[FFmpeg-devel] [PATCH] avformat/mov: ensure pasp box derived SAR is used if present

[James Almer]

It's meant to override any codec specific (but container level) information,
but its position is not guaranteed, so apply the values after the entire trak
structure has been parsed.
Also, replace the ugly roundabout int -> double -> int method to set SAR from
existing dimensions while at it.

Signed-off-by: James Almer <jamrial at gmail.com>
---
 libavformat/isom.h |  2 ++
 libavformat/mov.c  | 16 ++++++++++++----
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/libavformat/isom.h b/libavformat/isom.h
index a0498f45e5..5b6125a908 100644
--- a/libavformat/isom.h
+++ b/libavformat/isom.h
@@ -215,6 +215,8 @@ typedef struct MOVStreamContext {
     int timecode_track;
     int width;            ///< tkhd width
     int height;           ///< tkhd height
+    int h_spacing;        ///< pasp hSpacing
+    int v_spacing;        ///< pasp vSpacing
     int dts_shift;        ///< dts shift when ctts is negative
     uint32_t palette[256];
     int has_palette;
diff --git a/libavformat/mov.c b/libavformat/mov.c
index ced4b2e6b3..ce95842ce5 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -1287,14 +1287,18 @@ static int mov_read_pasp(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     const int num = avio_rb32(pb);
     const int den = avio_rb32(pb);
     AVStream *st;
+    MOVStreamContext *sc;
 
     if (c->fc->nb_streams < 1)
         return 0;
     st = c->fc->streams[c->fc->nb_streams-1];
+    sc = st->priv_data;
+
+    av_log(c->fc, AV_LOG_TRACE, "pasp: hSpacing %d, vSpacing %d\n", num, den);
 
     if (den != 0) {
-        av_reduce(&st->sample_aspect_ratio.num, &st->sample_aspect_ratio.den,
-                  num, den, 32767);
+        sc->h_spacing = num;
+        sc->v_spacing = den;
     }
     return 0;
 }
@@ -5031,11 +5035,15 @@ static int mov_read_trak(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     }
 
     if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
+        if (sc->h_spacing && sc->v_spacing)
+            av_reduce(&st->sample_aspect_ratio.num, &st->sample_aspect_ratio.den,
+                      sc->h_spacing, sc->v_spacing, INT_MAX);
         if (!st->sample_aspect_ratio.num && st->codecpar->width && st->codecpar->height &&
             sc->height && sc->width &&
             (st->codecpar->width != sc->width || st->codecpar->height != sc->height)) {
-            st->sample_aspect_ratio = av_d2q(((double)st->codecpar->height * sc->width) /
-                                             ((double)st->codecpar->width * sc->height), INT_MAX);
+            av_reduce(&st->sample_aspect_ratio.num, &st->sample_aspect_ratio.den,
+                      (int64_t)st->codecpar->height * sc->width,
+                      (int64_t)st->codecpar->width  * sc->height, INT_MAX);
         }
 
 #if FF_API_R_FRAME_RATE
-- 
2.45.2