From 45782a98b629234042b1cf3e60d393109209ff75 Mon Sep 17 00:00:00 2001
From: Carl Eugen Hoyos <cehoyos@ag.or.at>
Date: Wed, 2 Apr 2014 00:20:36 +0200
Subject: [PATCH] Write aspect ratio when muxing gif.

---
 libavformat/gif.c     | 21 ++++++++++++++-------
 libavformat/version.h |  2 +-
 tests/ref/lavf/gif    |  2 +-
 3 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/libavformat/gif.c b/libavformat/gif.c
index e52498d42b..68320c6f23 100644
--- a/libavformat/gif.c
+++ b/libavformat/gif.c
@@ -28,10 +28,18 @@
 #include "libavutil/log.h"
 #include "libavutil/opt.h"
 
-static int gif_image_write_header(AVIOContext *pb, int width, int height,
+static int gif_image_write_header(AVFormatContext *s, int width, int height,
                                   int loop_count, uint32_t *palette)
 {
-    int i;
+    AVIOContext *pb = s->pb;
+    AVRational sar = s->streams[0]->codec->sample_aspect_ratio;
+    int i, aspect = 0;
+
+    if (sar.num > 0 && sar.den > 0) {
+        aspect = sar.num * 64 / sar.den - 15;
+        if (aspect < 0 || aspect > 255)
+            aspect = 0;
+    }
 
     avio_write(pb, "GIF", 3);
     avio_write(pb, "89a", 3);
@@ -41,7 +49,7 @@ static int gif_image_write_header(AVIOContext *pb, int width, int height,
     if (palette) {
         avio_w8(pb, 0xf7); /* flags: global clut, 256 entries */
         avio_w8(pb, 0x1f); /* background color index */
-        avio_w8(pb, 0);    /* aspect ratio */
+        avio_w8(pb, aspect);
         for (i = 0; i < 256; i++) {
             const uint32_t v = palette[i] & 0xffffff;
             avio_wb24(pb, v);
@@ -49,7 +57,7 @@ static int gif_image_write_header(AVIOContext *pb, int width, int height,
     } else {
         avio_w8(pb, 0); /* flags */
         avio_w8(pb, 0); /* background color index */
-        avio_w8(pb, 0); /* aspect ratio */
+        avio_w8(pb, aspect);
     }
 
 
@@ -79,7 +87,6 @@ typedef struct {
 static int gif_write_header(AVFormatContext *s)
 {
     GIFContext *gif = s->priv_data;
-    AVIOContext *pb = s->pb;
     AVCodecContext *video_enc;
     int width, height;
     uint32_t palette[AVPALETTE_COUNT];
@@ -99,9 +106,9 @@ static int gif_write_header(AVFormatContext *s)
     avpriv_set_pts_info(s->streams[0], 64, 1, 100);
     if (avpriv_set_systematic_pal2(palette, video_enc->pix_fmt) < 0) {
         av_assert0(video_enc->pix_fmt == AV_PIX_FMT_PAL8);
-        gif_image_write_header(pb, width, height, gif->loop, NULL);
+        gif_image_write_header(s, width, height, gif->loop, NULL);
     } else {
-        gif_image_write_header(pb, width, height, gif->loop, palette);
+        gif_image_write_header(s, width, height, gif->loop, palette);
     }
 
     avio_flush(s->pb);
diff --git a/libavformat/version.h b/libavformat/version.h
index cb17faee16..fb4043ed51 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -31,7 +31,7 @@
 
 #define LIBAVFORMAT_VERSION_MAJOR 55
 #define LIBAVFORMAT_VERSION_MINOR 36
-#define LIBAVFORMAT_VERSION_MICRO 100
+#define LIBAVFORMAT_VERSION_MICRO 101
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
                                                LIBAVFORMAT_VERSION_MINOR, \
diff --git a/tests/ref/lavf/gif b/tests/ref/lavf/gif
index 4d90abe38f..07506dfcd6 100644
--- a/tests/ref/lavf/gif
+++ b/tests/ref/lavf/gif
@@ -1,3 +1,3 @@
-8aef8081e8afa445f63f320f4a1c5edb *./tests/data/lavf/lavf.gif
+a7365d5015b227f495210e9846d6f3ed *./tests/data/lavf/lavf.gif
 2030198 ./tests/data/lavf/lavf.gif
 ./tests/data/lavf/lavf.gif CRC=0x0dc5477c