ffmpeg: Add -time_base option to hint the time base

Signed-off-by: Michael Bradshaw <mjbshaw@google.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

1 files changed, 4 insertions, 2 deletions

diff --git a/ffmpeg.c b/ffmpeg.c
index df0ad32b5c..6d1e358a85 100644
--- a/ffmpeg.c
+++ b/ffmpeg.c
@@ -2905,7 +2905,8 @@ static int init_output_stream_streamcopy(OutputStream *ost)
         return ret;
 
     // copy timebase while removing common factors
-    ost->st->time_base = av_add_q(av_stream_get_codec_timebase(ost->st), (AVRational){0, 1});
+    if (ost->st->time_base.num <= 0 || ost->st->time_base.den <= 0)
+        ost->st->time_base = av_add_q(av_stream_get_codec_timebase(ost->st), (AVRational){0, 1});
 
     // copy disposition
     ost->st->disposition = ist->st->disposition;
@@ -3330,7 +3331,8 @@ static int init_output_stream(OutputStream *ost, char *error, int error_len)
         }
 
         // copy timebase while removing common factors
-        ost->st->time_base = av_add_q(ost->enc_ctx->time_base, (AVRational){0, 1});
+        if (ost->st->time_base.num <= 0 || ost->st->time_base.den <= 0)
+            ost->st->time_base = av_add_q(ost->enc_ctx->time_base, (AVRational){0, 1});
         ost->st->codec->codec= ost->enc_ctx->codec;
     } else if (ost->stream_copy) {
         ret = init_output_stream_streamcopy(ost);