[FFmpeg-cvslog] ffmpeg: fix wrap correction code.

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Fri Aug 24 01:39:32 2012 +0200| [91c18beb9d670a2f64f3ffbc1d60d443eb2ef858] | committer: Michael Niedermayer

ffmpeg: fix wrap correction code.

The code failed with negative timestamps due to using unsigned numbers

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=91c18beb9d670a2f64f3ffbc1d60d443eb2ef858
---

 ffmpeg.c |   13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/ffmpeg.c b/ffmpeg.c
index 4e8d32d..3a9c705 100644
--- a/ffmpeg.c
+++ b/ffmpeg.c
@@ -2739,15 +2739,16 @@ static int process_input(int file_index)
         goto discard_packet;
 
     if(!ist->wrap_correction_done && input_files[file_index]->ctx->start_time != AV_NOPTS_VALUE && ist->st->pts_wrap_bits < 64){
-        uint64_t stime = av_rescale_q(input_files[file_index]->ctx->start_time, AV_TIME_BASE_Q, ist->st->time_base);
-        uint64_t stime2= stime + (1LL<<ist->st->pts_wrap_bits);
+        int64_t stime = av_rescale_q(input_files[file_index]->ctx->start_time, AV_TIME_BASE_Q, ist->st->time_base);
+        int64_t stime2= stime + (1ULL<<ist->st->pts_wrap_bits);
         ist->wrap_correction_done = 1;
-        if(pkt.dts != AV_NOPTS_VALUE && pkt.dts > stime && pkt.dts - stime > stime2 - pkt.dts) {
-            pkt.dts -= 1LL<<ist->st->pts_wrap_bits;
+
+        if(stime2 > stime && pkt.dts != AV_NOPTS_VALUE && pkt.dts > stime + (1LL<<(ist->st->pts_wrap_bits-1))) {
+            pkt.dts -= 1ULL<<ist->st->pts_wrap_bits;
             ist->wrap_correction_done = 0;
         }
-        if(pkt.pts != AV_NOPTS_VALUE && pkt.pts > stime && pkt.pts - stime > stime2 - pkt.pts) {
-            pkt.pts -= 1LL<<ist->st->pts_wrap_bits;
+        if(stime2 > stime && pkt.pts != AV_NOPTS_VALUE && pkt.pts > stime + (1LL<<(ist->st->pts_wrap_bits-1))) {
+            pkt.pts -= 1ULL<<ist->st->pts_wrap_bits;
             ist->wrap_correction_done = 0;
         }
     }