[FFmpeg-devel] [PATCH V2] lavf/flvdec: Fix AMF NUMBER type to metadata lost precision

[Jun Zhao]

From: Jun Zhao <barryjzhao at tencent.com>

Use %.12g replace %.f when save AMF NUMBER(double) type to
metadata. And update fate ref.

before this fix, we get FLV metadata like:

 Metadata:
    lasttimestamp   : 113
    lastkeyframetimestamp: 112

after this fix:

 Metadata:
    lasttimestamp   : 113.005
    lastkeyframetimestamp: 111.678

Signed-off-by: Jun Zhao <barryjzhao at tencent.com>
---
 libavformat/flvdec.c                  |    2 +-
 tests/ref/fate/flv-add_keyframe_index |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavformat/flvdec.c b/libavformat/flvdec.c
index 445d58d..12bfd4b 100644
--- a/libavformat/flvdec.c
+++ b/libavformat/flvdec.c
@@ -649,7 +649,7 @@ static int amf_parse_object(AVFormatContext *s, AVStream *astream,
                        sizeof(str_val));
             av_dict_set(&s->metadata, key, str_val, 0);
         } else if (amf_type == AMF_DATA_TYPE_NUMBER) {
-            snprintf(str_val, sizeof(str_val), "%.f", num_val);
+            snprintf(str_val, sizeof(str_val), "%.12g", num_val);
             av_dict_set(&s->metadata, key, str_val, 0);
         } else if (amf_type == AMF_DATA_TYPE_STRING) {
             av_dict_set(&s->metadata, key, str_val, 0);
diff --git a/tests/ref/fate/flv-add_keyframe_index b/tests/ref/fate/flv-add_keyframe_index
index 1c4da65..ce3809e 100644
--- a/tests/ref/fate/flv-add_keyframe_index
+++ b/tests/ref/fate/flv-add_keyframe_index
@@ -7,6 +7,6 @@ canSeekToEnd=true
 datasize=629776
 videosize=629381
 audiosize=0
-lasttimestamp=20
+lasttimestamp=19.8571428571
 lastkeyframetimestamp=19
 lastkeyframelocation=597963
-- 
1.7.1