ffmpeg: Add display_{rotation, hflip, vflip} options

This enables overriding the rotation as well as horizontal/vertical
flip state of a specific video stream on the input side.

Additionally, switch the singular test that was utilizing the rotation
metadata to instead override the input display rotation, thus leading
to the same result.

2 files changed, 56 insertions, 0 deletions

diff --git a/fftools/ffmpeg.h b/fftools/ffmpeg.h
index 91c5cfa3ab..13a2100439 100644
--- a/fftools/ffmpeg.h
+++ b/fftools/ffmpeg.h
@@ -194,6 +194,12 @@ typedef struct OptionsContext {
     int        nb_force_fps;
     SpecifierOpt *frame_aspect_ratios;
     int        nb_frame_aspect_ratios;
+    SpecifierOpt *display_rotations;
+    int        nb_display_rotations;
+    SpecifierOpt *display_hflips;
+    int        nb_display_hflips;
+    SpecifierOpt *display_vflips;
+    int        nb_display_vflips;
     SpecifierOpt *rc_overrides;
     int        nb_rc_overrides;
     SpecifierOpt *intra_matrices;
diff --git a/fftools/ffmpeg_opt.c b/fftools/ffmpeg_opt.c
index 7fdbf08a18..ead4ee1b38 100644
--- a/fftools/ffmpeg_opt.c
+++ b/fftools/ffmpeg_opt.c
@@ -20,6 +20,7 @@
 
 #include "config.h"
 
+#include <float.h>
 #include <stdint.h>
 
 #if HAVE_SYS_RESOURCE_H
@@ -44,6 +45,7 @@
 #include "libavutil/avutil.h"
 #include "libavutil/bprint.h"
 #include "libavutil/channel_layout.h"
+#include "libavutil/display.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/fifo.h"
 #include "libavutil/mathematics.h"
@@ -66,6 +68,9 @@ static const char *const opt_name_fix_sub_duration[]          = {"fix_sub_durati
 static const char *const opt_name_canvas_sizes[]              = {"canvas_size", NULL};
 static const char *const opt_name_guess_layout_max[]          = {"guess_layout_max", NULL};
 static const char *const opt_name_discard[]                   = {"discard", NULL};
+static const char *const opt_name_display_rotations[]         = {"display_rotation", NULL};
+static const char *const opt_name_display_hflips[]            = {"display_hflip", NULL};
+static const char *const opt_name_display_vflips[]            = {"display_vflip", NULL};
 
 HWDevice *filter_hw_device;
 
@@ -595,6 +600,39 @@ static int opt_recording_timestamp(void *optctx, const char *opt, const char *ar
     return 0;
 }
 
+static void add_display_matrix_to_stream(OptionsContext *o,
+                                         AVFormatContext *ctx, AVStream *st)
+{
+    double rotation = DBL_MAX;
+    int hflip = -1, vflip = -1;
+    int hflip_set = 0, vflip_set = 0, rotation_set = 0;
+    int32_t *buf;
+
+    MATCH_PER_STREAM_OPT(display_rotations, dbl, rotation, ctx, st);
+    MATCH_PER_STREAM_OPT(display_hflips,    i,   hflip,    ctx, st);
+    MATCH_PER_STREAM_OPT(display_vflips,    i,   vflip,    ctx, st);
+
+    rotation_set = rotation != DBL_MAX;
+    hflip_set    = hflip != -1;
+    vflip_set    = vflip != -1;
+
+    if (!rotation_set && !hflip_set && !vflip_set)
+        return;
+
+    buf = (int32_t *)av_stream_new_side_data(st, AV_PKT_DATA_DISPLAYMATRIX, sizeof(int32_t) * 9);
+    if (!buf) {
+        av_log(NULL, AV_LOG_FATAL, "Failed to generate a display matrix!\n");
+        exit_program(1);
+    }
+
+    av_display_rotation_set(buf,
+                            rotation_set ? -(rotation) : -0.0f);
+
+    av_display_matrix_flip(buf,
+                           hflip_set ? hflip : 0,
+                           vflip_set ? vflip : 0);
+}
+
 const AVCodec *find_codec_or_die(const char *name, enum AVMediaType type, int encoder)
 {
     const AVCodecDescriptor *desc;
@@ -729,6 +767,8 @@ static void add_input_streams(OptionsContext *o, AVFormatContext *ic)
         }
 
         if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
+            add_display_matrix_to_stream(o, ic, st);
+
             MATCH_PER_STREAM_OPT(hwaccels, str, hwaccel, ic, st);
             MATCH_PER_STREAM_OPT(hwaccel_output_formats, str,
                                  hwaccel_output_format, ic, st);
@@ -2127,6 +2167,16 @@ const OptionDef options[] = {
     { "pix_fmt",      OPT_VIDEO | HAS_ARG | OPT_EXPERT  | OPT_STRING | OPT_SPEC |
                       OPT_INPUT | OPT_OUTPUT,                                    { .off = OFFSET(frame_pix_fmts) },
         "set pixel format", "format" },
+    { "display_rotation", OPT_VIDEO | HAS_ARG | OPT_DOUBLE | OPT_SPEC |
+                          OPT_INPUT,                                             { .off = OFFSET(display_rotations) },
+        "set pure counter-clockwise rotation in degrees for stream(s)",
+        "angle" },
+    { "display_hflip", OPT_VIDEO | OPT_BOOL | OPT_SPEC | OPT_INPUT,              { .off = OFFSET(display_hflips) },
+        "set display horizontal flip for stream(s) "
+        "(overrides any display rotation if it is not set)"},
+    { "display_vflip", OPT_VIDEO | OPT_BOOL | OPT_SPEC | OPT_INPUT,              { .off = OFFSET(display_vflips) },
+        "set display vertical flip for stream(s) "
+        "(overrides any display rotation if it is not set)"},
     { "vn",           OPT_VIDEO | OPT_BOOL  | OPT_OFFSET | OPT_INPUT | OPT_OUTPUT,{ .off = OFFSET(video_disable) },
         "disable video" },
     { "rc_override",  OPT_VIDEO | HAS_ARG | OPT_EXPERT  | OPT_STRING | OPT_SPEC |