c
+++ b/libavutil/display.c
@@ -71,3 +71,17 @@ void av_display_matrix_flip(int32_t matrix[9], int hflip, int vflip)
         for (i = 0; i < 9; i++)
             matrix[i] *= flip[i % 3];
 }
+
+double av_display_rotation_hflip_get(const int32_t matrix[9], int *hflip)
+{
+    int32_t m[9];
+    *hflip = 0;
+    memcpy(m, matrix, sizeof(m));
+
+    if (m[0] > 0 && m[4] < 0 || m[0] < 0 && m[4] > 0 || 
+        m[1] > 0 && m[3] > 0 || m[1] < 0 && m[3] < 0) {
+        *hflip = 1;
+        av_display_matrix_flip(m, 1, 0);
+    }
+    return av_display_rotation_get(m);
+}
\ No newline at end of file
diff --git a/libavutil/display.h b/libavutil/display.h
index 515adad795..23d71a0bc5 100644
--- a/libavutil/display.h
+++ b/libavutil/display.h
@@ -106,6 +106,20 @@ void av_display_rotation_set(int32_t matrix[9], double angle);
  */
 void av_display_matrix_flip(int32_t matrix[9], int hflip, int vflip);
 
+/**
+ * Extract the rotation component and hflip status of the transformation matrix.
+ *
+ * @param matrix the transformation matrix
+ * @param hflip wille be set to 1 if the matrix need horizontal flipped
+ * @return the angle (in degrees) by which the transformation rotates the frame
+ *         counterclockwise. The angle will be in range [-180.0, 180.0],
+ *         or NaN if the matrix is singular.
+ *
+ * @note floating point numbers are inherently inexact, so callers are
+ *       recommended to round the return value to nearest integer before use.
+ */
+double av_display_rotation_hflip_get(const int32_t matrix[9], int* hflip);
+
 /**
  * @}
  * @}
diff --git a/libavutil/tests/display.c b/libavutil/tests/display.c
index 893ebb5543..65a0971e7b 100644
--- a/libavutil/tests/display.c
+++ b/libavutil/tests/display.c
@@ -35,6 +35,8 @@ static void print_matrix(int32_t matrix[9])
 int main(void)
 {
     int32_t matrix[9];
+    int hflip = 0;
+    double degree;
 
     // Set the matrix to 90 degrees
     av_display_rotation_set(matrix, 90);
@@ -56,6 +58,12 @@ int main(void)
     print_matrix(matrix);
     printf("degrees: %f\n", av_display_rotation_get(matrix));
 
+    // flip vertical
+    av_display_matrix_flip(matrix, 0, 1);
+    print_matrix(matrix);
+    degree = av_display_rotation_hflip_get(matrix, &hflip);
+    printf("degrees: %f, hflip: %i\n", degree, hflip);
+
     return 0;
 
 }
diff --git a/tests/ref/fate/display b/tests/ref/fate/display
index 251e7e0cdf..14b4c7db7c 100644
--- a/tests/ref/fate/display
+++ b/tests/ref/fate/display
@@ -14,3 +14,7 @@ degrees: 135.000000
 -46340 -46340 0
 0 0 1073741824
 degrees: -135.000000
+-46340 -46340 0
+-46340 46340 0
+0 0 1073741824
+degrees: 45.000000, hflip: 1
-- 
2.17.1



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